Excreta Disposal 55v4h

Some we need to know REFUSE: Solid or semisolid waste matter produced in the normal course of human activities. Generated from street sweepings, markets, stable litter, industrial refuse, commercial refuse, etc.

RUBBISH: Solid wastes originating in houses, commercial establishments, industries, excluding garbage and ash.

GARBAGE: Animal & vegetable wastes resulting from the handling, storage, sale, preparation, cooking and serving of food.

ASH: Residue from burning of wood, coal, charcoal and other combustible materials used for cooking and heating purposes in houses, industries etc.

EXCRETA

Spread of disease from excreta

Sanitation barrier

Methods of excreta disposal

INSANITARY METHODS 1. Open defecation 2. Conservancy system/Cartage

SANITARY METHODS WATER CARRIAGE SYSTEM

Methods of excreta disposal SANITARY METHODS 1. Pit latrine 2. Pour flush/Water seal latrine 3. Composting latrine 4. Aquaprivy 5. Septic Tank 6. Chemical closet 7. Biogas plant 8. Latrines suitable for camps and temporary use

INSANITARY METHODS OF EXCRETA DISPOSAL

1. Open defecation

2. Cartage (Conservancy system) •Example: Bucket latrine •Disadvantages: Smell Flies Health risk to people handling the excreta Health risk from food crops fertilized with raw excreta Bucket latrine

SANITARY METHODS OF EXCRETA DISPOSAL

1. Simple pit latrine

Location of a pit latrine

Advantages & Disadvantages

•Advantages: •Easy and cheap to construct •Slab and shelter can be reused •Excreta are isolated

•Disadvantages: •Unpleasant odors •Flies

1b. VIP latrine & 1c. ROEC

•Ventilated Improved pit latrine •Reed Odorless Earth Closet

Ventilated Improved Pit Latrine

0.5 m

Semi dark Shelter

Windshear effect drawing air up the vent pipe

2. Pour Flush/Water-seal Latrine • Pour flush latrines use a pit for excreta disposal and have a special pan provided with a “water-seal” of 2030 mm. • They need 1-3 liters of water for flushing each time they are used. • Advantages: • No fly or smell problems • Easy maintenance

• Disadvantages: • Water is needed for their operation • More expensive than pit latrines

Water seal latrine

The Water Seal

2. Direct & Indirect WS Latrine

Direct

Indirect

3. Composting Latrine •Composting latrines are shallow vaults, into which excreta, kitchen waste and similar wastes are added. •The waste & excreta breakdown together to produce compost – fertilizer. •Two shallow vaults are usually provided - when one is full it is covered with soil and left for at least two years – compost. •The vaults must not receive water

Advantages & Disadvantages

•Advantages: •Does not need to be moved and new vaults do not have to be dug. •Produces compost used as a fertilizer •Disposes kitchen waste as well

•Disadvantages: •More expensive and more difficult to build than VIP or WS latrine

4. Aquaprivy

•The aquaprivy is a water tight tank filled with water into which excreta fall via a drop pipe, connected to a seepage pit to dispose of sullage and effluent. •Drop pipe must reach below surface of the water.

The AQUAPRIVY

Advantages & Disadvantages

•Advantages: • Cannot be blocked with bulky anal cleaning material • Nil problem with odor or flies • Can be connected to a sewerage system at a later date

•Disadvantages: • Expensive to build • Need large volumes of water to work • Water seal may be hard to maintain • Tanks must be emptied about every 3 years

5. Septic Tank

•Septic tanks are watertight chambers (single, double or multi chambered) which receive excreta and wastewater. •They are connected to a soakaway which receives liquid overflowing from the tank.

• Solids (“sludge”) settle down and are purified

Working of Septic Tank

by anaerobic digestion. • The liquids (“effluent”) undergoes aerobic oxidation in the upper layers of the soil, outside the septic tank proper.

Advantages & Disadvantages

•Advantages: • Isolation and treatment of excreta • No odor or fly problems • May be connected to sewerage system at a later date

•Disadvantages: • High cost of construction • Need for periodic mechanical emptying • Need for large volumes of flushing water • Only suitable where flush toilets are used

7. Chemical closet •It consists of a metal tank containing a disinfectant fluid (Formaldehyde). A seat with

cover is placed directly over the tank. •Water should not be thrown into the tank.

8. Biogas Plant

9ai. Shallow Trench latrine Poles to attach screening

Security screening

Trench depth approx. 150 mm

Access path Handwashing facility Dug soil (for back filling)

Superstructure

5m

4m

1.5 m

Approx. 300mm

Plan View

9aii. Deep Trench latrine

Superstructure

II. SEWERED AREAS

WATER 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: 1.

HOUSEHOLD SANITARY FITTINGS: The usual household sanitary fittings: i.Water closet, ii.Urinal, & iii.Wash basin.

i.

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 2.53.75cm 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 s the public drain iii. Where surface wastes water enters the drain.