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close this bookOperation and Maintenance of Water and Sewerage Systems (Ministry of Water - Tanzania - Rwegarulila Water Resources Institute, 1999, 90 p.)
close this folderD. Operation and Maintenance Tasks and Their Frequencies
View the document1. Water Supply
View the document2. Sanitation

2. Sanitation

a. VIP Latrine

Cleaning

· Individual Household: Regular cleaning is undertaken by the owner.
· Communal/:Regular cleaning is shared by all the people who use the public latrine, working on rotation basis; or Regular cleaning is undertaken by the people paid to do it.

Maintenance

· Regular emptying of the latrine
· Regular inspection and repair or replacement of fly screen, vent pipe, floors, walls, door and roof, if necessary.


b. Septic Tank
Cleaning

· Periodic cleaning of toilet facility
· Periodic disinfection of toilet by hand-spraying with “Lysol”.

Maintenance and Repairs

· Emptying of the pit by vacuum truck.
· Replacement of broken squatting pan
· Repair and maintenance of toilet tank and superstructure.

c. Septic tank

Cleaning

· Flushing after use.
· Regular cleaning of toilet facility.

Maintenance and repairs

· Emptying the sludge tank by vacuum truck
· Regular checking of drainage pipe for effluent disposal

d. Sewerage

Cleaning

· Regular cleaning of sewer line and appurtenances is undertaken by the sewerage authority.
· Regular cleaning is done at manholes, rain inlets, grease traps and spillways.

Maintenance and Repairs

· Cleaning of clogged sewer line
· Repair/replacement of broken sewer, manholes and other appurtenances.
· Maintenance of wastewater treatment plant if sewage water is treated prior to disposal.

e. Waste Stabilization Pond

Operation

· It is generally desirable to fill it to a small depth with dilute sewage and allow a spontaneous growth of algae to establish itself in the pond within a short time.

· Operate and pond with full flow

· Periodic visit by an operator for satisfactory operation.

· Periodic reading of flow in the measuring weir

Maintenance

· Regular weed and grass trimming and other usual measures to prevent mosquito breeding
· Regular removal of floating scums and mats
· Desluddging once every few years.

OPERATION AND MAINTENANCE TASKS



OPERATIONAL TASKS TO BE CARRIED OUT

ANNUAL

NO.

WORK ITEM

DAILY

MONTHLY

3 MONTHS

6 MONTHS


1

INTAKE STRUCTURE

- clean screens
- inspect all valves
- measure and record flow or level of water source.
- Record qty of water extracted.

- Inspect and remove deposits at intake chamber
- Clean for valves
- Clear bush around intake

- clean intake chamber and disinfect with 50ppm c/2 soln.



2

PUMPING STATION

- inspect all valves
- priming process
- clean pump house
- remove dirty from pumping units
- record flow of water in pipe main
- record power or fuel used
- record pressure gauges.

- Inspect packing
- Inspect performance of valves meters and tanks
- Lubrication of machine parts
- Tighten foundation bolts
- Replace oil filters and waterseals.

- inspect roof flow and walls
- replace lubricating oil, and filters as per manufacture instructions.


- overhaul engine + pump as per specified numbers of running hours by manufacturer.

3

TREATMENT PLANT

- record and maintain flows in the treatment units.
- Remove of sludge in sedimentation tank if mechanical devices used.
- Dosing respective chemicals required for treatment
- Record inflows and outflows
- General cleanliness
- Check position of all values
- Check leakages.

- removal of sludge if manual
- back washing of R.S.F.
- inspect valves and wall

- scraping of top 3cm thick, clean the sand dry and store in slow sand filters.

- clean gravel in roughing filters.
- apply plain or white wash walls of chambers.


4

WATER MAINS

- inspect routes of me mains
- inspect leakages
- inspect wash outs and air valves.

- Inspect air valves washouts
- Inspect sluice valves.




5

STORAGE TANKS

- check the operating valves

- clear bush around tank
- cleaning of inside of tank
- flust sludge through washout valve.

- inspect cracks in walls and chambers.


- white wash or any colour application to tank walls.

6

DISTRIBUTION NETWORK

- Investigate and report on leakages
- Sampling for water quality analysis
- Attend customer problems
- Inspect misuse of water by the customers
- New connections

- inspect routes and flush dead end and wash outs.
- Inspect hydrants

- check air valves,
- inspect washouts and chambers.
- Inspect illegal connections
- Check both domestic and public stand pipes.
- Re-connection of disconnected customers.

7

SEWARAGE SYSTEM

- check overflows and spillage of sewage in streets.

- cleaning of sewer line and appurtenances

- cleaning of manholes, rain inlets, grease traps and spillways.

- remove sediments with high pressure pipes.


No.

ITEM DESCRIPTION

MAINTENANCE TASKS

FREQUENCY

1

INTAKE STRUCTURE

- Repair or replacement of screens and strainers
- Remove of depositions in intake chamber and disinfect
- Repair of crack in wing walls and floor of intake

Water needed
Weekly or twice per month depending on season.
- when occurs

2

PUMPING STATION

- cleans and sweep floors and walls
- clean drains and disinfect
- clean dirt, oil in pumping units
- repair pump and engine
- overhaul engine and pumps

- Daily
- Monthly
- Daily
- When required
- As specified by manufacturer

3

TREATMENT PLANT

- repair of the operating valves
- removal and disposal of sludge from sedimentation tanks
- replacement of filter media to designed depth inspection and repair
- the underdrainage system of filter units
- inspection and repair of cracks in walls of filter units, raw water and clear water reservoirs

- when needed
- Daily/weekly
- when needed
- annually
- monthly

4

WATER MAINS

- inspect and repair leakages
- inspect and repair valves e.g. air valves washout gate valves
- repair of valve chambers and covers
- cut bush and trees in the line

- when occurs
- every 3 months
- every 6 months
- seasonal

5

STORAGE TANKS

- Remove of sludge in tank floor & chambers
- Repair valves
- Paint tank wall and ladders

- weekly
- as needed
- annual

6

DISTRIBUTION NETWORK

- Inspection and repair of pipe bursts
- Inspection and repair leakages
- To repair valves and other fittings

- As occurs
- As occurs
- As needed.


Water treatment plant “Berenplaat” (Rotterdam)