Non-functioning of STP components and design shortcomings resulted in poor quality of effluent being released into surface water bodies. In a large number of STPs, criteria for quality of treated effluent were not being met. Sludge treatment was inadequate.
Functioning of STP components
Joint physical inspection and scrutiny of records of 24 test-checked STPs revealed that various STP components were non-functional, as detailed in Table-2.2.4 below:
STP components remaining non-functional meant that expenditure of about Rs. 3.69 crore was rendered unfruitful, sewage treatment process was adversely impacted leading to poor quality of treated effluent, and sludge was not being adequately dried rendering it unfit for re-use.
Deficiencies in STP design
Scrutiny of DPRs and joint physical inspection of 24 test-checked STPs revealed deficiencies in STP design as detailed in Table-2.2.5 below:
In the exit conference the E-in-C, IPH accepted the observations and stated that initiatives were being taken to improve the efficiency of sewage treatment.
The above design deficiencies in STPs resulted in reduced efficiency of the sewage treatment process and pathogen-associated risk to lower riparian areas where the treated effluent was being discharged.
Adherence to norms for treated effluent
The objective of sewage treatment is to reduce polluting substances to the standards laid down by the Ministry of Environment and Forests (MoEF), HPSPCB, and the National River Conservation Directorate (NRCD). HPSPCB had prescribed standards for treated effluent/ sewage from STPs on biochemical oxygen demand, suspended solids, chemical oxygen demand, oil and grease, and pH. The CPHEEO Manual recommends that a minimum of 20 percent of treated effluent shall be re-used for agriculture, farm forestry, industrial cooling, etc. In the above context, the following was observed:
(i) The treated effluent was not being re-used in any of 24 test-checked STPs and was instead being discharged into surface water bodies.
(ii) HPSPCB had not prescribed any standards for fecal coliforms, dissolved phosphorus, and total nitrogen, which was recommended by the CPHEEO Manual in case of effluent being discharged into surface water bodies. Thus, neither the risk of pathogenic disease-causing organisms of fecal origin nor the risk of eutrophication in receiving waters due to dissolved phosphorus and nitrogen was being assessed.
(iii) Records of HPSPCB showed that out of the 1,449 samples collected from the 24 test-checked STPs during 2013-18, 393 samples (27 percent) from 20 STPs did not meet the prescribed standards. The failure rate was over 50 percent in the case of three STPs: Malyana (78 percent); Dhalli (53 percent), and Lalpani (52 percent). This was attributable to STPs being over-stressed (Dhalli and Malyana) and non-functional components adversely impacting the treatment process (Lalpani).
The non-adherence to discharge standards in 20 STPs meant that the treated effluent/ sewage from these STPs was not safe for the surface water bodies into which it was being directly or indirectly discharged. This would not only have an adverse impact on the ecosystem but also on the health of populations residing and using such water in lower riparian areas. Although HPSPCB had served notices during 2013-18 to the divisions to take remedial measures, action liable to be taken under the respective laws had not been initiated.
In the exit conference the Secretary, IPH stated that a system of weekly review of effluent parameters had been put in place and efforts were being made to monitor and improve the quality of effluent from the STPs. In this context, the Audit observed that proposals had been moved and DPRs had been prepared to upgrade 29 out of the 41 STPs in the State.