Slamming the Brihanmumbai Municipal Corporation (BMC), the Comptroller and Auditor General has said that 49 per cent sewage was released into the sea or creeks without being treated.

The CAG in its report on local bodies for the year ended March 31, 2016 was tabled in both the Houses of Maharashtra legislature today.

The report stated that Mumbai generated 2,146 MLD (million litres) per day, of which only 1,098 MLD sewage was being treated per day and remaining 1,048 MLD (49 per cent) sewage was outside the sewage collection system and was discharged into the sea/creeks without any treatment.

"This combined with poor treatment quality of sewage at four out of seven Waste Water Treatment Facility (WWTF) was polluting the sea water. As a result, Biochemical Oxygen Demand (BOD) level of sea had increased (2011-13)," it stated.

This ranged between 10.9 mg/l and 13 mg/l against the desired level of 3 mg/l as per the Environment Protection Rules, 1986 and consent issued by the MPCB to BMC.

"This was due to inadequate coverage of sewage network and low capacity utilisation of treatment facilities," the report stated.

Sewer lines proposed under the Master Plan and feasibility works undertaken by the Sewage Project (SP) were executed to the extent of 43.06 per cent (49.81 kms out of 115.67 kms).

Similarly, only 17 per cent work of rehabilitation of old lines was executed and no improvement took place in WWTFs.

The rate analysis of composite items of works prepared by SP and Sewarage Operation (SO) was found faulty in many cases leading to excess/overpayments to contractor.

Besides, the composite rates quoted by bidders were not analysed properly along with supporting documents before finalisation of the contracts. Instead, the department concerned negotiated with lowest bidders on lumpsum basis resulting in award of contracts at higher rates.

For slum rehabilitation, the BMC did not prepare comprehensive plans in coordination with the NGOs. The works executed did not meet the norms.

Out of the total 477 work orders issued (between 2006 and 2015), 134 work orders were cancelled and 5,797 toilet seats were constructed leaving a deficit of 20,195 toilet seats as on March 2016.

"This defeated the objective of containing open defecation. The slow progress in construction of toilet blocks and connecting them to existing sewer lines resulted in continued discharge of untreated sewage into open nullahs/creeks/sea