second revision no. 5-nfpa 820-2014 [ section no. 2.3.1 ] · second revision no. 17-nfpa 820-2014 [...

Second Revision No. 5-NFPA 820-2014 [ Section No. 2.3.1 ]

2.3.1 ASTM Publications.

ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.

ASTM E 84 E84 , Standard Test Method for Surface Burning Characteristics of Building Materials, 2013a 2014 .

ASTM E 108, Standard Test Methods for Fire Tests of Roof Coverings , 2011.

ASTM E 136 E136 , Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750°C, 2012.

ASTM E 2652 E2652 , Standard Test Method for Behavior of Materials in a Tube Furnace with a Cone-shaped AirflowStabilizer, at 750°C, 2012.

IEEE/ASTM SI 10, Use of the International System of Units (SI): the Modern Metric System, 1997 2010 .

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Submittal Date: Tue Oct 07 11:14:11 EDT 2014

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Committee Statement: Update year dates

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Public Comment No. 6-NFPA 820-2014 [Section No. 2.3.1]

National Fire Protection Association Report http://submittals.nfpa.org/TerraViewWeb/ContentFetcher?commentPara...

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3.3.22* Flame Spread Index.

A number obtained according to ASTM E 84, Standard Test Method for Surface Burning Characteristics of BuildingMaterials , or ANSI/UL 723, Standard for Test for Surface Burning Characteristics of Building Materials . [ 220,2015] See 8.2.3.4 .




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Submittal Date: Thu Oct 16 11:23:37 EDT 2014

Committee Statement

CommitteeStatement:

The definition of flame spread index was moved into Chapter 8 along with definitions of limited and noncombustible so that all the definitions applicable to Chapter 8 were in one the same location in the document.

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2 of 51 12/1/2014 1:18 PM


3.3.23 Flammable Limits. Lower Explosive Limit (LEL).

See Lower Flammable Limit (LFL) 3.3.24 .




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Submittal Date: Thu Oct 16 08:55:26 EDT 2014

Committee Statement

CommitteeStatement:

While the preferred term for NFPA use is lower flammable limit, the industry still uses the term LEL andmanufacturers of combustible gas detectors continue to use the LEL acronym on monitors and meters. A crossreference to LFL has been provided.

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3 of 51 12/1/2014 1:18 PM

Second Revision No. 2-NFPA 820-2014 [ Section No. 4.2 ]

4.2* Design and Construction.

The design and construction of collection system facilities shall conform to Table 4.2.1 , which summarizes thevarious components associated with wastewater collection and transport systems.

4.2.1

The design and construction of buildings and structures containing wastewater collection and transport systems shallcomply with the applicable building code and the additional requirements in Chapters 7 through 9 .


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4.2.2


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The design and construction of the components associated with the wastewater collection and transportation systemsshall conform to Table 4.2.1 Table 4.2.2 .

Table 4.2.2 Collection Systems

Rowa Linea

Location

and

Function

Fire andExplosion

Hazard Ventilationb

Extent ofClassified

Area

NEC -Area NECArea ElectricalClassification

(All Class I,Group D)

Materials ofConstruction

forBuildings or

Structures c

FireProtectionMeasures

1 MATERIALS USEDIN REHABILITATION,RECONSTRUCTION,OR SLIP-LINING OFSEWERS

NA N/A NA N/A NA N/A NA N/A In accordancewith8.3.1 8.3.5

NA N/A

2 INDUSTRIALSEWER Sewertransporting industrialwastewater only (nosanitary wastewater)

Not included within the scope of this standard

3 STORM SEWERSewer transportingstorm water only (nosanitary wastewater)

Possibleignition offlammablegases andfloatingflammableliquids

NNV Inside ofsewer

Division 2 In accordancewith8.3.1 8.3.5

NR

4 STORM WATERPUMPING STATIONWET WELLS

Liquid side ofpumping stationserving only a stormsewer system


NNV Entire roomor space

Division 2 NC, LC, orLFS

NR

5 a STORM WATERPUMPING STATIONDRY WELLS

Dry side of apumping stationserving only a stormsewer system andphysically separatedfrom wet well

Buildup ofvapors fromflammableorcombustibleliquids

D Entire drywell


FE

b C Entire drywell

Unclassified NC, LC, orLFS

FE

6 PRESSURE SEWER(Force main) Sewerunder pressure(flooded dischargepipe from pump ortank)


7 BUILDING SEWER(Lateral sewer ordrain) Sewer servinga house or singlebuilding (plumbing)


8 INDIVIDUALRESIDENTIALSEWER

Sewer serving one ormore individualresidences with atotal flow of not morethan 1500 gallons perday (gpd)

NA N/A NNV Withinenclosedspace

Unclassified NR NR


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Rowa Linea

Location

and

Function

Fire andExplosion

Hazard Ventilationb

Extent ofClassified

Area

NEC -Area NECArea Electrical

Classification (AllClass I, Group D)


forBuildings or

Structures c


9 INDIVIDUALRESIDENTIALPUMPING UNITS

Pumping unitsserving one or moreindividual residenceswith a total flow of notmore than 1500gallons per day (gpd)(e.g., grinder pumps,septic tank effluentpumps, ejectorpumps)

NA N/A NNV Withinenclosedspace

Unclassified NR NR

10 a RESIDENTIALSEWER

Sewer transportingprimarily residentialwastewater


NNV Withinenclosedspace


NR

b B Withinenclosedspace

Unclassified In accordancewith8.3.1 8.3.5

NR

11 a RESIDENTIALWASTEWATERPUMPING STATIONWET WELL

Pumping stationtransporting primarilyresidentialwastewater


A Entire roomor space


CGD

b B Entire roomor space


CGD

12 a RESIDENTIALWASTEWATERPUMPING STATIONDRY WELL

Dry side of apumping stationtransporting primarilyresidentialwastewater


D Entire roomor space


FE

b C Entire roomor space


FE

13 OUTFALL SEWERFinal discharge pipefrom a treatmentplant, transportingtreated wastewater

NA N/A NNV NA N/A Unclassified NR NR

14 a SANITARY SEWERSewer transportingdomestic,commercial, andindustrial wastewater


NNV Inside ofsewer


NR

b B Inside ofsewer


NR

15 a COMBINED SEWERSewer transportingdomestic,commercial, andindustrial wastewaterand storm water


NNV Inside ofsewer


NR

b B Inside ofsewer


NR


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Rowa Linea

Location

and

Function

Fire andExplosion

Hazard Ventilationb

Extent ofClassified

Area




forBuildings or

Structures c


16 a WASTEWATERPUMPING STATIONWET WELLS

Liquid side of apumping stationserving a sanitarysewer or combinedsystem


A Entire roomor space


CGDrequired ifmechanicallyventilated oropens into abuildinginterior

b B Entire roomor space


CGD

17 a BELOWGRADE ORPARTIALLYBELOWGRADEWASTEWATERPUMPING STATIONDRY WELL

Pump roomphysically separatedfrom wet well;pumping ofwastewater from asanitary or combinedsewer systemthrough closedpumps and pipes


C Entire spaceor room


FE

b D Entire spaceor room


FE

18 ABOVEGRADEWASTEWATERPUMPING STATIONPump roomphysically separatedwith no personnelaccess to wet well;pumping ofwastewater from asanitary or combinedsewer systemthrough closedpumps and pipes

NA N/A NR NA N/A Unclassified NC, LC, orLFS

FE

19 a ABOVEGRADEWASTEWATERPUMPING STATIONPump room notphysically separatedfrom wet well;pumping ofwastewater from asanitary or combinedsewer systemthrough closedpumps and pipes


A Entire spaceor room

Division 1 NC FE

b B Entire spaceor room


FE

20 a ODOR-CONTROLAND VENTILATIONSYSTEMS SERVINGCLASSIFIED AREAS

Leakageand ignitionofflammablegases andvapors

D Entire areaif enclosed


CGD andFDS

b C Areas within0.9 m (3 ft)of leakagesourcessuch asfans,dampers,flexible


CGD andFDS


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Rowa Linea

Location

and

Function

Fire andExplosion

Hazard Ventilationb

Extent ofClassified

Area




forBuildings or

Structures c


connections,flanges,pressurizedunweldedductwork,andodor-controlvessels

c C Areasbeyond 0.9m (3 ft)


CGD andFDS

d Not enclosed,open to theatmosphere

Areas within0.9 m (3 ft)of leakagesourcessuch asfans,dampers,flexibleconnections,flanges,pressurizedunweldedductwork,andodor-controlvessels

Division 2 NC, LC, LFS FE

e Not enclosed,open to theatmosphere

Areasbeyond 0.9m (3 ft)

Unclassified NC,LC, LFS FE

21 a MAINTENANCEHOLES

Access to sewer forpersonnel entry


NNV Inside Division 1 In accordancewith8.3.1 8.3.5

NR

b B Inside Division 2 In accordancewith8.3.1 8.3.5

NR

22 a JUNCTIONCHAMBERS

Structure wheresewers intersect


NNV Inside Division 1 In accordancewith8.3.1 8.3.5

NR

b B Open andabove gradeor insideandventilated


NR

23 INVERTEDSIPHONS Depressedsection of gravitysewer


NNV Interior ofinlet andoutletstructures

Division 1 NC NR

24 CATCH BASINS(Curb inlet) Inletwhere street waterenters a storm orcombined sewer


NNV Enclosedspace


NR


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Rowa Linea

Location

and

Function

Fire andExplosion

Hazard Ventilationb

Extent ofClassified

Area




forBuildings or

Structures c


25 a RESIDENTIALDIVERSIONSTRUCTURES

Enclosed structureswhere residentialwastewater can bediverted


NNV Enclosedspace

Division 2 In accordancewith Chapter 8

NR

b B Enclosedspace

Unclassified In accordancewith Chapter 8

NR

26 a RESIDENTIALBELOWGRADEVALVE VAULT

With an exposedresidentialwastewater surface

Possibleignition ofgases andfloatingflammableliquids

NNV Enclosedspace


NR

b B Enclosedspace


NR

27 a RESIDENTIALCONTROLSTRUCTURESEnclosed structureswhere residentialwastewater flow isregulated


A Enclosedspace


NR

b B Enclosedspace

Unclassified In accordancewith Chapter 8

NR

28 a RESIDENTIALBELOWGRADEMETERING VAULT

With an exposedresidentialwastewater surface


NNV Enclosedspace


NR

b B Enclosedspace


NR

29 a DIVERSIONSTRUCTURESEnclosed structureswhere wastewatercan be diverted


NNV Enclosedspace


NR

b B Division 2 In accordancewith Chapter 8

NR

30 ABOVEGRADEVALVE VAULT

Physically separatedfrom the wet well;valves in vault inclosed piping system


NR

31 a BELOWGRADEVALVE VAULTPhysically separatedfrom the wet well andwith closed pipingsystem


NNV Enclosedspace


NR

b C Enclosedspace


NR

32 a BELOWGRADEVALVE VAULT Withan exposedwastewater surface

Possibleignition ofgases andfloatingflammableliquids

NNV Enclosedspace

Division 1 NC NR

b B Enclosedspace


NR

33 a CONTROLSTRUCTURESEnclosed structureswhere wastewater orstorm water flow isregulated


A Enclosedspace


NR

b B Enclosedspace


NR


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Rowa Linea

Location

and

Function

Fire andExplosion

Hazard Ventilationb

Extent ofClassified

Area




forBuildings or

Structures c


34 a WASTEWATERHOLDING BASINSEnclosed structurestemporarily holdinguntreated or partiallytreated wastewater


A Enclosedspace

Division 1 NC NR

b B Enclosedspace


NR

35 WASTEWATERHOLDING BASINS,LINED OR UNLINEDOpen structuresholding storm water,combinedwastewater,untreated or partiallytreated wastewater

NR NR NR NR NR NR

36 a BELOWGRADEMETERING VAULTPhysically separatedfrom the wet well andwith closed pipingsystem


NNV Enclosedspace


NR

b C Enclosedspace


NR

37 a BELOWGRADEMETERING VAULTWith an exposedwastewater surface


NNV Enclosedspace

Division 1 NC NR

b B Enclosedspace


NR

38 COARSE AND FINESCREENFACILITIES (See“Coarse and FineScreen Facilities” inTable 5.2.)

Note: The following codes are used in this table:

A: No ventilation or ventilated at less than 12 air changes per hour.

B: Continuously ventilated at 12 changes per hour in accordance with Chapter 9.

C: Continuously ventilated at 6 six air changes per hour in accordance with Chapter 9.

CGD: Combustible gas detection system.

D: No ventilation or ventilated at less than 6 six air changes per hour.

FDS: Fire detection system.

FE: Portable fire extinguisher.

LC: Limited-combustible material.

LFS: Low flame spread index material.

NA N/A : Not applicable.

NC: Noncombustible material.

NEC: In accordance with NFPA 70.

NNV: Not normally ventilated.

NR: No requirement.

a The "Row" and "Line" columns are used to refer to specific figures in A.4.2 and specific requirements for eachlocation and function.


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**The NR designation in the "Ventilation" column indicates that no ventilation requirements are established for thespace, and, therefore, Table 9.1.1.4 also has no requirements.

b This column indicates the ventilation requirements for processes. Additional ventilation requirements are provided inChapter 9. Ventilation signaling and alarm requirements are provided in Chapter 7.

c This column indicates the materials of construction for processes. Materials of construction for buildings in whichthese processes are housed are in accordance with the applicable building code and construction requirementsprovided in Chapter 8.

Supplemental Information

File Name Description

ComparisonFDtoSDChapter_4.docx For editorial use only.

FINALSDMtgREVChapter_4.docx For editorial use only.




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Submittal Date: Mon Oct 06 20:24:19 EDT 2014

Committee Statement

CommitteeStatement:

Section 4.2.2 explains that building codes cover general building construction but the components within thebuilding are covered in the table. The Table Column for materials was reworded to better indicate that the generalbuilding construction requirements are provided in chapter 8 but that the materials of construction for particularlocations within the facility are provided in the tables. The table footnotes were modified to better direct the user tothe appropriate chapters in NFPA 820 related to the subject column.

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12 of 51 12/1/2014 1:18 PM

Chapter 4 Collection Systems

4.1* General.

4.1.1

This chapter shall establish minimum criteria for protection against fire and explosion hazards in the

collection and transportation of municipal wastewater.

4.1.2

This chapter shall not apply to on-site systems, force mains, or those sewers that principally convey

industrial wastes.


4.2.1 The design and construction of collection system facilities shall conform to Table 4.2, which

summarizes the variousthe components associated with wastewater collection and transport

systems shall conform to Table 4.2.

4.2.2 The design and construction of buildings and structures containing wastewater collection and

transport systems shall comply with the applicable building code and the additional requirements in

Chapters 7-9.

Table 4.2 Collection Systems

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

1 MATERIALS

USED IN

REHABILITAT

ION,

RECONSTRU

CTION, OR

SLIP-LINING

OF SEWERS

NA NA NA NA In

accordance

with 8.3.1

NA

2 INDUSTRIAL

SEWER

Sewer

transporting

industrial

wastewater

only (no


Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

sanitary

wastewater)

3 STORM

SEWER

Sewer

transporting

storm water

only (no

sanitary

wastewater)

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

NNV Inside of

sewer

Division

2

In

accordance

with 8.3.1

NR

4 STORM

WATER

PUMPING

STATION

WET WELLS .

Liquid side of

pumping

station serving

only a storm

sewer system

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

NNV Entire

room or

space

Division

2

NC, LC, or

LFS

NR

5 a STORM

WATER

PUMPING

STATION

DRY WELLS .

Dry side of a

pumping

station serving

only a storm

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

D Entire

dry well

Division

2

NC, LC, or

LFS

FE

b C Entire

dry well

Unclassif

ied

NC, LC, or

LFS

FE

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

sewer system

and physically

separated

from wet well

6 PRESSURE

SEWER

(Force main)

Sewer under

pressure

(flooded

discharge pipe

from pump or

tank)


7 BUILDING

SEWER

(Lateral sewer

or drain)

Sewer serving

a house or

single building

(plumbing)


8 INDIVIDUAL

RESIDENTIAL

SEWER .

Sewer serving

one or more

individual

residences

with a total

flow of not

more than

1500 gallons

per day (gpd)

NA NNV Within

enclose

d space

Unclassif

ied

NR NR

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

9 INDIVIDUAL

RESIDENTIAL

PUMPING

UNITS .

Pumping units

serving one or

more

individual

residences

with a total

flow of not

more than

1500 gallons

per day (gpd)

(e.g., grinder

pumps, septic

tank effluent

pumps, ejector

pumps)

NA NNV Within

enclose

d space

Unclassif

ied

NR NR

10 a RESIDENTIAL

SEWER .

Sewer

transporting

primarily

residential

wastewater

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

NNV Within

enclose

d space

Division

2

In

accordance

with 8.3.1

NR

b B Within

enclose

d space

Unclassif

ied

In

accordance

with 8.3.1

NR

11 a RESIDENTIAL

WASTEWATE

R PUMPING

Possibl

e

ignition

A Entire

room or

space

Division

2

NC, LC, or

LFS

CGD

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

b STATION

WET WELL .

Pumping

station

transporting

primarily

residential

wastewater

of

flamma

ble

gases

and

floating

flamma

ble

liquids

B Entire

room or

space

Unclassif

ied

NC, LC, or

LFS

CGD

12 a RESIDENTIAL

WASTEWATE

R PUMPING

STATION

DRY WELL .

Dry side of a

pumping

station

transporting

primarily

residential

wastewater

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

D Entire

room or

space

Division

2

NC, LC, or

LFS

FE

b C Entire

room or

space

Unclassif

ied

NC, LC, or

LFS

FE

13 OUTFALL

SEWER Final

discharge pipe

from a

treatment

plant,

transporting

treated

wastewater

NA NNV NA Unclassif

ied

NR NR

14 a SANITARY

SEWER

Sewer

Possibl

e

ignition

NNV Inside of

sewer

Division

1

In

accordance

with 8.3.1

NR

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

b transporting

domestic,

commercial,

and industrial

wastewater

of

flamma

ble

gases

and

floating

flamma

ble

liquids

B Inside of

sewer

Division

2

In

accordance

with 8.3.1

NR

15 a COMBINED

SEWER

Sewer

transporting

domestic,

commercial,

and industrial

wastewater

and storm

water

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

NNV Inside of

sewer

Division

1

In

accordance

with 8.3.1

NR

b B Inside of

sewer

Division

2

In

accordance

with 8.3.1

NR

16 a WASTEWATE

R PUMPING

STATION

WET WELLS .

Liquid side of

a pumping

station serving

a sanitary

sewer or

combined

system

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

A Entire

room or

space

Division

1

NC, LC, or

LFS

CGD

required

if

mechani

cally

ventilate

d or

opens

into a

building

interior

b B Entire

room or

space

Division

2

NC, LC, or

LFS

CGD

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

17 a BELOWGRAD

E OR

PARTIALLY

BELOWGRAD

E

WASTEWATE

R PUMPING

STATION

DRY WELL .

Pump room

physically

separated

from wet well;

pumping of

wastewater

from a sanitary

or combined

sewer system

through closed

pumps and

pipes

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

C Entire

space or

room

Unclassif

ied

NC, LC, or

LFS

FE

b D Entire

space or

room

Division

2

NC, LC, or

LFS

FE

18 ABOVEGRAD

E

WASTEWATE

R PUMPING

STATION

Pump room

physically

separated with

no personnel

access to wet

well; pumping

of wastewater

from a sanitary

or combined

sewer system

NA NR NA Unclassif

ied

NC, LC, or

LFS

FE

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

through closed

pumps and

pipes

19 a ABOVEGRAD

E

WASTEWATE

R PUMPING

STATION

Pump room

not physically

separated

from wet well;

pumping of

wastewater

from a sanitary

or combined

sewer system

through closed

pumps and

pipes

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

A Entire

space or

room

Division

1

NC FE

b B Entire

space or

room

Division

2

NC, LC, or

LFS

FE

20 a ODOR-

CONTROL

AND

VENTILATION

SYSTEMSSE

RVING

CLASSIFIED

AREAS

Leakag

e and

ignition

of

flamma

ble

gases

and

vapors

D Entire

area if

enclose

d

Division

2

NC, LC, or

LFS

CGD

and FDS

b C Areas

within

0.9 m (3

ft) of

leakage

sources

such as

fans,

damper

s,

flexible

Division

2

NC, LC, or

LFS

CGD

and FDS

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

connecti

ons,

flanges,

pressuri

zed

unwelde

d

ductwor

k, and

odor-

control

vessels

c C Areas

beyond

0.9 m (3

ft)

Unclassif

ied

NC, LC, or

LFS

CGD

and FDS

d Not enclosed,

open to the

atmosphere

Areas

within

0.9 m (3

ft) of

leakage

sources

such as

fans,

damper

s,

flexible

connecti

ons,

flanges,

pressuri

zed

unwelde

d

ductwor

k, and

Division

2

NC,LC,

LFS

FE

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

odor-

control

vessels

e Not enclosed,

open to the

atmosphere

Areas

beyond

0.9 m (3

ft)

Unclassif

ied

NC,LC,

LFS

FE

21 a MAINTENANC

E HOLES .

Access to

sewer for

personnel

entry

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

NNV Inside Division

1

In

accordance

with 8.3.1

NR

b B Inside Division

2

In

accordance

with 8.3.1

NR

22 a JUNCTION

CHAMBERS .

Structure

where sewers

intersect

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

NNV Inside Division

1

In

accordance

with 8.3.1

NR

b B Open

and

above

grade or

inside

and

ventilate

d

Division

2

In

accordance

with 8.3.1

NR

23 INVERTED

SIPHONS

Depressed

section of

gravity sewer

Possibl

e

ignition

of

flamma

NNV Interior

of inlet

and

outlet

Division

1

NC NR

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

ble

gases

and

floating

flamma

ble

liquids

structur

es

24 CATCH

BASINS (Curb

inlet) Inlet

where street

water enters a

storm or

combined

sewer

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

NNV Enclose

d space

Division

1

In

accordance

with 8.3.1

NR

25 a RESIDENTIAL

DIVERSION

STRUCTURE

S .

Enclosed

structures

where

residential

wastewater

can be

diverted

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

NNV Enclose

d space

Division

2

In

accordance

with

Chapter 8

NR

b B Enclose

d space

Unclassif

ied

In

accordance

with

Chapter 8

NR

26 a RESIDENTIAL

BELOWGRAD

E VALVE

VAULT .

With an

exposed

residential

Possibl

e

ignition

of

gases

and

floating

flamma

NNV Enclose

d space

Division

2

In

accordance

with 8.3.1

NR

b B Enclose

d space

Unclassif

ied

In

accordance

with 8.3.1

NR

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

wastewater

surface

ble

liquids

27 a RESIDENTIAL

CONTROL

STRUCTURE

S Enclosed

structures

where

residential

wastewater

flow is

regulated

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

A Enclose

d space

Division

2

In

accordance

with

Chapter 8

NR

b B Enclose

d space

Unclassif

ied

In

accordance

with

Chapter 8

NR

28 a RESIDENTIAL

BELOWGRAD

E METERING

VAULT .

With an

exposed

residential

wastewater

surface

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

NNV Enclose

d space

Division

2

In

accordance

with 8.3.1

NR

b B Enclose

d space

Unclassif

ied

In

accordance

with 8.3.1

NR

29 a DIVERSION

STRUCTURE

S Enclosed

structures

where

wastewater

can be

diverted

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

NNV Enclose

d space

Division

1

In

accordance

with

Chapter 8

NR

b B Division

2

In

accordance

with

Chapter 8

NR

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

30 ABOVEGRAD

E VALVE

VAULT .

Physically

separated

from the wet

well; valves in

vault in closed

piping system

NA NR NA Unclassif

ied

NC, LC, or

LFS

NR

31 a BELOWGRAD

E VALVE

VAULT

Physically

separated

from the wet

well and with

closed piping

system

Buildup

of

vapors

from

flamma

ble or

combus

tible

liquids

NNV Enclose

d space

Division

2

NC, LC, or

LFS

NR

b C Enclose

d space

Unclassif

ied

NC, LC, or

LFS

NR

32 a BELOWGRAD

E VALVE

VAULT With

an exposed

wastewater

surface

Possibl

e

ignition

of

gases

and

floating

flamma

ble

liquids

NNV Enclose

d space

Division

1

NC NR

b B Enclose

d space

Division

2

NC, LC, or

LFS

NR

33 a CONTROL

STRUCTURE

S Enclosed

structures

where

wastewater or

storm water

Buildup

of

vapors

from

flamma

ble or

combus

A Enclose

d space

Division

1

In

accordance

with

Chapter 8

NR

b B Enclose

d space

Division

2

In

accordance

NR

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

flow is

regulated

tible

liquids

with

Chapter 8

34 a WASTEWATE

R HOLDING

BASINS

Enclosed

structures

temporarily

holding

untreated or

partially

treated

wastewater

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

A Enclose

d space

Division

1

NC NR

b B Enclose

d space

Division

2

NC, LC, or

LFS

NR

35 WASTEWATE

R HOLDING

BASINS,

LINED OR

UNLINED

Open

structures

holding storm

water,

combined

wastewater,

untreated or

partially

treated

wastewater

NR NR NR NR NR NR

36 a BELOWGRAD

E METERING

VAULT

Physically

separated

from the wet

Buildup

of

vapors

from

flamma

ble or

NNV Enclose

d space

Division

2

NC, LC, or

LFS

NR

b C Enclose

d space

Unclassif

ied

NC, LC, or

LFS

NR

Row*R

owa

Line*Li

nea

Location .

and .

Function

Fire and

Explosi

on

Hazard

Ventilation**Ven

tilationb

Extent of

Classifie

d Area

NEC-

Area

Electrical

Classific

ation (All

Class I,

Group D)

MaterialMat

erials of

Constructio

n for

Buildings

or

Structuresc

Fire

Protectio

n

Measure

s

well and with

closed piping

system

combus

tible

liquids

37 a BELOWGRAD

E METERING

VAULT With

an exposed

wastewater

surface

Possibl

e

ignition

of

flamma

ble

gases

and

floating

flamma

ble

liquids

NNV Enclose

d space

Division

1

NC NR

b B Enclose

d space

Division

2

NC, LC, or

LFS

NR

38 COARSE AND

FINE

SCREEN

FACILITIES

(See “Coarse

and Fine

Screen

Facilities” in

Table 5.2.)



B: Continuously ventilated at 12 changes per hour in accordance with Chapter 9.

C: Continuously ventilated at 6 air changes per hour in accordance with Chapter 9.


D: No ventilation or ventilated at less than 6 air changes per hour.





NA: Not applicable.




NR: No requirement.

*a The "Row" and "Line" columns are used to refer to specific figures in A.4.2 and specific

requirements for each location and function.

**The NR designation in the "Ventilation"b

This column indicates that nothe ventilation requirements for processes. Additional ventilation

requirements are established for provided in Chapter 9. Ventilation signaling and alarm

requirements are provided in Chapter 7.

c This column indicates the space, and, therefore, Table 9.1.1.4 also has no requirements.materials

of construction for processes. Materials of construction for buildings in which these processes are

housed are in accordance with the applicable building code and construction requirements provided

in Chapter 8.

Chapter 4 Collection Systems

4.1* General.

4.1.1

This chapter shall establish minimum criteria for protection against fire and explosion hazards in the

collection and transportation of municipal wastewater.

4.1.2

This chapter shall not apply to on-site systems, force mains, or those sewers that principally convey

industrial wastes.


4.2.1 The design and construction of the components associated with wastewater collection and

transport systems shall conform to Table 4.2.

4.2.2 The design and construction of buildings and structures containing wastewater collection and

transport systems shall comply with the applicable building code and the additional requirements in

Chapters 7-9.

Table 4.2 Collection Systems

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

1 MATERIALS

USED IN

REHABILITATION

,

RECONSTRUCTI

ON, OR SLIP-

LINING OF

SEWERS

NA NA NA NA In

accordanc

e with

8.3.1

NA

2 INDUSTRIAL

SEWER Sewer

transporting

industrial

wastewater only

(no sanitary

wastewater)


3 STORM SEWER

Sewer transporting

Possible

ignition of

NNV Inside of

sewer

Division 2 In

accordanc

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

storm water only

(no sanitary

wastewater)

flammable

gases and

floating

flammable

liquids

e with

8.3.1

4 STORM WATER

PUMPING

STATION WET

WELLS .

Liquid side of

pumping station

serving only a

storm sewer

system

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Entire

room or

space

Division 2 NC, LC, or

LFS

NR

5 a STORM WATER

PUMPING

STATION DRY

WELLS .

Dry side of a

pumping station

serving only a

storm sewer

system and

physically

separated from

wet well

Buildup of

vapors

from

flammable

or

combustib

le liquids

D Entire dry

well


LFS

FE

b C Entire dry

well

Unclassifie

d

NC, LC, or

LFS

FE

6 PRESSURE

SEWER (Force

main) Sewer under

pressure (flooded

discharge pipe

from pump or tank)


7 BUILDING

SEWER (Lateral

sewer or drain)

Sewer serving a


Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

house or single

building (plumbing)

8 INDIVIDUAL

RESIDENTIAL

SEWER .

Sewer serving one

or more individual

residences with a

total flow of not

more than 1500

gallons per day

(gpd)

NA NNV Within

enclosed

space

Unclassifie

d

NR NR

9 INDIVIDUAL

RESIDENTIAL

PUMPING UNITS .

Pumping units

serving one or

more individual

residences with a

total flow of not

more than 1500

gallons per day

(gpd) (e.g., grinder

pumps, septic tank

effluent pumps,

ejector pumps)

NA NNV Within

enclosed

space

Unclassifie

d

NR NR

10 a RESIDENTIAL

SEWER .

Sewer transporting

primarily

residential

wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Within

enclosed

space

Division 2 In

accordanc

e with

8.3.1

NR

b B Within

enclosed

space

Unclassifie

d

In

accordanc

e with

8.3.1

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

11 a RESIDENTIAL

WASTEWATER

PUMPING

STATION WET

WELL .

Pumping station

transporting

primarily

residential

wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Entire

room or

space


LFS

CGD

b B Entire

room or

space

Unclassifie

d

NC, LC, or

LFS

CGD

12 a RESIDENTIAL

WASTEWATER

PUMPING

STATION DRY

WELL .

Dry side of a

pumping station

transporting

primarily

residential

wastewater

Buildup of

vapors

from

flammable

or

combustib

le liquids

D Entire

room or

space


LFS

FE

b C Entire

room or

space

Unclassifie

d

NC, LC, or

LFS

FE

13 OUTFALL SEWER

Final discharge

pipe from a

treatment plant,

transporting

treated wastewater

NA NNV NA Unclassifie

d

NR NR

14 a SANITARY

SEWER Sewer

transporting

domestic,

commercial, and

industrial

wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Inside of

sewer

Division 1 In

accordanc

e with

8.3.1

NR

b B Inside of

sewer

Division 2 In

accordanc

e with

8.3.1

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

15 a COMBINED

SEWER Sewer

transporting

domestic,

commercial, and

industrial

wastewater and

storm water

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Inside of

sewer

Division 1 In

accordanc

e with

8.3.1

NR

b B Inside of

sewer

Division 2 In

accordanc

e with

8.3.1

NR

16 a WASTEWATER

PUMPING

STATION WET

WELLS .

Liquid side of a

pumping station

serving a sanitary

sewer or combined

system

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Entire

room or

space


LFS

CGD

required if

mechanica

lly

ventilated

or opens

into a

building

interior

b B Entire

room or

space


LFS

CGD

17 a BELOWGRADE

OR PARTIALLY

BELOWGRADE

WASTEWATER

PUMPING

STATION DRY

WELL .

Pump room

physically

separated from

wet well; pumping

of wastewater from

a sanitary or

combined sewer

system through

Buildup of

vapors

from

flammable

or

combustib

le liquids

C Entire

space or

room

Unclassifie

d

NC, LC, or

LFS

FE

b D Entire

space or

room


LFS

FE

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

closed pumps and

pipes

18 ABOVEGRADE

WASTEWATER

PUMPING

STATION Pump

room physically

separated with no

personnel access

to wet well;

pumping of

wastewater from a

sanitary or

combined sewer

system through

closed pumps and

pipes

NA NR NA Unclassifie

d

NC, LC, or

LFS

FE

19 a ABOVEGRADE

WASTEWATER

PUMPING

STATION Pump

room not

physically

separated from

wet well; pumping

of wastewater from

a sanitary or

combined sewer

system through

closed pumps and

pipes

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Entire

space or

room

Division 1 NC FE

b B Entire

space or

room


LFS

FE

20 a ODOR-CONTROL

AND

VENTILATION

SYSTEMSSERVI

Leakage

and

ignition of

flammable

D Entire

area if

enclosed


LFS

CGD and

FDS

b C Areas

within 0.9


LFS

CGD and

FDS

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

NG CLASSIFIED

AREAS

gases and

vapors

m (3 ft) of

leakage

sources

such as

fans,

dampers,

flexible

connection

s, flanges,

pressurize

d

unwelded

ductwork,

and odor-

control

vessels

c C Areas

beyond

0.9 m (3 ft)

Unclassifie

d

NC, LC, or

LFS

CGD and

FDS

d Not

enclosed,

open to

the

atmosphe

re

Areas

within 0.9

m (3 ft) of

leakage

sources

such as

fans,

dampers,

flexible

connection

s, flanges,

pressurize

d

unwelded

ductwork,

and odor-

control

vessels

Division 2 NC,LC,

LFS

FE

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

e Not

enclosed,

open to

the

atmosphe

re

Areas

beyond

0.9 m (3 ft)

Unclassifie

d

NC,LC,

LFS

FE

21 a MAINTENANCE

HOLES .

Access to sewer

for personnel entry

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Inside Division 1 In

accordanc

e with

8.3.1

NR

b B Inside Division 2 In

accordanc

e with

8.3.1

NR

22 a JUNCTION

CHAMBERS .

Structure where

sewers intersect

Buildup of

vapors

from

flammable

or

combustib

le liquids

NNV Inside Division 1 In

accordanc

e with

8.3.1

NR

b B Open and

above

grade or

inside and

ventilated

Division 2 In

accordanc

e with

8.3.1

NR

23 INVERTED

SIPHONS

Depressed section

of gravity sewer

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Interior of

inlet and

outlet

structures

Division 1 NC NR

24 CATCH BASINS

(Curb inlet) Inlet

where street water

enters a storm or

combined sewer

Buildup of

vapors

from

flammable

or

NNV Enclosed

space

Division 1 In

accordanc

e with

8.3.1

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

combustib

le liquids

25 a RESIDENTIAL

DIVERSION

STRUCTURES .

Enclosed

structures where

residential

wastewater can be

diverted

Buildup of

vapors

from

flammable

or

combustib

le liquids

NNV Enclosed

space

Division 2 In

accordanc

e with

Chapter 8

NR

b B Enclosed

space

Unclassifie

d

In

accordanc

e with

Chapter 8

NR

26 a RESIDENTIAL

BELOWGRADE

VALVE VAULT .

With an exposed

residential

wastewater

surface

Possible

ignition of

gases and

floating

flammable

liquids

NNV Enclosed

space

Division 2 In

accordanc

e with

8.3.1

NR

b B Enclosed

space

Unclassifie

d

In

accordanc

e with

8.3.1

NR

27 a RESIDENTIAL

CONTROL

STRUCTURES

Enclosed

structures where

residential

wastewater flow is

regulated

Buildup of

vapors

from

flammable

or

combustib

le liquids

A Enclosed

space

Division 2 In

accordanc

e with

Chapter 8

NR

b B Enclosed

space

Unclassifie

d

In

accordanc

e with

Chapter 8

NR

28 a RESIDENTIAL

BELOWGRADE

METERING

VAULT .

With an exposed

residential

wastewater

surface

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Enclosed

space

Division 2 In

accordanc

e with

8.3.1

NR

b B Enclosed

space

Unclassifie

d

In

accordanc

e with

8.3.1

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

29 a DIVERSION

STRUCTURES

Enclosed

structures where

wastewater can be

diverted

Buildup of

vapors

from

flammable

or

combustib

le liquids

NNV Enclosed

space

Division 1 In

accordanc

e with

Chapter 8

NR

b B Division 2 In

accordanc

e with

Chapter 8

NR

30 ABOVEGRADE

VALVE VAULT .

Physically

separated from the

wet well; valves in

vault in closed

piping system


d

NC, LC, or

LFS

NR

31 a BELOWGRADE

VALVE VAULT

Physically

separated from the

wet well and with

closed piping

system

Buildup of

vapors

from

flammable

or

combustib

le liquids

NNV Enclosed

space


LFS

NR

b C Enclosed

space

Unclassifie

d

NC, LC, or

LFS

NR

32 a BELOWGRADE

VALVE VAULT

With an exposed

wastewater

surface

Possible

ignition of

gases and

floating

flammable

liquids

NNV Enclosed

space

Division 1 NC NR

b B Enclosed

space


LFS

NR

33 a CONTROL

STRUCTURES

Enclosed

structures where

wastewater or

storm water flow is

regulated

Buildup of

vapors

from

flammable

or

combustib

le liquids

A Enclosed

space

Division 1 In

accordanc

e with

Chapter 8

NR

b B Enclosed

space

Division 2 In

accordanc

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

e with

Chapter 8

34 a WASTEWATER

HOLDING

BASINS Enclosed

structures

temporarily holding

untreated or

partially treated

wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Enclosed

space

Division 1 NC NR

b B Enclosed

space


LFS

NR

35 WASTEWATER

HOLDING

BASINS, LINED

OR UNLINED

Open structures

holding storm

water, combined

wastewater,

untreated or

partially treated

wastewater

NR NR NR NR NR NR

36 a BELOWGRADE

METERING

VAULT Physically

separated from the

wet well and with

closed piping

system

Buildup of

vapors

from

flammable

or

combustib

le liquids

NNV Enclosed

space


LFS

NR

b C Enclosed

space

Unclassifie

d

NC, LC, or

LFS

NR

37 a BELOWGRADE

METERING

VAULT With an

exposed

wastewater

surface

Possible

ignition of

flammable

gases and

floating

flammable

liquids

NNV Enclosed

space

Division 1 NC NR

b B Enclosed

space


LFS

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)

Materials

of

Constructi

on c

Fire

Protection

Measures

38 COARSE AND

FINE SCREEN

FACILITIES (See

“Coarse and Fine

Screen Facilities”

in Table 5.2.)



B: Continuously ventilated at 12 changes per hour

C: Continuously ventilated at 6 air changes per hour







NA: Not applicable.




NR: No requirement.

a The "Row" and "Line" columns are used to refer to specific figures in A.4.2 and specific


b

This column indicates the ventilation requirements for processes. Additional ventilation

requirements are provided in Chapter 9. Ventilation signaling and alarm requirements are provided

in Chapter 7.

c This column indicates the materials of construction for processes. Materials of construction for

buildings in which these processes are housed are in accordance with the applicable building code

and construction requirements provided in Chapter 8.



The design and construction of liquid stream treatment processes shall conform to Table 5.2 .

5.2.1

The design and construction of liquid stream treatment processes associated with wastewater liquids treatment shallcomply with the applicable building code and the additional requirements in Chapters 7 through 9 .


13 of 51 12/1/2014 1:18 PM

5.2.2


14 of 51 12/1/2014 1:18 PM

The design and construction of liquid stream treatment processes associated with wastewater liquids treatment shallconform to Table 5.2.2 Table 5.2 Table 5.2.1 .

Table 5.2.2 Liquid Stream Treatment Processes

Rowa LineaLocation

and

Function

Fire andExplosion

HazardVentilationb

Extent ofClassified

Areac

NEC -Area NEC AreaElectrical Classification

(All Class I, Group D)d


forBuildings or

Structures e


1 a DIVERSION ANDCONTROLSTRUCTURESNot preceded byprimary treatment


A Enclosed--entire —entirespace

Division 1 NC FE, H; CGDif enclosedin building

b B Enclosed--entire —entirespace


FE, H; CGDif enclosedin a building

c Notenclosed,open toatmosphere

Within a 3 m(10 ft)envelopearoundequipmentand openchannel


FE and H

2 a COARSE ANDFINE SCREENFACILITIES

Removal ofscreenings fromraw wastewater


A Enclosed—entire space

Division 1 NC FE, H, CGD

b B Enclosed—entire space


FE, H, CGD


Within a 3 m(10 ft)envelopearoundequipmentand openchannel


FE, H

3 PUMPINGSTATIONS,DIVERSIONSTRUCTURESAND CONTROLSTRUCTURES

(See “CollectionSystems,” Table4.2.)

4 a FLOWEQUALIZATIONTANKS Storage ofraw or partiallytreated wastewater



Division 1 NC FE, H;CGDif enclosedin a building





Within a 3 m(10 ft)envelopearoundequipmentand open

channele , f f,g


FE, H

5 a GRIT REMOVALTANKS Separationof grit from rawwastewater



Division 1 NC FE, H;CGDif enclosedin a building





15 of 51 12/1/2014 1:18 PM

Rowa LineaLocation

and

Function

Fire andExplosion

HazardVentilationb

Extent ofClassified

Areac




forBuildings or

Structures e




channele,f f,g


FE, H

6 a PRE-AERATIONTANKSConditioning ofwastewater prior tofurther treatment



Division 1 NC H;CGD ifenclosed ina building



H; CGD ifenclosed ina building



channele,f f,g


H

7 a PRIMARYSEDIMENTATIONTANKS Separationof floating orsettleable solidsfrom rawwastewater



Division 1 NC H;CGD ifenclosed ina building



H; CGD ifenclosed ina building


Interior of thetank from theminimumoperatingwater surfaceto the top ofthe tank wall;envelope 0.46m (18 in.)above the topof the tankand extending0.46 m (18 in.)beyond theexterior wall;envelope 0.46m (18 in.)above gradeextending 3 m(10 ft)horizontallyfrom theexterior tankwalls


H

8 AERATIONBASIN, POND,LAGOON,OXIDATIONDITCH, AEROBICSUSPENDEDGROWTHSYSTEMS,

NA N/A NR Classified (see PrimarySedimentation)

Unclassified if process ispreceded by primarysedimentation

NR H


16 of 51 12/1/2014 1:18 PM

Rowa LineaLocation

and

Function

Fire andExplosion

HazardVentilationb

Extent ofClassified

Areac




forBuildings or

Structures e


SEQUENCINGBATCHREACTORSAerobic treatmentof wastewateropen to theatmosphere

9 a1 ENCLOSEDAERATIONBASIN, AEROBICOR SUSPENDEDGROWTHSYSTEMS,MEMBRANEBIOLOGICALREACTORS

Aerobic treatmentnot preceded byprimary treatment

Possibleignition offlammablegases orfloatingflammableliquids

A (Interior oftank)

Entireenclosedspace or tankof system

Division 1 NC NR

a2 A (Interior oftank)

Exterior ofenclosedspace or tank,installed in abuilding


NR


Exterior ofenclosedspace or tank,installedoutdoors;envelope 0.46m (18 in.)surroundingtank


NR

b1 B (Interior oftankmaintained atnegativepressure)



NR




NR


Exterior ofenclosedspace or tank,installedoutdoors


NR


Interior of tankfrom theminimumoperatingwater surfaceto the top ofthe tank wall;envelope 0.46m (18 in.)above the topof the tankand extending0.46 m (18 in.)beyondexterior wall;envelope 0.46m (18 in.)above gradeand extending


NR


17 of 51 12/1/2014 1:18 PM

Rowa LineaLocation

and

Function

Fire andExplosion

HazardVentilationb

Extent ofClassified

Areac




forBuildings or

Structures e


3 m (10 ft)horizontallyfrom theexterior tankwalls

10 a1 RESIDENTIALENCLOSEDAERATIONBASIN, AEROBICOR SUSPENDEDGROWTHSYSTEMS,MEMBRANEBIOLOGICALREACTORSAerobic treatmentnot preceded byprimary treatment,serving one but notmore than fivedwellings

Possibleignition offlammablegases orfloatingflammableliquids

A (Interior oftank)


Division 2 NC NR




NR


Exterior ofenclosedspace or tank,installedoutdoors


NR

11 ENCLOSEDAERATIONBASIN, AEROBICOR SUSPENDEDGROWTHSYSTEMS,MEMBRANEBIOLOGICALREACTORS

Aerobic treatmentof wastewaterpreceded byprimary treatment

NA N/A NR Entireenclosedspace


NR

12 TRICKLINGFILTER,BIO-TOWER,AEROBICFIXED-FILMSYSTEMS

Aerobic biologicaltreatment ofwastewater

Notnormally asignificanthazard;however,theseprocessesmightcontainmaterialsthat arecombustibleundercertainconditions

NR NA N/A Classified (see See PrimarySedimentation sedimentation )

Unclassified if unit process ispreceded by primarysedimentation.

NR H

13 a ANAEROBICTOWERS,ANAEROBICFIXED-FILMSYSTEM

Anaerobicbiologicaltreatment if sealedfrom atmosphere

Normallyproducescombustiblegas astreatmentprocessby-product

NA N/A Tank interior Division 1 NC FE and H

b NA N/A 3 m (10 ft)envelopearound tank


FE and H


18 of 51 12/1/2014 1:18 PM

Rowa LineaLocation

and

Function

Fire andExplosion

HazardVentilationb

Extent ofClassified

Areac




forBuildings or

Structures e


14 a GAS-HANDLINGSYSTEMS FORLIQUIDTREATMENTPROCESSES

Combustiblegas, oftenunderpressure


Division 1 NC FE and H



FE and H


Within a 3 m(10 ft)envelopearound

equipmente f


FE and H

15 OXYGENAERATION TANKSTanks for aerobictreatment ofwastewater usinghigh-purity oxygenrather than air

Ignition offlammablegases andfloatingflammableliquids in anoxygen-

enrichedenvironment

NA N/A Enclosedspace

Division 2 (If unit process isnot preceded by primarysedimentation, see PrimarySedimentation sedimentationTanks in Table 5.2 forclassification.)

Anyequipment ormaterial withinthe reactorspace shall besafe forexposure tovolatile in anoxygen-

enrichedatmosphere

Specialprovisionfor LFLmonitoringandautomaticisolation ofequipmentand oxygensupply

16 INTERMEDIATE,SECONDARY, ORTERTIARYSEDIMENTATIONTANKS

Separate floatingand settleablesolids fromwastewater atvarious treatmentstages

NA N/A NR NA N/A Classified (see See PrimarySedimentation sedimentation )


NR H

17 FLASH MIXER ORFLOCCULATIONTANKS

Tanks for mixingvarious treatmentchemicals withwastewater



NR H

18 NITRIFICATIONANDDENITRIFICATIONTANKS

Tertiary treatmentof wastewater toreduce or removenitrogen



NR H

19 BREAKPOINTCHLORINATIONTANKS ANDCHLORINECONTACT TANKS

Application ofchlorine inaqueous solutionto wastewater

NA N/A NR NA N/A Unclassified NR (Theseunit processesuse corrosivechemicals thatrequire theuse of specificmaterials ofconstruction.Specialconsiderationshall be given

H


19 of 51 12/1/2014 1:18 PM

Rowa LineaLocation

and

Function

Fire andExplosion

HazardVentilationb

Extent ofClassified

Areac




forBuildings or

Structures e


to thesematerials ofconstruction.)

20 AMMONIASTRIPPINGTOWERS

(See“ TricklingFilter” filterin Table5.2.)

NA N/A NA N/A Unclassified NR (Theseunit processesuse corrosivechemicals.Specialconsiderationshall be givento thesematerials ofconstruction.)

H

21 INTERMEDIATEOR FINALPUMPINGSTATIONS ANDOTHER UNITPROCESSESANDSTRUCTURESNOTSPECIFICALLYADDRESSED INTHIS TABLE.Preceded byprimary treatment

NA N/A NR NA N/A Unclassified NR H

22 GRAVITY ANDPRESSUREFILTERS

Filtering of treatedwastewaterthrough sand orother media


23 CARBONCOLUMN ORTANKS

Vessels containingcarbon for tertiarytreatment ofwastewater

Significanthazard fromcombustiblecarbonmaterial

NA N/A NA N//A Unclassified NR H

24 ON-SITE OZONEGENERATIONSYSTEM ANDOZONE CONTACTTANKS

Ozone generationand purification fordisinfection ofwastewater

Similar tooxygengenerationwithaddition ofbeing highlycorrosive(see SeeTable D.1.1)

NA N/A NA N/A Not covered in this standard NR NR

25 BACKWASHWATER ANDWASTEBACKWASHWATER HOLDINGTANKS

Tanks fortemporary storage

NA N/A NA N/A NA N/A Unclassified NR H


20 of 51 12/1/2014 1:18 PM

Rowa LineaLocation

and

Function

Fire andExplosion

HazardVentilationb

Extent ofClassified

Areac




forBuildings or

Structures e


of backwash water

26 ULTRAVIOLETDISINFECTIONUNIT

Disinfection ofwastewatereffluent byultraviolet radiation


27 EFFLUENTSTRUCTURESVarious structuresconveying treatedwastewater awayfrom treatmentprocesses


28 a ODOR-CONTROLANDVENTILATIONSYSTEMSSERVINGCLASSIFIEDAREAS

(See " CollectionSystems, Table4.2)

b

c



B: Continuously ventilated at 12 air changes per hour in accordance with Chapter 9.






H: Hydrant protection in accordance with 7.2.4.






NR: No requirement.

aThe "Row" and "Line" columns are used to refer to specific figures in Figure A.5.2 and specific requirements for eachlocation and function.

b The NR designation in the "Ventilation" column indicates that no ventilation requirements are established for thespace, and, therefore, Table 9.1.1.4 also has no requirements.


cOpen channels and open structures upstream from the unit processes are classified the same as the downstreamprocesses they supply.


21 of 51 12/1/2014 1:18 PM

dThese unit processes use corrosive chemicals that can have a deteriorating effect on conductors and equipment.Electrical equipment shall be identified for use in the operating environment.

e This column indicates the materials of construction for processes. Materials of construction for buildings in whichthese processes are housed are in accordance with the applicable building code and construction requirementsprovided in Chapter 8.

e f The area beyond the envelope is unclassified.

f g Where liquid turbulence is not induced by aeration or other factors, the following criteria apply: (1) interior of the tankfrom the minimum operating water surface to the top of the tank wall; (2) envelope 0.46 m (18 in.) above the top of thetank and extending 0.46 m (18 in.) beyond the exterior wall; (3) envelope 0.46 m (18 in.) above grade extending 3 m(10 ft) horizontally from the exterior tank walls.



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22 of 51 12/1/2014 1:18 PM

Chapter 5 Liquid Stream Treatment Processes

5.1* General.

5.1.1

This chapter shall establish minimum criteria for protection against fire and explosion hazards

associated with liquid stream treatment processes.

5.1.2

This chapter shall not apply to treatment systems serving individual structures or treatment systems

that principally treat industrial wastes.


The5.2.1The design and construction of liquid stream treatment processes associated with

wastewater liquid treatment shall conform to Table 5.2.

5.2.2 The design and construction of buildings and structures containing liquid stream treatment

processes associated with wastewater liquid treatment shall comply with the applicable building

code and the additional requirements of Chapters 7-9.

Table 5.2 Liquid Stream Treatment Processes

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

1 a DIVERSION AND

CONTROL

STRUCTURES

Not preceded by

primary treatment

Possible

ignition

of

flammabl

e gases

and

floating

flammabl

e liquids

A Enclosed--entire

space

Division 1 NC FE, H;

CGD if

enclose

d in

building

b B Enclosed--entire

space


LFS

FE, H;

CGD if

enclose

d in a

building

c Not

enclose

d, open

to

atmosph

ere

Within a 3 m (10

ft) envelope

around

equipment and

open channel


LFS

FE and

H

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

2 a COARSE AND

FINE SCREEN

FACILITIES .

Removal of

screenings from

raw wastewater

Possible

ignition

of

flammabl

e gases

and

floating

flammabl

e liquids

A Enclosed—

entire space

Division 1 NC FE, H,

CGD

b B Enclosed—

entire space


LFS

FE, H,

CGD

c Not

enclose

d, open

to

atmosph

ere

Within a 3 m (10

ft) envelope

around

equipment and

open channel


LFS

FE, H

3 PUMPING

STATIONS,

DIVERSION

STRUCTURES

AND CONTROL

STRUCTURES .

(See “Collection

Systems,” Table

4.2.)

4 a FLOW

EQUALIZATION

TANKS Storage of

raw or partially

treated wastewater

Possible

ignition

of

flammabl

e gases

and

floating

flammabl

e liquids

A Enclosed—

entire space

Division 1 NC FE,

H;CGD

if

enclose

d in a

building

b B Enclosed—

entire space


LFS

FE, H;

CGD if

enclose

d in a

building

c Not

enclose

d, open

to

Within a 3 m (10

ft) envelope

around

equipment and

open


LFS

FE, H

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

atmosph

ere

channele,fchann

elf,g

5 a GRIT REMOVAL

TANKS Separation

of grit from raw

wastewater

Possible

ignition

of

flammabl

e gases

and

floating

flammabl

e liquids

A Enclosed—

entire space

Division 1 NC FE,

H;CGD

if

enclose

d in a

building

b B Enclosed—

entire space


LFS

FE, H;

CGD if

enclose

d in a

building

c Not

enclose

d, open

to

atmosph

ere

Within a 3 m (10

ft) envelope

around

equipment and

open

channele,fchann

elf,g


LFS

FE, H

6 a PRE-AERATION

TANKS

Conditioning of

wastewater prior to

further treatment

Possible

ignition

of

flammabl

e gases

and

floating

flammabl

e liquids

A Enclosed—

entire space

Division 1 NC H;CGD

if

enclose

d in a

building

b B Enclosed—

entire space


LFS

H; CGD

if

enclose

d in a

building

c Not

enclose

d, open

to

Within a 3 m (10

ft) envelope

around

equipment and

open


LFS

H

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

atmosph

ere

channele,fchann

elf,g

7 a PRIMARY

SEDIMENTATION

TANKS Separation

of floating or

settleable solids

from raw

wastewater

Possible

ignition

of

flammabl

e gases

and

floating

flammabl

e liquids

A Enclosed—

entire space

Division 1 NC H;CGD

if

enclose

d in a

building

b B Enclosed—

entire space


LFS

H; CGD

if

enclose

d in a

building

c Not

enclose

d, open

to

atmosph

ere

Interior of the

tank from the

minimum

operating water

surface to the

top of the tank

wall; envelope

0.46 m (18 in.)

above the top of

the tank and

extending 0.46

m (18 in.)

beyond the

exterior wall;

envelope 0.46 m

(18 in.) above

grade extending

3 m (10 ft)

horizontally from

the exterior tank

walls


LFS

H

8 AERATION

BASIN, POND,

LAGOON,

NA NR Classified

(see

Primary

NR H

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

OXIDATION

DITCH, AEROBIC

SUSPENDED

GROWTH

SYSTEMS,

SEQUENCING

BATCH

REACTORS

Aerobic treatment

of wastewater

open to the

atmosphere

Sedimenta

tion) .

Unclassifie

d if

process is

preceded

by primary

sedimentat

ion

9 a1 ENCLOSED

AERATION

BASIN, AEROBIC

OR SUSPENDED

GROWTH

SYSTEMS,

MEMBRANE

BIOLOGICAL

REACTORS .

Aerobic treatment

not preceded by

primary treatment

Possible

ignition

of

flammabl

e gases

or

floating

flammabl

e liquids

A

(Interior

of tank)

Entire enclosed

space or tank of

system

Division 1 NC NR

a2 A

(Interior

of tank)

Exterior of

enclosed space

or tank, installed

in a building


LFS

NR

a3 A

(Interior

of tank)

Exterior of

enclosed space

or tank, installed

outdoors;

envelope 0.46 m

(18 in.)

surrounding

tank


LFS

NR

b1 B

(Interior

of tank

maintain

ed at

negative

pressure

)

Entire enclosed

space or tank of

system


LFS

NR

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

b2 B

(Interior

of tank

maintain

ed at

negative

pressure

)

Exterior of

enclosed space

or tank, installed

in a building

Unclassifie

d

NC, LC, or

LFS

NR

b3 B

(Interior

of tank

maintain

ed at

negative

pressure

)

Exterior of

enclosed space

or tank, installed

outdoors

Unclassifie

d

NC, LC, or

LFS

NR

c Not

enclose

d, open

to

atmosph

ere

Interior of tank

from the

minimum

operating water

surface to the

top of the tank

wall; envelope

0.46 m (18 in.)

above the top of

the tank and

extending 0.46

m (18 in.)

beyond exterior

wall; envelope

0.46 m (18 in.)

above grade

and extending 3

m (10 ft)

horizontally from

the exterior tank

walls


LFS

NR

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

10 a1 RESIDENTIAL

ENCLOSED

AERATION

BASIN, AEROBIC

OR SUSPENDED

GROWTH

SYSTEMS,

MEMBRANE

BIOLOGICAL

REACTORS

Aerobic treatment

not preceded by

primary treatment,

serving one but not

more than five

dwellings

Possible

ignition

of

flammabl

e gases

or

floating

flammabl

e liquids

A

(Interior

of tank)

Entire enclosed

space or tank of

system

Division 2 NC NR

a2 A

(Interior

of tank)

Exterior of

enclosed space

or tank, installed

in a building

Unclassifie

d

NC, LC, or

LFS

NR

a3 A

(Interior

of tank)

Exterior of

enclosed space

or tank, installed

outdoors

Unclassifie

d

NC, LC, or

LFS

NR

11 ENCLOSED

AERATION

BASIN, AEROBIC

OR SUSPENDED

GROWTH

SYSTEMS,

MEMBRANE

BIOLOGICAL

REACTORS .

Aerobic treatment

of wastewater

preceded by

primary treatment

NA NR Entire enclosed

space

Unclassifie

d

NC, LC, or

LFS

NR

12 TRICKLING

FILTER, BIO-

TOWER,

AEROBIC FIXED-

FILM SYSTEMS .

Aerobic biological

treatment of

wastewater

Not

normally

a

significan

t hazard;

however,

these

processe

NR NA Classified

(see

Primary

Sedimenta

tion) .

Unclassifie

d if unit

process is

NR H

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

s might

contain

materials

that are

combusti

ble under

certain

condition

s

preceded

by primary

sedimentat

ion.

13 a ANAEROBIC

TOWERS,

ANAEROBIC

FIXED-FILM

SYSTEM .

Anaerobic

biological

treatment if sealed

from atmosphere

Normally

produces

combusti

ble gas

as

treatmen

t process

by-

product

NA Tank interior Division 1 NC FE and

H

b NA 3 m (10 ft)

envelope

around tank


LFS

FE and

H

14 a GAS-HANDLING

SYSTEMS FOR

LIQUID

TREATMENT

PROCESSES

Combust

ible gas,

often

under

pressure

A Enclosed—

entire space

Division 1 NC FE and

H

b B Enclosed—

entire space


LFS

FE and

H

c Not

enclose

d, open

to

atmosph

ere

Within a 3 m (10

ft) envelope

around

equipmenteequi

pmentf


LFS

FE and

H

15 OXYGEN

AERATION

TANKS Tanks for

aerobic treatment

of wastewater

using high-purity

Ignition

of

flammabl

e gases

and

floating

flammabl

NA Enclosed space Division 2

(If unit

process is

not

preceded

by primary

sedimentat

Any

equipment

or material

within the

reactor

space shall

be safe for

Special

provisio

n for

LFL

monitor

ing and

automa

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

oxygen rather than

air

e liquids

in an

oxygen- .

enriched

environm

ent

ion, see

Primary

Sedimenta

tion Tanks

in Table

5.2 for

classificati

on.)

exposure to

volatile in an

oxygen- .

enriched

atmosphere

tic

isolatio

n of

equipm

ent and

oxygen

supply

16 INTERMEDIATE,

SECONDARY, OR

TERTIARY

SEDIMENTATION

TANKS .

Separate floating

and settleable

solids from

wastewater at

various treatment

stages

NA NR NA Classified

(see

Primary

Sedimenta

tion) .

Unclassifie

d if unit

process is

preceded

by primary

sedimentat

ion.

NR H

17 FLASH MIXER OR

FLOCCULATION

TANKS .

Tanks for mixing

various treatment

chemicals with

wastewater

NA NR NA Classified

(see

Primary

Sedimenta

tion) .

Unclassifie

d if unit

process is

preceded

by primary

sedimentat

ion.

NR H

18 NITRIFICATION

AND

DENITRIFICATIO

N TANKS .

NA NR NA Classified

(see

Primary

NR H

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

Tertiary treatment

of wastewater to

reduce or remove

nitrogen

Sedimenta

tion) .

Unclassifie

d if unit

process is

preceded

by primary

sedimentat

ion.

19 BREAKPOINT

CHLORINATION

TANKS AND

CHLORINE

CONTACT TANKS .

Application of

chlorine in

aqueous solution

to wastewater


d

NR (These

unit

processes

use

corrosive

chemicals

that require

the use of

specific

materials of

construction.

Special

consideratio

n shall be

given to

these

materials of

construction.

)

H

20 AMMONIA

STRIPPING

TOWERS

(See

“Trickling

Filter” in

Table

5.2.)

NA NA Unclassifie

d

NR (These

unit

processes

use

corrosive

chemicals.

Special

consideratio

n shall be

H

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

given to

these

materials of

construction.

)

21 INTERMEDIATE

OR FINAL

PUMPING

STATIONS AND

OTHER UNIT

PROCESSES

AND

STRUCTURES

NOT

SPECIFICALLY

ADDRESSED IN

THIS TABLE.

Preceded by

primary treatment


d

NR H

22 GRAVITY AND

PRESSURE

FILTERS .

Filtering of treated

wastewater

through sand or

other media


d

NR H

23 CARBON

COLUMN OR

TANKS .

Vessels containing

carbon for tertiary

treatment of

wastewater

Significa

nt hazard

from

combusti

ble

carbon

material

NA NA Unclassifie

d

NR H

24 ON-SITE OZONE

GENERATION

SYSTEM AND

Similar to

oxygen

generatio

NA NA Not

covered in

NR NR

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

OZONE

CONTACT TANKS .

Ozone generation

and purification for

disinfection of

wastewater

n with

addition

of being

highly

corrosive

(see

Table

D.1.1)

this

standard

25 BACKWASH

WATER AND

WASTE

BACKWASH

WATER HOLDING

TANKS .

Tanks for

temporary storage

of backwash water

NA NA NA Unclassifie

d

NR H

26 ULTRAVIOLET

DISINFECTION

UNIT .

Disinfection of

wastewater

effluent by

ultraviolet radiation


d

NR H

27 EFFLUENT

STRUCTURES

Various structures

conveying treated

wastewater away

from treatment

processes


d

NR H

28 a ODOR-CONTROL

AND

VENTILATIONSY

STEMS SERVING

b

c

Ro

wa

Lin

ea

Location .

and .

Function

Fire and

Explosio

n Hazard

Ventilati

onb

Extent of

Classified Areac

NEC-Area

Electrical

Classificati

on .

(All Class I,

Group D)d

MaterialMate

rials of

Constructio

n for

Buildings or

Structurese

Fire

Protecti

on

Measur

es

CLASSIFIED

AREAS .

(See "Collection

Systems, Table

4.2)












NA: Not applicable.



NR: No requirement.

aThe "Row" and "Line" columns are used to refer to Figure A.5.specific figures in A..2 and specific

requirements for each location and function. bThe NR designation in the "Ventilation" bThis column indicates that nothe ventilation requirements for processes. Additional ventilation

requirements are established for the space,provided in Chapter 9. Ventilation signaling and,

therefore, Table 9.1.1.4 also has no alarm requirements. are provided in Chapter 7.

cOpen channels and open structures upstream from the unit processes are classified the same as

the downstream processes they supply.

dThese unit processes use corrosive chemicals that can have a deteriorating effect on conductors

and equipment. Electrical equipment shall be identified for use in the operating environment. eThe

eThis column indicates the materials of construction for processes. Materials of construction for



fThe area beyond the envelope is unclassified. fWhere gWhere liquid turbulence is not induced by aeration or other factors, the following criteria apply: (1)

interior of the tank from the minimum operating water surface to the top of the tank wall; (2)

envelope 0.46 m (18 in.) above the top of the tank and extending 0.46 m (18 in.) beyond the exterior

wall; (3) envelope 0.46 m (18 in.) above grade extending 3 m (10 ft) horizontally from the exterior

tank walls.

Chapter 5 Liquid Stream Treatment Processes

5.1* General.

5.1.1


associated with liquid stream treatment processes.

5.1.2

This chapter shall not apply to treatment systems serving individual structures or treatment systems

that principally treat industrial wastes.


5.2.1The design and construction of liquid stream treatment processes associated with wastewater

liquid treatment shall conform to Table 5.2.

5.2.2 The design and construction of buildings and structures containing liquid stream treatment

processes associated with wastewater liquid treatment shall comply with the applicable building

code and the additional requirements of Chapters 7-9.

Table 5.2 Liquid Stream Treatment Processes

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

1 a DIVERSION AND

CONTROL

STRUCTURES Not

preceded by primary

treatment

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Enclosed-

-entire

space

Division 1 NC FE, H;

CGD if

enclose

d in

building

b B Enclosed-

-entire

space


LFS

FE, H;

CGD if

enclose

d in a

building

c Not

enclosed,

open to

atmosphe

re

Within a 3

m (10 ft)

envelope

around

equipmen

t and


LFS

FE and

H

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

open

channel

2 a COARSE AND FINE

SCREEN

FACILITIES .

Removal of

screenings from raw

wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC FE, H,

CGD

b B Enclosed

— entire

space


LFS

FE, H,

CGD

c Not

enclosed,

open to

atmosphe

re

Within a 3

m (10 ft)

envelope

around

equipmen

t and

open

channel


LFS

FE, H

3 PUMPING

STATIONS,

DIVERSION

STRUCTURES AND

CONTROL

STRUCTURES .

(See “Collection

Systems,” Table 4.2.)

4 a FLOW

EQUALIZATION

TANKS Storage of

raw or partially

treated wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC FE,

H;CGD

if

enclose

d in a

building

b B Enclosed

— entire

space


LFS

FE, H;

CGD if

enclose

d in a

building

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

c Not

enclosed,

open to

atmosphe

re

Within a 3

m (10 ft)

envelope

around

equipmen

t and

open

channelf,g


LFS

FE, H

5 a GRIT REMOVAL

TANKS Separation of

grit from raw

wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC FE,

H;CGD

if

enclose

d in a

building

b B Enclosed

— entire

space


LFS

FE, H;

CGD if

enclose

d in a

building

c Not

enclosed,

open to

atmosphe

re

Within a 3

m (10 ft)

envelope

around

equipmen

t and

open

channelf,g


LFS

FE, H

6 a PRE-AERATION

TANKS Conditioning

of wastewater prior to

further treatment

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC H;CGD

if

enclose

d in a

building

b B Enclosed

— entire

space


LFS

H; CGD

if

enclose

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

d in a

building

c Not

enclosed,

open to

atmosphe

re

Within a 3

m (10 ft)

envelope

around

equipmen

t and

open

channelf,g


LFS

H

7 a PRIMARY

SEDIMENTATION

TANKS Separation of

floating or settleable

solids from raw

wastewater

Possible

ignition of

flammable

gases and

floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC H;CGD

if

enclose

d in a

building

b B Enclosed

— entire

space


LFS

H; CGD

if

enclose

d in a

building

c Not

enclosed,

open to

atmosphe

re

Interior of

the tank

from the

minimum

operating

water

surface to

the top of

the tank

wall;

envelope

0.46 m

(18 in.)

above the

top of the

tank and


LFS

H

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

extending

0.46 m

(18 in.)

beyond

the

exterior

wall;

envelope

0.46 m

(18 in.)

above

grade

extending

3 m (10

ft)

horizontal

ly from

the

exterior

tank walls

8 AERATION BASIN,

POND, LAGOON,

OXIDATION DITCH,

AEROBIC

SUSPENDED

GROWTH

SYSTEMS,

SEQUENCING

BATCH REACTORS

Aerobic treatment of

wastewater open to

the atmosphere

NA NR Classified

(see Primary

Sedimentati

on) .

Unclassified

if process is

preceded by

primary

sedimentatio

n

NR H

9 a1 ENCLOSED

AERATION BASIN,

AEROBIC OR

SUSPENDED

GROWTH

Possible

ignition of

flammable

gases or

floating

A (Interior

of tank)

Entire

enclosed

space or

tank of

system

Division 1 NC NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

a2 SYSTEMS,

MEMBRANE

BIOLOGICAL

REACTORS .

Aerobic treatment not

preceded by primary

treatment

flammable

liquids

A (Interior

of tank)

Exterior

of

enclosed

space or

tank,

installed

in a

building


LFS

NR

a3 A (Interior

of tank)

Exterior

of

enclosed

space or

tank,

installed

outdoors;

envelope

0.46 m

(18 in.)

surroundi

ng tank


LFS

NR

b1 B (Interior

of tank

maintaine

d at

negative

pressure)

Entire

enclosed

space or

tank of

system


LFS

NR

b2 B (Interior

of tank

maintaine

d at

negative

pressure)

Exterior

of

enclosed

space or

tank,

installed

in a

building

Unclassified NC, LC, or

LFS

NR

b3 B (Interior

of tank

Exterior

of


LFS

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

maintaine

d at

negative

pressure)

enclosed

space or

tank,

installed

outdoors

c Not

enclosed,

open to

atmosphe

re

Interior of

tank from

the

minimum

operating

water

surface to

the top of

the tank

wall;

envelope

0.46 m

(18 in.)

above the

top of the

tank and

extending

0.46 m

(18 in.)

beyond

exterior

wall;

envelope

0.46 m

(18 in.)

above

grade

and

extending

3 m (10

ft)

horizontal


LFS

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

ly from

the

exterior

tank walls

10 a1 RESIDENTIAL

ENCLOSED

AERATION BASIN,

AEROBIC OR

SUSPENDED

GROWTH

SYSTEMS,

MEMBRANE

BIOLOGICAL

REACTORS Aerobic

treatment not

preceded by primary

treatment, serving

one but not more

than five dwellings

Possible

ignition of

flammable

gases or

floating

flammable

liquids

A (Interior

of tank)

Entire

enclosed

space or

tank of

system

Division 2 NC NR

a2 A (Interior

of tank)

Exterior

of

enclosed

space or

tank,

installed

in a

building


LFS

NR

a3 A (Interior

of tank)

Exterior

of

enclosed

space or

tank,

installed

outdoors


LFS

NR

11 ENCLOSED

AERATION BASIN,

AEROBIC OR

SUSPENDED

GROWTH

SYSTEMS,

MEMBRANE

BIOLOGICAL

REACTORS .

Aerobic treatment of

wastewater preceded

by primary treatment

NA NR Entire

enclosed

space


LFS

NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

12 TRICKLING FILTER,

BIO-TOWER,

AEROBIC FIXED-

FILM SYSTEMS .

Aerobic biological

treatment of

wastewater

Not

normally a

significant

hazard;

however,

these

processes

might

contain

materials

that are

combustib

le under

certain

conditions

NR NA Classified

(see Primary

Sedimentati

on) .

Unclassified

if unit

process is

preceded by

primary

sedimentatio

n.

NR H

13 a ANAEROBIC

TOWERS,

ANAEROBIC FIXED-

FILM SYSTEM .

Anaerobic biological

treatment if sealed

from atmosphere

Normally

produces

combustib

le gas as

treatment

process

by-

product

NA Tank

interior


H

b NA 3 m (10

ft)

envelope

around

tank


LFS

FE and

H

14 a GAS-HANDLING

SYSTEMS FOR

LIQUID

TREATMENT

PROCESSES

Combusti

ble gas,

often

under

pressure

A Enclosed

— entire

space


H

b B Enclosed

— entire

space


LFS

FE and

H

c Not

enclosed,

open to

atmosphe

re

Within a 3

m (10 ft)

envelope

around

equipmen

tf


LFS

FE and

H

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

15 OXYGEN

AERATION TANKS

Tanks for aerobic

treatment of

wastewater using

high-purity oxygen

rather than air

Ignition of

flammable

gases and

floating

flammable

liquids in

an

oxygen- .

enriched

environme

nt

NA Enclosed

space

Division 2 (If

unit process

is not

preceded by

primary

sedimentatio

n, see

Primary

Sedimentati

on Tanks in

Table 5.2 for

classification

.)

Any

equipment

or material

within the

reactor

space shall

be safe for

exposure

to volatile

in an

oxygen- .

enriched

atmospher

e

Special

provisio

n for

LFL

monitori

ng and

automati

c

isolation

of

equipme

nt and

oxygen

supply

16 INTERMEDIATE,

SECONDARY, OR

TERTIARY

SEDIMENTATION

TANKS .

Separate floating and

settleable solids from

wastewater at

various treatment

stages

NA NR NA Classified

(see Primary

Sedimentati

on) .

Unclassified

if unit

process is

preceded by

primary

sedimentatio

n.

NR H

17 FLASH MIXER OR

FLOCCULATION

TANKS .

Tanks for mixing

various treatment

chemicals with

wastewater

NA NR NA Classified

(see Primary

Sedimentati

on) .

Unclassified

if unit

process is

preceded by

primary

sedimentatio

n.

NR H

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

18 NITRIFICATION

AND

DENITRIFICATION

TANKS .

Tertiary treatment of

wastewater to reduce

or remove nitrogen

NA NR NA Classified

(see Primary

Sedimentati

on) .

Unclassified

if unit

process is

preceded by

primary

sedimentatio

n.

NR H

19 BREAKPOINT

CHLORINATION

TANKS AND

CHLORINE

CONTACT TANKS .

Application of

chlorine in aqueous

solution to

wastewater

NA NR NA Unclassified NR (These

unit

processes

use

corrosive

chemicals

that require

the use of

specific

materials

of

constructio

n. Special

considerati

on shall be

given to

these

materials

of

constructio

n.)

H

20 AMMONIA

STRIPPING

TOWERS

(See

“Trickling

Filter” in

Table

5.2.)

NA NA Unclassified NR (These

unit

processes

use

corrosive

H

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

chemicals.

Special

considerati

on shall be

given to

these

materials

of

constructio

n.)

21 INTERMEDIATE OR

FINAL PUMPING

STATIONS AND

OTHER UNIT

PROCESSES AND

STRUCTURES NOT

SPECIFICALLY

ADDRESSED IN

THIS TABLE.

Preceded by primary

treatment

NA NR NA Unclassified NR H

22 GRAVITY AND

PRESSURE

FILTERS .

Filtering of treated

wastewater through

sand or other media


23 CARBON COLUMN

OR TANKS .

Vessels containing

carbon for tertiary

treatment of

wastewater

Significant

hazard

from

combustib

le carbon

material

NA NA Unclassified NR H

24 ON-SITE OZONE

GENERATION

SYSTEM AND

Similar to

oxygen

generatio

NA NA Not covered

in this

standard

NR NR

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

OZONE CONTACT

TANKS .

Ozone generation

and purification for

disinfection of

wastewater

n with

addition of

being

highly

corrosive

(see

Table

D.1.1)

25 BACKWASH

WATER AND

WASTE BACKWASH

WATER HOLDING

TANKS .

Tanks for temporary

storage of backwash

water

NA NA NA Unclassified NR H

26 ULTRAVIOLET

DISINFECTION

UNIT .

Disinfection of

wastewater effluent

by ultraviolet

radiation


27 EFFLUENT

STRUCTURES

Various structures

conveying treated

wastewater away

from treatment

processes


28 a ODOR-CONTROL

AND

VENTILATIONSYST

EMS SERVING

CLASSIFIED AREAS .

b

c

Rowa

Linea

Location .

and .

Function

Fire and

Explosion

Hazard

Ventilatio

nb

Extent of

Classified

Areac

NEC-Area

Electrical

Classificatio

n .

(All Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protectio

n

Measure

s

(See "Collection

Systems, Table 4.2)












NA: Not applicable.



NR: No requirement.

aThe "Row" and "Line" columns are used to refer to specific figures in A.5.2 and specific


bThis column indicates the ventilation requirements for processes. Additional ventilation


in Chapter 7.

cOpen channels and open structures upstream from the unit processes are classified the same as

the downstream processes they supply.


and equipment. Electrical equipment shall be identified for use in the operating environment.

eThis column indicates the materials of construction for processes. Materials of construction for



fThe area beyond the envelope is unclassified.

gWhere liquid turbulence is not induced by aeration or other factors, the following criteria apply: (1)

interior of the tank from the minimum operating water surface to the top of the tank wall; (2)

envelope 0.46 m (18 in.) above the top of the tank and extending 0.46 m (18 in.) beyond the exterior

wall; (3) envelope 0.46 m (18 in.) above grade extending 3 m (10 ft) horizontally from the exterior

tank walls.



The design and construction of solids treatment processes shall conform to Table 6.2(a) and Table 6.2(b) .

6.2.1

The design and construction of buildings and structures containing solids treatment processes associated withwastewater solids treatment shall comply with the applicable building code and the additional requirements ofChapters 7 through 9 .


23 of 51 12/1/2014 1:18 PM

6.2.2


24 of 51 12/1/2014 1:18 PM

The design and construction of solids treatment processes associated with wastewater solids treatment shall conformto Table 6.2.2(a) Table 6.2(a) Table 6.2.1(a) and Table 6.2.2(b) Table 6.2(b) Table 6.2.1(b) .

Table 6.2.2(a) Solids Treatment Processes

Rowa Linea Location andFunction

Fire andExplosion

HazardVentilationb,c,d

Extent ofClassified

Area

NEC -Area NECArea ElectricalClassification(All Class I,

Group D)d


forBuildings or

Structures e


1 COARSE AND FINESCREENINGS-

HANDLINGBUILDINGS

Storage, conveying,or dewatering ofscreenings (noexposed flow ofwastewater throughbuilding or area)


H, FE, andFAS

2 GRIT-HANDLINGBUILDING

Storage, conveying,and dewatering ofheavy smallscreenings and grit(no exposed flow ofwastewater throughbuilding or area)


H, FE, andFAS

3 a SCUM-HANDLINGBUILDING ORAREA Holding,dewatering, orstorage

Possiblegrease orflammableliquidscarryover

A Enclosedspace


H andFE;CGD ifenclosed inbuilding

b B Enclosedspace


H and FE;CGD ifenclosed inbuilding

c Not enclosed,open toatmosphere

NA N/A Unclassified NC, LC, orLFS

H and FE

4 a SCUM PITS Buildup ofvapors fromflammable orcombustibleliquids


Division 1 NC HandFE;CGD ifenclosed inbuilding



H and FE;CGD ifenclosed inbuilding


Within a 3 m(10 ft)envelopearoundequipment and

open channelc


H and FE

5 a SCUM-PUMPINGAREAS Pumping ofscum, wet side ofpumping station

Buildup ofvapors fromflammable orcombustibleliquids.

A Enclosed —entire space

Division 1 NC Hand FE;CGD ifenclosed inbuilding

b B Enclosed —entire space


Hand FE;CGD ifenclosed inbuilding


25 of 51 12/1/2014 1:18 PM


Fire andExplosion


Extent ofClassified

Area


Classification (AllClass I, Group

D)d


forBuildings or

Structures e



Within a 3 m(10 ft)envelopearoundequipment and

open channelc


H and FE

6 a SCUM-PUMPINGAREAS Pumping ofscum, dry side ofpumping station

Buildup ofvapors fromflammable andcombustibleliquids.

D Enclosedspace


H and FE

b C Enclosedspace


H and FE


NA N/A Unclassified NC, LC, orLFS

H and FE

7 SCUM

INCINERATORSef

Elimination of scumthrough burning

Fireboxexplosion frompossiblecarryover offlammablescum

NR Incineratorarea ifseparated fromscum storage


FSS (ifindoors), H,and FE

8 a SLUDGETHICKENER(CLARIFIER) Sludgeconcentration andremoval, gravity, ordissolved airflotation

Possiblegeneration ofmethane fromsludge;carryover offloatingflammableliquids


Division 1 NC HandFE;CGD ifenclosed inbuilding





Envelope 0.46m (18 in.)above watersurface and

3 m (10 ft)horizontallyfrom wetted

wallsc

H and FE

9 a SLUDGE PUMPINGSTATION DRYWELLS

Dry side of a sludgepumping station

Buildup ofmethane gasor flammablevapors

D Entire dry wellwhenphysicallyseparated froma wet well orseparatestructures


H and FE

b C Entire dry wellwhenphysicallyseparated froma wet well orseparatestructures


H and FE

10 a SLUDGE STORAGEWET WELLS, PITS,AND HOLDINGTANKS

Possiblegeneration ofmethane gasin explosiveconcentrations;


Division 1 NC CGD, H,and FE iftankenclosed inbuilding


26 of 51 12/1/2014 1:18 PM


Fire andExplosion


Extent ofClassified

Area



D)d


forBuildings or

Structures e


Retaining of sludge carryover offloatingflammableliquids



CGD, H,and FE iftankenclosed inbuilding




wallsc


NR

11 a SLUDGE-BLENDING TANKSAND HOLDINGWELLS

Retaining of sludgewith some agitation

Possiblegeneration ofmethane gasin explosiveconcentrations;carryover offloatingflammableliquids


Division 1 NC H, FE, andCGD if tankenclosed inbuilding



H, FE, andCGD if tankenclosed inbuilding




wallsc


NR

12 a DEWATERINGBUILDINGSCONTAININGCENTRIFUGES,GRAVITY BELTTHICKENERS,BELT ANDVACUUM FILTERS,AND FILTERPRESSES

Removal of waterfrom sludge and theconveyance ofsludge cake

Accumulationof methanegas

C Entire room Unclassified NC, LC, orLFS

H, FE, andFAS

b D Entire room Division 2 NC, LC, orLFS

H, FE, andFAS

13 a ENCLOSEDSLUDGE CAKESTORAGE Storageof dewatered sludgecake andconveyance ofsludge cake

Accumulationof methanegas

C Entire room Unclassified NC, LC, orLFS

H, FE, andFAS

b D Entire room Division 2 NC, LC, orLFS

H, FE, andFAS

14 INCINERATORSe f

AND INCINERATORBUILDINGS

Conveying andburning of sludgecake

Fireboxexplosion

NR NA N/A Unclassified NC, LC, orLFS

FSS (ifindoors), H,and FE


27 of 51 12/1/2014 1:18 PM


Fire andExplosion


Extent ofClassified

Area



D)d


forBuildings or

Structures e


15 HEAT TREATMENTUNITS, LOW- ORHIGH-PRESSUREOXIDATION UNITS

Closed oxidation ofsludge

None, otherthan inhigh-pressuresystems

NR NA N/A Unclassified NC, LC, orLFS

H and FE

16 a ANAEROBICDIGESTERS, BOTHFIXED ROOF ANDFLOATING COVERGeneration of sludgegas from digestingsludge

Leakage ofgas fromcover, piping,emergencyrelief valves,andappurtenances

Not enclosed,open toatmosphere

Tank interior;areas aboveand arounddigester cover;envelope 3 m(10 ft) abovethe highestpoint of cover,when cover isat its maximumelevation, and1.5 m (5 ft)from any wall

Division 1 NC H and FE

b Not enclosed,open toatmosphere

Envelope

4.6 m (15 ft)above Division1 area overcover and 1.5m (5 ft) beyondDivision 1 areaaround tankwalls

Division 2 NC H and FE

c A For digestertanks enclosedin a building:tank interior;entire areainside building

Division 1 NC CGD ifenclosed inbuilding

d B For digestertanks enclosedin a building:tank interior;areas aboveand arounddigester cover;envelope 3 m(10 ft) abovehighest point ofcover, whencover is at itsmaximumelevation, and1.5 m (5 ft)from any wallof digester tank

Division 1 NC CGD ifenclosed inbuilding

e B Remainingspace inenclosed area


CGD ifenclosed inbuilding

17 a ANAEROBICDIGESTER

Leaking andignition of

A Entire building Division 1 NC CGD, H,and FE


28 of 51 12/1/2014 1:18 PM


Fire andExplosion


Extent ofClassified

Area



D)d


forBuildings or

Structures e


CONTROLBUILDING

Storage, handling, orburning of sludgegas

sludge gasb B Enclosed areasthat containgas-handlingequipment


CGD, H,and FE

c C Physicallyseparated fromgas-handlingequipment


CGD, H,and FE

18 a DIGESTERGAS-PROCESSINGROOMS Gascompression,handling, andprocessing

Sludge gasignition

A Entire room Division 1 NC CGD, H,and FE

b B Within 1.5 m (5ft) ofequipment


CGD, H,and FE

c B Entire room Division 2 NC, LC, orLFS

CGD, H,and FE

19 ANAEROBICDIGESTER GASSTORAGE

Storage of sludgegas

Gas storagepiping andhandling

NNV Within a 3 m(10 ft)envelope oftanks, valves,andappurtenances



20 a WASTE

GAS

BURNERS

Combusting excessgas

Gas piping andappurtenances

NA N/A Within 3 m (10ft) envelope ofall fixtures,appurtenances,and housing

Division 1 NC NR

b Envelope

4.6 m (15 ft)above Division1 envelope and1.5 m (5 ft) onall sides

Division 2 NC NR

21 CHLORINEOXIDATION UNITS

Chlorine reactionwith sludge

Chlorine is avery strongoxidizing agent

NR NA N/A Unclassified NR (Theseunit processesuse corrosivechemicals thatrequire theuse of specificmaterials ofconstruction.Specialconsiderationshall be givento suchmaterials ofconstruction.)

H and FE

22 a UNDERGROUND(PIPING) TUNNELSCONTAININGNATURAL GASPIPING ORSLUDGE GASPIPING

Transmission of gas,sludge, water, air,and steam viapiping; also might

Ignition ofnatural gas orsludge gases

D Within 3 m (10ft) of valvesandappurtenances


CGD, FDS,and FE

b D Entire tunnel Division 2 NC, LC, orLFS

CGD, FDS,and FE

c C Areas within 3m (10 ft) ofvalves, meters,gas checkvalves,


CGD, FDS,and FE


29 of 51 12/1/2014 1:18 PM


Fire andExplosion


Extent ofClassified

Area



D)d


forBuildings or

Structures e


contain power cableand conduit

condensatetraps, andother pipingappurtenances

d C Areas beyond3 m (10 ft)


CGD, FDS,and FE

23 UNDERGROUND(PIPING) TUNNELSNOT CONTAININGNATURAL GASPIPING ORSLUDGE GASPIPINGTransmissionof sludge, water, air,and steam piping;also might containpower cable andconduit


FDS andFE

24 a COMPOSTINGPILES

Aerobic sludgereduction

Liberation ofammonia andtoxic gas(compostingmaterials canself-ignite)

D Enclosed area Division 2 NC, LC, orLFS

H and FDS

b C Enclosed area Unclassified NC, LC, orLFS

H and FDS

25 a IN-VESSELCOMPOSTINGAerobic sludgereduction

Liberation ofammonia andtoxic gas(compostingmaterials canself-ignite)

As required byprocess

If enclosed,interior ofreactor vesselplus a 3 m (10ft) envelopearound reactorvessel

Division 2 NC H and FDS

b As required byprocess

Areas beyond3 m (10 ft)

Unclassified NC H and FDS

26 ODOR-CONTROLAND VENTILATIONSYSTEMSSERVINGCLASSIFIEDAREAS ((See"CollectionSystems," Table 4.2)

27 PUMPING OFDRAINAGE FROMDIGESTEDSLUDGE-

DEWATERINGPROCESSESPumping of centrate,filtrate, leachate,drying beds, and soforth


H







30 of 51 12/1/2014 1:18 PM


FAS: Fire alarm system.



FSS: Fire suppression system (e.g., automatic sprinkler, water spray, foam, gaseous, or dry chemical).








NR: No requirement.

aThe “Row” and “Line” columns are used to refer to specific figures in A.6.2 and specific requirements for each locationand function.

b The NR designation in the "Ventilation" column indicates that no ventilation requirements are established for thespace, and, therefore, Table 9.1.1.4 also has no requirements.


cThe area beyond the envelope is unclassified.

dThese unit processes use corrosive chemicals that can have a deteriorating effect on conductors and equipment.Electrical equipment shall be identified for use in the operating environment.

e This column indicates the materials of construction for processes. Materials of construction for buildings in whichthese processes are housed are in accordance with the applicable building code and construction requirementsprovided in Chapter 8.

e f See NFPA 54, NFPA 82, and NFPA 85.

Table 6.2.2(b) Solids Treatment Processes — Sludge Drying

Row LineLocation and

Function

Fire andExplosion

HazardVentilationa,b

Extent ofClassified

Area

NEC -Area NECArea ElectricalClassification(All Class II,

Group G)c


forBuildings or

Structures d


1 a SLUDGE-DRYING

PROCESSESd e

Potentialfor ignitionof dust

NR If exposedtocombustibleparticulatesolids,entire

roome f

Division 1 NC(Constructionin accordancewith NFPA 30,NFPA 68,NFPA 69,NFPA 499,and NFPA654)

H, FAS,and FSS(See NFPA30, NFPA61, NFPA69, NFPA85, NFPA499, andNFPA 654)

b NR Areaswithinequipmentprocessingcombustibleparticulatesolids

Division 1 NC(Constructionin accordancewith NFPA 30,NFPA 68,NFPA 69,NFPA 499,and NFPA654)


c NR Areaswithin 3 m(10 ft) of

Division 2 NC(Constructionin accordance

H, FAS,and FSS(See NFPA


31 of 51 12/1/2014 1:18 PM

Row LineLocation and

Function

Fire andExplosion

HazardVentilationa,b

Extent ofClassified

Area


Classification (AllClass II, Group

G)c


forBuildings or

Structures d


equipmentprocessingcombustibleparticulatesolids

with NFPA 30,NFPA 68,NFPA 69,NFPA 499,and NFPA654)

30, NFPA61, NFPA69, NFPA85, NFPA499, andNFPA 654)

d NR Areasbeyond 3 m(10 ft) ofequipmentprocessingcombustibleparticulatesolids

Unclassified NC(Constructionin accordancewith NFPA 30,NFPA 68,NFPA 69,NFPA 499,and NFPA654)


2 a DRIED SLUDGESTORAGEAREAS, IFENCLOSED

Potentialfor ignitionof dust

NR If exposedto driedsludge,entire

roome

Division 1 NC(Constructionin accordancewith NFPA 68and NFPA 69,NFPA 499,and NFPA654)

H, FAS(See NFPA61, NFPA69, NFPA497, andNPFA 654)

b NR Areaswithin tanksstoringdriedsludge

Division 1 NC(Constructionin accordancewith NFPA 68,NFPA 69,NFPA 499,and NFPA654)

H and FAS(See NFPA61, NFPA69, NFPA497, andNFPA 654)

c NR Areaswithin 3 m(10 ft) oftanksstoringdriedsludge

Division 2 NC(Constructionin accordancewith NFPA 68,NFPA 69,NFPA 499,and NFPA654)


d NR Areasbeyond 3 m(10 ft) oftanksstoringdriedsludge

Unclassified NC(Constructionin accordancewith NFPA 68,NFPA 69,NFPA 499,and NFPA654)




FSS: Fire suppression system (e.g., automatic sprinkler, water spray, foam, gaseous, or dry chemical).




NR: No requirement.

aThe NR designation in the “Ventilation” This column indicates that no the ventilation requirements are established for


32 of 51 12/1/2014 1:18 PM

the space, and, therefore, Table 9.1.1.4 also has no requirements. for processes. Additional ventilation requirementsare provided in Chapter 9. Ventilation signaling and alarm requirements are provided in Chapter 7.

bFor sludge-drying processes that use flammable or combustible liquids, ventilate in accordance with NFPA 30.

cOr if acceptable to the authority having jurisdiction with classification in NFPA 499.

d This column indicates the materials of construction for processes. Materials of construction for buildings in whichthese processes are housed are in accordance with the applicable building code and construction requirementsprovided in Chapter 8.

d e See NFPA 54, NFPA 85, NFPA 499, and NFPA 654. For sludge-drying processes that use flammable orcombustible liquids, see NFPA 30.

e f The area beyond the envelope is unclassified.



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33 of 51 12/1/2014 1:18 PM

Chapter 6 Solids Treatment Processes

6.1* General.

6.1.1


associated with solids treatment processes.

6.1.2

This chapter shall not apply to the treatment of solids from industrial waste treatment processes.


The6.2.1The design and construction of solids treatment processes associated with wastewater

solids treatment shall conform to Table 6.2(a) and Table 6.2(b).

6.2.2 The design and construction of buildings and structures containing solids treatment processes

associated with wastewater solids treatment shall comply with the applicable building code and the

additional requirements of Chapters 7-9.

Table 6.2(a) Solids Treatment Processes

Ro

wa

Lin

ea Location and Function

Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

1 COARSE AND FINE

SCREENINGS- .

HANDLING BUILDINGS .

Storage, conveying, or

dewatering of screenings

(no exposed flow of

wastewater through

building or area)

NA NR NA Unclassifi

ed

NC, LC, or

LFS

H, FE,

and

FAS

2 GRIT-HANDLING

BUILDING .

Storage, conveying, and

dewatering of heavy

small screenings and grit

(no exposed flow of

wastewater through

building or area)

NA NR NA Unclassifi

ed

NC, LC, or

LFS

H, FE,

and

FAS

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

3 a SCUM-HANDLING

BUILDING OR AREA

Holding, dewatering, or

storage

Possible

grease or

flammable

liquids

carryover

A Enclosed

space


LFS

H and

FE;CG

D if

enclos

ed in

buildin

g

b B Enclosed

space

Unclassifi

ed

NC, LC, or

LFS

H and

FE;

CGD if

enclos

ed in

buildin

g

c Not

enclosed,

open to

atmosphe

re

NA Unclassifi

ed

NC, LC, or

LFS

H and

FE

4 a SCUM PITS Buildup of

vapors

from

flammable

or

combustibl

e liquids

A Enclosed

— entire

space

Division 1 NC Hand

FE;CG

D if

enclos

ed in

buildin

g

b B Enclosed

— entire

space


LFS

H and

FE;

CGD if

enclos

ed in

buildin

g

c Not

enclosed,

open to

Within a 3

m (10 ft)

envelope


LFS

H and

FE

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

atmosphe

re

around

equipment

and open

channelc

5 a SCUM-PUMPING

AREAS Pumping of

scum, wet side of

pumping station

Buildup of

vapors

from

flammable

or

combustibl

e liquids.

A Enclosed

— entire

space

Division 1 NC Hand

FE;

CGD if

enclos

ed in

buildin

g

b B Enclosed

— entire

space


LFS

Hand

FE;

CGD if

enclos

ed in

buildin

g

c Not

enclosed,

open to

atmosphe

re

Within a 3

m (10 ft)

envelope

around

equipment

and open

channelc


LFS

H and

FE

6 a SCUM-PUMPING

AREAS Pumping of

scum, dry side of

pumping station

Buildup of

vapors

from

flammable

and

combustibl

e liquids.

D Enclosed

space


LFS

H and

FE

b C Enclosed

space

Unclassifi

ed

NC, LC, or

LFS

H and

FE

c Not

enclosed,

open to

atmosphe

re

NA Unclassifi

ed

NC, LC, or

LFS

H and

FE

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

7 SCUM

INCINERATORSeINCIN

ERATORSf Elimination of

scum through burning

Firebox

explosion

from

possible

carryover

of

flammable

scum

NR Incinerator

area if

separated

from scum

storage

Unclassifi

ed

NC, LC, or

LFS

FSS (if

indoor

s), H,

and FE

8 a SLUDGE THICKENER

(CLARIFIER) Sludge

concentration and

removal, gravity, or

dissolved air flotation

Possible

generation

of

methane

from

sludge;

carryover

of floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC Hand

FE;CG

D if

enclos

ed in

buildin

g

b B Enclosed

— entire

space


LFS

Hand

FE;

CGD if

enclos

ed in

buildin

g

c Not

enclosed,

open to

atmosphe

re

Envelope

0.46 m (18

in.) above

water

surface

and .

3 m (10 ft)

horizontall

y from

wetted

wallsc

H and

FE

9 a SLUDGE PUMPING

STATION DRY WELLS .

Buildup of

methane

gas or

D Entire dry

well when

physically


LFS

H and

FE

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

Dry side of a sludge

pumping station

flammable

vapors

separated

from a wet

well or

separate

structures

b C Entire dry

well when

physically

separated

from a wet

well or

separate

structures

Unclassifi

ed

NC, LC, or

LFS

H and

FE

10 a SLUDGE STORAGE

WET WELLS, PITS,

AND HOLDING TANKS .

Retaining of sludge

Possible

generation

of

methane

gas in

explosive

concentrat

ions;

carryover

of floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC CGD,

H, and

FE if

tank

enclos

ed in

buildin

g

b B Enclosed

— entire

space


LFS

CGD,

H, and

FE if

tank

enclos

ed in

buildin

g

c Not

enclosed,

open to

atmosphe

re

Envelope

0.46 m (18

in.) above

water

surface

and .


LFS

NR

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

3 m (10 ft)

horizontall

y from

wetted

wallsc

11 a SLUDGE-BLENDING

TANKS AND HOLDING

WELLS .

Retaining of sludge with

some agitation

Possible

generation

of

methane

gas in

explosive

concentrat

ions;

carryover

of floating

flammable

liquids

A Enclosed

— entire

space

Division 1 NC H, FE,

and

CGD if

tank

enclos

ed in

buildin

g

b B Enclosed

— entire

space


LFS

H, FE,

and

CGD if

tank

enclos

ed in

buildin

g

c Not

enclosed,

open to

atmosphe

re

Envelope

0.46 m (18

in.) above

water

surface

and .

3 m (10 ft)

horizontall

y from

wetted

wallsc


LFS

NR

12 a DEWATERING

BUILDINGS

CONTAINING

Accumulat

ion of

C Entire

room

Unclassifi

ed

NC, LC, or

LFS

H, FE,

and

FAS

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

b CENTRIFUGES,

GRAVITY BELT

THICKENERS, BELT

AND VACUUM

FILTERS, AND FILTER

PRESSES .

Removal of water from

sludge and the

conveyance of sludge

cake

methane

gas

D Entire

room


LFS

H, FE,

and

FAS

13 a ENCLOSED SLUDGE

CAKE STORAGE

Storage of dewatered

sludge cake and

conveyance of sludge

cake

Accumulat

ion of

methane

gas

C Entire

room

Unclassifi

ed

NC, LC, or

LFS

H, FE,

and

FAS

b D Entire

room


LFS

H, FE,

and

FAS

14 INCINERATORSeINCIN

ERATORS f AND INCINERATOR

BUILDINGS .

Conveying and burning

of sludge cake

Firebox

explosion

NR NA Unclassifi

ed

NC, LC, or

LFS

FSS (if

indoor

s), H,

and FE

15 HEAT TREATMENT

UNITS, LOW- OR HIGH-

PRESSURE

OXIDATION UNITS .

Closed oxidation of

sludge

None,

other than

in high-

pressure

systems

NR NA Unclassifi

ed

NC, LC, or

LFS

H and

FE

16 a ANAEROBIC

DIGESTERS, BOTH

FIXED ROOF AND

FLOATING COVER

Generation of sludge gas

from digesting sludge

Leakage

of gas

from

cover,

piping,

emergenc

y relief

Not

enclosed,

open to

atmosphe

re

Tank

interior;

areas

above and

around

digester

cover;

Division 1 NC H and

FE

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

valves,

and

appurtena

nces

envelope 3

m (10 ft)

above the

highest

point of

cover,

when

cover is at

its

maximum

elevation,

and 1.5 m

(5 ft) from

any wall

b Not

enclosed,

open to

atmosphe

re

Envelope .

4.6 m (15

ft) above

Division 1

area over

cover and

1.5 m (5 ft)

beyond

Division 1

area

around

tank walls

Division 2 NC H and

FE

c A For

digester

tanks

enclosed

in a

building:

tank

interior;

entire area

inside

building

Division 1 NC CGD if

enclos

ed in

buildin

g

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

d B For

digester

tanks

enclosed

in a

building:

tank

interior;

areas

above and

around

digester

cover;

envelope 3

m (10 ft)

above

highest

point of

cover,

when

cover is at

its

maximum

elevation,

and 1.5 m

(5 ft) from

any wall of

digester

tank


enclos

ed in

buildin

g

e B Remaining

space in

enclosed

area


LFS

CGD if

enclos

ed in

buildin

g

17 a ANAEROBIC

DIGESTER CONTROL

BUILDING

Leaking

and

A Entire

building

Division 1 NC CGD,

H, and

FE

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

b .

Storage, handling, or

burning of sludge gas

ignition of

sludge gas

B Enclosed

areas that

contain

gas-

handling

equipment


LFS

CGD,

H, and

FE

c C Physically

separated

from gas-

handling

equipment

Unclassifi

ed

NC, LC, or

LFS

CGD,

H, and

FE

18 a DIGESTER GAS-

PROCESSING ROOMS

Gas compression,

handling, and processing

Sludge

gas

ignition

A Entire

room

Division 1 NC CGD,

H, and

FE

b B Within 1.5

m (5 ft) of

equipment


LFS

CGD,

H, and

FE

c B Entire

room


LFS

CGD,

H, and

FE

19 ANAEROBIC

DIGESTER GAS

STORAGE .

Storage of sludge gas

Gas

storage

piping and

handling

NNV Within a 3

m (10 ft)

envelope

of tanks,

valves,

and

appurtena

nces


LFS

Hand

FE;

CGD if

enclos

ed in

buildin

g

20 a WASTE .

GAS .

BURNERS .

Combusting excess gas

Gas piping

and

appurtena

nces

NA Within 3 m

(10 ft)

envelope

of all

fixtures,

appurtena

Division 1 NC NR

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

nces, and

housing

b Envelope .

4.6 m (15

ft) above

Division 1

envelope

and 1.5 m

(5 ft) on all

sides

Division 2 NC NR

21 CHLORINE OXIDATION

UNITS .

Chlorine reaction with

sludge

Chlorine is

a very

strong

oxidizing

agent

NR NA Unclassifi

ed

NR (These

unit

processes

use

corrosive

chemicals

that require

the use of

specific

materials of

construction

. Special

consideratio

n shall be

given to

such

materials of

construction

.)

H and

FE

22 a UNDERGROUND

(PIPING) TUNNELS

CONTAINING NATURAL

GAS PIPING OR

SLUDGE GAS PIPING

Ignition of

natural

gas or

sludge

gases

D Within 3 m

(10 ft) of

valves and

appurtena

nces


LFS

CGD,

FDS,

and FE

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

b .

Transmission of gas,

sludge, water, air, and

steam via piping; also

might contain power

cable and conduit

D Entire

tunnel


LFS

CGD,

FDS,

and FE

c C Areas

within 3 m

(10 ft) of

valves,

meters,

gas check

valves,

condensat

e traps,

and other

piping

appurtena

nces


LFS

CGD,

FDS,

and FE

d C Areas

beyond 3

m (10 ft)

Unclassifi

ed

NC, LC, or

LFS

CGD,

FDS,

and FE

23 UNDERGROUND

(PIPING) TUNNELS

NOT CONTAINING

NATURAL GAS PIPING

OR SLUDGE GAS

PIPING Transmission of

sludge, water, air, and

steam piping; also might

contain power cable and

conduit

NA NR NA Unclassifi

ed

NC, LC, or

LFS

FDS

and FE

24 a COMPOSTING PILES .

Aerobic sludge reduction

Liberation

of

ammonia

and toxic

gas

(composti

ng

D Enclosed

area


LFS

H and

FDS

b C Enclosed

area

Unclassifi

ed

NC, LC, or

LFS

H and

FDS

Ro

wa

Lin


Fire and

Explosion

Hazard

Ventilatio

nb,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classifica

tion (All

Class I,

Group D)d

MaterialMat

erials of

Constructio

n for

Buildings or

Structurese

Fire

Protect

ion

Measur

es

materials

can self-

ignite)

25 a IN-VESSEL

COMPOSTING Aerobic

sludge reduction

Liberation

of

ammonia

and toxic

gas

(composti

ng

materials

can self-

ignite)

As

required

by

process

If

enclosed,

interior of

reactor

vessel

plus a 3 m

(10 ft)

envelope

around

reactor

vessel

Division 2 NC H and

FDS

b As

required

by

process

Areas

beyond 3

m (10 ft)

Unclassifi

ed

NC H and

FDS

26 ODOR-CONTROL AND

VENTILATION

SYSTEMSSERVING

CLASSIFIED AREAS (

(See "Collection

Systems," Table 4.2)

27 PUMPING OF

DRAINAGE FROM

DIGESTED SLUDGE- .

DEWATERING

PROCESSES Pumping

of centrate, filtrate,

leachate, drying beds,

and so forth

NA NR NA Unclassifi

ed

NC, LC, or

LFS

H










FSS: Fire suppression system (e.g., automatic sprinkler, water spray, foam, gaseous, or dry

chemical).




NA: Not applicable.




NR: No requirement.

aThe “Row” and “Line” columns are used to refer to specific figures in A.6.2 and specific


bThe NR designation in the "Ventilation"b This column indicates that nothe ventilation requirements

for processes. Additional ventilation requirements are established for the space,provided in

Chapter 9. Ventilation signaling and, therefore, Table 9.1.1.4 also has no alarm requirements. are

provided in Chapter 7.



and equipment. Electrical equipment shall be identified for use in the operating environment. eSee e This column indicates the materials of construction for processes. Materials of construction for



f See NFPA 54, NFPA 82, and NFPA 85.

Table 6.2(b) Solids Treatment Processes — Sludge Drying

Ro

w

Lin

e Location and Function

Fire and

Explosi

on

Hazard

Ventilationa,b

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class II,

Group G)c

Material of

Constructi

on for

Buildings

or

Structuresd

Fire

Protecti

on

Measure

s

1 a SLUDGE- DRYING

PROCESSESdPROCES

SESe

Potentia

l for

ignition

of dust

NR If

exposed

to

combustib

le

particulat

e solids,

entire

roomeroo

mf

Division 1 NC

(Constructi

on in

accordanc

e with

NFPA 30,

NFPA 68,

NFPA 69,

NFPA 499,

and NFPA

654)

H, FAS,

and

FSS

(See

NFPA

30,

NFPA

61,

NFPA

69,

NFPA

85,

NFPA

499,

and

NFPA

654)

b NR Areas

within

equipmen

t

processin

g

combustib

le

particulat

e solids

Division 1 NC

(Constructi

on in

accordanc

e with

NFPA 30,

NFPA 68,

NFPA 69,

NFPA 499,

and NFPA

654)

H, FAS,

and

FSS

(See

NFPA

30,

NFPA

61,

NFPA

69,

NFPA

85,

NFPA

499,

and

NFPA

654)

c NR Areas

within 3 m

(10 ft) of

Division 2 NC

(Constructi

on in

H, FAS,

and

FSS

Ro

w

Lin


Fire and

Explosi

on

Hazard

Ventilationa,b

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class II,

Group G)c

Material of

Constructi

on for

Buildings

or

Structuresd

Fire

Protecti

on

Measure

s

equipmen

t

processin

g

combustib

le

particulat

e solids

accordanc

e with

NFPA 30,

NFPA 68,

NFPA 69,

NFPA 499,

and NFPA

654)

(See

NFPA

30,

NFPA

61,

NFPA

69,

NFPA

85,

NFPA

499,

and

NFPA

654)

d NR Areas

beyond 3

m (10 ft)

of

equipmen

t

processin

g

combustib

le

particulat

e solids

Unclassifie

d

NC

(Constructi

on in

accordanc

e with

NFPA 30,

NFPA 68,

NFPA 69,

NFPA 499,

and NFPA

654)

H, FAS,

and

FSS

(See

NFPA

30,

NFPA

61,

NFPA

69,

NFPA

85,

NFPA

499,

and

NFPA

654)

2 a DRIED SLUDGE

STORAGE AREAS, IF

ENCLOSED

Potentia

l for

ignition

of dust

NR If

exposed

to dried

sludge,

entire

roome

Division 1 NC

(Constructi

on in

accordanc

e with

NFPA 68

H, FAS

(See

NFPA

61,

NFPA

69,

Ro

w

Lin


Fire and

Explosi

on

Hazard

Ventilationa,b

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class II,

Group G)c

Material of

Constructi

on for

Buildings

or

Structuresd

Fire

Protecti

on

Measure

s

and NFPA

69, NFPA

499, and

NFPA 654)

NFPA

497,

and

NPFA

654)

b NR Areas

within

tanks

storing

dried

sludge

Division 1 NC

(Constructi

on in

accordanc

e with

NFPA 68,

NFPA 69,

NFPA 499,

and NFPA

654)

H and

FAS

(See

NFPA

61,

NFPA

69,

NFPA

497,

and

NFPA

654)

c NR Areas

within 3 m

(10 ft) of

tanks

storing

dried

sludge

Division 2 NC

(Constructi

on in

accordanc

e with

NFPA 68,

NFPA 69,

NFPA 499,

and NFPA

654)

H and

FAS

(See

NFPA

61,

NFPA

69,

NFPA

497,

and

NFPA

654)

d NR Areas

beyond 3

m (10 ft)

of tanks

storing

dried

sludge

Unclassifie

d

NC

(Constructi

on in

accordanc

e with

NFPA 68,

NFPA 69,

NFPA 499,

H and

FAS

(See

NFPA

61,

NFPA

69,

NFPA

Ro

w

Lin


Fire and

Explosi

on

Hazard

Ventilationa,b

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class II,

Group G)c

Material of

Constructi

on for

Buildings

or

Structuresd

Fire

Protecti

on

Measure

s

and NFPA

654)

497,

and

NFPA

654)




chemical).




NR: No requirement.

aThe NR designation in the “Ventilation”a This column indicates that nothe ventilation requirements

for processes. Additional ventilation requirements are established for the space,provided in

Chapter 9. Ventilation signaling and, therefore, Table 9.1.1.4 also has no alarm requirements. are

provided in Chapter 7.

bFor sludge-drying processes that use flammable or combustible liquids, ventilate in accordance

with NFPA 30.

cOr if acceptable to the authority having jurisdiction with classification in NFPA 499. dSeed This column indicates the materials of construction for processes. Materials of construction

for buildings in which these processes are housed are in accordance with the applicable building

code and construction requirements provided in Chapter 8.

eSee NFPA 54, NFPA 85, NFPA 499, and NFPA 654. For sludge-drying processes that use

flammable or combustible liquids, see NFPA 30.

eThefThe area beyond the envelope is unclassified.

Chapter 6 Solids Treatment Processes

6.1* General.

6.1.1


associated with solids treatment processes.

6.1.2

This chapter shall not apply to the treatment of solids from industrial waste treatment processes.


6.2.1The design and construction of solids treatment processes associated with wastewater solids

treatment shall conform to Table 6.2(a) and Table 6.2(b).

6.2.2 The design and construction of buildings and structures containing solids treatment processes

associated with wastewater solids treatment shall comply with the applicable building code and the

additional requirements of Chapters 7-9.

Table 6.2(a) Solids Treatment Processes

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

1 COARSE AND

FINE

SCREENINGS- .

HANDLING

BUILDINGS .

Storage,

conveying, or

dewatering of

screenings (no

exposed flow of

wastewater

through building

or area)


d

NC, LC, or

LFS

H, FE,

and

FAS

2 GRIT-

HANDLING

BUILDING .


d

NC, LC, or

LFS

H, FE,

and

FAS

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

Storage,

conveying, and

dewatering of

heavy small

screenings and

grit (no exposed

flow of

wastewater

through building

or area)

3 a SCUM-

HANDLING

BUILDING OR

AREA Holding,

dewatering, or

storage

Possible

grease or

flammable

liquids

carryover

A Enclosed

space


LFS

H and

FE;CG

D if

enclose

d in

building

b B Enclosed

space

Unclassifie

d

NC, LC, or

LFS

H and

FE;

CGD if

enclose

d in

building

c Not

enclosed,

open to

atmospher

e

NA Unclassifie

d

NC, LC, or

LFS

H and

FE

4 a SCUM PITS Buildup of

vapors from

flammable

or

combustible

liquids

A Enclosed—

entire space

Division 1 NC Hand

FE;CG

D if

enclose

d in

building

b B Enclosed—

entire space


LFS

H and

FE;

CGD if

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

enclose

d in

building

c Not

enclosed,

open to

atmospher

e

Within a 3 m

(10 ft)

envelope

around

equipment

and open

channelc


LFS

H and

FE

5 a SCUM-

PUMPING

AREAS Pumping

of scum, wet side

of pumping

station

Buildup of

vapors from

flammable

or

combustible

liquids.

A Enclosed—

entire space

Division 1 NC Hand

FE;

CGD if

enclose

d in

building

b B Enclosed—

entire space


LFS

Hand

FE;

CGD if

enclose

d in

building

c Not

enclosed,

open to

atmospher

e

Within a 3 m

(10 ft)

envelope

around

equipment

and open

channelc


LFS

H and

FE

6 a SCUM-

PUMPING

AREAS Pumping

of scum, dry side

of pumping

station

Buildup of

vapors from

flammable

and

combustible

liquids.

D Enclosed

space


LFS

H and

FE

b C Enclosed

space

Unclassifie

d

NC, LC, or

LFS

H and

FE

c Not

enclosed,

NA Unclassifie

d

NC, LC, or

LFS

H and

FE

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

open to

atmospher

e

7 SCUM

INCINERATORSf Elimination of

scum through

burning

Firebox

explosion

from

possible

carryover of

flammable

scum

NR Incinerator

area if

separated

from scum

storage

Unclassifie

d

NC, LC, or

LFS

FSS (if

indoors)

, H, and

FE

8 a SLUDGE

THICKENER

(CLARIFIER)

Sludge

concentration

and removal,

gravity, or

dissolved air

flotation

Possible

generation

of methane

from sludge;

carryover of

floating

flammable

liquids

A Enclosed—

entire space

Division 1 NC Hand

FE;CG

D if

enclose

d in

building

b B Enclosed—

entire space


LFS

Hand

FE;

CGD if

enclose

d in

building

c Not

enclosed,

open to

atmospher

e

Envelope

0.46 m (18

in.) above

water

surface and .

3 m (10 ft)

horizontally

from wetted

wallsc

H and

FE

9 a SLUDGE

PUMPING

STATION DRY

WELLS

Buildup of

methane

gas or

D Entire dry

well when

physically

separated


LFS

H and

FE

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

.

Dry side of a

sludge pumping

station

flammable

vapors

from a wet

well or

separate

structures

b C Entire dry

well when

physically

separated

from a wet

well or

separate

structures

Unclassifie

d

NC, LC, or

LFS

H and

FE

10 a SLUDGE

STORAGE WET

WELLS, PITS,

AND HOLDING

TANKS .

Retaining of

sludge

Possible

generation

of methane

gas in

explosive

concentratio

ns;

carryover of

floating

flammable

liquids

A Enclosed—

entire space

Division 1 NC CGD,

H, and

FE if

tank

enclose

d in

building

b B Enclosed—

entire space


LFS

CGD,

H, and

FE if

tank

enclose

d in

building

c Not

enclosed,

open to

atmospher

e

Envelope

0.46 m (18

in.) above

water

surface and .

3 m (10 ft)

horizontally

from wetted

wallsc


LFS

NR

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

11 a SLUDGE-

BLENDING

TANKS AND

HOLDING

WELLS .

Retaining of

sludge with some

agitation

Possible

generation

of methane

gas in

explosive

concentratio

ns;

carryover of

floating

flammable

liquids

A Enclosed—

entire space

Division 1 NC H, FE,

and

CGD if

tank

enclose

d in

building

b B Enclosed—

entire space


LFS

H, FE,

and

CGD if

tank

enclose

d in

building

c Not

enclosed,

open to

atmospher

e

Envelope

0.46 m (18

in.) above

water

surface and .

3 m (10 ft)

horizontally

from wetted

wallsc


LFS

NR

12 a DEWATERING

BUILDINGS

CONTAINING

CENTRIFUGES,

GRAVITY BELT

THICKENERS,

BELT AND

VACUUM

FILTERS, AND

FILTER

PRESSES .

Removal of

water from

Accumulatio

n of

methane

gas

C Entire room Unclassifie

d

NC, LC, or

LFS

H, FE,

and

FAS

b D Entire room Division 2 NC, LC, or

LFS

H, FE,

and

FAS

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

sludge and the

conveyance of

sludge cake

13 a ENCLOSED

SLUDGE CAKE

STORAGE

Storage of

dewatered

sludge cake and

conveyance of

sludge cake

Accumulatio

n of

methane

gas

C Entire room Unclassifie

d

NC, LC, or

LFS

H, FE,

and

FAS

b D Entire room Division 2 NC, LC, or

LFS

H, FE,

and

FAS

14 INCINERATORS f AND

INCINERATOR

BUILDINGS .

Conveying and

burning of sludge

cake

Firebox

explosion

NR NA Unclassifie

d

NC, LC, or

LFS

FSS (if

indoors)

, H, and

FE

15 HEAT

TREATMENT

UNITS, LOW-

OR HIGH-

PRESSURE

OXIDATION

UNITS .

Closed oxidation

of sludge

None, other

than in high-

pressure

systems

NR NA Unclassifie

d

NC, LC, or

LFS

H and

FE

16 a ANAEROBIC

DIGESTERS,

BOTH FIXED

ROOF AND

FLOATING

COVER

Generation of

sludge gas from

digesting sludge

Leakage of

gas from

cover,

piping,

emergency

relief valves,

and

appurtenanc

es

Not

enclosed,

open to

atmospher

e

Tank

interior;

areas above

and around

digester

cover;

envelope 3

m (10 ft)

above the

Division 1 NC H and

FE

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

highest point

of cover,

when cover

is at its

maximum

elevation,

and 1.5 m (5

ft) from any

wall

b Not

enclosed,

open to

atmospher

e

Envelope .

4.6 m (15 ft)

above

Division 1

area over

cover and

1.5 m (5 ft)

beyond

Division 1

area around

tank walls

Division 2 NC H and

FE

c A For digester

tanks

enclosed in

a building:

tank interior;

entire area

inside

building


enclose

d in

building

d B For digester

tanks

enclosed in

a building:

tank interior;

areas above

and around

digester


enclose

d in

building

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

cover;

envelope 3

m (10 ft)

above

highest point

of cover,

when cover

is at its

maximum

elevation,

and 1.5 m (5

ft) from any

wall of

digester tank

e B Remaining

space in

enclosed

area


LFS

CGD if

enclose

d in

building

17 a ANAEROBIC

DIGESTER

CONTROL

BUILDING .

Storage,

handling, or

burning of sludge

gas

Leaking and

ignition of

sludge gas

A Entire

building

Division 1 NC CGD,

H, and

FE

b B Enclosed

areas that

contain gas-

handling

equipment


LFS

CGD,

H, and

FE

c C Physically

separated

from gas-

handling

equipment

Unclassifie

d

NC, LC, or

LFS

CGD,

H, and

FE

18 a DIGESTER

GAS-

PROCESSING

Sludge gas

ignition

A Entire room Division 1 NC CGD,

H, and

FE

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

b ROOMS Gas

compression,

handling, and

processing

B Within 1.5 m

(5 ft) of

equipment


LFS

CGD,

H, and

FE

c B Entire room Division 2 NC, LC, or

LFS

CGD,

H, and

FE

19 ANAEROBIC

DIGESTER GAS

STORAGE .

Storage of

sludge gas

Gas storage

piping and

handling

NNV Within a 3 m

(10 ft)

envelope of

tanks,

valves, and

appurtenanc

es


LFS

Hand

FE;

CGD if

enclose

d in

building

20 a WASTE .

GAS .

BURNERS .

Combusting

excess gas

Gas piping

and

appurtenanc

es

NA Within 3 m

(10 ft)

envelope of

all fixtures,

appurtenanc

es, and

housing

Division 1 NC NR

b Envelope .

4.6 m (15 ft)

above

Division 1

envelope

and 1.5 m (5

ft) on all

sides

Division 2 NC NR

21 CHLORINE

OXIDATION

UNITS .

Chlorine reaction

with sludge

Chlorine is a

very strong

oxidizing

agent

NR NA Unclassifie

d

NR (These

unit

processes

use

corrosive

chemicals

that

require the

H and

FE

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

use of

specific

materials

of

constructio

n. Special

considerati

on shall be

given to

such

materials

of

constructio

n.)

22 a UNDERGROUN

D (PIPING)

TUNNELS

CONTAINING

NATURAL GAS

PIPING OR

SLUDGE GAS

PIPING .

Transmission of

gas, sludge,

water, air, and

steam via piping;

also might

contain power

cable and

conduit

Ignition of

natural gas

or sludge

gases

D Within 3 m

(10 ft) of

valves and

appurtenanc

es


LFS

CGD,

FDS,

and FE

b D Entire tunnel Division 2 NC, LC, or

LFS

CGD,

FDS,

and FE

c C Areas within

3 m (10 ft) of

valves,

meters, gas

check

valves,

condensate

traps, and

other piping

appurtenanc

es


LFS

CGD,

FDS,

and FE

d C Areas

beyond 3 m

(10 ft)

Unclassifie

d

NC, LC, or

LFS

CGD,

FDS,

and FE

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

23 UNDERGROUN

D (PIPING)

TUNNELS NOT

CONTAINING

NATURAL GAS

PIPING OR

SLUDGE GAS

PIPING

Transmission of

sludge, water,

air, and steam

piping; also

might contain

power cable and

conduit


d

NC, LC, or

LFS

FDS

and FE

24 a COMPOSTING

PILES .

Aerobic sludge

reduction

Liberation of

ammonia

and toxic

gas

(composting

materials

can self-

ignite)

D Enclosed

area


LFS

H and

FDS

b C Enclosed

area

Unclassifie

d

NC, LC, or

LFS

H and

FDS

25 a IN-VESSEL

COMPOSTING

Aerobic sludge

reduction

Liberation of

ammonia

and toxic

gas

(composting

materials

can self-

ignite)

As required

by process

If enclosed,

interior of

reactor

vessel plus

a 3 m (10 ft)

envelope

around

reactor

vessel

Division 2 NC H and

FDS

b As required

by process

Areas

beyond 3 m

(10 ft)

Unclassifie

d

NC H and

FDS

26

Rowa

Linea

Location and

Function

Fire and

Explosion

Hazard

Ventilationb

,c,d

Extent of

Classified

Area

NEC-Area

Electrical

Classificati

on (All

Class I,

Group D)d

Materials

of

Constructi

on e

Fire

Protecti

on

Measure

s

ODOR-

CONTROL AND

VENTILATION

SYSTEMSSERV

ING

CLASSIFIED

AREAS ( (See

"Collection

Systems," Table

4.2)

27 PUMPING OF

DRAINAGE

FROM

DIGESTED

SLUDGE- .

DEWATERING

PROCESSES

Pumping of

centrate, filtrate,

leachate, drying

beds, and so

forth


d

NC, LC, or

LFS

H











chemical).




NA: Not applicable.




NR: No requirement.

aThe “Row” and “Line” columns are used to refer to specific figures in A.6.2 and specific


b This column indicates the ventilation requirements for processes. Additional ventilation


in Chapter 7.



and equipment. Electrical equipment shall be identified for use in the operating environment.

e This column indicates the materials of construction for processes. Materials of construction for



f See NFPA 54, NFPA 82, and NFPA 85.

Table 6.2(b) Solids Treatment Processes — Sludge Drying

Ro

w

Lin

e

Location and

Function

Fire and

Explosio

n Hazard

Ventilationa,

b

Extent of

Classified

Area

NEC-Area

Electrical

Classificatio

n (All Class

II, Group G)c

Material of

Construction d

Fire

Protectio

n

Measures

1 a SLUDGE-

DRYING

PROCESSESe

Potential

for

ignition of

dust

NR If exposed

to

combustibl

e

particulate

solids,

entire roomf

Division 1 NC

(Constructio

n in

accordance

with NFPA

30, NFPA

68, NFPA

69, NFPA

H, FAS,

and FSS

(See

NFPA 30,

NFPA 61,

NFPA 69,

NFPA 85,

NFPA

Ro

w

Lin

e

Location and

Function

Fire and

Explosio

n Hazard

Ventilationa,

b

Extent of

Classified

Area

NEC-Area

Electrical

Classificatio

n (All Class

II, Group G)c

Material of

Construction d

Fire

Protectio

n

Measures

499, and

NFPA 654)

499, and

NFPA

654)

b NR Areas

within

equipment

processing

combustibl

e

particulate

solids

Division 1 NC

(Constructio

n in

accordance

with NFPA

30, NFPA

68, NFPA

69, NFPA

499, and

NFPA 654)

H, FAS,

and FSS

(See

NFPA 30,

NFPA 61,

NFPA 69,

NFPA 85,

NFPA

499, and

NFPA

654)

c NR Areas

within 3 m

(10 ft) of

equipment

processing

combustibl

e

particulate

solids

Division 2 NC

(Constructio

n in

accordance

with NFPA

30, NFPA

68, NFPA

69, NFPA

499, and

NFPA 654)

H, FAS,

and FSS

(See

NFPA 30,

NFPA 61,

NFPA 69,

NFPA 85,

NFPA

499, and

NFPA

654)

d NR Areas

beyond 3 m

(10 ft) of

equipment

processing

combustibl

e

particulate

solids

Unclassified NC

(Constructio

n in

accordance

with NFPA

30, NFPA

68, NFPA

69, NFPA

499, and

NFPA 654)

H, FAS,

and FSS

(See

NFPA 30,

NFPA 61,

NFPA 69,

NFPA 85,

NFPA

499, and

NFPA

654)

Ro

w

Lin

e

Location and

Function

Fire and

Explosio

n Hazard

Ventilationa,

b

Extent of

Classified

Area

NEC-Area

Electrical

Classificatio

n (All Class

II, Group G)c

Material of

Construction d

Fire

Protectio

n

Measures

2 a DRIED

SLUDGE

STORAGE

AREAS, IF

ENCLOSED

Potential

for

ignition of

dust

NR If exposed

to dried

sludge,

entire

roome

Division 1 NC

(Constructio

n in

accordance

with NFPA

68 and

NFPA 69,

NFPA 499,

and NFPA

654)

H, FAS

(See

NFPA 61,

NFPA 69,

NFPA

497, and

NPFA

654)

b NR Areas

within tanks

storing

dried

sludge

Division 1 NC

(Constructio

n in

accordance

with NFPA

68, NFPA

69, NFPA

499, and

NFPA 654)

H and

FAS (See

NFPA 61,

NFPA 69,

NFPA

497, and

NFPA

654)

c NR Areas

within 3 m

(10 ft) of

tanks

storing

dried

sludge

Division 2 NC

(Constructio

n in

accordance

with NFPA

68, NFPA

69, NFPA

499, and

NFPA 654)

H and

FAS (See

NFPA 61,

NFPA 69,

NFPA

497, and

NFPA

654)

d NR Areas

beyond 3 m

(10 ft) of

tanks

storing

dried

sludge

Unclassified NC

(Constructio

n in

accordance

with NFPA

68, NFPA

69, NFPA

499, and

NFPA 654)

H and

FAS (See

NFPA 61,

NFPA 69,

NFPA

497, and

NFPA

654)




chemical).




NR: No requirement.

a This column indicates the ventilation requirements for processes. Additional ventilation


in Chapter 7.

bFor sludge-drying processes that use flammable or combustible liquids, ventilate in accordance

with NFPA 30.

cOr if acceptable to the authority having jurisdiction with classification in NFPA 499. d This column indicates the materials of construction for processes. Materials of construction for



eSee NFPA 54, NFPA 85, NFPA 499, and NFPA 654. For sludge-drying processes that use

flammable or combustible liquids, see NFPA 30.

fThe area beyond the envelope is unclassified.

Second Revision No. 15-NFPA 820-2014 [ Chapter 7 ]

Chapter 7 Fire and Explosion Prevention and Protection

7.1* Scope.

This chapter shall establish minimum requirements for overall protection against fire and explosion hazards inwastewater facilities and associated collection systems.

7.1.1

Gases, liquids, and solids shall be assigned to one of the following two categories:

Flammable/combustible hazards

Safety and health hazards

This standard shall apply to the flammability properties of a particular substance, process, or area within wastewaterand collection facilities.

7.1.2

This standard shall apply to the flammability aspects of a particular substance, process, or area within wastewater andcollection facilities Chapter 10 shall be referenced for additional requirements to protect against fire and safetyhazards .

7.1.3

Chapter 10 shall be referenced for additional requirements to protect against fire and safety hazards.

7.2 Fire Protection Measures.

7.2.1 General.

7.2.1.1

Collection systems, liquid stream treatment processes, and solids-handling processes shall be provided with fireprotection for the fire hazards, as described in Table 4.2.2 Table 4.2 , Table 5.2.2 Table 5.2 , Table 6.2.2(a) Table6.2(a) , and Table 6.2.2(b) Table 6.2(b) .

7.2.1.2

Enclosed spaces classified as explosion hazard areas under this document shall be physically separated from allunclassified enclosures.

7.2.1.3

In addition to the fire protection specified in Chapter 8, buildings, structures, and process elements, under someconditions, shall be provided with automatic-extinguishing systems in accordance with this chapter.

7.2.2 Automatic Sprinkler Systems.

7.2.2.1

An automatic Automatic sprinkler systems , where required by this standard or by referenced publications, shallconform to NFPA 13 and shall be approved by the authority having jurisdiction.

7.2.2.2

Other automatic-extinguishing systems shall be permitted in certain areas of the wastewater treatment plant, such asthe following:

(1) Chemical storage

(2) Underground tunnels or structures

(3) Areas where electrical hazard is a principal concern

(4) Areas where water damage would seriously impair the integrity of the treatment plant

7.2.3 Other Automatic-Extinguishing Systems.

Where required or used in place of automatic sprinkler systems, special hazard–extinguishing systems andnonwater non-water automatic-extinguishing systems shall be designed, installed, and maintained in accordance withthe following standards, as applicable:

(1) NFPA 11, Standard for Low-, Medium-, and High-Expansion Foam

(2) NFPA 12, Standard on Caron Dioxide Extinguishing Systems

(3) NFPA 12A, Standard on Halon 1301 Fire Extinguishing Systems

(4) NFPA 15, Standard for Water Spray Fixed Systems for Fire Protection

(5) NFPA 16, Standard for Installation of Foam-Water Sprinkler and Foam-Water Spray Systems

(6) NFPA 17, Standard for Dry Chemical Extinguishing Systems

(7) NFPA 2001, Standard for Fixed Aerosol Fire-Extinguishing Systems


34 of 51 12/1/2014 1:18 PM

7.2.4 Water Supplies, Standpipes, Hose Systems, and Hydrants.

7.2.4.1

Water supplies shall be capable of delivering the total demand of sprinklers, hose streams, and foam systems.

7.2.4.1.1

In areas where there is no public water supply or where the supply is not capable of meeting the total demandrequired, treatment plant effluent shall be permitted for fire protection use.

7.2.4.1.2

The requirements of the public health authority having jurisdiction shall be determined and followed.

7.2.4.2

Water supplies and hydrants shall be installed in accordance with the following standards, as applicable:

(1) NFPA 22, Standard for Water Tanks for Private Fire Protection

(2) NFPA 24, Standard for the Installation of Private Fire Service Mains and Their Appurtenances

(3) NFPA 1142, Standard for Suburban and Rural Fire Fighting

7.2.4.3

Standpipes and hose systems shall be installed and inspected in accordance with NFPA 14.

7.2.4.4

Where fire pumps are used as a separate and sole source of supply, the system shall provide capacity to meetsimultaneous fire water flow requirements for both manual and automatic fire suppression systems and the followingshall apply:

(1) A standby power supply shall be provided.

(2) Pumps shall be automatic starting and manual shutdown.

(3) Pumps shall be installed in accordance with NFPA 20.

7.2.5 Portable Fire Extinguishers.

7.2.5.1

Portable fire extinguishers shall be installed, located, and maintained in accordance with NFPA 10.

7.2.5.2

The requirement for portable fire extinguishers shall be permitted to be waived where areas are not commonlyoccupied and the approval of the authority having jurisdiction has been obtained.

7.3 Fire Detection and Alarm Systems.

7.3.1

Fire detection and alarm systems for each treatment and collection facility area shall be provided as identified in Table4.2.2 Table 4.2 , Table 5.2.2 Table 5.2 , Table 6.2.2(a) Table 6.2(a) , and Table 6.2.2(b) Table 6.2(b) or in accordancewith referenced publications.

7.3.2

Fire detection and alarm systems shall be installed and maintained in accordance with NFPA 72.

7.4 Combustible Gas Detection.

7.4.1

Combustible gas detectors shall be located in accordance with Table 4.2.2 Table 4.2 , Table 5.2.2 Table 5.2 , andTable 6.2.2(a) Table 6.2(a) .

7.4.2*

The selection of combustible gas detector types and their placement shall be determined by a qualified person asdefined by NFPA 70 .

7.4.3*

Combustible gas detectors shall be listed and labeled for the intended application and shall be listed for theatmosphere in which it is installed.

7.4.4

Detectors and signaling systems shall be provided with an auxilliary auxiliary power supply to ensure continuousoperation during any failure of normal power supply.

7.4.5

The installation, calibration, and maintenance, and testing of combustible gas detectors shall be in accordance withtheir listing requirements and the manufacturers' instructions.

7.4.6

Combustible gas detection equipment located in hazardous (classified) locations, as defined in accordance withNFPA 70 , shall be listed for use in such atmospheres. Detectors required as fire protection measures in Table4.2.2 Table 4.2 , Table 5.2.2 Table 5.2 , Table 6.2.2(a) Table 6.2(a) and Table 6.2.2(b) Table 6.2(b) shall be set toalarm at 10 percent of the lower explosive limit (LEL) in accordance with the manufacturers’ calibration instructionsand shall be connected to alarm signaling systems that shall comply with the requirements of Section 7.6 .


35 of 51 12/1/2014 1:18 PM

7.4.6.1

Where permitted by the authority having jurisdiction, the alarm limits shall be permitted to be set at higher than 10percent of the lower explosive limit (LEL), also known as the lower flammable limit (LFL), where experience indicatesambient levels would produce spurious alarms.

7.4.7

Detectors required as fire protection measures in Chapters 4 , 5 , and 6 of this standard shall be set to alarm at10 percent of the lower flammable limit (LFL) in accordance with the manufacturers’ calibration instructions and shallbe connected to alarm signaling systems that shall comply with the requirements of 7.6 .

7.4.7.1

Where permitted by the authority having jurisdiction, the alarm limits shall be permitted to be set at higher than 10percent of the lower flammable limit where experience indicates ambient levels would produce spurious alarms.

7.5 Ventilation Monitoring.

7.5.1

All continuous ventilation systems that are used to reduce the classification of a space shall be fitted with flow detectiondevices connected to alarm signaling systems to indicate inadequate ventilation and ventilation system failure toprovide the required air changes .

7.5.1.1

The flow detection devices shall monitor both the supply and exhaust fans, where a two-fan system is used.

7.5.2

The alarm signaling systems shall comply with the requirements of Section 7.6.

7.6 Alarm Signaling Systems.

7.6.1*

Distinct local and remote alarms shall be displayed in accordance with Table 7.6.1.

Table 7.6.1 Location and Type of Alarm Signaling Notification Appliances Required in 7.7.1 7.6.1

Location Alarm Notification Appliances

Entrance(s) to spaces*

in occupied facilitiesVisual and audible alarms

Entrances to remote spaces that are not constantly attendedVisual and audible alarms or a dual light warningsystem

Within spaces Visual and audible alarms

Constantly attended location (local or remote) Visual and audible alarms

*Where locations are not constantly attended, the use of a nonaudible signal is permitted if a dual-light system isused. A dual-light system is to include a “go”/”no go” or green light/red light type of warning system instead of theaudible alarm.

7.6.2*

Local and remote alarms required in Table 7.6.1 shall be located so as to be readily heard and seen by responsiblepersonnel.

7.6.3

Alarm signaling system equipment shall be provided with an auxiliary power supply to ensure continuous operationduring the failure of the normal power supply and shall be of sufficient duration to alert responsible personnel.

7.6.4

A telephone dialer shall be allowed to meet the intent of the constantly attended location listing in Table 7.6.1.

7.6.5

Visual and audible alarms required in Table 7.6.1 shall be tested quarterly to verify their functionality or in accordancewith 7.6.6.

7.6.6

The quarterly testing requirement shall be permitted to be reduced to semiannually where the conductors of the visualand audible notification appliances are continuously monitored for open circuits, short circuits, and ground faults.

7.7 Laboratories.

Fire protection for laboratories shall be in accordance with NFPA 45 .

7.8 Pressurization Monitoring.

All pressurization systems used to downgrade the electrical classification of a space shall be in accordance withNFPA 496 . Failure of the pressurization system shall activate alarm signaling systems that comply with therequirements of 7.6 .

7.8 Laboratories.


7.8 Special Fire Protection Measures.


36 of 51 12/1/2014 1:18 PM

7.8.1 Fire Protection During Construction.

Fire protection measures during construction at both new and existing wastewater facilities shall be provided inaccordance with NFPA 241.

7.8.2 Lightning Protection.

Lightning protection shall be provided in accordance with NFPA 780.

7.8.3 Drainage.

7.8.3.1

Provisions shall be made in all fire areas of the plant for removal of all liquids for containment in the fire area withoutflooding of equipment and without endangering other areas.

7.8.3.2

The provisions for drainage and any associated drainage facilities shall be sized to simultaneously accommodatesimultaneously all of the following:

(1) The spill of the largest single container of any flammable or combustible liquids in the area

(2) The maximum expected number of fire hose lines [31.5 L/sec (500 gal/min) minimum] operating for a minimum of10 minutes

(3) The maximum design discharge of fixed fire suppression systems operating for a minimum of 10 minutes



ComparisonFDtoSDChapter_7.docx For editorial use only.

FINALSDMtgREVChapter_7.docx For editorial use only.

A.7.4.2NEW.docx




Street Address:

City:

State:

Zip:


Committee Statement

CommitteeStatement:

The chapter was revised to further clarify changes made in first draft. Key chapter revisions were made at firstdraft so as not to conflict with NFPA 72. Note that the term LFL was changed back to LEL since manufacturersof CGD still use the term LEL.

ResponseMessage:


37 of 51 12/1/2014 1:18 PM


7.1* Scope.

This chapter shall establish minimum requirements for overall protection against fire and explosion

hazards in wastewater facilities and associated collection systems.

7.1.1

Gases, liquids, and solids shall be assigned to one of the following two categories:

(1) Flammable/combustible hazards

(2) Safety and health hazards

This standard shall apply to the flammability properties of a particular substance, process, or area

within wastewater and collection facilities.

7.1.2

This standard shall apply to the flammability aspects of a particular substance, process, or area


7.1.3

Chapter 10shall10 shall be referenced for additional requirements to protect against fire and safety

hazards.


7.2.1 General.

7.2.1.1

Collection1Collection systems, liquid stream treatment processes, and solids-handling processes shall be

provided with fire protection for the fire hazards, as described in Table 4.2, Table 5.2, Table 6.2(a), and

Table 6.2(b).

7.2.1.2

Enclosed spaces classified as explosion hazard areas under this document shall be physically separated

from all unclassified enclosures.

7.2.1.3

In addition to the fire protection specified in Chapter 8, buildings, structures, and process elements, under

some conditions, shall be provided with automatic-extinguishing systems in accordance with this chapter.


7.2.2.1

An automaticAutomatic sprinkler system, wheresystems required by this standard or by referenced

publications, shall conform to NFPA 13 and shall be approved by the authority having jurisdiction.

7.2.2.2 Other automatic-extinguishing systems shall be permitted in certain areas of the wastewater

treatment plant, such as the following:






Where required or used in place of automatic sprinkler systems, special hazard–extinguishing systems

and nonwaternon-water automatic-extinguishing systems shall be designed, installed, and maintained in

accordance with the following standards, as applicable:

(1) NFPA 11

(2) NFPA 12

(3) NFPA 12A

(4) NFPA 15

(5) NFPA 16

(6) NFPA 17

(7) NFPA 2001


7.2.4.1

Water supplies shall be capable of delivering the total demand of sprinklers, hose streams, and foam

systems.

7.2.4.1.1

In areas where there is no public water supply or where the supply is not capable of meeting the total

demand required, treatment plant effluent shall be permitted for fire protection use.

7.2.4.1.2


7.2.4.2

Water supplies and hydrants shall be installed in accordance with the following standards, as applicable:

(1) NFPA 22

(2) NFPA 24

(3) NFPA 1142

7.2.4.3


7.2.4.4

Where fire pumps are used as a separate and sole source of supply, the system shall provide capacity to

meet simultaneous fire water flow requirements for both manual and automatic fire suppression systems

and the following shall apply:





7.2.5.1


7.2.5.2

The requirement for portable fire extinguishers shall be permitted to be waived where areas are not

commonly occupied and the approval of the authority having jurisdiction has been obtained.


7.3.1

Fire detection and alarm systems for each treatment and collection facility area shall be provided as

identified in Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b) or in accordance with referenced

publications.

7.3.2



7.4.1*

Combustible gas detectors shall be located in accordance with Table 4.2, Table 5.2, and Table 6.2(a).

7.4.2*

The selection of combustible gas detector types and their placement shall be determined by a qualified

person as defined by NFPA 70..

7.4.3*

Combustible gas detectors shall be listed and labeled for the intended application and shall be listed for

the atmosphere in which it is installed.

7.4.4

Detectors and signaling systems shall be provided with an auxilliaryauxiliary power supply to ensure

continuous operation during any failure of normal power supply.

7.4.5

The installation, calibration, and maintenance, and testing of combustible gas detectors shall be in

accordance with their listing requirements and the manufacturers' instructions.

7.4.6

Combustible gas detection equipment located in hazardous (classified) locations, as defined in

accordance with NFPA 70, shall be listed for use in such atmospheres.

7.4.7

Detectors required as fire protection measures in ChaptersTable 4,.2, Table 5,.2, Table 6.2(a), and 6 of

this standardTable 6.2(b) shall be set to alarm at 10 percent of the lower flammableexplosive limit

(LFLLEL) in accordance with the manufacturers’ calibration instructions and shall be connected to alarm

signaling systems that shall comply with the requirements of 7.6.

7.4.76.1

Where permitted by the authority having jurisdiction, the alarm limits shall be permitted to be set at higher

than 10 percent of the lower explosive limit (lower flammable limit) where experience indicates ambient

levels would produce spurious alarms.


7.5.1

All continuous ventilation systems that are used to reduce the classification of a space shall be fitted with

flow detection devices connected to alarm signaling systems to indicate inadequate ventilation and

ventilation system failure to provide the required air changes..

7.5.1.1 The flow detection devices shall monitor both the supply and exhaust fans, where a two fan

system is used.

7.5.2

The alarm signaling systems shall comply with the requirements of 7.6.


7.6.1*


Table 7.6.1 Location and Type of Alarm Signaling Notification Appliances Required in 7.76.1


Entrance(s) to spaces* in occupied facilities VisualVisibleual and audible alarms

Entrances to remote spaces that are not constantly

attended.

Visibleual and audible alarms or a dual light

warning system.



*Where locations are not constantly attended, the use of a nonaudible signal is permitted if a dual-light

system is used. A dual-light system is to include a “go”/”no go” or green light/red light type of warning

system instead of the audible alarm.

7.6.2*

Local and remote alarms required in Table 7.6.1 shall be located so as to be readily heard and seen by

responsible personnel.

7.6.3

Alarm signaling system equipment shall be provided with an auxiliary power supply to ensure continuous

operation during the failure of the normal power supply and shall be of sufficient duration to alert

responsible personnel.

7.6.4

A telephone dialer shall be allowed to meet the intent of the constantly attended location listing in Table

7.6.1.

7.6.5

Visual and audible alarms required in Table 7.6.1 shall be tested quarterly to verify their functionality or in

accordance with 7.6.6.

7.6.6

The quarterly testing requirement shall be permitted to be reduced to semiannually where the conductors

of the visual and audible notification appliances are continuously monitored for open circuits, short

circuits, and ground faults.


All pressurization systems used to downgrade the electrical classification of a space shall be in

accordance with NFPA 496. Failure of the pressurization system shall activate alarm signaling systems

that comply with the requirements of 7.6.

7.8 Laboratories.

Fire protection for laboratories shall be in accordance with NFPA 45.



Fire protection measures during construction at both new and existing wastewater facilities shall be

provided in accordance with NFPA 241.



7.9.3 Drainage.

7.9.3.1

Provisions shall be made in all fire areas of the plant for removal of all liquids for containment in the fire

area without flooding of equipment and without endangering other areas.

7.9.3.2

The provisions for drainage and any associated drainage facilities shall be sized to simultaneously

accommodate all of the following:


(2) The maximum expected number of fire hose lines [31.5 L/sec (500 gal/min) minimum] operating for a

minimum of 10 minutes

(3) The maximum design discharge of fixed fire suppression systems operating for a minimum of 10

minutes


7.1* Scope.

This chapter shall establish minimum requirements for overall protection against fire and explosion

hazards in wastewater facilities and associated collection systems.

7.1.1

This standard shall apply to the flammability properties of a particular substance, process, or area


7.1.2

Chapter 10 shall be referenced for additional requirements to protect against fire and safety

hazards.


7.2.1 General.

7.2.1.1Collection systems, liquid stream treatment processes, and solids-handling processes shall

be provided with fire protection for the fire hazards, as described in Table 4.2, Table 5.2, Table

6.2(a), and Table 6.2(b).

7.2.1.2

Enclosed spaces classified as explosion hazard areas under this document shall be physically

separated from all unclassified enclosures.

7.2.1.3

In addition to the fire protection specified in Chapter 8, buildings, structures, and process elements,

under some conditions, shall be provided with automatic-extinguishing systems in accordance with

this chapter.


7.2.2.1 Automatic sprinkler systems required by this standard shall conform to NFPA 13 and shall

be approved by the authority having jurisdiction.

7.2.2.2 Other automatic-extinguishing systems shall be permitted in certain areas of the wastewater

treatment plant, such as the following:






Where required or used in place of automatic sprinkler systems, special hazard–extinguishing

systems and non-water automatic-extinguishing systems shall be designed, installed, and

maintained in accordance with the following standards, as applicable:

(1) NFPA 11

(2) NFPA 12

(3) NFPA 12A

(4) NFPA 15

(5) NFPA 16

(6) NFPA 17

(7) NFPA 2001


7.2.4.1

Water supplies shall be capable of delivering the total demand of sprinklers, hose streams, and

foam systems.

7.2.4.1.1

In areas where there is no public water supply or where the supply is not capable of meeting the

total demand required, treatment plant effluent shall be permitted for fire protection use.

7.2.4.1.2


7.2.4.2

Water supplies and hydrants shall be installed in accordance with the following standards, as

applicable:

(1) NFPA 22

(2) NFPA 24

(3) NFPA 1142

7.2.4.3


7.2.4.4

Where fire pumps are used as a separate and sole source of supply, the system shall provide

capacity to meet simultaneous fire water flow requirements for both manual and automatic fire

suppression systems and the following shall apply:





7.2.5.1


7.2.5.2

The requirement for portable fire extinguishers shall be permitted to be waived where areas are not

commonly occupied and the approval of the authority having jurisdiction has been obtained.


7.3.1

Fire detection and alarm systems for each treatment and collection facility area shall be provided as

identified in Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b) or in accordance with referenced

publications.

7.3.2



7.4.1

Combustible gas detectors shall be located in accordance with Table 4.2, Table 5.2, and Table

6.2(a).

7.4.2*

The selection of combustible gas detector types and their placement shall be determined by a

qualified person.

7.4.3*

Combustible gas detectors shall be listed and labeled for the intended application and shall be listed

for the atmosphere in which it is installed.

7.4.4

Detectors and signaling systems shall be provided with an auxiliary power supply to ensure

continuous operation during any failure of normal power supply.

7.4.5

The installation, calibration, and maintenance, and testing of combustible gas detectors shall be in

accordance with their listing requirements and the manufacturers' instructions.

7.4.6 Detectors required as fire protection measures in Table 4.2, Table 5.2, Table 6.2(a), and Table

6.2(b) shall be set to alarm at 10 percent of the lower explosive limit (LEL) in accordance with the

manufacturers’ calibration instructions and shall be connected to alarm signaling systems that shall

comply with the requirements of 7.6.

7.4.6.1

Where permitted by the authority having jurisdiction, the alarm limits shall be permitted to be set at

higher than 10 percent of the lower explosive limit (lower flammable limit) where experience

indicates ambient levels would produce spurious alarms.


7.5.1

All continuous ventilation systems that are used to reduce the classification of a space shall be fitted

with flow detection devices connected to alarm signaling systems to indicate inadequate ventilation

and ventilation system failure.

7.5.1.1 The flow detection devices shall monitor both the supply and exhaust fans, where a two fan

system is used.

7.5.2

The alarm signaling systems shall comply with the requirements of 7.6.


7.6.1*


Table 7.6.1 Location and Type of Alarm Signaling Notification Appliances Required in 7.6.1


Entrance(s) to spaces in occupied facilities Visible and audible alarms

Entrances to remote spaces that are not constantly

attended.

Visible and audible alarms or a dual light warning

system.



7.6.2*

Local and remote alarms required in Table 7.6.1 shall be located so as to be readily heard and seen

by responsible personnel.

7.6.3

Alarm signaling system equipment shall be provided with an auxiliary power supply to ensure

continuous operation during the failure of the normal power supply and shall be of sufficient duration

to alert responsible personnel.

7.6.4

A telephone dialer shall be allowed to meet the intent of the constantly attended location listing in

Table 7.6.1.

7.6.5

Visual and audible alarms required in Table 7.6.1 shall be tested quarterly to verify their functionality

or in accordance with 7.6.6.

7.6.6

The quarterly testing requirement shall be permitted to be reduced to semiannually where the

conductors of the visual and audible notification appliances are continuously monitored for open

circuits, short circuits, and ground faults.

7.7 Laboratories.

Fire protection for laboratories shall be in accordance with NFPA 45.



Fire protection measures during construction at both new and existing wastewater facilities shall be

provided in accordance with NFPA 241.



7.9.3 Drainage.

7.9.3.1

Provisions shall be made in all fire areas of the plant for removal of all liquids for containment in the

fire area without flooding of equipment and without endangering other areas.

7.9.3.2

The provisions for drainage and any associated drainage facilities shall be sized to simultaneously

accommodate all of the following:


(2) The maximum expected number of fire hose lines [31.5 L/sec (500 gal/min) minimum] operating

for a minimum of 10 minutes

(3) The maximum design discharge of fixed fire suppression systems operating for a

minimum of 10 minutes

A.7.4.2 Other types of detectors, such as heat and smoke detectors, have standards recommending

spacing usually based on a certain area per detector. There are no known recognized standards or

guidelines for the locating or spacing of combustible gas detectors.

Whether natural or mechanical, air movement is a very important consideration in installing combustible

gas detectors. This aspect should be carefully investigated, including the effect of doors, windows, vents,

and other openings. It could be necessary to conduct a ventilation study that could involve a nontoxic

smoke movement analysis.

Dispersion characteristics can also affect detector placement. Vapors and gases will disperse inversely

proportional to their specific density in a quiescent environment. Vapors and gases with densities less

than that of air will diffuse quickly at first until the vapor or gas becomes diluted. Heavier-than-air vapors

and gases will tend to settle at a low area and not diffuse into the atmosphere unless dispersed by

ventilation or temperature currents. Vapors with densities close to that of air will exhibit little mixing effect

and will be transported largely by air currents.

There are various types of sensing devices. It is important to select the proper sensing device for each

application and for the environment in which it will be placed. Most organic and inorganic compounds can

be monitored safely with a catalytic combustion–type sensor. However, organic and metallic solvents

containing lead, silicones, plasticizers, or halogens can poison the catalytic element.

Qualified means one who, by possession of a recognized degree, certificate, or professional standing, or

who by extensive knowledge, training and experience, has successfully demonstrated his ability to solve

or resolve problems relating to the subject matter, the work, or the project.


7.7 Laboratories.



All pressurization systems used to downgrade the electrical classification of a space shall be in accordance withNFPA 496 . Failure of the pressurization system shall activate alarm signaling systems that comply with therequirements of 7.6 .




Street Address:

City:

State:

Zip:


Committee Statement

Committee Statement: The term reduce is used to be consistent with terminology used elsewhere in the document.

Response Message:


38 of 51 12/1/2014 1:18 PM

Second Revision No. 7-NFPA 820-2014 [ Chapter 8 ]

Chapter 8 Materials of Construction

8.1 General.

This chapter shall apply to the selection of materials of construction for buildings, structures, and process elementsfor protection against fire and explosion in wastewater treatment plants and associated collection systems.

8.1.1*

This chapter shall apply to the selection of materials of construction for buildings, structures, and process elements forprotection against fire and explosion in wastewater treatment plants and associated collection systems. Facilities shallbe constructed in accordance with the applicable building code and the additional requirements in this standard.

8.1.2

Materials of construction and interior coatings and finishes shall provide a maximum degree of fire resistance with theminimum amount of flame spread and smoke generation associated with a particular application. In areas wherecorrosive environments are present, including classified areas, the mitigation of corrosion problems in the selectionand use of materials for nonstructural assemblies shall include the use of the following:

(1) Corrosion-resistant metallic or nonmetallic grating

(2) Corrosion-resistant railings, steps and stairs, conduit

(3) Corrosion-resistant electric equipment enclosures

8.1.3

Materials shall be selected that reduce or eliminate the effects of fire and explosion by maintaining structural integrity,controlling flame spread and smoke generation, minimizing the release of toxic products of combustion, andmaintaining the serviceability and operation of critical processes.

8.1.3.1

The purpose of the criteria for selecting materials of construction shall not be to provide protection of personnel fromthe risk of exposure to an asphyxiating or toxic atmosphere generated during a fire.

8.1.3.2

Criteria for selecting materials of construction shall not apply to nonprocess contents of the building, structure, orassembly where such contents are not a part of the building, structure, or assembly, including the following:

Equipment or equipment enclosures

Grating, walkways, ladders, railings, weirs, process piping, and appurtenances

Process media

Aeration devices

Slide and sluice gates

Pump packing and seal material

Electrical conduit

Hardware

Liners for basins that are open to the atmosphere

Materials used in rehabilitation or for lining existing sewer pipes

Other components as allowed by the AHJ

8.1.4

In areas where corrosive environments are present, including classified areas, the mitigation of corrosion problems inthe selection and use of materials for nonstructural assemblies shall include the use of the following:

Corrosion-resistant metallic or nonmetallic grating

Railings, steps and stairs, conduit

Electric equipment enclosures

8.2 Materials Selection.

8.2.1

Materials shall be selected based on the criteria for a particular the intended application.


39 of 51 12/1/2014 1:18 PM

8.2.2 Limited-Combustible Material.

A material shall be considered a limited-combustible material where both of the following conditions of 8.2.2(1) , and8.2.2(2) , and the conditions of either 8.2.2.1 or 8.2.2.2 are met:

The material does not comply with the requirements for a noncombustible material in accordance with 8.2.3.

The material, in the form in which it is used, exhibits a potential heat value not exceeding 3500 Btu/lb (8141kJ/kg), when tested in accordance with NFPA 259, Standard Test Method for Potential Heat of BuildingMaterials . [ 5000: 7.1.4.2]

Selection criteria shall include specification of the following:

(1) Structural requirements

(2) Location and operating environment

(3) Fire resistance rating

(4) Flame spread index value

(5)

(6) Products of combustion

(7) Corrosion resistance

8.2.2.1

The material shall have a structural base of noncombustible material with a surfacing not exceeding a thickness of1 ⁄8 in. (3.2 mm) where the surfacing exhibits a flame spread index not greater than 50 when tested in accordancewith ASTM E 84, Standard Test Method for Surface Burning Characteristics of Building Materials , or ANSI/UL 723,Standard for Test for Surface Burning Characteristics of Building Materials . [ 5000: 7.1.4.2.1]

8.2.2.2

The material shall be composed of materials that in the form and thickness used, neither exhibit a flame spread indexgreater than 25 nor evidence of continued progressive combustion when tested in accordance with ASTM E 84 orANSI/UL 723 and are of such composition that all surfaces that would be exposed by cutting through the material onany plane would neither exhibit a flame spread index greater than 25 nor exhibit evidence of continued progressivecombustion when tested in accordance with ASTM E 84 or ANSI/UL 723. [ 5000: 7.1.4.2.2]

8.2.2.3

Where the term limited-combustible is used in this standard, it shall also include the term noncombustible .[ 5000: 7.1.4.2.3]

8.2.3 Noncombustible Material.

A material that complies with any one of the following shall be considered a noncombustible material:

The material is reported as passing ASTM E 136, Standard Test Method for Behavior of Materials in a VerticalTube Furnace at 750 Degrees C

The material is reported as complying with the pass/fail criteria of ASTM E 136 when tested in accordance withthe test method and procedure in ASTM E 2652, Standard Test Method for Behavior of Materials in a TubeFurnace with a Cone-shaped Airflow Stabilizer, at 750 Degrees C

[5000: 7.1.4.1.1]

For the purpose of this document, materials of construction shall be divided into the following four basic categories asdefined in 8.2.3.1 through 8.2.3.4 :

(1) Combustible

(2) Noncombustible

(3) Limited-combustible

(4) Low flame spread index

8.2.3.1 Combustible Material.

Where the term limited-combustible is used in this standard, it shall also include the term noncombustible .[ 5000: 7.1.4.1.2] A material that, in the form in which it is used and under the conditions anticipated, will ignite andburn; a material that does not meet the definition of noncombustible or limited-combustible shall be considered acombustible material.

8.2.3.2* Noncombustible Material.

* Smoke developed index or other smoke generation values

* The material, in the form in which it is used, and under the conditions anticipated, will not ignite, burn, supportcombustion, or release flammable vapors when subjected to fire or heat


40 of 51 12/1/2014 1:18 PM

A material that complies with any one of the following shall be considered a noncombustible material:

(1)

(2) The material is reported as passing ASTM E136, Standard Test Method for Behavior of Materials in a VerticalTube Furnace at 750 Degrees C .

(3) The material is reported as complying with the pass/fail criteria of ASTM E136 when tested in accordance withthe test method and procedure in ASTM E2652, Standard Test Method for Behavior of Materials in a TubeFurnace with a Cone-shaped Airflow Stabilizer , at 750 Degrees C.

[ 5000: 7.1.4.1.1]

8.2.3.2.1

Where the term limited-combustible is used in this standard, it shall also include the term noncombustible .

[ 5000: 7.1.4.1.2]

8.2.3.3* Limited-Combustible Material.

A material shall be considered a limited-combustible material where both of the following conditions of 8.2.2(1) ,8.2.2(2) , and the conditions of either 8.2.3.3.1 or 8.2.3.3.2 are met:

(1) The material does not comply with the requirements for a noncombustible material in accordance with 8.2.3 .

(2) The material, in the form in which it is used, exhibits a potential heat value not exceeding 3500 Btu/lb (8141kJ/kg), when tested in accordance with NFPA 259 . [ 5000: 7.1.4.2]

8.2.3.3.1

The material shall have a structural base of noncombustible material with a surfacing not exceeding a thickness of1 ⁄8 in. (3.2 mm) where the surfacing exhibits a flame spread index not greater than 50 when tested in accordancewith ASTM E84, Standard Test Method for Surface Burning Characteristics of Building Materials , or ANSI/UL 723,Standard for Test for Surface Burning Characteristics of Building Materials . [ 5000: 7.1.4.2.1]

8.2.3.3.2

The material shall be composed of materials that in the form and thickness used, neither exhibit a flame spread indexgreater than 25 nor evidence of continued progressive combustion when tested in accordance with ASTM E84 orANSI/UL 723 and are of such composition that all surfaces that would be exposed by cutting through the material onany plane would neither exhibit a flame spread index greater than 25 nor exhibit evidence of continued progressivecombustion when tested in accordance with ASTM E84 or ANSI/UL 723. [ 5000: 7.1.4.2.2]

8.2.3.3.3

Where the term limited-combustible is used in this standard, it shall also include the term noncombustible .[ 5000: 7.1.4.2.3]

8.2.3.4*

Flame spread index shall be considered a comparative measure, expressed as a dimensionless number, derivedfrom visual measurements of the spread of flame versus time for a material tested in accordance with ASTM E84,Standard Test Method for Surface Burning Characteristics of Building Materials , or UL 723, Standard for Test forSurface Burning Characteristics of Building Materials .

8.2.4

Selection criteria shall include the following:

Structural requirements

Location and operating environment

Fire resistance rating

Flame spread index value

Smoke developed index or other smoke generation values

Products of combustion

Corrosion resistance

Materials of construction used for unit processes located in classified areas shall be selected based upon adocumented fire risk evaluation.

* The material, in the form in which it is used, and under the conditions anticipated, will not ignite, burn,support combustion, or release flammable vapors when subjected to fire or heat.


41 of 51 12/1/2014 1:18 PM

8.2.4.1

Where conditions or applications warrant the selection of combustible materials, limited-combustible, or low flamespread index materials, the following shall be included as part of the fire risk evaluation:

(1) Flame spread

(2) Smoke generation



(5) Impact of a fire or explosion on the structural integrity and operability

(6) Economic and environmental consequences of having the facility out of service

8.2.5

For the purpose of this document, materials of construction shall be divided into the following four basic categories:

Combustible

Noncombustible

Limited-combustible

Low flame spread index

8.2.6

Materials of construction used for unit processes located in areas with an NFPA 70 classification of Class I, Division1 or Division 2, and Class II shall be selected based on an overall evaluation, including the following:

Fire risk of the material attributes

Economic impact of replacing the unit process

Potential environmental dangers caused by having the unit process out of service for an extended period oftime due to fire or explosion

8.3 Applications.

8.3.1 Sewers and Appurtenances General .

Buildings and structures, including domes and covers, shall be constructed of materials in accordance with Table4.2 , Table 5.2 , Table 6.2(a) , and Table 6.2(b) except as indicated in 8.3.1.1 or 8.3.1.2 .

8.3.1.1

Small aboveground buildings and structures, including domes and covers, with a floor or surface area of 9.3 m 2

(100 ft 2 ) or less that are physically separated from other buildings or structures and that do not present a firehazard to other buildings or structures shall be permitted to be constructed of any appropriate materials.

8.3.1.2

Materials other than those required by Table 4.2 , Table 5.2 , Table 6.2(a) and Table 6.2(b) shall be permitted inbuildings or structures that are fully sprinklered in accordance with NFPA 13 and approved by the AHJ.

8.3.2* Pumping Facilities Critical Unit Processes .


42 of 51 12/1/2014 1:18 PM

Materials selected for wastewater pumping facilities shall be in accordance with Table 4.2 unless otherwise specifiedby either of the following:

Where conditions or applications warrant the selection of combustible materials for pumping facilities, thefollowing shall be included as part of the fire risk evaluation:

Flame spread

Smoke generation



Impact of a fire or explosion on the structural integrity and operability of the pumping facility

Economic and environmental consequences of having the pumping facility out of service

Small aboveground pumping facilities with a floor area of 9.3 m 2 (100 ft 2 ) or less and physically separatedfrom the wet well and that do not present a fire hazard to other buildings or structures shall be permitted to beconstructed of any appropriate materials.

Buildings and structures containing critical unit processes shall be of noncombustible materials in accordance withTable 4.2 , Table 5.2 , Table 6.2(a) and Table 6.2(b) .

8.3.2.1

Where structural assemblies and partitions are required in critical unit process areas for fire separation in accordancewith the fire risk evaluation, they shall have a minimum 3-hour fire rating.

8.3.2.2

Nonstructural assemblies such as ventilation ducts and piping shall be constructed of noncombustible, limited-combustible, or low flame spread index materials.

8.3.3* Buildings and Structures Essential Unit Processes .

Buildings and structures containing essential unit processes shall be constructed of materials meeting the definitionsof noncombustible, limited-combustible, or low flame spread index in accordance with Table 4.2 , Table 5.2 , Table6.2(a) and Table 6.2(b) .

8.3.3.1 General.

Buildings and structures, including domes and covers, shall be constructed of materials in accordance with Table 4.2 ,Table 5.2 , Table 6.2(a) , and Table 6.2(b) , unless otherwise specified by any of the following:

Where conditions or applications warrant the selection of combustible materials for buildings and structures, thefollowing shall be included as part of the fire risk evaluation:

Flame spread

Smoke generation



Impact of a fire or explosion on structural integrity and operability of the facility

Economic and environmental consequences of having the facility out of service

Small aboveground buildings and structures, including domes and covers, with a floor or surface area of 9.3

m 2 (100 ft 2 ) or less that are physically separated from other buildings or structures and that do not present afire hazard to other buildings or structures shall be permitted to be constructed of any appropriate materials.

Materials other than those required by Table 4.2 , Table 5.2 , Table 6.2(a) , and Table 6.2(b) shall bepermitted in buildings or structures that are fully sprinklered in accordance with NFPA 13 .

Where structural assemblies and partitions are used in essential unit process areas for fire separation, they shall havea minimum 2-hour fire rating.

8.3.3.2* Critical Unit Processes.


8.3.3.2.1

Buildings and structures, including domes and covers, containing unit processes that are critical to maintaining theintegrity of the treatment plant (e.g., headworks, main pumping facility, primary clarifiers), and that if out of service foreven a few hours could permanently damage the environment or endanger public health by allowing the release ofraw wastewater or sludge, shall be constructed of materials meeting the definition of noncombustible.


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8.3.3.2.2

The requirements of 8.3.3.2.1 shall not apply where otherwise permitted by 8.3.3.1 .

8.3.3.2.3

Where structural assemblies and partitions are required in critical unit process areas for fire separation in accordancewith the fire risk evaluation, they shall have a minimum 3-hour fire rating.

8.3.3.2.4


8.3.3.3 Essential Unit Processes.

8.3.3.3.1

Buildings or structures, including domes and covers, containing unit processes that are essential to maintaining theintegrity of the treatment plant (e.g., secondary biological treatment, secondary clarifiers, or disinfection facilities),and that if out of service for short periods of time would not permanently damage the environment or endanger publichealth but would become critical if out of service for several days, shall be constructed of materials meeting thedefinitions of noncombustible, limited-combustible, or low flame spread index.

8.3.3.3.2


8.3.3.3.3

Where structural assemblies and partitions are used in essential unit process areas for fire separation, they shallhave a minimum 2-hour fire rating.

8.3.3.3.4*


8.3.3.4 Other Unit Processes.

8.3.3.4.1

Buildings and structures containing unit processes, including sludge-processing operations, that are not critical oressential to maintaining the integrity of the treatment plant, and that if out of service for long periods of time (i.e., aweek or more) would not permanently damage the environment or endanger public health, shall be constructed ofmaterials considered applicable by the authority having jurisdiction.

8.3.3.4.2


8.3.3.4.3

Where structural assemblies and partitions are used in other unit process areas for fire separation, they shall have aminimum 1-hour fire rating.

8.3.3.4.4

Nonstructural assemblies such as ventilation ducts and piping shall be constructed of materials meeting thedefinitions of noncombustible, limited-combustible, or low flame spread index.

8.3.3.5 Combustible Gas Generation and Combustion Processes.

8.3.3.5.1

Buildings and structures containing unit processes that generate, process, or utilize combustible gases (e.g.,anaerobic wastewater treatment processes, anaerobic digesters, compressors, storage spheres, piping, waste gasburners, gas-fired equipment including sludge incinerators) shall be constructed of materials meeting the definition ofnoncombustible.

8.3.3.5.2


8.3.3.6 Air Supply and Exhaust.

8.3.3.6.1

Noncombustible, limited-combustible, or low flame spread index materials shall be used for air supply and exhaustsystems.

8.3.3.6.2

Systems supplying or exhausting air at a rate greater than 56.6 m 3 /min (2000 ft 3 /min) shall include listed smokedampers, listed fire dampers, and smoke detection and shall cause the ventilation system to shut down upondetection of smoke.

8.3.3.6.3

Separate smoke ventilation systems shall be used where applicable, unless otherwise permitted by the following:

Smoke venting shall be permitted to be integrated into installed ventilation systems using automatic ormanually positioned dampers and motor speed control in accordance with NFPA 90A , and NFPA 204 shallbe reviewed for further information.

Smoke venting also shall be permitted to be accomplished through the use of portable smoke ejectors.


44 of 51 12/1/2014 1:18 PM

8.3.3.7 Miscellaneous Materials.

8.3.3.7.1

Cellular or foamed plastic materials shall only be used in accordance with NFPA 101 ® .

8.3.3.7.2

Roof coverings shall be Class A in accordance with ASTM E 108, Standard Test Methods for Fire Tests of RoofCoverings , or UL 790, Standard Test Methods for Fire Tests of Roof Coverings .

8.3.3.7.3

Metal roof deck construction shall be Class I or shall be fire classified.

8.3.3.7.4

Class II metal roof deck construction shall be permitted in buildings or structures that are fully sprinklered inaccordance with 7.2.2 .

8.3.4* Combustible Gas Generation and Combustion Processes.

Buildings and structures containing other unit processes shall be constructed of materials as determined by the firerisk evaluation.

8.3.5* Sewers and Appurtenances.

Materials of construction for sewers and appurtenances such as maintenance holes, junction chambers, and catchbasins shall be based on the results of a written materials risk assessment.

8.3.6 Pumping Facilities.

Materials selected for wastewater pumping facilities shall be in accordance with Table 4.2 , except as indicated in8.3.6.1 .

8.3.6.1

Small aboveground pumping facilities with a floor area of 9.3 m 2 (100 ft 2 ) or less and physically separated fromthe wet well and that do not present a fire hazard to other buildings or structures shall be permitted to be constructedof any appropriate materials.

8.3.7* Other Unit Processes.

Buildings and structures containing other unit processes shall be constructed of materials as determined by the firerisk evaluation.

8.3.7.1

Where structural assemblies and partitions are used in other unit process areas for fire separation, they shall have aminimum 1-hour fire rating.

8.3.7.2

Nonstructural assemblies such as ventilation ducts and piping shall be constructed of materials meeting thedefinitions of noncombustible, limited-combustible, or low flame spread index.

8.3.8 Air Supply and Exhaust.

8.3.8.1

Noncombustible, limited-combustible, or low flame spread index materials shall be used for air supply and exhaustsystems.

8.3.8.2

Systems supplying or exhausting air at a rate greater than 56.6 m 3 /min (2000 ft 3 /min) shall include listed smokedampers, listed fire dampers, and smoke detection and shall cause the ventilation system to shut down upondetection of smoke.

8.3.8.3

Separate smoke ventilation systems designed and installed in accordance with NFPA 92 or NFPA 204 shall beused where applicable, unless otherwise permitted by the following:

(1) Smoke venting shall be permitted to be integrated into installed ventilation systems using automatic ormanually positioned dampers and motor speed control in accordance with NFPA 90A , NFPA 92 , and NFPA204 .

(2) Smoke venting also shall be permitted to be accomplished using listed portable smoke ejectors.



ComparisonFDtoSDChapter_8.docx For Committee use to compare first draft to second draft.

FINALSDMtgREVChapter_8.docx New Chapter 8 to be inserted. For editorial use.

AnnexA_Chapter8_820.docx New Annex A material for chapter 8 to be inserted. For editorial use.



45 of 51 12/1/2014 1:18 PM



Street Address:

City:

State:

Zip:


Committee Statement

CommitteeStatement:

A task group was formed to review the building construction requirements and a second revision was created toreference the building code where appropriate and retain provisions specific for wastewater treatment facilitieswhere building codes do not cover these requirements. Definitions were added to the chapter and the order of theprocesses was modified to provide requirements for critical processes before non critical processes.

ResponseMessage:

Public Comment No. 7-NFPA 820-2014 [Chapter 8]


46 of 51 12/1/2014 1:18 PM


8.1 General.

8.1.1

This chapter shall apply to the selection of materials of construction for buildings, structures, and

process elements for protection against fire and explosion in wastewater treatment plants and

associated collection systems.

8.1.2

Materials of construction and interior coatings and finishes shall provide a maximum degree of fire

resistance with the minimum amount of flame spread and smoke generation associated with a

particular application.

8.1.1.3 *

Materials shall be selected that reduce or eliminate the effects of fire and explosion by maintaining

structural integrity, controlling flame spread and smoke generation, minimizing the release of toxic

products of combustion, and maintaining the serviceability and operation of critical processes.

8.1.3.1

The purpose of the criteria for selecting materials of construction shall not be to provide protection of

personnel from the risk of exposure to an asphyxiating or toxic atmosphere generated during a fire.

8.1.3.2

Criteria for selecting materials of construction shall not apply to nonprocess contents of the building,

structure, or assembly where such contents are not a part of the building, structure, or assembly,

including the following:

(1) Equipment or equipment enclosures

(2) Grating, walkways, ladders, railings, weirs, process piping, and appurtenances

(3) Process media

(4) Aeration devices

(5) Slide and sluice gates

(6) Pump packing and seal material

(7) Electrical conduit

(8) Hardware

(9) Liners for basins that are open to the atmosphere

(10) Materials used in rehabilitation or for lining existing sewer pipes

(11) Other components as allowed by the AHJ

8.1.4Facilities shall be constructed in accordance with the applicable building code and the

additional requirements in this standard.

8.1.2

In areas where corrosive environments are present, including classified areas, the mitigation of

corrosion problems in the selection and use of materials for nonstructural assemblies shall include

the use of the following:


(2) RailingsCorrosion-resistant railings, steps and stairs, conduit

(3) ElectricCorrosion-resistant electric equipment enclosures

8.2 Materials Selection .

8.2.1 Materials shall be selected based on the criteria for a particularthe intended application.

8.2.2*






(5) *Smoke developed index or other smoke generation values



8.2.3

For the purpose of this document, materials of construction shall be divided into the following four

basic categories as defined in 8.2.3.1-8.2.3.4:

(1) Combustible

(2) Noncombustible


(4) Low flame spread index Limited- 8.2.3.1 Combustible Material. A material that, in the form in which it is used and under the conditions anticipated, will ignite and burn; a material that does not meet the definition of noncombustible or limited-combustible shall be considered a combustible material.

A material shall be considered a limited-combustible material where both of the following conditions

of 8.2.2(1), and 8.2.2(2), and the conditions of either 8.2.2.1 or 8.2.2.2 are met:

(1) The material does not comply with the requirements for a noncombustible material in


(2) The material, in the form in which it is used, exhibits a potential heat value not exceeding 3500

Btu/lb (8141 kJ/kg), when tested in accordance with NFPA 259, Standard Test Method for Potential

Heat of Building Materials. [5000:7.1.4.2]

8.2.3.2.1

The material shall have a structural base of noncombustible material with a surfacing not exceeding

a thickness of 1⁄8 in. (3.2 mm) where the surfacing exhibits a flame spread index not greater than

50 when tested in accordance with ASTM E 84, Standard Test Method for Surface Burning

Characteristics of Building Materials, or ANSI/UL 723, Standard for Test for Surface Burning

Characteristics of Building Materials. [5000:7.1.4.2.1]

8.2.2.2

The material shall be composed of materials that in the form and thickness used, neither exhibit a

flame spread index greater than 25 nor evidence of continued progressive combustion when tested

in accordance with ASTM E 84 or ANSI/UL 723 and are of such composition that all surfaces that

would be exposed by cutting through the material on any plane would neither exhibit a flame

spread index greater than 25 nor exhibit evidence of continued progressive combustion when

tested in accordance with ASTM E 84 or ANSI/UL 723. [5000:7.1.4.2.2]

8.2.2.3

Where the term limited-combustible is used in this standard, it shall also include the term

noncombustible. [5000:7.1.4.2.3]

8.2.3* Noncombustible Material. ( A.8.2.3 here and A.8.2.3(1) here)

A material that complies with any one of the following shall be considered a noncombustible

material:

(1) *The material, in the form in which it is used, and under the conditions anticipated, will not

ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat

(2) The material is reported as passing ASTM E 136, Standard Test Method for Behavior of

Materials in a Vertical Tube Furnace at 750 Degrees C

(3) The material is reported as complying with the pass/fail criteria of ASTM E 136 when tested in

accordance with the test method and procedure in ASTM E 2652, Standard Test Method for

Behavior of Materials in a Tube Furnace with a Cone-shaped Airflow Stabilizer, at 750 Degrees C

[5000:7.1.4.1.1]

8.2.3.2.1



8.2.4*

Selection criteria shall include the following:





(5) Smoke developed index or other smoke generation values



8.2.5


basic categories:

(1) 3.3* Limited-Combustible Material.


of 8.2.2(1), and 8.2.2(2), and the conditions of either 8.2.3.3.1 or 8.2.3.3.2 are met:






(2) Noncombustible


(4) Low flame spread index 8.2.3.3.1






8.2.3.3.2







8.2.3.3.3



6

8.2.3.4 *Flame Spread Index. A comparative measure, expressed as a dimensionless number, derived from visual measurements of the spread of flame versus time for a material tested in accordance with ASTM E 84, Standard Test Method for Surface Burning Characteristics of Building Materials; or UL 723, Standard for Test for Surface Burning Characteristics of Building Materials.

8.2.4 Materials of construction used for unit processes located in classified areas with an NFPA 70 classification of Class I, Division 1 or Division 2, and Class II shall be selected based on an overall upon a documented fire risk evaluation, including the following:.

(1) Fire risk of the material attributes

(2) Economic impact of replacing the unit process

(3) Potential environmental dangers caused by having the unit process out of service for an

extended period of time due to fire or explosion

8.3 Applications.


Materials of construction for sewers and appurtenances such as maintenance holes, junction

chambers, and catch basins shall be based on the results of a written materials risk assessment.


Materials selected for wastewater pumping facilities shall be in accordance with Table 2.4.2 unless

otherwise specified by either of the following:

(1 ) Where conditions or applications warrant the selection of combustible materials for pumping

facilitieslimited-combustible, or low flame spread index materials, the following shall be included as

part of the fire risk evaluation:

(a) Flame spread

(b) Smoke generation

(c) Corrosion resistance

(d) Products of combustion

(e) Impact of a fire or explosion on the structural integrity and operability of the pumping facility

(f) Economic and environmental consequences of having the pumping facility out of service

(2) Small aboveground pumping facilities with a floor area of 9.3 m2 (100 ft2) or less and physically

separated from the wet well and that do not present a fire hazard to other buildings or structures

shall be permitted to be constructed of any appropriate materials.

8.3 Applications

8.3.3 Buildings and Structures.

8.3.3.1 General.

Buildings and structures, including domes and covers, shall be constructed of materials in

accordance with Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b), unless otherwise specified by

any of the following:) except as indicated in 8.3.1.1 or 8.3.1.2.

8.3.(1) Where conditions or applications warrant the selection of combustible materials for

buildings and structures, the following shall be included as part of the fire risk evaluation:

(a) Flame spread




(e) Impact of a fire or explosion on structural integrity and operability of the facility

(f) Economic and environmental consequences of having the facility out of service

(2)1.1 Small aboveground buildings and structures, including domes and covers, with a floor or

surface area of 9.3 m2 (100 ft2) or less that are physically separated from other buildings or

structures and that do not present a fire hazard to other buildings or structures shall be permitted to

be constructed of any appropriate materials.

(

8.3).1.2 Materials other than those required by Table 4.2, Table 5.2, Table 6.2(a), and Table

6.2(b) shall be permitted in buildings or structures that are fully sprinklered in accordance with

NFPA 13 and approved by the AHJ.

8.3.3.2* Critical Unit Processes.

8.3.3.2.1

Buildings and structures, including domes and covers, containing critical unit processes that are

critical to maintaining the integrity of the treatment plant (e.g., headworks, main pumping facility,

primary clarifiers), and that if out of service for even a few hours could permanently damage the

environment or endanger public health by allowing the release of raw wastewater or sludge, shall

be constructed of non-combustible materials meeting the definition of noncombustible.in

accordance with Table 4.2, Table 5

8.3.3.2, Table 6.2

The requirements of 8.3.3(a), and Table 6.2.1 shall not apply where otherwise permitted by

8.3.3.1.(b).

8.3.3.2.31

Where structural assemblies and partitions are required in critical unit process areas for fire

separation in accordance with the fire risk evaluation, they shall have a minimum 3-hour fire rating.

8.3.3.2.4

Nonstructural assemblies such as ventilation ducts and piping shall be constructed of

noncombustible, limited-combustible, or low flame spread index materials.

8.3.3.3 Essential Unit Processes.

8.3.3.3.1

Buildings or structures, including domes and covers, containing unit processes that are essential to

maintaining the integrity of the treatment plant (e.g., secondary biological treatment, secondary

clarifiers, or disinfection facilities), and that if out of service for short periods of time would not

permanently damage the environment or endanger public health but would become critical if out of

service for several days, shall be constructed of materials meeting the definitions of noncombustible,

limited-combustible, or low flame spread index.

8.3.3.3.2

The requirements of 8.3.3.3.1 shall not apply where otherwise permitted by 8.3.3.1.

8.3.3.3.3

Where structural assemblies and partitions are used in essential unit process areas for fire

separation, they shall have a minimum 2-hour fire rating.

8.3.3.3.4*



8.3.3.4 Other* Essential Unit Processes.

8.3.3.4.1

(2) Buildings and structures containing essential unit processes, including sludge-processing

operations, that are not critical or essential to maintaining the integrity of the treatment plant, and

that if out of service for long periods of time (i.e., a week or more) would not permanently damage

the environment or endanger public health, shall be constructed of materials considered applicable

by the authority having jurisdiction.meeting the definitions of noncombustible, limited-combustible,

or low flame spread index in accordance with Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b).

8.3.3.1



4.2

The requirements of

8.3.3.2* Nonstructural assemblies such as ventilation ducts and piping shall be constructed of


8.3.3.4.1* Combustible Gas Generation and Combustion Processes.

Buildings and structures containing other unit processes shall be constructed of materials as

determined by the fire risk evaluation.





Materials selected for wastewater pumping facilities shall be in accordance with Table 4.2 except as

indicated in 8.3.6.1.

8.3.6.1 Small aboveground pumping facilities with a floor area of 9.3 m2 (100 ft2) or less and

physically separated from the wet well and that do not apply where otherwisepresent a fire hazard

to other buildings or structures shall be permitted to be constructed of any appropriate materials.



determined by 8.3.3.1.the fire risk evaluation.

8.3.3.4.37.1

Where structural assemblies and partitions are used in other unit process areas for fire separation,

they shall have a minimum 1-hour fire rating.

8.3.3.4.47.2

Nonstructural assemblies such as ventilation ducts and piping shall be constructed of materials

meeting the definitions of noncombustible, limited-combustible, or low flame spread index.

8.3.3.5 Combustible Gas Generation and Combustion Processes.

8.3.3.5.1

Buildings and structures containing unit processes that generate, process, or utilize combustible

gases (e.g., anaerobic wastewater treatment processes, anaerobic digesters, compressors, storage

spheres, piping, waste gas burners, gas-fired equipment including sludge incinerators) shall be

constructed of materials meeting the definition of noncombustible.

8.3.3.5.2

The requirements of 8.3.3.5.1 shall not apply where otherwise permitted by 8.3.3.1.

8.3.3.6 Air Supply and Exhaust.

8.3.3.68.1

Noncombustible, limited-combustible, or low flame spread index materials shall be used for air

supply and exhaust systems.

8.3.3.68.2

Systems supplying or exhausting air at a rate greater than 56.6 m3/min (2000 ft3/min) shall include

listed smoke dampers, listed fire dampers, and smoke detection and shall cause the ventilation

system to shut down upon detection of smoke.

8.3.8.3.6.3

Separate smoke ventilation systems designed and installed in accordance with NFPA 92 or NFPA

204 shall be used where applicable, unless otherwise permitted by the following:

(1) Smoke venting shall be permitted to be integrated into installed ventilation systems using

automatic or manually positioned dampers and motor speed control in accordance with NFPA 90A,

NFPA 92 and NFPA 204 shall be reviewed for further information..

(2) Smoke venting also shall be permitted to be accomplished through the use of listed portable

smoke ejectors.

8.3.3.7 Miscellaneous Materials.

8.3.3.7.1

Cellular or foamed plastic materials shall only be used in accordance with NFPA 101® .

8.3.3.7.2

Roof coverings shall be Class A in accordance with ASTM E 108, Standard Test Methods for Fire

Tests of Roof Coverings, or UL 790, Standard Test Methods for Fire Tests of Roof Coverings.

8.3.3.7.3

Metal roof deck construction shall be Class I or shall be fire classified.

8.3.3.7.4

Class II metal roof deck construction shall be permitted in buildings or structures that are fully

sprinklered in accordance with 7.2.2.


8.1 General

This chapter shall apply to the selection of materials of construction for buildings, structures, and

process elements for protection against fire and explosion in wastewater treatment plants and

associated collection systems.

8.1.1 *

Facilities shall be constructed in accordance with the applicable building code and the additional

requirements in this standard.

8.1.2

In areas where corrosive environments are present, including classified areas, the mitigation of

corrosion problems in the selection and use of materials for nonstructural assemblies shall include

the use of the following:


(2) Corrosion-resistant railings, steps and stairs, conduit

(3) Corrosion-resistant electric equipment enclosures

8.2 Materials Selection

8.2.1 Materials shall be selected based on the criteria for the intended application.

8.2.2*






(5) *Smoke developed index or other smoke generation values



8.2.3


basic categories as defined in 8.2.3.1-8.2.3.4:

(1) Combustible

(2) Noncombustible


(4) Low flame spread index

8.2.3.1 Combustible Material. A material that, in the form in which it is used and under the conditions anticipated, will ignite and burn; a material that does not meet the definition of noncombustible or limited-combustible shall be considered a combustible material.

8.2.3.2* Noncombustible Material.

A material that complies with any one of the following shall be considered a noncombustible

material:

(1) *The material, in the form in which it is used, and under the conditions anticipated, will not

ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat

(2) The material is reported as passing ASTM E 136, Standard Test Method for Behavior of

Materials in a Vertical Tube Furnace at 750 Degrees C

(3) The material is reported as complying with the pass/fail criteria of ASTM E 136 when tested in

accordance with the test method and procedure in ASTM E 2652, Standard Test Method for

Behavior of Materials in a Tube Furnace with a Cone-shaped Airflow Stabilizer, at 750 Degrees C

[5000:7.1.4.1.1]

8.2.3.2.1



8.2.3.3* Limited-Combustible Material.


of 8.2.2(1), and 8.2.2(2), and the conditions of either 8.2.3.3.1 or 8.2.3.3.2 are met:






8.2.3.3.1






8.2.3.3.2







8.2.3.3.3



8.2.3.4 *Flame Spread Index shall be considered a comparative measure, expressed as a dimensionless number, derived from visual measurements of the spread of flame versus time for a material tested in accordance with ASTM E 84, Standard Test Method for Surface Burning Characteristics of Building Materials; or UL 723, Standard for Test for Surface Burning Characteristics of Building Materials.

8.2.4 Materials of construction used for unit processes located in classified areas shall be selected based upon a documented fire risk evaluation.

8.2.4.1 Where conditions or applications warrant the selection of combustible materials limited-

combustible, or low flame spread index materials, the following shall be included as part of the fire

risk evaluation:

(a) Flame spread




(e) Impact of a fire or explosion on the structural integrity and operability

(f) Economic and environmental consequences of having the facility out of service

8.3 Applications

8.3.1 General.

Buildings and structures, including domes and covers, shall be constructed of materials in

accordance with Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b) except as indicated in 8.3.1.1

or 8.3.1.2.

8.3.1.1 Small aboveground buildings and structures, including domes and covers, with a floor or

surface area of 9.3 m2 (100 ft2) or less that are physically separated from other buildings or

structures and that do not present a fire hazard to other buildings or structures shall be permitted to

be constructed of any appropriate materials.

8.3.1.2 Materials other than those required by Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b)

shall be permitted in buildings or structures that are fully sprinklered in accordance with NFPA 13

and approved by the AHJ.

8.3.2* Critical Unit Processes.

Buildings and structures containing critical unit processes shall be of non-combustible materials in

accordance with Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b).

8.3.2.1

Where structural assemblies and partitions are required in critical unit process areas for fire

separation in accordance with the fire risk evaluation, they shall have a minimum 3-hour fire rating.

8.3.2.2



Formatted: Font: Not Bold

8.3.3* Essential Unit Processes. (2) Buildings and structures containing essential unit processes

shall be constructed of materials meeting the definitions of noncombustible, limited-combustible, or

low flame spread index in accordance with Table 4.2, Table 5.2, Table 6.2(a), and Table 6.2(b).

8.3.3.1



8.3.3.2* Nonstructural assemblies such as ventilation ducts and piping shall be constructed of


8.3.4* Combustible Gas Generation and Combustion Processes.







Materials selected for wastewater pumping facilities shall be in accordance with Table 4.2 except as

indicated in 8.3.6.1.

8.3.6.1 Small aboveground pumping facilities with a floor area of 9.3 m2 (100 ft2) or less and

physically separated from the wet well and that do not present a fire hazard to other buildings or

structures shall be permitted to be constructed of any appropriate materials.




8.3.7.1

Where structural assemblies and partitions are used in other unit process areas for fire separation,

they shall have a minimum 1-hour fire rating.

8.3.7.2

Nonstructural assemblies such as ventilation ducts and piping shall be constructed of materials

meeting the definitions of noncombustible, limited-combustible, or low flame spread index.

8.3.8 Air Supply and Exhaust.

8.3.8.1

Noncombustible, limited-combustible, or low flame spread index materials shall be used for air

supply and exhaust systems.

Formatted: Font: Bold

8.3.8.2

Systems supplying or exhausting air at a rate greater than 56.6 m3/min (2000 ft3/min) shall include

listed smoke dampers, listed fire dampers, and smoke detection and shall cause the ventilation

system to shut down upon detection of smoke.

8.3.8.3

Separate smoke ventilation systems designed and installed in accordance with NFPA 92 or NFPA

204 shall be used where applicable, unless otherwise permitted by the following:

(1) Smoke venting shall be permitted to be integrated into installed ventilation systems using

automatic or manually positioned dampers and motor speed control in accordance with NFPA 90A,

NFPA 92 and NFPA 204.

(2) Smoke venting also shall be permitted to be accomplished through the use of listed portable

smoke ejectors.

A.8.1.1 For more information on building construction types refer to the applicable building code or NFPA 5000®, Building Construction and Safety Code® and NFPA 220, Standard on Types of Building Construction. These NFPA documents provide additional details and cross-references for the building construction types described in four other model building codes. For AHJs where one of these model building codes are used, the cross references provide helpful information to assist in the proper application of the materials of construction requirements in NFPA 820.

A.8.2.2 (5)

The smoke developed index is assessed by means of testing via ASTM E 84 or ANSI/UL 723.The smoke

developed index is assessed by means of testing via ASTM E 84 or ANSI/UL 723.

A.8.2.3.2

The provisions of 7.1.4.1 of NFPA 5000 do not require inherently noncombustible materials to be tested in

order to be classified as noncombustible materials.

A.8.2.3.2 (1)

Examples of such materials include steel, concrete, masonry, and glass.

A.8.2.3.3

Materials subject to increase in combustibility or flame spread index beyond the limits herein established

through the effects of age, moisture, or other atmospheric conditions are considered combustible. (See

NFPA 259, Standard Test Method for Potential Heat of Building Materials, and NFPA 220, Standard on

Types of Building Construction.)

A.8.2.3.4 A flame spread index of 25 or less (LFS) is a flame spread index for a Class A material in

accordance with ASTM E 84 and is generally considered a low flame spread index.

A.8.3.2 Buildings and structures, including domes and covers, containing unit processes that are critical

to maintaining the integrity of the treatment plant (e.g., headworks, main pumping facility, primary

clarifiers), and that if out of service for even a few hours could permanently damage the environment or

endanger public health by allowing the release of raw wastewater or sludge.

A.8.3.3 Buildings or structures, including domes and covers, containing unit processes that are essential

to maintaining the integrity of the treatment plant (e.g., secondary biological treatment, secondary

clarifiers, or disinfection facilities), and that if out of service for short periods of time would not

permanently damage the environment or endanger public health but would become critical if out of

service for several days.

A.8.3.3.2

Plastic or fiberglass-reinforced plastic products are often used as materials of construction in unit

processes such as rotating biological contactors (RBC), bio-towers, trickling filters, inclined plate (tube)

settlers, ventilation ducts, and other equipment that might be subject to corrosion. Under normal operating

conditions, these plastic or fiberglass-reinforced plastic materials might be submerged. However, during

maintenance or repair, they can become exposed. During maintenance and repair operations, extreme

care should be taken with open flame such as cutting torches, because these exposed plastic or

fiberglass-reinforced plastic materials might present a considerable fuel load if ignited.

A. 8.3.4

Buildings and structures containing unit processes that generate, process, or utilize combustible gases

(e.g., anaerobic wastewater treatment processes, anaerobic digesters, compressors, storage spheres,

piping, waste gas burners, gas-fired equipment including sludge incinerators) should be constructed of

materials meeting the definition of noncombustible.

A.8.3.5

See Annex C of this document.

A.8.3.7 Buildings and structures containing unit processes, including sludge-processing operations, that

are not critical or essential to maintaining the integrity of the treatment plant, and that if out of service for

long periods of time (i.e., a week or more) would not permanently damage the environment or endanger

public health, should be constructed of materials considered applicable by the authority having

jurisdiction.

Second Revision No. 13-NFPA 820-2014 [ New Section after 9.1.1.1 ]




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Committee Statement

Committee Statement: This has been added to point to the alarm and signaling requirements in Chapter 7.

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9.2.7

Ventilation systems for hazardous areas that are designed to operate intermittently or only when the space is occupiedshall not be permitted to be used for the purpose of downgrading reducing the electrical classification of areas. (SeeChapters 4, 5, and 6 for further information.)




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Committee Statement

Committee Statement: Changed terminology to match that in 9.3.2. Reducing is a better term than downgrading.

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10.4 Fire Prevention Program.

Each plant shall establish a fire prevention program that includes all of the following items:

(1) Fire safety information for all employees and contractors that includes, as a minimum, the following:

(a) Familiarization with fire protection equipment and procedures

(b) Plant emergency alarms and procedures

(c) Procedures for reporting a fire

(2) Documented plant inspections, including provisions for handling remedial actions to correct conditions thatincrease fire hazards

(3) Description of the general housekeeping procedures and the control of transient combustibles, including control ofsuch materials stored in areas containing toxic or reactive chemicals

(4) Control of flammable and combustible liquids and gases in accordance with NFPA 30 and NFPA 54

(5) Control of ignition sources that include smoking, grinding, welding, and cutting in accordance with NFPA 51B

(6) Fire prevention surveillance in accordance with NFPA 601

(7)

(8) Planning documents and training conducted in accordance with NFPA 56 for flammable gas piping repairs,cleaning, purging and planned releases of gases


Submitter Full Name: Sonia Barbosa


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Committee Statement

CommitteeStatement:

NFPA 56 contains numerous safe work practices related to cleaning, repairing, and purging flammable gaspiping systems. This comment provides a reference for the inclusion of NFPA 56 by reference as per PI #33and PC #2.

ResponseMessage:

Public Comment No. 2-NFPA 820-2014 [New Section after 10.4]

* Fire report, including an investigation and a statement on the corrective action to be taken


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Second Revision No. 9-NFPA 820-2014 [ Section No. A.3.3.16.1 ]

A.3.3.16.1 Gas-Handling Equipment.

Gas-handling equipment does not include equipment or devices for the utilization of the gas, such as boilers, andengines, and waste gas burners .




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CommitteeStatement:

Waste gas burners was added to the requirements in table 6.2(a) Row 20 therefore this needed to beremoved from the annex material for gas handling equipment since it conflicts with the new requirements.

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Second Revision No. 1-NFPA 820-2014 [ Sections A.3.3.34.1, A.3.3.34.2 ]

A.3.3.35.1 Combustible Liquid.

Definition applies as determined by the test procedures and apparatus set forth in Chapter 4 of NFPA 30, Flammableand Combustible Liquids Code . Combustible liquids are classified as Class II or Class III as follows:

(1) Class II — Any any liquid that has a flash point at or above 37.8°C (100°F) and below 60°C (140°F)

(2) Class IIIA — Any any liquid that has a flash point at or above 60°C (140°F), but below 93°C (200°F)

(3) Class IIIB — Any any liquid that has a flash point at or above 93°C (200°F)

A.3.3.35.2 Flammable Liquid.

See NFPA 30 . Definition applies as determined by the test procedures and apparatus set forth in Chapter 4 of NFPA30. Flammable liquids are further subclassified in accordance with the following:

(1) Class IA Liquid — any liquid that has a flash point below 73°F (22.8°C) and a boiling point below 100°F(37.8°C)

(2) Class IB Liquid — any liquid that has a flash point below 73°F (22.8°C) and a boiling point at or above 100°F(37.8°C)

(3) Class IC Liquid — any liquid that has a flash point at or above 73°F (22.8°C), but below 100°F (37.8°C)




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Committee Statement

CommitteeStatement:

Added annex to be consistent with the annex for combustible liquids. Definitions and annex have beentaken from NFPA 30.

Response Message:


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second revision no. 5-nfpa 820-2014 [ section no. 2.3.1 ] · second revision no. 17-nfpa 820-2014 [...

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