wet weather flows 2010...kdhe annual water & wastewater school august 5, 2010 wet-weather flows...

91st Annual Water andWastewater School

August 3 - 6 2010

WetWet--Weather FlowsWeather Flows

Jim Fitzpatrick

KDHE Annual Water & Wastewater School August 5, 2010

Overview

Wet-Weather Flow Treatment Challenges

Auxiliary Treatment Strategy

High-Rate Treatment Processes and Technologies

Closing Thoughts

B&V - 2

KDHE Annual Water & Wastewater School



Totally different set of technical and ecological issues than dry-weather flow treatment

Totally different set of technical and ecological issues than dry-weather flow treatment


Aggressive SSO or CSO control usually results in higher peak flows to treat

Realistic long-term I/I removal goalsOld sewers leak…new sewers will leak when they get old.

Significant effort and continuous expense. Year after year afteryear…after year...after year…

Private property issues

Increased storage may not eliminate need for high-rate treatment

Storage dewatering rates, back-to-back storms, etc.

Too much storage may be more detrimental to environment

Cost/benefit of I/I removal vs. conveyance & treatment determined through comprehensive analysis

B&V - 4


Wet-weather flows are generally highly variable and infrequent…

Mill Creek WWTP (Cincinnati, OH)Influent Flow Probability Curve

0

50

100

150

200

250

300

350

400

450

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Percentage of Data At or Below Value

Raw

Influ

ent F

low

, M

GD

Daily Average Data (1/1/03 - 11/24/08)Annual Average Design CapacityMaximum Monthly Average Design CapacityPeak Daily Average Design Capacity

Lawrence, KS WWTP Influent Excess Flows

0

5

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70Run time, hrs

Flow

, mgd

0

20

40

60

80

100

120

140

160

180

Flow

, ML/

d

30-Aug-03 13-Sep-03 4-Mar-0410-Mar-04 13-May-04 25-May-042-Jul-04 7-Jul-04 16-Jul-0426-Jul-04 27-Jul-04 29-Jul-0417-Aug-04 18-Aug-04 24-Aug-0428-Aug-04 8-Oct-04 5-Jan-057-Feb-05 13-Feb-05 13-May-051-Jun-05 3-Jun-05 11-Jun-0512-Jun-05 13-Aug-05 20-Aug-0526-Aug-05 23-Sep-05 20-Oct-0530-Apr-06 1-May-06 28-Aug-0622-Mar-07 12-Apr-07 14-Apr-076-May-07 19-Jun-07 30-Jun-074-Oct-07 17-Oct-07 18-Oct-0717-Feb-08 3-Mar-08 17-Mar-0819-Mar-08 9-Jun-08 13-Jun-0813-Sep-08 8-Mar-09 27-Apr-0930-Apr-09 16-May-09

QPKHR ≈ 5 to 10 x QAA

Similar for other CSS and SSS communities

Site-specific climatesB&V - 5


…with highly variable influent qualityMill Creek WWTP (Cincinnati, OH)

Influent Characteristics (Jan '03 - Nov '08)

0

100

200

300

400

500

600

700

800

900

1000

50 100 150 200 250 300 350 400 450

Raw Influent Flow, MGD

Raw

Influ

ent C

once

ntra

tion,

mg/

L

Annual Average Design CapacityDaily Average TSSDaily Average BODBest Fit (TSS)Best Fit (BOD)

Nelson WWTP Complex (Johnson County, KS)Influent Characteristics (Jan '03 - Nov '08)

0

100

200

300

400

500

600

700

800

900

0 1 2 3 4 5 6 7Sewershed Flow Peaking Factor (Daily Average/30-day Average)

Influ

ent B

OD

, mg/

L

No PEFTF OperationPEFTF OperationTrendline (y=ax^b)

C << CAA after first flush

Similar for other CSS and SSS communities

B&V - 6


Pollutants of concern are generally different than normal dry-weather conditions

D.O. sags generally much less of a concern vs. dry weather.High flows/volumes, turbulence, etc. in receiving stream

Larger assimilative capacity

Main wet-weather POCs are generally:Floatables. Trash, plastics, etc. Ingestion and entanglement by wildlife. Aesthetics

Solids. Prevent silt and sediments from burying eggs and larvae.

Biological pathogens (bacteria, viruses, etc.). Human health concern vs. aquatic toxicity concern.

Predominantly non-point sourcesB&V - 7


Biological treatment processes can be optimized, but have inherent limitations

Wet-weather capacity is inexact. Different storm-to-storm, antecedent conditions, etc.Cold influent (snowmelt) challenges.Building more biological treatment units will not necessarily increase wet weather capacity. Biomass has finite capacity.Save Your Biomass

Absolutely critical component of POTWRecovery can take weeks or monthsBNR biomass are particularly sensitive

Capacity bottleneck is usually existing clarifiers and/or filters (physical/chemical process units)

Don’t Upset Your Bugs!

B&V - 8

KDHE Annual Water & Wastewater School August 5, 2010B&V - 9


???????????????

Misinterpretation of “Secondary Treatment”

BiologicalProcess

BiologicalProcess

Auxiliary Treatment Facilities for Wet Weather

Excess FlowsSecondary ≠ Biological. Unintended consequence from focusing only on dry weather.

SecondaryTreatment

PrimaryClarifier

PrimaryClarifier

PrimaryTreatment

SecondaryClarifier

SecondaryClarifier

SecondaryTreatment

PrimaryTreatment

B&V - 10


We don’t currently have technology-based effluent limits for wet-weather conditions

40 CFR 133 assumes long-term average influent…TSS/BOD = 200/200 mg/L.Long-term effluent from entire POTW…not short-term performance criteria for biological trains…not wet-weather influent conditions.Narrative allowances in 40 CFR 133 and 122(m) for wet weather.

Parameter Units

40 CFR 133.102 40 CFR 133.105

Secondary Treatment Equivalent to Secondary Treatment

Max Min Weekly Average

Monthly Average Max Min Weekly

AverageMonthly Average

pH SU 9.0 6.0 - - 9.0 6.0 - -

TSSmg/L - - ≤45 ≤30 - - ≤65 ≤45

% Removal - - - ≥85% A - - - ≥65% A

BOD5mg/L - - ≤45 ≤30 - - ≤65 ≤45

% Removal - - - ≥85% A - - - ≥65% A

Notes:A. Based on monthly average influent and effluent concentrations only. Special considerations for

lower requirements with combined sewers and less concentrated influent for separate sewers.B&V - 11


Primary Treatment Secondary Treatment

“Secondary Treatment” per 40 CFR 133 & 122.41(m)

BulkSolids

Removal

BiologicalProcess

Liquid/Solid Separation

BulkSolids

Removal

BiologicalProcess



Excess Flows

SecondaryTreatment

Optional

B&V - 12


Auxiliary Treatment StrategyAuxiliary Treatment StrategyA proven strategy for treating wet-weather flows…

…while minimizing SSOs or CSOs

A proven strategy for treating wet-weather flows…

…while minimizing SSOs or CSOs


Parallel auxiliary treatment has a long track record as an effective wet-weather strategy

Complement the inherent wet-weather limitations of biological processes

Auxiliary treatment facilities optimized for wet weather influent

Enable POTW to achieve secondary treatment effluent quality during both dry and wet weather

Biological Treatment Facilities

River

Auxiliary Treatment Facilities

Qpeak

~2Qavg

QXS

August 5, 2010B&V - 14


Some lessons learned from CSO control…R

iver

QpeakFlow

Control

QXS

Reduce via NMCOptimize per NMC

~2Qavg BiologicalTreatmentFacilities D

isin

fect

ion

Prel

imin

ary

Trea

tmen

t

B&V - 15


Additional treatment presumed by USEPA 1994 CSO Control Policy Minimum Required, Except:

(i) ≤ 4 to 6 events per yearOR

(ii) ≤ 15% of system-wide annual average collected volume


Additional treatment per CSO Control Policy...R

iver

QpeakFlow

Control

QXS

QXS2

Reduce per LTCP


isin

fect

ion

Prel

imin

ary

Trea

tmen

t

LTCP implementation scenario that many POTWs are now tackling.

QXS1

Wet-Weather Auxiliary Treatment Facilities

Floa

tabl

esR

emov

al

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

Flow Control

B&V - 17


Integrated CSO Pollution Control FacilitiesR

iver

QpeakFlow

Control

QXS2


isin

fect

ion

Prel

imin

ary

Trea

tmen

tWet-Weather Auxiliary

Treatment Facilities

Floa

tabl

esR

emov

al

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

QXS1Flow Control

Optimal design in many cases for event response, operations, maintenance, etc….

…so, may be optimal design for water quality protection.B&V - 18


How far can we go with integrated facilities?R

iver

QpeakFlow

Control

QXS2

Site-specific design constraints (levees, effluent pumping, etc.) may make single outfall desirable.


isin

fect

ion

Prel

imin

ary

Trea

tmen



Floa

tabl

esR

emov

al

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

QXS1Flow Control

B&V - 19



iver

QpeakFlow

Control

QXS2

Instead of separate monitoring sites, specify separate monitoring conditions


isin

fect

ion

Prel

imin

ary

Trea

tmen



Floa

tabl

esR

emov

al

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

QXS1Flow Control

Dis

infe

ctio

n

Combined disinfection facilities may be optimal design alternative.

B&V - 20



iver

QpeakFlow

Control

QXS2


isin

fect

ion

Prel

imin

ary

Trea

tmen



Floa

tabl

esR

emov

al

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

QXS1Flow Control

Dis

infe

ctio

n

Combined preliminary treatment facilities (screening & grit removal) may be optimal design alternative.

Prel

imin

ary

Trea

tmen

t

B&V - 21



iver

QpeakFlow

Control

QXS2

~2Qavg

BiologicalTreatmentFacilities D

isin

fect

ion

Wet-Weather Auxiliary Treatment

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

QXS1

Dis

infe

ctio

n

Same as previous slide, except flow split is after preliminary treatment.

Prel

imin

ary

Trea

tmen

t

Flow

Con

trol

B&V - 22


Wet-weather events lend themselves to a parallel auxiliary treatment strategy

Complement the inherent wet-weather limitations of biological processes

Auxiliary treatment facilities optimized for wet weather influent

Enable POTW to achieve secondary treatment effluent quality during both dry and wet weather

Biological Treatment Facilities

River

Auxiliary Treatment Facilities

Qpeak

~2Qavg

QXS

August 5, 2010B&V - 23


What are “auxiliary treatment facilities”?

Permitted use implied at 40 CFR 122.41(m)(4)(i)(B)

Wet-weather influent characteristics are amenable to advanced physical or chemical treatment and not optimal for biological treatment.

USEPA (2008), Emerging Technologies for Wastewater Treatment and In-Plant Wet Weather Flow Management, EPA 832-R-06-006

USEPA (2007), Wastewater Management Fact Sheet, In-Plant Wet Weather Peak Flow Management, EPA 832-F-07-016

WEF (2006), Guide to Managing Peak Wet Weather Flows in Municipal Wastewater Collection and Treatment Systems

USEPA (2004), Report to Congress, Impacts and Control of CSOs and SSOs, EPA 833-R-04-001

B&V - 24


Some perspective on auxiliary treatment technologies…

Conventional Sedimentation + DisinfectionLong understood by POTWs to generally support CWA and codified secondary effluent quality (40 CFR 133)General consensus among scientists and engineers in the treatment profession. Perhaps some site specific exceptions.Supported by USEPA 1994 CSO Control Policy

Today’s Advanced HRT AlternativesBuilt upon proven physical/chemical mechanismsProduce very high quality wet-weather effluentSmall footprint…high capacity

B&V - 25


High-Rate Treatment Technologies

High-Rate Treatment Technologies

Today’s advanced physical or chemical technologies were not envisioned by the

NPDES program when “blending” or “bypassing” was defined.

Today’s advanced physical or chemical technologies were not envisioned by the

NPDES program when “blending” or “bypassing” was defined.


Auxiliary treatment facilities generally consist of multiple process units

Influent or Effluent Pumping

Screening

Grit Removal

BOD & TSS Removal

Effluent Disinfection

Solids Handling

Considerations

Various technology and design

alternatives for each process unit

B&V - 27


Effluent DisinfectionEffluent Disinfection


Effluent Disinfection Alternatives Include…

Chlorination

Gas vs. HypochloriteOnsite generation?

UVLow Pressure High Output

Medium Pressure

Open Channel

Closed Vessel

Other? O3, ClO2, PAA, BCDMHB&V - 29


BOD & TSS RemovalBOD & TSS Removal


Many of today’s HRT technologies weren’t available when NPDES regulations were formed

Sedimentation(a.k.a. Clarification)

Filtration

Conventional

Chemically Enhanced

Lamella Settlers

Sludge Recirculation

Ballasted Floc

Shallow Sand

Deep Sand

Cloth Media

Compressible Media

HRCHRF

High-Rate Treatment

(HRT)B&V - 31


Conventional Sedimentation

Also known as:

Primary Clarification

Settling

Gravity Settling

Primary Treatment

B&V - 32


1500 BC - Alum coagulation by Egyptians

1740 AD - Chemical sewage treatment in Paris

Today – a.k.a. CEPT (Chemically Enhanced Primary Treatment) or CEC (Chemically Enhanced Clarification) or CES (Chemically Enhanced Settling or Sedimentation)

Chemically enhanced sedimentation continues to prove its effectiveness

NoChemicals

AfterChemical

Dosing

FinalEffluent

2007 CEPT Trials at 75th & Nall PEFTF

B&V - 33


The 4 Basic Steps of CEPT

Step 1 – Coagulant Addition: Rapid mixing of metal salt and/or cationic polymer.

Step 3 – Flocculation: Low turbulence to agglomerate particles into floc.

Step 4 – Settling: Quiescent zone to separate floc from clarified effluent.

Turbulence

Step 2 – Flocculant Addition: Rapid mixing of anionic polymer. If ballast or other measures also taken, CEPT HRC.

B&V - 34


What are we trying to do with coagulants and flocculants?

Most particles in water tend to have a negative surface charge.

Coagulants result in cations adsorbing to particle, canceling repulsive forces.

Flocculants help to compensate for coagulant overdosing and imperfect flocculation conditions. Glue particles together into a floc. “Sweep floc coagulation”

-

--

--

--

--

--

--

-- - -

--

--

--

--

--

--

-- -Repulsion

----

--

- --

- --

-

-- -

--

- ---

- --

+

+

++

+

+

+

++

+

+

+

+

+

++

+

+

--

--

--

--

-

- --

-

--

-

--

--

--

- --

B&V - 35


CEPT can be implemented different ways

2°Peak

Q

River

2 – 2.5 Avg Q

DisinfectHead-works

Coagulant

DisinfectCEPT

Flocculant

1°

Additional CEPT Facilities

CEPT with Existing Facilities

2°Peak

Q

River

2 – 2.5 Avg Q

1° DisinfectHead-works

Coagulant

Flocculant

“Split Treatment”concept.

Potential enhancement for existing peak flow clarifiers.

B&V - 36


Sludge Recirculation and Ballasted Flocculation

Same chemical enhancements as CEPT, but:

Use lamella settlers to decrease settling tank footprint

Recirculate solids to further enhance flocculation

Add ballast or other mechanism to create denser floc

Generally higher chemical dose than CEPT, but not always

Also known as Chemically Enhanced High Rate Settling, Ballasted Flocculation (and others).

B&V - 37


HRC - Ballasted Flocculation (Sand)

CSO/SSO43 worldwide, 15 U.S. (July, 2008)

1 2 3 41 2 3 4

B&V - 38


HRC - Ballasted Flocculation (Magnetite)

CoMagTM

B&V - 39

MagSep


Lawrence, Kansas Excess Flow Treatment Upgrades

Main WWTP

Splitter/Screening Facility

Chemical Feed Facility

Actiflo® Treatment Basins

Chlorine Contact BasinDechlorination Basin

(Shared)

XS Flow

XS Flow Pump Station

B&V - 40


Lawrence Wet Weather Flow Schematic

65mgdWWTP

Course Screening

SodiumBisulfite

Splitter / Screening

Facility

25mgd

40 mgd

65mgd

20mgd

20mgd

ACTIFLO

Chlorine ContactBasin

Ferric ChlorideSodiumBisulfite

Sludge Sludge/Microsand

Microsand

FineScreening

Polymer

Kansas River

Main WWTP

Course Screening

Splitter / Screening

Facility

Actiflo® Units

Chlorine ContactBasin

Ferric Chloride

Sludge Sludge/MicrosandMicrosand

FineScreening

Polymer

Excess Flow Treatment

95 ML/d(25 mgd)

246 ML/d(65 mgd)

151 ML/d(40 mgd)

75.7 ML/d(20 mgd)

246 ML/d(65 mgd)

B&V - 41


Lawrence Wet Weather Flows

0

5

10

15

20

25

30

35

40

45

50

55

60

65A

ug-0

3N

ov-0

3Fe

b-04

May

-04

Aug

-04

Nov

-04

Feb-

05M

ay-0

5A

ug-0

5N

ov-0

5Fe

b-06

May

-06

Aug

-06

Nov

-06

Feb-

07M

ay-0

7A

ug-0

7N

ov-0

7Fe

b-08

May

-08

Aug

-08

Nov

-08

Feb-

09M

ay-0

9

Flow

, mgd

0

20

40

60

80

100

120

140

160

180

200

220

240

Flow

, ML/

d

Total Plant Influent (Hourly Average)Annual Average Total Plant Influent

B&V - 42


Lawrence Wet Weather Influent TSS

0

50

100

150

200

250

300

350

400

450

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70Run time, hrs

Con

cent

ratio

n, m

g/L

30-Aug-03 13-Sep-03 4-Mar-0410-Mar-04 13-May-04 25-May-042-Jul-04 7-Jul-04 16-Jul-0426-Jul-04 27-Jul-04 29-Jul-0417-Aug-04 18-Aug-04 24-Aug-0428-Aug-04 8-Oct-04 5-Jan-057-Feb-05 13-Feb-05 13-May-051-Jun-05 3-Jun-05 11-Jun-0512-Jun-05 13-Aug-05 20-Aug-0526-Aug-05 23-Sep-05 20-Oct-0530-Apr-06 1-May-06 28-Aug-0622-Mar-07 12-Apr-07 14-Apr-076-May-07 19-Jun-07 30-Jun-074-Oct-07 17-Oct-07 18-Oct-0717-Feb-08 3-Mar-08 17-Mar-0819-Mar-08 9-Jun-08 13-Jun-0813-Sep-08 8-Mar-09 27-Apr-0930-Apr-09 16-May-09

B&V - 43


Lawrence Wet Weather Effluent TSS

0

10

20

30

40

50

60

70Se

p-03

Mar

-04

May

-04

Jul-0

4Ju

l-04

Jul-0

4A

ug-0

4A

ug-0

4Ja

n-05

Feb-

05Ju

n-05

Jun-

05A

ug-0

5A

ug-0

5O

ct-0

5M

ay-0

6A

pr-0

7M

ay-0

7Ju

n-07

Oct

-07

Feb-

08M

ar-0

8Ju

n-08

Sep-

08A

pr-0

9M

ay-0

9Volu

me-

Wei

ghte

d Ev

ent A

vera

ge C

once

ntra

tion,

mg/

L

HRC Effluent TSSOverall POTW Effluent TSSNPDES Permit Weekly Average TSS Limit

FeCl3 contaminated with ferrous iron (Fe2+)

B&V - 44


0

20

40

60

80

100

120

140

160Se

p-03

Mar

-04

May

-04

Jul-0

4Ju

l-04

Jul-0

4A

ug-0

4A

ug-0

4Ja

n-05

Feb-

05Ju

n-05

Jun-

05A

ug-0

5A

ug-0

5O

ct-0

5M

ay-0

6A

pr-0

7M

ay-0

7Ju

n-07

Oct

-07

Feb-

08M

ar-0

8Ju

n-08

Sep-

08A

pr-0

9M

ay-0

9Volu

me-

Wei

ghte

d Ev

ent A

vera

ge C

once

ntra

tion,

mg/

L

HRC Effluent COD

Overall POTW Effluent COD

Lawrence Wet Weather Effluent COD

52 events in 70 months of operation.

Coordinated operation of HRC and activated sludge trains always achieved NPDES permit limits.

Handled wet-weather peak flows >6 times annual average flow.

Don’t extrapolate AS performance too far. It was protected by HRC from upset.

B&V - 45


Lawrence WWTP Monthly Average Results

0

5

10

15

20

25

30

35

40

Jan-0

0Ju

l-00

Jan-0

1Ju

l-01

Jan-0

2Ju

l-02

Jan-0

3Ju

l-03

Jan-0

4Ju

l-04

Jan-0

5Ju

l-05

Jan-0

6Ju

l-06

Jan-0

7Ju

l-07

Jan-0

8Ju

l-08

Jan-0

9Ju

l-09

Efflu

ent C

once

ntra

tion

(mg/

L)

50

55

60

65

70

75

80

85

90

95

100

Rem

oval

(%)

Effluent TSSEffluent BODTSS RemovalBOD Removal

Parallel excess flow treatment system commissioned in summer 2003

B&V - 46


1 2 3 41 2 3 4

HRC - Sludge Recirculation

CSO/SSO11 worldwide, 2 U.S. (July, 2008)

B&V - 47


Excess Flow Treatment at Bay View WWTP (Toledo, Ohio)

232 MGD HRC17 MG

EQ

4 MG EQ 4 MG

EQ

B&V - 48


Toledo DensaDeg HRC System

B&V - 49


BAY VIEW PUMP

STATION

GRITREMOVAL

SKIMMINGSREMOVAL

PRIMARYCLARIFIERS

AERATION BASINS

CHLORINECONTACT

BASIN

SECONDARYCLARIFIERS

EQ BASIN

SCREENING& GRIT

REMOVAL

High Rate Clarification

CHLORINECONTACT

&REAERATION

EFFLUENTPUMPING

636 ML/d(168 mgd)

878 ML/d(232 mgd)

UP TO1514 ML/d(400 mgd)

UP TO738 ML/d(195 mgd)

102 ML/d(27 mgd) UP TO

776 ML/d(205 mgd)

PRIMARYCLARIFIERS UP TO

1514 ML/d(400 mgd)

Bay View WWTP Wet Weather Flow Schematic

B&V - 50


Bay View WWTP Wet Weather Flows

0

50

100

150

200

250

300

350A

pr-0

7

May

-07

Jun-

07

Jul-0

7

Aug

-07

Sep-

07

Oct

-07

Nov

-07

Dec

-07

Jan-

08

Feb-

08

Mar

-08

Apr

-08

May

-08

Jun-

08

Flow

, mgd

0

200

400

600

800

1000

1200

Flow

, ML/

d

Total Plant Influent Daily AverageAnnual Average ~70 mgd

B&V - 51


0

100

200

300

400

500

600

mg/L

1/5/07 1/6/07 1/15/07 1/16/07 3/2/07 4/25/07 4/26/07 6/3/07 6/4/07 8/20/07

Date

Wet Weather Event TSS Concentrations

Influent AS Effluent HRC Effluent

Toledo Parallel Excess Flow Treatment

Better than overstressed activated sludge (1/15 & 4/25)

All under 40 mg/L, all but 2 under 30 mg/L

Consistently achieved permit limits

2007 = 3rd wettest year on record in Toledo

Don’t extrapolate AS performance too far. It was protected by HRC from upset.

B&V - 52


HRF alternatives offer similar TSS & BOD as HRC, but no chemicals required

Schreiber Fuzzy FilterSchreiber Fuzzy Filter

CMF Media

SchreiberWWETCO

2000 BC - Granular filtration in ancient Sanskrit writings

TodayDeep-bed granular mediaCompressible mediaCloth media

Compressed Media Filter

Varies with Filter Cell Size

Varies with Number of Filter Cells

WWETCO Filter

August 5, 2010B&V - 53


Full-scale CMF wet-weather treatment facilities

West Point Lake

GA

AtlantaAtlanta

Columbus, GAColumbus, GA

Chattahoochee River Chattahoochee River WatershedWatershed

Walter F. George Reservoir

www.cleanwateratlanta.org

www.cwwga.org

Atlanta, GAAtlanta, GA

ALGA

FL

August 5, 2010B&V - 54


CMF

August 5, 2010B&V - 55


Columbus LTCP Implementation and Keys to Compliance Success

1990 to 1995: CSO Control Program Development

1996 to 2001: Regional Watershed Studies

2001 to Present Day: Watershed Controls Implementation and DemonstrationsSatellite auxiliary treatment facilities

Monthly monitoring and reporting of events, bacteria, TSS and phosphorous

Demonstration approach. Comprehensive multi-year post-construction watershed monitoring and modeling study and water quality compliance analysis.

Development of science-based frequency criteria for WQS

Impaired water definitions from USEPA Guidance for 2006 Assessment, Listing and Reporting Requirements, p. 67http://www.epa.gov/owow/tmdl/2006IRG/report/2006irg-report.pdf

TMDL evaluation and implementation plan with Georgia reasonable potential analysis. Columbus LTCP has no reasonable potential to violate WQS. CSO control facilities have no numerical effluent limits.

Columbus will be able to show the Chattahoochee River at Columbus is not impaired and request a Record of Decision to be removed from the impaired water classification (next impairment cycle is 2010)

B&V - 56


CMF Media

SchreiberWWETCO

August 5, 2010B&V - 57


CMF – Fuzzy Filter

August 5, 2010B&V - 58


85 mgd Fuzzy Filter at West Area CSO Treatment Facility (Atlanta, Georgia)

August 5, 2010B&V - 59


Compressible Media

Flexible Membrane

Filtered Water Underdrain

Air Supply for Backwashing

Filter Housing

Filter Basin

Backwash TroughsPerforated Plates

CMF – WWETCO

Uncompressed

Compressed

Fill & Compress

Filter Start

Filter EndDrain & Uncompress

Air Scour Backwash

August 5, 2010B&V - 60


CMF Backwash

PHOTO AFTER PRIMARY INFLUENT FILTRATION.

PHOTO NEAR END OF BACKWASH

August 5, 2010B&V - 61


10 mgd WWETCO Filter at Weracoba Creek Stormwater BMP (Columbus, Georgia)

UncompressedFilter Media

Bottom Perforated Plate

Top Perforated

PlateBackwash

Trough

Flexible Membrane

CompressedFilter Media

Compressible Filter Media

Top Perforated Plates

Backwash Trough

Filter Influent

CMF

August 5, 2010B&V - 62


Triple bottom line evaluations of satellite PEFTFs in Johnson County, Kansas…

Belinder Road Peak Excess Flow Treatment FacilityJohnson County, Kansas

Sedimentation and Chlorination Basins

Diversion ChamberElectrical/Controls Fine ScreensPumpsChemicals

Bench-scale (Jar Testing)

HRC: CEPT, ballasted flocculation, sludge recirculation

Full-scale trials

CEPT

August 5, 2010B&V - 63


Dynamic Tangential

Filter Unit

Compressible Media

Filter Unit

Influent Piping

Filter Feed Tank

Fine Screen Unit

Cloth Disc Filter Unit

Influent Sampler

Screenings and Pass-through Piping

…led to side-by-side HRF testing in 2008

August 5, 2010B&V - 64


Influent Characteristics - JCW 2008 Filter Pilot

0

50

100

150

200

250

300

350

40019

-May

21-M

ay

23-M

ay

25-M

ay

27-M

ay

29-M

ay

31-M

ay

2-Ju

n

4-Ju

n

6-Ju

n

8-Ju

n

10-J

un

12-J

un

14-J

un

16-J

un

18-J

un

Con

cent

ratio

n (m

g/L)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Prec

ipita

tion

(inch

es)

Mission Main WWTP Rain Influent TSS (Composite) Influent BOD5 (Composite) Influent Soluble BOD5 (Composite)

PE PI PE PI PE

B&V - 65


Effluent TSS - JCW 2008 Filter Pilot

0

50

100

150

200

250

300

350

400

19-M

ay21

-May

23-M

ay25

-May

27-M

ay29

-May

31-M

ay2-J

un4-J

un6-J

un8-J

un10

-Jun

12-Ju

n14

-Jun

16-Ju

n18

-Jun

Even

t Com

posi

te T

SS (m

g/L)

Influent

Dynamic Tangential Filter Effluent

Cloth Disc Filter Effluent

Compressible Media Filter Effluent

B&V - 66


Wet Weather Treatability Tests (St. Joseph, Missouri Water Protection Facility

Not used during actual wet-weather

conditions

Coarse Screened& Degritted

Influent

Secondary Effluent

Mixing Tee CMFTest Unit

Treated Effluent

Treated Effluent

CEPTTest Unit

HRCTest Unit

CompositeCollection

Tank

Treated Effluent

Collected during CMF test run for CEPT and

HRC jar tests

B&V - 67


April 2009 Wet-weather Treatability Testing (St. Joseph, MO)

Compressible Media Filter Test Unit

UntreatedTreated

B&V - 68


TSS and BOD – St. Joseph, MO (April, 2009)

106

127136

6

2113

27 2635

26

69

12 9 9

33

10

0

20

40

60

80

100

120

140

Untrea

ted (C

MF)Unt

reated

(HRC)

Untrea

ted (C

EPT)

CMF

HRC (ferr

ic) E

fflue

nt

HRC (alum) E

ffluen

t

CEPT (fer

ric) E

ffluen

t

CEPT (alum

) Effl

uent

Con

cent

ratio

n, m

g/L

TSS BOD5

B&V - 69


Effluents were tested for both hypochlorite and UV dose response…

St. Joseph, MO Jar Tests (April 10, 2009)

1

10

100

1,000

10,000

100,000

1,000,000

0 1 3 5 10 15 30Contact Time After 6 mg/L Chlorine Dose (min)

E. C

oli C

ount

(MPN

/100

mL)

CMF CEPT- Ferric CEPT- Alum HRC- Ferric HRC- Alum

126 MPN/100 mL

St. Joseph, MO Jar Tests (April 10, 2009)

1

10

100

1,000

10,000

100,000

0 10 20 40 60 80Collimated Beam UV Dose (mJ/cm2)

E. C

oli C

ount

(MPN

/100

mL)

CMF CEPT- Ferric CEPT- Alum HRC- Ferric HRC- Alum

126 MPN/100 mL

August 5, 2010B&V - 70


Screening and Grit RemovalScreening and Grit Removal


Screening and Grit Removal

Best alternatives are highly site-specific.

Depends upon downstream treatment technologies.

Something like a “rock box” + coarse screens may be fine for conventional processes…but some TSS removal designs need enhanced grit and screenings removal.

Many equipment alternatives to choose from.B&V - 72


Screen Geometry

Reference: Schier etal WEFTEC 2005

B&V - 73


Many grit removal alternatives

Level needed is highly site-specific.

Besides downstream liquids train, remember solids train (digesters, sludge pumps, etc.).

Some screens are sensitive to grit and some grit units are sensitive to screenings.

HeadworksSettling channel, stilling well, “rock box”

Detritus tank

Aerated basin

Vortex separator – hydraulic or mechanically induced

Detritus

B&V - 74


Closing ThoughtsClosing Thoughts


Latest Regulatory Activities2005 draft Peak Wet Weather Discharge Policy

Has not been finalized.2009 - Numerous comments on Draft UA Guidance2010 – EPA public comment period on SSO and Peak Flows Policy

B&V - 76


Source: USEPA, Sanitary Sewer Overflows and Peak Flows Listening Session, June 30, 2010

Many WWTPs also have a grit removal step…sometimes upstream of screening…sometimes downstream…sometimes on primary sludge. Various technology and design alternatives.

Parallel solids treatment processes not shown, but required. Various technology and design alternatives.

Various technology and design alternatives for screening, primary clarification, biological treatment and disinfection depending upon effluent quality goals.

“Secondary Treatment”per 40 CFR 133

Many WWTPs don’t have primary clarifiers. Various design alternatives.

B&V - 77



B&V - 78



B&V - 79



“Secondary Treatment”per 40 CFR 133

This is “auxiliary treatment”…not “bypass”…not “blending”. Various technologies and design alternatives depending upon effluent quality goals.

B&V - 80


Holistic view is needed to stay focused on sustainable water quality protection

Primary Treatment Secondary Treatment

BulkSolids

Removal

BiologicalProcess


BulkSolids

Removal

BiologicalProcess



Excess Flows

SecondaryTreatment

Optional

40 CFR 133.102Secondary Treatment ≠ 100% Biological Treatment. It just so happens that biological treatment has proven to be the optimal technology for dry-weather influent characteristics.

40 CFR 122.41(m)Intended to prevent taking units out of service unnecessarily during dry weather (i.e. lower level of treatment).

Never intended to prevent from bringing additional units into service to provide higher level of treatment during wet weather.

Auxiliary treatment facilities are simply another treatment train within the overall secondary treatment boundary. Uses technologies optimized for wet-weather influent characteristics.

1994 CSO Control Policy does not even require “secondary treatment” of excess flows

B&V - 81


Potential regulatory disconnects without holistic view…

August 5, 2010

River

QpeakFlow

Control

QXS2


isin

fect

ion

Prel

imin

ary

Trea

tmen

t


Floa

tabl

esR

emov

al

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

QXS1Flow Control

River

QpeakFlow

Control

QXS

QXS2


isin

fect

ion

Prel

imin

ary

Trea

tmen

t

QXS1


Floa

tabl

esR

emov

al

BO

D &

TSS

Rem

oval

Dis

infe

ctio

n

Flow Control

Parallel auxiliary wet-weather treatment approach is allowed and encouraged by the 1994 CSO Control Policy…

…but integrating the same or higher levels of water quality protection into a WWTP is discouraged by recent interpretations of the 2005 draft Peak Flow Discharge Policy.

B&V - 82


Summary and Conclusions

Sewer systems will always have significant wet weather peaking factors.

The 2005 proposed Peak Wet Weather Discharge Policy has not been enacted…EPA considering new SSO and Peak Flows Policy rulemaking.

Clean Water Act regulations focus on dry-weather and have not established science-based wet weather water quality criteria, treatment standards or effluent limitations

Floatables, solids and biological pathogens are the primary pollutants of concern

Auxiliary treatment of excess flows with physical or chemical technologies is a proven and sound approach

B&V - 83


For Additional Information…

Jim FitzpatrickWet Weather Treatment [email protected]

Larry JaworskiWet Weather Practice Leaderand Former WEF President

[email protected]

Matt BondWastewater Treatment Practice

[email protected]

B&V - 84

Mike OrthClient Account ManagerLower [email protected]


DiscussionDiscussion

- 2

Creek

Effluent from Activated SludgeFacilities at POTW

Effluent from Peak Wet-WeatherLagoons at POTW

B&V - 85


ExtrasExtras


Parallel excess flow treatment ≠ bypass (cont’d)

Diversion involves decreasing flows. Parallel treatment concept does not decrease flows to any

portion of the treatment facility. We are increasing flows to all portions

of the treatment facility.

40 CFR 122.41(m)(1)(i)



The use of auxiliary treatment facilities is a feasible alternative

to a bypass; therefore, using them can’t be a bypass

40 CFR 122.41(m)(4)(i)(B)



Parallel excess flow treatment is not bypass, but does provide

essential maintenance of biomass to assure efficient operation.

40 CFR 122.41(m)(2)


Biological treatment probably has many more unknowns than other technology alternatives

Filtration2000 BC - Granular filtration in Greece and IndiaToday - Particle size distribution data or pilot trials to confirm solids loading rates, hydraulic loading rates, backwash frequencies, etc.

Sedimentation1500 BC - Alum coagulation by Egyptians1740 AD - Chemical sewage treatment in ParisToday - Jar tests to optimize chemicals. Pilot and full-scale stress tests to confirm design SOR for CEPT.

BiologicalEarly 1900’s - First activated sludge WWTPsToday - Wet-weather capacity is inherently inexact. Many, many variables affect biomass behavior.

Site-Specific R&D

Process R&D

KDHE Annual Water & Wastewater School 11/04/2009B&V - 91

High-Rate Contact Stabilization Concept

Activated Sludge System

Receiving Stream

CEPT,HRC, HRF, DAF, etc.

~2Qavg

BioContact

RAS Sludge/Backwash

Ye olde contact stabilization configuration of activated sludge…with high-rate solid/liquid separation technologies.

Another parallel auxiliary treatment strategy.

QXS

Qpeak


Potential R&D needs for high-rate contact stabilization concept

Actual wet-weather influent (vs. surrogate influent).

Repeatable results from site to site?

Concerns about extrapolating and generalizing results based on statistically small dataset.

Is claimed biological uptake significant?

Conventional “soluble” BOD includes colloidal fraction largely removed by advanced phys/chem.

What about adsorption onto hydrous metal complexes similar to the latest thinking on chemical phosphorus removal?


Potential R&D needs for high-rate contact stabilization concept (cont’d)

Capacity of available biomass must be considered.Any added risk to biomass health?

What about BNR bugs or unintended inhibition to BNR processes?

May not be able to truly assess biomass impacts without auxiliary treatment facilities at same scale as dry-weather activated sludge facilities.

Piloting to date limited to activated sludge operated in contact-stabilization mode.

What about fixed-film (TF, MBBR, IFAS, BAF, SAF)?

What about other AS operating modes or configurations?

Any significant water quality benefits to warrant the significant additional complexity and expense above and beyond today’s advanced physical/chemical alternatives?

wet weather flows 2010...kdhe annual water & wastewater school august 5, 2010 wet-weather flows...

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