JaEla and Ratmalana wastewater treatment
Recently Colombo National Water Supply & Drainage Board decided to collect and treat the combined (industrial and domestic) wastewater at both areas before it is being discharged into the receiving waters.
New sewer systems and two wastewater treatment plants will therefore be constructed. The target treatment plant sizes are 82,000 and 167,000 person equivalents respectively.
The reason for the two projects is the high degree of pollution of surface and ground waters in the two areas. This is a result of uncontrolled discharges of wastewater to streams and other surface waters, and of infiltration of wastewater into the ground.
The project will comprise the following main components:
• A sewer system for collection of the industrial and domestic wastewaters, including sewer pipes and pumping stations
• A biological wastewater treatment plant – inJaEla/Ekala a completely new plant will be constructed; in Ratmalana/Moratuwa a new plant will replace an old plant
• A discharge pipe – in the case of JaEla/Ekala dicharging to a nearby river close to its outfall into the ocean; in the case of Ratmalana/Moratuwa the discharge will be directly to the ocean.
The sewer systems and treatment plants will be constructed in stages. The construction started in February 2008.
The sewer systems will be extensive. In the JaEla/Elkala area about 22 km of pipes and 5 pumping stations are planned, while about 44 km of pipes and 7 pumping stations are required in the Ratmalana/Moratuwa area.