Raipur, Nov 2 (Inditop.com) Chhattisgarh’s Environment Conservation Board has served notices to four steel units on the outskirts of this state capital city for defying pollution control norms, a board official said Monday.

The notices were served to the four units for not using electro-static precipitator (ESP) — an air pollution control device — at night.

Last week, the board issued similar notices to 15 industrial units in the same area for defying pollution control norms.

“We have sent notices to four units in the Urla and Siltara industrial area for failing to use ESP, which is a must for the 145 units based within a periphery of 20 km of Raipur,” the official told IANS.

The Urla and Siltara industrial areas off the National Highway 200 are home to 43 sponge iron plants and some 100 rolling mills and ferro-alloy units, which have been identified as “red category” industries because of their high pollution potential.