2. Maintenance Of Sewage System
Procedure For Maintenance Of Sewage System.
Causes Of Trouble And Odour.
Sewer Cleaning Operations.
Requirements For Maintenance Of Sewers.
Functions Of Maintenance Equipments And Tools.
Selection Of Equipment For Given Maintenance
Job.
Explosions In Sewers.
Safety Measure For Sewer man.
3. Procedure for maintenance of
sewarage system
The following works are involved in the
maintenance and repair of sewage system.
1. Repair of manholes.
2. Repair of other sewer appurtenance.
3. Construction of new manholes.
4. Replacing stolen manholes covers.
5. Raising height of manholes with raising the road
levels.
6. Repair of broken sewer line
4. Causes of troubles and odour
a) Clogging Of Flow.
b) Breakage In Sewer.
c) Odour Formation.
8. Cleaning and flushing
In case of large sewers, cleaning is done
manually. The man enters the sewers
through manholes and scraps the sides of
sewer by brushes. The scraped material is
removed through man holes.
In case of small sewer, cleaning is done by
flushing.
10. Flushing method
The following methods may be adopted to
clean the sewer.
i. Flexible rod
ii. Mechanical tools
iii. Use of pills
11. Flexible rod
• A flexible rod of about 30m length is
inserted into the sewer.
• The movements of rod dislocates the
obstruction and it becomes easy to remove
them by flushing.
12. Mechanical tools
• In this methods, special cleaning tools are
attached to the front portion of the rod and
the cleaning of sewer is then carried out by
moving the rod back and forth.
• The tools may be double-worm screw, drain
brush, wire brush, etc.
13. Use of pills
In this method, small pills or
balls made of wood or rubber or
hollow mental covered with
canvas are put in the manhole
above the obstruction.
The pills floats in the sewage
and when it comes near the
obstruction, it is caught there and
the sewage starts collecting
behind it.
When sufficient head is
developed, the accumulated
sewage removes the obstruction
and the pills is caught in the next
manholes.
14. Requirements for maintenance of sewers
1. Crew or staff for maintenance.
2. Equipments for maintenance.
3. Tools for maintenance.
4. Trucks for transportation of material and
staff.
5. Map of sewage system.
15. Selection of equipment for given
maintenance job
1. Select the equipment for the type of work to be
done.
2. Initial cost should be low.
3. It should be easily available.
4. It should be easy to operate.
5. It should be easy to repair.
6. Allied equipments should be easily available.
7. It should have long life.
16. Explosions in sewers
Explosions in sewer lines may occur and the man hole
cover may be blown into the air if the sewers are not
properly ventilated.
• the main sewer gases are:
i. Naptha
ii. Methane gas
iii. Carbon dioxide
iv. Hydrogen sulphide
v. Hydrogen
vi. Ammonia etc.
17. Safety measure for sewer men
1. Emergency first aid kit should be provided to take care of all
minor injuries, cuts and burns to the gang.
2. In case of emergency the services of a doctor should be
available.
3. No smoking or open flumes should be allowed.
4. Worker should use gum-boots.
5. Gas masks and oxygen breathing apparatus should be made
available.
