Sinking in our own sewage – and the way out

 Sinking in our own sewage – and the way out.

 In 1994 Istanbul was treating less than 15% of the sewage produced by its residents.   By 2016, 100 % of Istanbul’s sewage (326 million gallons per day) was being sent to the treatment plants before being released to sea.  In yet another country called Pakistan, 99% raw municipal sewage and industrial effluent is dumped into sea and other water bodies.  Its once functional sewage treatment plants in Karachi, Islamabad, Lahore and Faisalabad have been largely rendered dysfunctional by encroachments, stolen machinery, ghost staff,  lack of maintenance and misgovernance. Sinking in one’s own sewage may best describe our existing environmental preference.

What makes this great nuclear nation so monumentally clueless and unconcerned towards such a crucial environmental disaster?  Clearly, the existing system, driven by contractual kickbacks,  lust for foreign loans and a dysfunctional bureaucracy has created a  cesspool that is deepening by the day.  The proposed S-III sewage treatment  project  that began its life with a budget of Rs. 8 billion in 2007 has already crossed Rs. 43 billion mark – with no respite at the end of the tunnel.  There is no way Pakistan can treat its sewage without treating parasites such as the KWSB,  that consume Rs.18 billion per year on their own sustenance, i.e. repair, maintenance, office expenses and salaries of 13000 real and imaginary employees.

Pakistan too can treat 100 % of its sewage.  This requires a shift from the conventional wastewater treatment plants that involve large capital, kickbacks and maintenance to Constructed Wetlands (CWs) that offer a natural and  low-cost alternative.   Constructed Wetlands are  environment friendly, simple to build, easy to maintain, involve little capital and use negligible energy.   The proposed treatment systems are characterised by;  a. no requirement for plant or machinery and hence negligible capital or maintenance cost; b. only a handful of employees to manage; c. no requirement of gas or electricity and d. the treated water is not sent to water bodies but stored and reused for plantation, parks and industrial applications.

Constructed Wetlands (CWs) consist of shallow ponds or channels which have been planted with aquatic plants and which rely upon natural microbial, biological, physical and chemical processes to treat wastewater. Depending on the type of system, they contain an inert porous media such as rock or gravel or sand.  Numerous cities, from Chicago to Kolkata use constructed wetlands to treat municipal wastewater, industrial effluent and agricultural drainage.  Though a resource constrained country, Pakistan has all the wherewithal to establish hundreds if not thousands of CWs using its own resources, people, plants and pebbles.

Karachi delivers approximately 500 MGD sewage to the sea on daily basis. A recent research study “Exploring Sustainable Solution for Wastewater Treatment: A case of Lyari River”, conducted at the Karachi’s NED University describes how 150 MGD can be treated at Lyari river by making 50 CW modules, each consisting of 10 wetland cells.  Built on an area of 13 acres, each CW module would also include  a recreational area and a lake for storage of treated water.  Similar modules can be built on Malir river and other streams of waste water.   All this can be done with just about one tenth of the annual maintenance expense of the KWSB.

A 400 square meter ‘Urban Forest’, built on a 3 acre park in Clifton Karachi  is an excellent example of how  sewage treatment using wetland channels can be integrated with developing an urban forest, an attractive public space, a lake for water storage and a compost generating facility.   Using treated sewage water from wetlands, such integrated urban forests can be built in thousands, all across Pakistan.  Combined with wetlands built on waste water carrying ‘nullahs’, Pakistan can become a 100 % sewage treating country within a span of 2-3 years. Here is an opportunity to meet and surpass our 2030  sustainable development goals.

Naeem Sadiq

Shahzad Qureshi

Published in The Express Tribune, April 29th, 2022.