Due to lax attitude in enforcing effluent discharge standards in Pakistan, the industries of various types, do not treat their wastewater, and as a result, industrial toxic effluents find their way to the municipal wastewater treatment plants. This is due to the fact that, quite often, we have combined sewer system here – meaning that both municipal and industrial wastewaters go in one sewer system.

The municipal wastewater treatment plants here are conventional in nature. And there are very few treatment plants. As everyone knows, conventional wastewater treatment plants cannot remove toxic chemicals. So, whatever goes in, come out in the effluent. Effluents from the treatment plants are discharged in surface water bodies. In Karachi, effluents are discharged into the sea.

There is also a bad practice of irrigating vegetables with raw industrial wastewaters. I remember, back in 1992, I took some World Bank people out to Korangi area, in Karachi, to show them irrigating of vegetables with industrial wastewaters, as they would not believe me, or shall I say, they refuse to believe me, when I told them so. I also told them that this is what they eat at the hotel, they were staying.

When they saw, with their own eyes, irrigation of vegetables with pink-colored industrial wastewaters, they took the night flight and flew out of Karachi right away!

While the problem of hazardous chemicals in the influent and effluent of the wastewater treatment plants is common in poor countries, it is a bit surprising to see the problem in US (see attachment). The publication says: “Management controls put in place by the EPA to regulate and control hazardous chemical discharges from sewage treatment plants to water resources have limited effectiveness. The EPA regulates hazardous chemical discharges to and from sewage treatment plants, but these regulations are not effective in controlling the discharge of hundreds of hazardous chemicals to surface waters such as lakes and streams. Sewage treatment plant staff do not monitor for hazardous chemicals discharged by industrial users.”

F H Mughal