Ground water in 5 districts of TN contaminated by heavy metals, Central Ground water Board

Chennai:

The ground water in five districts of Tamil Nadu are being contaminated by heavy metals like lead, cadmium and Chromium which are beyond the permissible limits of Bureau of Indian Standards (BIS), according to a study by Central Ground Water Board.

Central Ground Water Board (CGWB), which regularly monitors ground water quality of shallow aquifers on a regional scale, once every year, have found that ground water in Dindigul, Thiruvallur and Kancheepuram contains lead above 0.01mg per litre.

Dindigul is one of the important places for its tannery units. It has more than 80 tannery units in and around the city and also posess Chromium above 0.05mg per litre which is above the BIS limit. Interestingly, CGWB states that ground water in Cuddalore, Erode, Kanchipuram and Thiruvallur districts are also contaminated by Chromium.

Chromium is used in the manufacture of alloys, corrosion, inhibitory paints, wood preservatives, fixatives for dyes and tanning, photographic sensitizers and as anticorrosive in cooking systems and boilers. Chromium contamination usually occurs via poor storage, leakage or incorrect disposal methods. High concentrations of chromium are toxic and carcinogenic.

Interestingly, the study also points out that ground water in Thiruvallur district is contaminated by Cadmium. This means the ground water in two neighbouring districts of Chennai is contaminated with heavy metals like lead cadmium and chromium and is not potable.

When Express contacted state government officials for their reaction to heavy metal polluting ground water resources, they said that they don’t monitor the heavy metal values in water as they don’t have the equipment. “We had the equipment in 1995 but then they became old. Now we are procuring new equipments and these will be in place in next couple of months,” a state ground water source said.

Besides heavy metal pollution, the ground water in 23 districts of Tamil Nadu has level of salinity above the prescribed BIS limits. Similarly, fluoride levels in ground water is above the BIS prescribed limits of 1.5mg per litre in 19 districts.

Similarly, arsenic pollution of ground water is reported in nine districts which has it above 0.01mg/l. Even nitrate pollution is reported in 27 districts of the state.

According to statistics Niti Aayog report, 600 million Indians face high to extreme water stress and about two lakh people die every year due to inadequate access to safe water.

Factfile:

Heavy metal pollution of ground water in districts:

Lead : Dindigul, Tiruvallur, Kancheepuram

Cadmium : Tiruvallur

Chromium: Cuddalore, Dindigul, Erode, Kanchipuram, Tiruvallur