"While warning to five industrial units have been issued for not regularly running effluent treatment plants (ETP) of their units, two plants have been warned as it is alleged that these weredischarging poisonous gas during night," said sub-divisional magistrate (SDM) Vishwa Bhushan Mishra, who along with area pollution control board officer V K Asthana made surprise checks in the units last evening.
Mishra said though the ETPs at the five plants "were found running", the drains in which their effluent was dischargingtolda different story.
He said the two other units, which are alleged to have been discharging some poisonous gas during night, have also been warned of punitive action, in case of violation of the norms.
"Wecannot compromise on pollution norms. Surprise raid in these units would again be conducted," Mishra said.