Packaged drinking water units in Tamil Nadu are indiscriminately exploiting ground water in the absence of a strong legal framework to regulate use of the resource, according to a report by the Comptroller and Auditor General of India (CAG) on economic sector for 2012-13.

In the Chennai region, the number of drinking water units that have obtained the Bureau of Indian Standards (BIS) packaged water quality licence far exceeds the number cleared by the state Water Resources Department.

State authorities have to issue a No Objection Certificate (NOC) for the units to draw water and to be able to apply for BIS licence. While only two of 49 units given NOCs were for packaging drinking water 440 units have managed to get BIS certification.

Also, the NOCs have to be renewed every three years but the validity of 47 units expired between November 2004 and December 2013 and only two applied for renewal.

The state authorities concerned have expressed their inability to prevent over exploitation as rules and regulations have not been framed, according to the CAG report tabled in the Assembly on Tuesday.

The report has recommended that the State revise its water policy and put in place a legal framework to manage surface and ground water resources effectively.

The Tamil Nadu government enacted the Tamil Nadu Ground Water (Development and Management) Act in 2003 but did not frame the rules and regulations and repealed the Act in September 2013 to put in place an updated law. But as of February 2014 this had not happened, the report said.