WORK SHOP TO MUNICIPAL COMMISSIONERS & MUNICIPAL ENGINEERS

ONCONSTRUCTION OF TOILETS IN URBAN AREAS DATE :

02-05-2015

SWACHHA ANDHRA CORPORATION SWAC

HHAANDH

RA

INTRODUCTION The GoI have issued Swachh Bharath guidelines for total sanitation

by construction of Individual Household Toilets and Community Toilets as per need.

GoAP is formed a Swachh Andhra Pradesh Corporation for implementation of construction of toilet programmes for the Urban households who are not having toilet facility, to eradicate open defecation and to improve sanitation in the urban area.

In this connection Technical guidelines are herewith prepared for the Municipal Commissioners and Municipal Engineers who will play major role in the implementation of the programme.

SWACHHA

ANDHRA

I. TECHNICAL OPTIONS The following are the various options for construction of New IHHTs as per Swachh Bharath Mission guidelines issued by GoI.

IHHT WITH TWIN PIT LATRINES / LEACH PITS

IHHT WITH SEPTIC TANK

BIO-DIGESTER TOILET (DEVELOPED BY DRDO)

BIO TANK / BIO TOILTES (PATENTED BY PRIVATE OPERATORS AND APPROVED BY THE DEPARTMENT OF SCIENCE & TECHNOLOGY)

SWACHHA

ANDHRA

TECHNICAL OPTION - I IHHT WITH TWIN LEACH PITS

Description: It consists of superstructure (Toilet) and treatment units (two chambers). The two underground chambers (pits) are provided to hold fecal sludge. These are normally offset from the toilet and should be at least 1 meter apart. A single pipe leads from the toilet to a small diversion chamber, from which separate pipes lead to the two underground chambers. The pits should be lined with open jointed brick work/ concrete rings

Specifications: i. Size options for Toilet/ Super Structure 750 mm x 900 mm x 1900mm; or 800 mm x 1000 mm x 1900 mm ii. Material : Brick work / FRP/ Pre-cast Cylindrical Unit

iii. Minimum Land Requirement : 40 Sq. ft. - 60 Sq. ft. (Depending upon the location of superstructure and distance between two pits)

SWACHHA

ANDHRA

SWACHHA

ANDHRA

900 115900 115115 1151000

900

115115

600

115

115

750

1130

Junction / Inspection chamber

SWACHHA

ANDHRA

7

SWACHH

A

ANDHRA

SWACHHA

ANDHRA

TECHNICAL OPTIONS - II

IHHT WITH SPETIC TANK

Description:

A septic tank is a buried chamber that collects, stores and treats the wastewater under anaerobic conditions. Effluent from septic tanks should be discharged into a soak pit. A well-managed septic tank will remove about 50 to 60 % of the biological load in the wastewater

Specifications:

i. Size options for Toilet/ Super Structure 750 mm x 900 mm x 1900mm; or 800 mm x 1000 mm x 1900 mm

ii. Material : Brick work / FRP/ Pre-cast Cylindrical Unit

iii. Minimum Land Requirement : 40 Sq. ft. - 60 Sq. ft. (Depending upon the location of superstructure)

SWACHHA

ANDHRA

iv. Soak-Pit Size :

The seepage pit may be of any suitable shape with the least cross- sectional dimension of 0.90 m and not less than 1 m in depth below the invert level of the inlet pipe. The construction shall be of perforated brickwork.

v. Size of Pits is shown in Table -1 below :

. *- only for IHL, **- Group household toilets

2 years 3 years5* 1.5 0.75 1 1.05

10** 2 0.9 1 1.415*** 2 0.9 1.3 220*** 2.3 1.1 1.3 1.8

No. of Users Length Breadth

Liquid depth (m)(Cleaning interval of)

SWACHHA

ANDHRA

Note 1 : The capacities are recommended on the assumption that discharge from only WC will be treated in the septic tank.Note 2: A provision of 300 mm should be made for free broad.Note 3: The sizes of septic tank are based on certain assumption on peak discharges, as estimated in IS: 2470 (part 1) and while choosing the size of septic tank exact calculations shall be made. Cost (for 5 Users) :

Tentative cost varies from Rs. 25,000/- to Rs. 30,000/- depending upon the construction material (toilet & septic tank). Pre fabricated septic tanks are available at lower cost in the market, which also may be explored to speed up the implementation.

SWACHHA

ANDHRA

SWACHHA

ANDHRA

TECHNICAL OPTION - III

BIODIGESTER TOILET (DEVELOPED BY DRDO)

Description:

A bio-digester toilet is an anaerobic multi-compartment tank with inoculums (anaerobic bacteria) which digests organic material biologically. The details of bio-digester toilets are shown in Figure . This system converts faecal waste into usable water and gases in an eco- friendly manner.

Specifications: i. Toilet Superstructure: Size of Toilet / Superstructure as shown in Fig.1 750 mm x 900 mm x 1900mm; or 800 mm x 1000 mm x 1900 mm ii. Material : Brick work (as per Fig. 1) / FRP/ Pre-cast Cylindrical Unit

SWACHHA

ANDHRA

iii. BIO Tank :

Land requirement - 25 Sq. ft. Tank internal dimensions – 1336mm x 1036 mm x 900 mm Diagonal partition wall of 8mm thickness (adequately stiffened by ribs) Tank is buried 600mm deep and anchored by 300mm long stainless steel(SS316) anchor bolts at corners FRP tanks of 8mm thickness. Provision of water sealed outlet from the tank. For 5-6 users: o- Total capacity: 700 liters (1000 mm x 700 mm & 1000mm depth). Where space is a constraint the depth of the tank can be increased to 1.5m o- Volume of anaerobic Compartment (30% of total capacity): 210 ltr o- Tank may be constructed with masonry also.

SWACHHA

ANDHRA

Table -3 Volume of bio-digester tank for various user groups:

Bio-digester tank as per Table-4 below

*- Group / Shared toilets

Toilet cost between Rs.12,000 and Rs. 15,000 depending on material of construction.

No. of users Size of bio-digester / bio-toilet Remarks

4-8 (Single family) 0.7m3 (FRP / RCC material) Individual

8-15 (two families) 1.2 m3 (FRP / RCC material) Group / shared

30-50 3.2 m3 (FRP / RCC material)

100-120 6.0 m3 (FRP / RCC material)

200-220 12.0 m3 (FRP / RCC material)

500-600 30.0 m3 (FRP / RCC material)

Community

No. of users / Capacity

MasonryPrecast

Cylindrical Unit

Fiber reinforced

Plastic

Bio-digester tank

5 to 7 users (700 Litre)

10 to 12 users (1000 Litre)*

Material of construction

17,100 11,600 22,000

19,000 13,600 24,000

SWACHHA

ANDHRA

SWACHHA

ANDHRA

TECHNICAL OPTION - IV

BIO TANK / BIO TOILETS (PATENTED BY PRIVATE

OPERATORS AND APPROVED BY THE DEPARTMENT OF SCIENCE & TECHNOLOGY)

Description:

This technology differs from that of the bio-digester toilets developed by DRDO since the process adopted is aerobic - which involves a different multi-strain of bacteria which breaks down the waste matter through oxidization. Bio-toilets consist of a purpose built multi chambered bio- tank in which the waste is stored

Specifications: i. Toilet Superstructure: Size of Toilet / Superstructure as shown in Fig.1 750 mm x 900 mm x 1900mm; or 800 mm x 1000 mm x 1900 mm ii. Material : Bricks and Mortar walls of Bio Digester tank and Superstructure, PCC tank floor, RCC Toilet Floor, PVC Door and Frame, RCC/PVC/GI sheet Toilet Roof.

SWACHHA

ANDHRA

iii. The Bio-Toilet System consist of : Bio digester Tank(Bricks & Mortar/FRP/Steel). Superstructure (Bricks * Mortar/FRP) Indian Pan/WC

Size: 4 feet x 4 feet tank base, 4 feet tank height , 6 feet superstructure height Maximum usage recommended : 30 defecations / day/bio-toilet (no limit on urination) Land Requirement – 16 Sq.ft.

Cost Estimates :

The Tentative cost of bio-toilet including super structure is approximately Rs.20,000/- depending upon the construction material.

The bio-toilets should be supplied by the manufacturers and the O&M for at least 5 years along with IEC by the manufacturer/supplier also should be built into the under taking

SWACHHA

ANDHRA

SWACHHA

ANDHRA

20

Concept of IHHT with Twin Pits

Pour-flush toilets linked to twin-pits (also

called Twin-pit Pour-flush (TPPF)) toilets

are improved pit latrines, allowing on-site

treatment and transformation of the

faecal sludge into a hygienised soil

amendment.

They are semi-dry toilet systems (not

linked to a piping system, but require

water for flushing).

Different models of different prices exist.

They require generally little

maintenance but due to the need of the

construction of two pits, initial

investment costs can be little high.

SWACHHA ANDHRA

21

A simple pour-flush squatting platform (porcelain or cement).

A water seal as a barrier for odour and flies

Set into a brick and concrete based.

The outlet is piped to a Y junction box.

From the box the blackwater (faeces, flush water, cleansing water) are directed to one of two shallow (leach or soak pits)

Pits are used in alteration

A superstructure is added for privacy and can be constructed from a wide range of locally available materials.

Water seal

Removable cover

Superstructure

Sewer junction (outlet blocked for unused pit)

Door

Leach pit / soak pit

Pit full. Sludge safe for

removal after two years

Pit in use

SWACHHA ANDHRA

22

Pits are lined with porous material: water infiltrates locally into the soil, solids (faeces) remain in the pits and are decomposed (by a mixed composting/digestion process).

The two pits are used in alteration: while one pit is filling, the other pit remains out of service.

When the first pit is full, it is covered and temporarily taken out of service.

When the second pit is full, the first pit is re-opened and emptied.

It should take a minimum of two years to fill a pit and during that time, the faeces in the pit out of service can continue to decompose.

The treated sludge can be used as solid fertiliser (i.e. humanure).

SWACHHA ANDHRAHow does it work

23

SWACHHA ANDHRA

24

Schematic overview of pour-flush toilet with two alternating leach pits made out of brick work

Source: MARA (1985)

SWACHHA ANDHRA

25

Leach pits made out ofbricks (much like a honeycomb) and perforated concrete

SWACHHA ANDHRA

26

Twin-Pit Pour-Flush Toilet

The pour-flush squatting pan consist

of a steep bottom slope and a water

seal trap.

From there, faeces and flushing water

is directed to one of two leach pits.

An inspection chamber containing a Y

junction is normally built between the

pits and the pan so that the excrete

can be channeled into either pit.

Each pit is designed to last for about

three years before it gets filled; filling

time is should be 2 years for all

pathogens to die off.

3. Design Principals

Pour-flush Toilet (Twin-pit Model)

SWACHHA ANDHRA

27

Pits location

If site conditions do not permit this layout, the pits can be placed on the side or even in front of the pan as shown, but this results in more water needed for flushing.

Toilets can be constructed inside the house, while the pits can be situated outside the house.

To remain accessible, pits should be constructed in open ground. But if no space is available, they can also be constructed below the toilet.

In cases where there is no space close to the toilet leach pits could be located even 15 metres away from the latrine cubicle provided the connecting pipe is laid at a slope of 1:5:1 to 15.

Pits should not be situated in drainage lines or the paths of storm water drains to prevent cross-contamination.

The pits should not be located in depressions where water is likely to collect.

The pits be constructed over 1 m from any structural foundation as leachate can negatively impact structural supports.  

3. Design Principals SWACHHA ANDHRA

28

Use Maintain correct squatting position so as excreta fall in the

center of the trap opening

Flushing and anal cleansing with 1.5 to 2 L, so that the excreta slide smoothly without sticking to the surface.

Operation and Maintenance (O&M)

Day-to-day maintenance

Washing the latrine floor.

Cleaning the squatting pan (brush with a long handle).

Only little water should used for cleaning and washing to reduce pit filling.

Bath, kitchen or rain water should not be added in large volumes because this would cause overflow of the pit

Solid waste (kitchen waste, sweepings etc.) should not be added as this would cause clogging

SWACHHA ANDHRA

29

Pit alternation

Every two years

The inspection chamber is opened and one of the pipes in the Y junction is stopped off ,while the other one is opened. A brick, stone, mound of clay or block of wood cam be used as stopper .

The pit is re-sealed to prevent gases escaping to the atmosphere.

About 15 cm of soil should be filled in the bottom of the first pit when before use.

After two years of rest, soil will be safe for handling, dry and without any foul smell. It can be dug out manually and used as soil amendment in kitchen gardens or field.

In case of humid sludge, it can be spread out and dried under the sun

The twin pits can be used indefinitely.

Long-term support facilities to remind and assist the user in changing and emptying pits will greatly improve operational success 

Operation and Maintenance (O&M)SWACHHA ANDHRA

30

Where water for flushing and anal cleansing is available

In areas with soils of soil good absorptive capacity (alleviates, silt ); Tightly packed or rocky soils (clay) are not appropriate.

Low groundwater tables, low risk of flooding.

Depending on soil conditions, a certain minimum vertical distance from the bottom of the pit to the groundwater is required to prevent its pollution.

If soil conditions are full-filled and water for flushing available, TPPFs can be constructed in both, rural and urban housings, but to many pits in dense housing areas will cause groundwater pollution and overflow as soil matrix may not can absorb all the water.

Applicability

Groundwater

SWACHHA ANDHRA

SWACHHA ANDHRA

SWACHHA ANDHRA

II. NORMS & SPECIFICATIONS FOR COMMUNITY AND PUBLIC TOILETS

Description: Community toilet block is a shared facility provided for a group of residents

or an entire settlement. Community toilet blocks are used primarily in low-income informal settlements where space and/or land are constraints. Pour flush option is generally used in this kind of OSS systems. It is also advisable to provide facilities like washing, bathing, and a small incinerator in this block for the use of the community.

Public toilets are provided for the floating population /general public in places such as markets, rain stations or other public areas, where there is a considerable number of people passing by.

SWACHHA

ANDHRA

Septic tanks for Public / Community toilets:

Recommended sizes of septic tanks for community / public toilets (up to 300 users) is given in Table 5 below

Source : Manual on Sewerage and Sewage Treatment Systems, 2013 Part A EngineeringNote 1 : A provision of 300 mm should be made for free broad. Note 2 : The sizes of septic tank are based on certain assumption on peak discharges, as estimated in IS: 2470 (part 1) and while choosing the size of septic tank exact calculations shall be made.Note 3 : For Population over 100, the tank may be divided into independent parallel chambers of maintenance and cleaning.

2 years 3 years50 5 2 1 1.24

100 7.5 2.65 1 1.24150 10 3 1 1.24200 12 3.3 1 1.24300 15 4 1 1.24

No. of Users

Length BreadthLiquid depth (m)

(Cleaning interval of)

SWACHHA

ANDHRA

Community Toilet – Norms for toilet seats

One seat for 35 men, one seat for 25 women, adequate bathing

facilities

Public Toilets – Norms for toilets seats:

3 UrinalsOne for 50 persons or part

thereofNil

2 Ablution Taps One in each W.C One in each W. C

4 Wash basinsOne per W. C. and urinal

providedOne per W. C. provided

S. No.

Sanitary Unit For Male For Female (A)

1 Water Closet

Two for 100 persons up to 200 persons; over 200 persons,

add at the rate of one per 100 persons or part thereof

One per 100 persons up to 400 persons; For over 400 persons, add at the rate of

one per 250 persons or part thereof

SWACHHA

ANDHRA

III. PRE-CONSTRUCTION ACTIVITY :

The Commissioners/ Municipal commissioners concerned shall prepare a day wise plan immediately after completion of the state level training programme scheduled on 1st and 2nd of May for verification of applications immediately in a week i.e., 3 rd to 10th of May with the help of Municipal Engineer.

After launching of the programme on 11th May the Commissioners/ Municipal commissioners shall direct the Municipal Engineers concerned to plan for procurement of required material like cement, bricks, sand, chips, RCC rings etc., well in advance i.e., atleast one week in advance (i.e., 23 rd May) for the foundation stone to be laid by Hon’ble Chief Minister of Andhra Pradesh of 1st or 2nd of June, to avoid delay in construction work.

The Commissioner/Municipal Commissioners shall plan and direct the Municipal Engineer to complete the entire target of IHTs by the end of June at any cost.

SWACHHA

ANDHRA

The Municipal Engineer shall collect the list of beneficiaries from their respective Commissioners /Municipal Commissioners and arrive the total no. of Individual House hold toilets to be constructed.

The total materials required for the completion of total IHTs in the respective Corporation or Municipality shall be assessed and can be estimated in the following manner for a toilet of size 750mm x 900mm with 2 pit system.

Engineer shall guide and facilitate the SLFs in procurement of material by i) identification of reputed material suppliers / agencies ii) grouping the no nearby SLFs so that the overheads like transportation etc. will reduce.

The Engineer shall advise the beneficiary/SLF to adopt suitable foundation as per the soil condition.

The municipal Engineer shall inspect the site of construction and shall Geo-tag the vacant site before construction.

SWACHHA

ANDHRA

1 2 3 4 5 6 5

1 Earth work 3.26 Cum 1 3.26 4802 40 metal 0.26 Cum 1 0.26 3423 Sand 0.32 Cum 1 0.32 2854 Cement 2 Bags 1 2 570

5In case of RR stones for basement 24 Nos 1 24 480

6 RCC Rings 8 Nos 1 8 22007 Labour charges 1787

Note:

For basement, Bricks (Burnt clay / Cement/ Fly ash /FAL-G)can also be utilized.Sub Total 6144

1 Sand 0.82 Cum 1 0.82 7802 Cement 2 Bags 1 2 570

4 Labour charges 1357Sub Total 4681

1 W.C. pan&P trap 1 Nos 1 1 560

3Connection pipe (PVC/HDPE/SWG) 4 Mtrs 1 4 335

4

Roof (AC sheet /FRC sheet/Polished shabad stone) 560

5

Door (MS shutter with MS frame / Solid board shutter with readymade RCC frame or any other) 1 Nos 1 1 545

6CI cover for junction chamber 1 Nos 1 1 175

7 Cement Jally 1 Nos 1 1 55

8Re-cast RCC cover per Twin pit 2 Nos 1 2 350

9Tap & Water supply pipe LS 350

10 Labour charges 1245Sub Total 4175

Grand Total 15000

Completion stage:

Bricks ( Burnt clay / Cement/ Fly ash/FAL-G

Total Amount Required (approx.)

Up to Basement stage:

Superstructure:

3 420 Nos 1 420 1974

S.No ItemQuantity per Unit

UnitTotal No of

toilets assessed

Total Quantity Required

IV. ACTIVITY DURING-CONSTRUCTION

Marking shall be given by the Municipal Engineer and shall inspect the construction activity at random at regular intervals.

He shall geo-tag the photograph of construction i) after completion of basement ii) completion of super structure.

Simultaneously, he may deploy the local Engineering’s/Engineering students engaged by the respective Commissioners for supervision.

He shall guide the SLFs in the construction procedure and also shall guide the mason(s) as and when required.

Procurement of material by i) identification of reputed material suppliers / agencies ii) grouping the no nearby SLFs so that the overheads like transportation etc. will reduce.

SWACHHA

ANDHRA

V. POST-CONSTRUCTION ACTIVITY :

He shall geo-tag the photograph of completion (of Roof and fixing of door and WC pan).

He shall inspect the functionality of the toilets after usage by the beneficiaries.

In case any defects are noticed, he shall guide them for rectification.

SWACHHA

ANDHRA

VI. RECORDING AND PAYMENT SYSTEM

In case of construction taken up by the SLFs:

a) After capturing of vacant site photograph though Geo-Tagging an amount of Rs.5000/- for each beneficiary shall be released to the respective SLF as 1st installment of release. The Asst. Engineer /Asst. Executive Engineer shall record that proceedings in the M.Book as the advance payment.

b) The Asst. Engineer /Asst. Executive Engineer shall record the M. Book after completion of basement level including Geo-tagging the photograph and recommend for payment for release of 2ndinstallment of Rs.5000/- as per the regular procedure of recording in regular engineering departments.

c) The Asst. Engineer /Asst. Executive Engineer shall record the M. Book after completion of toilet in full shape including Geo-tagging the photograph and recommend for payment for release of 3rdinstallment of Rs.5000/- as per the regular procedure of recording in regular engineering departments.

SWACHHA

ANDHRA

In case of construction taken up by the Individual Beneficiaries: The Asst. Engineer /Asst. Executive Engineer shall record the M.

Book after completion of basement level including Geo-tagging the photograph and recommend for payment for release of 1st installment of Rs.5000/- as per the regular procedure of recording in regular engineering departments.

The Asst. Engineer /Asst. Executive Engineer shall record the M. Book after completion of super Structure (up to roof level) including Geo-tagging the photograph and recommend for payment for release of 2nd installment of Rs.5000/- as per the regular procedure of recording in regular engineering departments.

The Asst. Engineer /Asst. Executive Engineer shall record the M. Book after completion of toilet in full shape including Geo-tagging the photograph and recommend for payment for release of 3rd installment of Rs.5000/- as per the regular procedure of recording in regular engineering departments.

SWACHHA

ANDHRA

METHOD OF CONSTRUCTION IN

DIFFERENT SOILS

Type I : Steps for construction of toilet in hard soils 1. Earth work excavation of 1’-3” to 1’-6” depth is advised.2. PCC (1:5:10) or (1:4:8) base concrete with 40mm metal of 0-4” thick is

proposed.3. 8” or 9” width cement blocks/clay bricks/RR stone may be used for

construction up to ground level (apply: to height of 0-11” to 1’-2” is proposed).

4. Above ground level again 8” or 9” width cement blocks/clay bricks/RR stone may be used for construction to a height of 1’-0” to 1’-6”.

5. Using 0-4” width cement blocks/clay bricks may be used for superstructure to height of 6’-0” to 7’-0”.

6. Construct two leach pits with 4 RCC rings in each pit.7. If necessary plastering is advised.8. Complete with flooring, fixing of pan and door shutter.

SWACHHA

ANDHRA

VII. TIME LINE Municipal Engineers shall prepare schedule of work and issue to the SLF for completion of works as per the Action Plan of the ULB. A model action plan in case of toilet with twin pits may be followed as follows:

Day Activity

Day 0-20The Municipal Engineer shall plan and guide the SLF for procurement

of entire materials required for number of toilets.

Day 21 Excavation of Basement and leach pits.

Day 22-23 Construction of Basement and placing of RCC rings.

Day 24 Allow for Curing.

Day 25-26 Construction of walls for super structure and Junction chamber.

Day 27 Allow for Curing.

Day 28-29 Plastering to super structure.

Day 30 Allow for Curing.

Day 31-35Fixing of Door Sanitary items i.e. WC, Connection pipe, Lid for the

leach pits and Fixing of Roof.

SWACHHA

ANDHRA