Stricter sewage treatment norms to help Maharashtra clean its polluted rivers
A notification issued on October 13 by the Ministry of Environment, Forests and Climate Change was made public on Mondaymumbai Updated: Oct 25, 2017 09:34 IST
Imposition of stricter pollution norms for industrial and domestic waste is significant for Maharashtra, because the state has 49 of the 315 most polluted river stretches in the country — the highest in the country.
A notification issued on October 13 by the Ministry of Environment, Forests and Climate Change (MoEF&CC), made public on Monday, states that sewage treatment plants (STP) will have to treat wastes more throughly before releasing it into water bodies. The new rules were drafted by the Central Pollution Control Board (CPCB) to improve water quality.
“We ensured that permissible standards for basic components to identify and regulate water quality of inland surface water, lakes, streams, and discharge at sea, is made stricter across the country with the growing population and pollution problem,” said D Saha, additional director, CPCB, who added that there was not enough dilution of treated sewage at the time of its release in to the natural water bodies, making it necessary to make stricter norms.
According to the new norms, the total suspended solids (dry-weight of particles trapped by a filter at any water body) in the treated sewage has to be ‘less than 50 mg/l’(from 100mg/l). Acidity levels (measured as pH) has to be between 6.5 to 9.0, compare to earlier norms that stipulated that the reading should be between ‘5.5 to 9.0’. High acidity makes it difficult for aquatic life to survive.
There are also stricter norms for concentration of faecal coliform (FC) in the sewage. A study by the National Environmental Engineering Research Institute (NEERI) found faecal count (FC) at Mumbai’s Bandra outfalls - that discharge treated sewage into the sea — at 15 million bacteria colonies (most probable number) per 100 millilitres (15 million CFU (Colony Forming Units)/100ml) as against the permissible limit of 100 bacteria cells per 100 ml (100 CFU/100ml) in the receiving water body. At the Worli outfall, FC count in the treated effluent was 3.1 million CFU/100ml. Similarly, FC count at Malad and Versova creek discharge points were found to be 21 millionCFU/100ml and 46 millionCFU/100ml.
“These standards shall apply to all STPs to be commissioned on or after June 1, 2019 and the ones existing shall achieve these standards in five years,” reads the notification signed Arun Kumar Mehta, additional secretary, MoEFCC. “In case of discharge of treated effluent into sea, it shall be through proper marine outfall and the existing shore discharge shall be converted to marine outfalls. Reuse and recycling of treated effluent shall also be encouraged.”
Saha said that it was the decision was taken by Centre to improve water quality so that it becomes safe for human consumption and survival of aquatic life. “The aim is to maintain hygienic conditions and ensure there is no eutrophication (water body becomes enriched with nutrients and leads to algal bloom, leading to oxygen depletion and decimation of aquatic life),” he said.