Margao: Even though there are three sewage treatment plants (STP) in the Sirvodem STP Complex in Margao of which two are sewerage plants which have recently been commissioned, untreated sewage is flowing out of the STP Complex into the rivulet which joins River Sal. Herald visited the STP complex to investigate the source of the untreated Sewage.
The STP Complex comprises of three STP Plants. A 20 MLD plant to the South is operated by a contractor named Ayaapa on behalf of PWD, a 6.5 MLD plant to the North is operated by another contractor and another old PWD plant which is not operational but is being used to pump raw sewage into the other two plants.
Sewage from the city first enters a common holding tank. From there, the two new STP plants, the 20MLD and the 6.5MLD use their pumps to draw the sewage to their respective treatment plants. Both the new plants, test their output water daily. Although Herald did not check their lab test reports, the operators of both the plants informed that their output is within permissible limits. Upon inquiring about the source of the untreated sewage discharge into the rivulet, the operator informed that the old PWD treatment plant is not operational. Untreated sewage is released from the holding tanks of the old plant through underground pipes into an underground sump. Here it gets mixed with the treated sewage water from the 6.5MLD plant and together it flows into a small open tank. In this tank, treated water from the 20MLD plant is released. The mixture of treated and untreated sewage flows through underground pipes and is released into the rivulet outside the STP Complex.
This is not the only shocking aspect of the STP complex. A large circular settling tank filled with sewage has mosquitoes breeding on its surface. There is another tank next to the PWD office which is filled with sewage and algae. The contractor of the 20MLD tank has built around 5-6 huts of metal sheets in the middle of the complex where the labour and their families are living inside and are breathing the air filled with methane and hydrogen sulphide gas on a daily basis. A Tata Winger minibus with the logos of “Public Works Department”, “JICA” and “KAM_AVIDA” is rusting inside the complex. The staff revealed that the vehicle was a mobile testing lab which has never been used. Ironically, the houses outside the STP do not have a sewage connection. There is a big cesspool filled with rainwater, sewage and algae which flows into the STP complex through a nulla and remains stagnated inside the complex. The PWD official informed that it is rainwater and not sewage. There were also mounds of sludge which was set on fire. The sludge which is a by-product of the treatment process can be used as fertiliser. However, the JICA supervisor informed that there are no takers for the sludge and therefore it is set on fire at the site.
Herald contacted the Assistant Engineer who said that the old PWD plant is not working and that other two plants are functioning. However, he denied that any untreated sewage is being discharged directly into the rivulet. [H]