Guard Ponds are “safeguard” mechanisms for preventing the discharge of “untreated/abnormal” effluents into marine environment. In line with the statutory directives, Rashtriya Ispat Nigam Limited (RINL) envisaged a specialised project for bio-monitoring the mechanical biological and chemical (MBC) treated effluent at guard ponds. Four guard ponds with in-house design were constructed at a cost of Rs 100 million, each pond with a capacity of 9,600 cubic metres for storing two days of treated effluent from Coke Ovens. Once the effluent is stored, it can be discharged into the marine environment after its quality is cross-checked by the Andhra Pradesh Pollution Control Board.
For the first time in India, a 3 mm thick HDPE membrane with a puncture resistance of 900N over 250 GSM protective geo-textile fabric and impervious clay layer was laid inside all the four ponds for zero leakage of bund. Skilled/specialised expert manpower was deployed for overlapping the joints through wedge welding by using specialised equipment for stitching the geo-textile sheet and joining the HDPE membrane.
Megaplast India Private Limited has manufactured and supplied a specialised 3mm thick HDPE sheet. The civil contractor who took up the turnkey job was Sai Lakshmi Enterprises, Visakhapatnam. Trenches were created all around the pond, at the top of the bund, for proper locking of the sheet and further backfilling of the trenches with slag. The most important part of this job was executed during the Covid-19 time, following proper protocol as prescribed by the government.
The major attraction in this guard pond work is the laying of geo-textile sheets and the 3 mm thick HDPE membrane. This ensures that 100 per cent of the effluent being discharged into the marine environment meets the prescribed norms. This is another environment-friendly measure taken by RINL to protect the surrounding environment.