In Faridabad, Water table up after mining was stopped, says study (Indian Express 12 March 2010)

Mining of silica sand, quartzite and other construction material in Faridabad has resulted in massive damage to the region’s fragile ecology, especially groundwater.
The effect on groundwater can be gauged from the findings of a Central Ground Water Board study, which says some areas in the district witnessed an increase in water level after mining was stopped in 2002 on the Supreme Court’s order.
The study was conducted by scientists Sanjay Marwaha, Sanjay Pandey and Shalinder Singh.
Claiming that stopping the mining activity in the fragile Aravalli zone has had a positive impact on the region, Marwaha said the areas where mining activity was concentrated witnessed the groundwater level rising between 1 and 8 metres from 2003 to 2008.
This, he said, is despite the fact that rainfall during this period was below normal. But he said a lot of damage that has been done is irreparable.
Residents of the area depend solely on groundwater for drinking and farming needs due to lack of canal and irrigation systems, so its recharge has to be quicker than the extraction, Marwaha said.
About the unscientific manner in which mining had been carried out, he stated in his report that there were more than 40 sites that had been dug up randomly. In case silica was not found, these pits were abandoned, exposing the groundwater and leading to evaporation of the already low water table, Marwaha said.
The scientists also observed that in large areas that had been dug up below the water level, the pits have converted into lakes. This, the study pointed out, caused loss of water through evaporation.
Notably, the areas showing a rise in water levels were located near the closed pits, it was found.
Shalinder Singh said water usually seeps through natural cracks in the rocks, thereby recharging the water table. “But as these rocks have now been removed by miners, the natural recharge method has been disturbed,” he added.
The natural drainage pattern has also been altered. He said miners had blocked seasonal drains by dumping waste material, and thereby affecting farmland in the valleys of the Aravalli Hills.
Mining of silica sand was mainly carried out below the water table. During 2001-02, extraction of silica sand, ordinary sand and stone was 0.21, 9.47, and 6.48 million metric tonnes respectively, the study says.
Suggesting measures to maintain ecological balance, the study has recommended that mining activity should be restricted to 3 metres above the water table. As evaporation loss of 8.86 lakh cubic metre of groundwater was occurring each year, the pits should be filled with locally available material, it suggests.
An action plan should be drafted, pressing for the adoption of various rainwater harvesting methods, the study has proposed.