NT NETWORK
PANAJI
Goa’s industrial effluent and sewage treatment plants have to first clean up their act before they can clean the environment, going by the findings of a Goa State Pollution Control Board (GSPCB) study.
GSPCB, which conducted a performance evaluation study of five treatment plants in the state found all five not functioning properly due to some or the other fault. The shortcomings of the treatment plants ranged between improper design, failure to comply with norms, technical deficiency, inadequate maintenance, etc.
Two PWD plants, viz the Sewerage Treatment Plant at Tonca and the Sewerage Treatment Plant at Baina, Vasco and three industrial plants of Seahath Canning Company, Margao, Varun Beverages, Arlem and Tata Consultancy Services, Tivim were evaluated in the study.
Of them the GSPCB mentioned the PWD plant at Baina as not functioning properly in terms of the required parameters. The mixed liquor suspended solid value of the aeration tank is 148 mg per litre which is way below the standard of 3000 mg-4000 mg per litre while the sludge plant of the facility is operating at very high flood to mass (FM) ratio, disclosed the study.
The GSPCB has recommended the STP plant to operate at optimum level so as to meet the required stipulated standards. It has also asked for further chlorination before discharge by the STP in Baina.
The STP at Tonca is functioning within the prescribed limits however it needs to maintain its sludge drying beds properly by cutting the shrubs and bushes around it. During monsoons, the sludge drying beds should be covered properly to prevent intrusion of rain water and overflow of sludge into nearby areas, the study recommended.
Meanwhile, the three industrial treatment plants are grossly larger in capacity in comparison to the waste water they treat, disclosed the GSPCB study. Of the three plants, the ETP of Seahath Canning faces insufficient aeration due to deficiency in design of the aeration tank while the ETP of Varun Beverages does not have flow meters in the influent and treated waste water tank. The STP of Tata Consultancy needs to adjust its cleaning solutions so as to get a better pH value in its final, treated water, the study recommended.
A common lacuna in all the five plants studied is insufficient records of the sludge generated and disposed and lack of green cover around the facility.
The performance evaluation study of the treatment plants is divulged in the GSPCB annual report 2015-16. While trade effluents and sewerage treatment plants are routinely set up by industry and government the GSPCB study reveals several inefficiencies in their functioning.