Panaji, Jul 21 (IANS): Goa's Water Resources Department (WRD) is advocating an innovative use of low-grade ore, cast away as mining rejects, to buffer up slopes surrounding water bodies instead of using clay or concrete.

The Goa State Pollution Control Board (GSPCB), in its report tabled in the legislative assembly, has quoted observations of the WRD on water management in areas where water bodies and water sources have been ripped up by mining.

"WRD recommends that the mining companies should provide a layer of impermeable mining rejects in between the existing back-filled area and future area proposed for back-filling in lieu of clay stones or concrete sub-surface dyke recommended by NEERI (National Environment Engineering Research Institute)," the report says.

WRD's proposed solution comes at a time when media reports quoting the state Public Works Department (PWD) say that there has been a sharp increase in the amount of manganese in the Selaulim water reservoir, which provides water to nearly half of Goa's population of 14 lakh.

The reservoir's water purification plant located 60 km from here treats nearly 180 million tonnes of water every day.

PWD official S.R. Paranjpe said the manganese content in the reservoir's water had gone up six-fold because of the rain-induced runoff, from ore stock-piled along water sources.

"We are finding it difficult to control the runoff as it is coming from several places," Paranjpe told reporters earlier this week.

According to data tabled by the Goa government in the assembly, the Selaulim reservoir is ringed by 19 mines, which are contributing to the pollution levels of the critical water body.

Goa exports nearly 50 million tonnes of ore sourced from more than 90 mines.