Contaminated boreholes latest blow for Harare

THE findings that half the boreholes in western and northern Harare are contaminated with a bacteria that marks potential faecal contamination is yet another health hazard facing the people of Zimbabwe’s capital and largest city.

While the report from City of Harare epidemiology and disease control officer Dr Michael Vere did not say how large was the sample of tested boreholes, and whether these included those privately-owned as well as the public boreholes, it is almost certain that a problem affecting some can easily affect all, and so even households relying on a private borehole have to be careful. Sources of contamination can be many. Leaking sewer pipes are one obvious source, but cannot be the only source, especially when we look at northern Harare where many areas do not have sewers, relying on septic tanks in backyards instead.

Those could also be a source of the E.coli bacteria markers, especially with the rapidly rising densities of housing in the suburbs without sewers.

Old colonial town planning laws required a minimum plot of 4 000 square metres for housing not connected to a sewer, and many at that time were a lot larger.

Even so, those who rely on septic tanks know that they can clog and need emptying, and in some areas Harare City Council was forced to extend its sewer network into the low-density suburbs because the ground was becoming sodden with the drainage from septic tanks, presumably with contamination.

Since then we have seen a rapid rise in cluster housing and other higher densities in the north of the city, sometimes with an extension of the sewer network, but sometimes with just an engineer’s report that the ground was suitable for more on-site sewage processing using septic tanks, which simply means that the fluids drain away, not that a borehole or a well close by will not be contaminated.

There are also problems of some boreholes being inadequately protected, allowing surface water to flow in, and very few people would risk drinking from puddles which is what those who drink water from an unprotected borehole are effectively doing.

People have been urged over the years to have the water in their boreholes tested, at least once a year, at one of the laboratories that now exist which can handle this quite cheaply.

In any case, wise households reliant on wells or boreholes have for many decades at least boiled their drinking water and in more recent times as cheap treatment chemicals have become available put in a drum with the recommended dose or pill. It seems that we all need to do that now if we have any uncertainty whatsoever about what we are drinking.

An extra problem is that many people rely for water on the private water companies that truck water into the city. These obtain their water from boreholes, and the more responsible do test their water supplies, but not everyone is responsible. So there is an additional source of risk.

Dr Vere has arranged for public boreholes to have inline chlorinators installed, so that the water is chlorinated before people take their turn and fill their buckets and drums, which should provide a great deal of protection.

He is reluctant to close down any boreholes at the moment, when so many rely on them, because the city council he works for is only pumping 300 megalitres a day of treated water, about a quarter of the potential demand of Harare Metropolitan province.

Admittedly the metropolitan area can cope with a lot less than 1 200 megalitres a day if people are taking care, as they are forced to do, but the fact remains that a lot of households and businesses are reliant on very intermittent water supplies, once a week from the council if they are lucky, or even get nothing from council so have to rely totally on borehole and well water.

Dr Vere clearly, and correctly, feels that even a moderately dubious supply is better than no supply and is concentrating his efforts on making that borehole supply a lot safer with his chlorination programme.

It would probably, considering the appalling test results, to mount a public campaign for people to boil or treat their own water supplies if these originate from a borehole or well, returning to the days when drinking water was boiled or laced with a bit of bleach and left to settle.

This could be part of the anti-cholera campaign that could probably be intensified. There could be sponsors in the private sector ready to help the council.

The Harare water committee set up by President Mnangagwa in October last year has already found that the garbage problem in the city can impact severely on water supplies and efforts to provide residents with clean and safe water. This has led to the pressure from the committee for the present garbage collection drive, plus practical measures, like provision of 60 tractors from Government, to ensure the city council can continue to clear garbage after the present blitz. This makes sense. If the water permeating the soil and recharging the aquifers is contaminated and filthy, or if the water flowing down the Mukuvisi, or Marimba or Ruwa, or other rivers and streams criss-crossing Harare is washing filthy and muck into the supply dams, then our water problems simply get worse.

When we discuss the water, sewage and garbage problems of Harare we need to remember that the breakdown we are now seeing is not pre-ordained but is largely self-inflicted.

Past councils put in the water pipes, starting from shortly before the Frist World War, and then gradually extended the network adding more dams and adding more treatment plants.

Past councils started treating sewage, and laying sewers and building sewage treatment plants. Past councils have been collecting garbage for well over a century and adding and improving the vehicles they needed to do this.

City residents paid for all this, and obviously expected that paying the same rates that were used to create the networks would allow the city council to maintain this huge infrastructure and replace the bits that wore out when they wore out.

Yet this has not been happening in recent years as water mains rust, sewers crack and break and garbage trucks are not replaced as they wear out. And that is where the problems start.