SEWERAGE SYSTEM
Kerala Water Authority is also responsible for the collection of waste water and disposal in the State of Kerala. The Authority has separate system for sewage and storm water collection.
Waste water includes Sewage and Sullage. Sewerage implies the collection of waste water from domestic sources and conveying it to Sewerage Treatment Plants (STP).
At present, sewerage schemes are under operation only in two cities in the State i.e. at Trivandrum city region and a part of Cochin. The work is in progress at Guruvayoor for implementation.
Trivandrum Sewerage Scheme
In 1938, action was taken for investigation of a "Comprehensive sewerage Scheme" on modern lines. The Thiruvananthapuram Corporation area has been divided into 7 Sewerage Blocks viz. A to G for the execution of the sewerage scheme. Sewerage facilities existing in A, B, C, D (Medical College-Kannmmoola zone and Medical College campus only) and E ( part of Peroorkada Zone only) Blocks.
The scheme for the disposal of sullage and sewage is an underground system based on principle of separate system. All the sewerage blocks had been considered to be provided with sewerage network draining into a main pumping station, where sewage would be pumped through pumping mains to Treatment and Disposal works situated at Valiyathura. The disposal system adopted is land treatment.
Block A
This system covers an area of 13.84 sq.km comprising most important portions of town such as Kowdiar, Vellayambalam, Vazhuthacaud, Thycaud, Thampanoor, Pazhavangadi, Puthenchanthai and Palayam. The main pumping station for this block is located at Kuriathy, where sewage from this entire area is collected and pumped out to the disposal works at Valiathura. Three sub-pumping stations were also proposed in this block to lift the sewage from Mudavanmugal, Arannoor and Thaliyal areas. The scheme was comissioned in 1945. For effective disposal of sewage from this block the system comprises of five intercepting sewers.
Block B
Covers an area of 5.51 sq.km. It comprises areas of the city such as Sreekanteswaram, Pettah, Kaithamukku, Pattom Valley, Nanthencode etc. with pump house at Pattoor. The system comprises three intercepting sewers.
Block C
Covers an area of 2.43 sq.km Commissioned in 1970. All the sewage from this block is collected at the main pumping station at Enchackkal. The system comprises two intercepting sewers.
Block D
Covers Medical College and Kannammoola areas. Partially commissioned during 1994. There are two pumping stations viz. the Medical College lift up pumping station catering the needs of Medical College complex and the Kannammoola main pumping station which discharges to the sewage farm at Valiathura.
Block E
Only a small portion of the Peroorkada-Ambalammukku and Jawahar Nagar area is commissioned in this block during 1990. There is one lifting pumping station in this block at Sasthamangalam near Pippinmoodu which discharges sewer into the main sewer (IS-1) in block A which ultimately reach the Kuriathy main pump house.
The proposed Trivandrum Sewerage scheme cpmprises of 7 blocks. The first 5 blocks covering a total area around 30% of the city area of 75 sq km. This covers only 40% of the total households. The remaining two blocks has no drainage facilities at present. The urban growth has been very rapid and about 80-85% of the water supplied is returned to public drainage. The sewage from the pumping stations at Kuriathy, Pattoor, Enchakkal and Kannammoola is pumped to the stilling chamber at Valiyathura and is disposed through sewage farming. The sewage farm is maintained by the Diary Development Department and fodder cultivation is done there.
Kochi Sewerage Scheme
In Kochi the entire area has been divided into 3 zones, Ernakulam South, Ernakulam North and Palluruthy-Mattancherry of providing sewerage facilities, Ernakulam South Zone is further divided into 5 Blocks. Block A and small portion of the Block B has been commissioned.
Sewerage System Components
| Sub Branch line | |
| Branch line | |
| Main line | |
| Intersecting line(IS) | |
| Sewage TreatmentPlants | |
| Pump Houses |
Barring the connection fee and deposit amount realized from the consumer, there is no revenue generation from the schemes. Sewerage is a service that is provided to selected areas. Apart from Kochi, Thiruvananthapuram and Guruvayoor, the KWA have concrete plans to expand the system to more areas.