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SANITARY DRAINAGE FITTINGSPRESENTED BY:Rimchi N Marak, CHSCAU 68Supta Sarkar, CHSCAU 75

CONTENTS:IntroductionMethod of excreta disposal 1.Unsewered Areas: -Service type latrines -Non-service type latrines 2.Sewered disposal -Water carriage system & sewage treatmentConclusion

INTRODUCTIONAccording to WHO: Sanitation generally refers to the provision of facilities and services for the safe disposal of human urine and faeces. Inadequate sanitation is a mojor cause of disease world-wide and improving sanitation is known to have a significant benefecial impact on health both in households and across communities.

METHOD OF EXCRETA DISPOSALI. UNSEWERED AREAS:

1. Service Type Latrines (Conservancy system): Night soil is collected from pail or bucket type of latrines by human agency, & later disposed of by burying or composting.2. Non-service type (Sanitary latrines):Borehole latrineDug well or pit latrine

c. Water-seal type of latrines i.P.R.A.I ii. R.C.A type iii. Sulabh Shauchalayad. Septic tanke. Aqua privy

3. Latrines suitable for camps & temporary use: a.Shallow trench latrine b.Deep trench latrine

SEWERED AREAS:1.Water-carriage System: a.Household sanitary fittings b.House drain c.Public sewer d.sewer appurtenances

2.Sewage Treatments: a.Primary Treatment -Screening -Removal of grit -Plain sedimentation

b.Secondary Treatment -Trickling filters -Activated sludge process

c. Other Methods: -Sea Outfall -River Outfall -Sewage Outfall -Oxidation ponds

Excreta disposal in unsewered areas:Service Type (Conservancy System):

Colletion & removal of night soil by human agency is called service type or conservancy system & the latrines are called as service latrinesThe night soil is carried by night soil carts to the place of final disposal where it is disposed by: i. Composting ii. Burial in shallow trenches

2. Non-service type of latrines (Sanitary Latrines):Excreta sould not contaminate the ground or surface waterExcreta should not pollute the soilExcreta should not be accesible to flies, rodents, animals & other vehicles of transmissionExcreta should create a nuisance due to odour or unsightly appearance

TYPES OF SANITARY LATRINES:BORE HOLE LATRINE:

It is the forerunner of the non-service type of latrines.First introduced by Rockefeller foundation during 1930s.It consist of a circular 30 to 40 cm in diameter dug vertically into the ground to a depth of 4-8 cm most commonly 6m.

Auger is required to dig a bore hole.In loose soils the hole is lined with bamboo matting or earthen ring.A suitable foot rests is placed over the holeWhen the contents reach within 50 cm the squatting plate is removed & the hole is closed.

Auger

MERITS:No need of services of a sweeperThe pit is dark & unsuitable for fly breedingIf the bore hole is located 15 m away from a source of water supply there should be no danger of water pollution.

DEMERITS:Bore hole fills up rapidlyAuger is required which may not be readily availableDifficult to dig a hole deeper than 3 m in loose soil

2.DUG WELL OR PIT LATRINE:First introduced in Singur, West Bengal in 1949-1950A circular pit about 75 cm in diameter & 3-3.5 m deep is dug into the ground.In sandy soil the pit deepness is reduced to 1.5- 2 m.Pit is lined with pottery rings to prevent caving of the soil.A concrete squatting plate is placed on top of the pit & the latrine is enclosed with a superstructure.

ADVANTAGES:

Easy to construct & no special equipment is required.The pit has longer life because of greater cubic capacity.A pit of 75 cm diameter & 3-3.5 m deep will last for about 5 yrs for a family.

3.WATER SEAL LATRINE:Improvement in the designing for rural families is the hand flushed water seal type latrine.Squatting plate is fitted with a water seal.2 important function: 1. Prevent access of flies by a small depth of water in a bent pipe called trap. 2. Prevents escape of odours & foul gases & thereby eliminate the nuisance from smell.

Sulabh shauchalaya:Invention of a patna-based firm.Low cost pour-flush, water seal type of latrine.It consist of specially designed pan & a water-seal trap.It is connected to a pit 3 feet square & as deep.Excreta undergoes bacterial decomposition & is converted to manure.Requires very little water.

4. SEPTIC TANKKey component of the septic system.A small-scale sewage treatment system common in areas with no connection to main sewage pipes provided by local governments on private corporations.It is a satisfacory means of disposing excreta & liquid wastes but do not have access to a public sewerage system.

DESIGN FEATURES:There are various designs: single chambered & double chambered septic tanks.Single chambered: for small installations.Two compartments are expensive.

The main design features:Capacity: The minimum capacity should be 500 gallon.Length: length is usually twice the breadth.Depth: 1.5-2 m.

Liquid depth: 1.2 m

Air space: Minimum of 30 cm between the level of liquid & undersurface of the cover.

Bottom:

Inlet & outlet:

Cover:

Retention period:

Working of Septic Tank:The solids settle down to form sludge.Lighter solids form scum.The first stage of purification called anaerobic digestion.A portion of solid is transferred into liquids & gases in the form of bubbles.Effluent contains numerous bacterial, cysts, organic matters in solution or fine suspension.The effluent is allowed to percolate into sub-soil by means of perforated or open-jointed pipes laid in trenches.

Millions of aerobic bacteria in the upper layers of soil attack the organic matter present in the effluent.Thus the organic matter is oxidised into stable end products.

Operation & Maintenance:Use of soap water & disinfectants should be avoided as they are injurious to bacterial flora.

Desludging: Contents of the tank should be bailed out atleast once a year.

New built tank is first filled with water & then seeded with ripe sludge from another septic tank.

5. AQUA PRIVY:It functions like a septic tank.It consist of a water-tight chamber.A short drop pipe dips from latrine floor into the water.The shape of the tank may be circular or rectangular.A capacity for 1 cubic m is recommended for 6 yrs or more.

Night soil undergoes purification by anaerobic digestion.

A vent should be provided for escape of gases.

It should be treated the same manner as the septic tank.

The digested sludge should be removed at intervals.

LATRINES SUITABLE FOR TEMPORARY USE:1. SHALLOW TRENCH LATRINE:

Simple trench

30 cm wide & 90-150 cm deep.

Length depends on number of users: 3-3.5 m for 100 people.

Seperate trenches for men & women should be provided.

Earth from trench should be piled up at the side.

Its an arrangement for a short period (1 week).

It must be covered when the trench is filled 30 cm below the ground level.

2. DEEP TRENCH LATRINE:Intended for longer duration( a few week- a few months)Its 1.8-2.5 m deep and 75-90 cm wide.A superstructure is built for privacy & protection.

II. SEWERED AREASWATER CARRIAGE SYSTEM:

Its collecting & transporting of human excreta & waste water by a network of sewers to the place of ultimate disposal.There are 2 types of carriage system: i.The combined sewer system: (sewage & surface water) ii.The seperate sewer system: (sewage)A Water Carriage System consists of the following elements:HOUSEHOLD SANITARY FITTINGS: The usual household sanitary fittings: i.Water closet, ii.Urinal, & iii.Wash basin.

WATER CLOSETS:

2 types: Indian Squatting type & Western Commode type.

The water closets are provided with a flushing rim.

The closet is connected to a cistern by a pipe 2.5-3.75cm in diameter.

The flushing cistern normally holds 15 l of water

For efficient performance of water closet:

-Water seal area should not be more than 7.5 cm.

-There should not be any sharp corners in the trap.

-The volume of water should not exceed 1.75 l to maintain a minimum of 50 mm deep water seal.

-The interior of the bowl should be vertical atleast 50-75 mm just above the surface of water seal.

2.HOUSE DRAIN:10 cm in diameter & is laid in the courtyard about 15 cm below the ground level.The house drain empties the sewage into the main sewer.

3.PUBLIC SEWER:Not less than 22.5 cm in diameter, bigger ones may be 2-3 m in diameter.Laid 3 m below ground level with self cleansing velocity of 2-3 feet per second.

4. SEWER APPURTANCES:These are manholes & traps.

Manholes are placed: i. whenever there is a change in direction of sewer.s ii. at the meeting point of 2 or more sewers. iii. at distance of 100 m in long straight runs.

Traps are placed in 3 situation:

i.under the basin of water closet

ii.where the house drain joins the public drain

iii.where surface wastes water enters the drain.

CONCLUSION

PRESENTED BY:Rimchi N Marak &Supta Sarkar