Only 79 of the 214 factories in Chittagong Export Processing Zone are now using the services of the central effluent treatment plant (ETP) because of high service charges.
The plant authorities have blamed non-cooperation by the Bangladesh Export Processing Zones Authority (Bepza) for this situation.
They said the Bepza is not asking the EPZ factories to use the services of the central ETP.
A factory has to pay an additional 40 percent of the total cost to take service from the central ETP, said Hasibul Islam, managing director of the central ETP.
Instead of giving subsidy, the Bepza is taking profits from the plant, said Zafar Alam, director of the Department of Environment (DoE) in Chittagong.
However, SM Abdur Rashid, general manager of CEPZ, said, “We are asking all the EPZ factories to subscribe to the ETP services, and they are joining gradually.”
All the 'red category' factories have subscribed to the services, he said. “We cannot force those who already have ETPs of their own.”
However, factories that have their own ETPs often dump wastes without treating, to minimise cost, said Harunur Rashid, an inspector of the DoE.
The DoE has fined some enterprises for discharging toxic wastes despite having ETPs of their own.
Effluents of CEPZ can go through two channels: one at the northwest corner at sector-7/a and the other at the southeast corner at sector-8 in the zone area.
The central ETP is situated at sector-7/a at the northwest corner where the main canal joins the sea.
Hasibul Islam said effluents from around 26 factories of sector-8 and 4/a can discharge their wastes through the latter without going through the central ETP.
The CEPZ authorities admitted that effluents of around five factories avoid the central ETP.
The central ETP has a capacity of treating around 45,000 tonnes of liquid wastes. Currently, it is treating around 35,000 tonnes of waste.
In a recent visit to the embankment where the effluents are passed to the Bay, this correspondent found that locals were using the water in their vegetable garden for irrigation.
Babul Hossain, a resident who has been living in the area for 14 years, said formerly the water discharged from the EPZ was coloured and stinky such that they could get the bad odour even hundred yards off the canal.
Dead fish fries were found aplenty in the canal before, said Md Ilias, a local fisherman.
The situation improved when the central ETP was set up in August 2012, locals said.
The plant not only neutralises the harmful chemicals but can also turn the whole amount into pure drinking water.