Guard ponds – An eco-friendly measure by Rashtriya Ispat Nigam Limited/Vizag Steel Plant

Guard ponds are safeguard mechanisms for preventing the discharge of untreated/abnormal effluents into the 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 treated effluent at guard ponds. Four guard ponds with in-house design have been 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 will be permitted to 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 geotextile fabric and impervious clay layer has been laid inside all the four ponds for zero leakage of bund. Skilled/Specialised expert manpower has been deployed for overlapping the joints through wedge welding by using specialised equipment for stitching the geotextile sheet and joining the HDPE membrane.

Megaplast India Private Limited has manufactured and supplied specialised the 3 mm HDPE sheet. The civil contractor that took up the turnkey job was Sai Lakshmi Enterprises, Visakhapatnam. Trenches where provided all around the pond at the top of the bund for properly locking the sheet and further backfilling the trenches with slag. The most important part of this job was executed during Covid-19 time, following proper protocol as prescribed by the government.

The major attraction in this guard pond work is laying of geotextile sheets and a 3 mm thick HDPE membrane. This ensures that the effluent is discharged into the marine environment only after it meets the prescribed norms. This is one more environment-friendly measure taken by RINL to protect the surrounding environment.