This case study reflects on a quantitative and qualitative enhancement of existing surface water treatment plant of capacity 69.6 MLD (18.39 MGD,US). The plant is located at Hazira, Gujarat State, India and is part of a Petrochemical complex of one of India's largest and most reputed firms, M/s Reliance India Ltd.
The source of raw water is a river 'Tapi', from which water is pumped over 16 km to storage ponds near the plant. The plant consisted of two Solids contact Clarifiers and six Rapid Sand Gravity Filters constructed in RCC. The treated water was used for Cooling Tower make-up, as feed to Demineralization for process and power, utilities and drinking. The plant capacity was enhanced up to 128.4 MLD (33.92 MGD) with minimum possible modifications and new structures, since the entire plant was on piles due to pre-dominant black cotton soil strata. In the process the finished water quality in terms of Turbidity, TOC and Colloidal Silica (in that order of preference). The potential to form the DBPs is to be kept as low as possible.