Chennai: In a bid to explore new sources of augmenting the city water supply from the lakes and abandoned quarries in Chennai, the CMWSSB (Chennai Metrowater Supply and Sewarage Board) has now completed feasibility study on Madhavaram RettaiEri and has submitted proposal for installation of an advanced technology modular water treatment plant near the lake.
A press release from the metrowater board,āWith a team of Engineers under its MD, Ashok Dongre IAS and Executive Director, Prabhushankar the drawing proposals are to be submitted to the government for augmentation. The team holds consultation with PWD and Institutions like Anna University and IIT, Chennai.ā
During the 2017 drought in Chennai, water supply CMWSSB constituted special team to explore and identify new sources to augment the city water supply.
The sources included ground water sources, lakes in and around Chennai and rain water stored in the abandoned quarries.
A new 4 MLD capacity water treatment plant was commissioned during 2017 at Porur lake and water from the lake has been put to use.
At the Sikkarayapuram quarries 600mm dia pipelines were laid for a length of 4.5 km and water from quarries were pumped at the rate of 30 MLD to Chembarmbakkam water treatment plant to the city water supply.
āNearly 4 lakh people were supplied safe drinking water from these sources during the drought. The Mogappair, Alandur, Valasarawakkam, Porur, Ramapuram, Nandambakkam and their adjacent areas benefitted from these works. These works are completed in three months and put into public use. The very less gestation period and relatively lower cost of these works are significant. The 34 MLD total supply capacity of quarry and porur works were completed at a very short duration of three months,ā said the release.
Subsequently in 2018 CMWSSB to make the study to be productive has divided it in to two phases, in the first phase it will identify potential lakes that can be linked through various works to the city water supply in the immediate future. It will then take-up identification of other possible sources and estimation of works for the long run.
The CMWSSB special team after surveying the studies done earlier and restoration programs under execution by different agencies adopted the criteria stated below in the selection of water bodies for feasibility studies:
Available Capacity (Hydrography survey and Source quality (for 45 parameters))
Previous Study Inputs
Domestic pollution abatement
Water supply intake and surplus arrangements
Other Uses at present and possibility of local objections
Availability of Existing Treatment and Transmission facilities
Land availability for creating onsite facilities
The sources were identified by direct visit, proximity to transmission pipelines, field enquiries and in further consultation with appropriate institutions such as PWD, Central ground water authority, Anna University and King Institute. Accordingly the remaining lakes and quarries identified for feasibility study is tabled below.
CMWSSB CARRIED OUT THE FOLLOWING FIELD STUDIES
Hydrography survey carried out to estimate the actual and existing capacity of the lake.
Water sample Quality test conducted at CMWSSB, Kings Institute and IIT.
Soil investigation and ground water quality tested.
Storm water drains and all possible pollution load points identified and checked.
Study report handed over to IIT with additional field samples for the study of appropriate treatment method in lab scale
Various treatment options studied in the lab at IIT, Chennai
Study concluded that augmentation of water from RettaiEri is feasible with recommended treatment and disinfection
CMWSSB has submitted an outline proposal and cost estimate for an 10MLDcapacity new modular water treatment plant with advanced technology at RettaiEri.
On successful completion of RettaiEri study CMWSSB has drawn up a study plan to complete the study for the balance lakes completely. The study will include Hydrography survey for estimation of quantity, Water quality survey, for pipeline feasibility.
LAKES
Manimangalam lake
Ayanambakkam lake
Thiruneermalai lake
Nemam
Ayyapakkam
Sriperumbudur
Thenneri
Thaiyur
Chithalapakkam
Mambakkam
ArasanKazhani
Perumbakkam
Korattur
QUARRIES
Sikkarayapuram
Erumaiyur
Nanmangalam
Pammal, Pallavaram
Thiruneermalai
Nallambakkam