The Harare City Council has for three months failed to test effluent discharged into the capital’s drinking water sources and has instead “estimated” pollution levels and the amount of water treatment chemicals required to make it fit for human consumption.
The dangers are two-fold: residents could be exposed to improperly treated water, and the council could be wasting money as it does not really know what chemicals it should be using.
Regulations mandate the council to carry out regular checks on the types and amounts of waste entering Harare’s main water bodies, which include Lake Chivero and its tributaries.
This enables chemists to determine the quantities and varieties of chemicals required to treat the water before it is released for consumption.
Industries are permitted to release waste with an 80 percent strength factor.
However, minutes from the most recent full Harare council meeting show that Town House has not been following its own prescribed standards, and industries have been discharging effluent with a strength factor of up to 600 percent.
Contacted last week, water works director Engineer Christopher Zvobgo blamed the situation on a resources shortage.
“There was a shortage of vehicles. However, we have now bought new ones for the department and test the water at least once a month. So, that issue has now been rectified.”
The minutes show that the department only sampled 279 companies out of a possible 5 057 in March 2014, with indications that the bulk of industries might be dumping toxins.
Part of the minutes read: “The number of sampled companies is materially small (3,9) percent compared to the estimated potential of companies eligible for sampling.
“According to the chief chemist, for the month of March 2014, only 279 (of which 82 have closed shop) out of a possible 5 057 were sampled. Sampling of industrial effluent enables the city chemist to determine the level of toxicity of effluent discharged into the system. “The chief chemist attributed manpower and transport problems as inhibiting the sampling of a bigger fraction of effluent disposing companies.”
Harare — like Zimbabwe’s other major cities — has been grappling with water pollution, which has mostly been blamed on industries, filling stations and food outlets.
In 2014, Government directed companies to set up on-site treatment plants to minimise effluent that is eventually discharged into the sewer system.
However, the high costs involved saw most firms struggling to comply.
A survey by the Environmental Management Agency that year revealed that councils were, in fact, largely behind the pollution. Harare topped the list as it discharged 3 885 mega-litres of raw sewage into water sources daily, with Bulawayo the second largest polluter at 13 mega-litres per day. Mutare, Masvingo, Gweru and Chegutu were also among the culprits.
EMA determined that raw sewage leaks through dilapidated pipe networks and flows directly into water sources.
Lake Chivero, Harare’s chief water source, is downstream of the capital, while Chitungwiza is within the Upper Manyame Sub-Catchment Area.
This means most sewer effluent from Harare and Chitungwiza ends up being reintroduced into the water sources.
The capital spends over US$3 million monthly on a cocktail of nine water treatment chemicals.
An urban planning expert who preferred anonymity said council was being irresponsible by putting residents at risk.
“We are behaving like a village lunatic who dirties the well meant to provide water supplies to everyone. This means the cost of purifying the water will be very high. In fact, Harare has the highest cost of water purification process in the country.
“It is also possible that some chemicals from the effluent are left untreated because of the large chemical components from the sewage effluent.”