Feature Article of Friday, 11 May 2012
Columnist: Oti, Douglas
Water quality and safety should be a national security and safety issue. This is how it is viewed at least in developed countries. The effort and the procedures instituted to safeguard the quality and safety of potable water in these nations should be adopted and supported by both the citizens and all the stakeholders in the sub-Saharan African countries, where water borne diseases and death as a result of ingestion of unsafe water could match that caused by malaria, responsible for 1 in 5 childhood death, a total of 655,000 death in 2010. And also costs sub-Saharan Africa US$12 billion GDP per year.
Water is one of the most important elements that support earth life which has been in existence for over 3.5 billion years. For us as tertiary consumers on the food chain/web, water is the only medium by which nutrients, carbon substrates, and energy from the producers, primary and secondary consumers we eat get transported to various subsystems in our body, for respiration and reproduction. Contaminated water in our body thus carries along contaminants in a form of pathogenic microbes or chemicals which attack our body cells and sometimes interfere with codes of DNA in our genes creating mutations. Many of the times the body fight back but most of time we fall sick and become economically unproductive and a sink putting economic burden on others as a result. On a national scale, the country loses its productive manpower and has to borrow from other nations to keep the wheel of its economy spinning. We therefore have to purify and protect the quality of our potable water from the source and to point of use (POU). Too many people are needlessly being incapacitated and are dying of diseases that are supposed to be in extinction, considering the level of advancement of man and medicine.
I was motivated by callers of Dr. Alexander Anim-Mensah’s presentation on water quality in Ghana last December at one of the FM stations in Accra. I also recognized the excellent contributions made by the CEO of Food and Drugs Board (FBD) and callers who brought to light the intensity of some of the water situations in Ghana. Some of the callers’ complaints included finding tadpoles and frogs in potable water they had fetched from taps at their own homes. That was the first time I ever heard such incredible incidents and so my immediate question was how did that happen? My assumption was that, the incidents were physical and could be explained with science. And that is what I am about to do but before I hypothesize, I would say that these incidents highlight the extent to which lack of responsibility and ownership of public institutions and also lack of demand by Ghanaians from these institutions for world class standard services have led the entire country to. They again show how unsafe we as Ghanaians are, drinking tap water thinking the water was well treated at the treatment facility to a safety standard and still remained safe as it flowed through the distribution system, exited through our taps and then into our cups. The finished water from the clear well to the point of entry (POE) of the distribution system through to the point of use (POU) always run a risk of coming into contact with pathogenic microbes or some form of toxic chemicals. This is not limited to only tap water but also to bottled water, sachet water, and well water. Chemicals used to make bottles and plastics under certain environmental conditions leach back into the contained water. Chemicals like BPA and their effect on consumers are some of the hot topics being discussed in the world of toxicology and water research. Well water is also prone to heavy metal contamination. In Ghana many wells in mining areas have been found to contain arsenic, a very toxic heavy metal that causes cancer. Pathogen contaminated water when ingested causes diseases like Typhoid, Cholera, Dysentery, Salmonellosis and this has incredibly been responsible for uncountable number of death in all over the sub-Saharan Africa.
Like a geologist who deciphers the chronology of geologic events that lead to a formation of an outcrop by visual inspection, my hypothesis of the presence of tadpoles and the frogs in peoples’ tap water is that backflow action sucked them into the water distribution system and rerouted them to other customer’s home away from the source. Prior to that, there was a sequence of critical events that took place. First there was an exposure of a pipe by some digging activities followed by a break in the pipe. Water gushed out but not strong enough to flow away, so it filled the dug out hole forming a puddle over the broken pipe. Some female frogs laid and hatched their eggs in the puddle. What happened next is where it becomes a bit tricky. There are two possible scenarios that could cause the backflow in a section of a distribution system. One is shift in the pressure head within the distribution network to one segment from other segments, and the other one is intentional shutdown of water flow. But water flow pattern in Ghana suggests both are common and both could be the culprit. The shift of pressure head happens when there is an overwhelming sudden shift of levels water demand from one segment of distribution network to another causing water to flow towards the higher water demand segment from the other segment in the distribution network. An example is when there is an asymmetric explosion of water demand due to settlement or industrial growth on one side of the distribution system. On the other hand, intentional water shut down of the water mains, at certain times, reverses the direction of water flow and it is true in hilly terrains. The external intruders in both cases get rerouted if sucked beyond pipe intersections. It is then pumped into other customers’ homes. The consequence is that the potable water becomes unsafe to drink without any further treatment. Boiling the water for awhile is advisable if the contamination is purely by microbes. Otherwise a professional treatment is necessary. The idea of chlorination becomes defeated if incredibly high concentrations of microbes intrude the water. Formation of trihalomethanes becomes inevitable because of presence of overwhelmingly high level of organics. These byproducts are concerned carcinogens. Too much Chlorine in water may also be dangerous to our health. There is a maximum concentration allowable in potable water beyond which chlorine becomes toxic, therefore chlorination should be left for experts. This is also an area of concern because of sales of some “chlorine tablets” to the public in the Ghanaian market.
My humble suggestion to combat this is as follows:
• Permits should be required for any digging in densely populated areas or in all cities.
• There should be a database for pipelines laid in all areas.
• Finished water should flow at all times.
• Backflow preventers should be put at all pipe intersections.
• Diligent planning and design of distribution system is essential and should always be done.
• There should be regular sampling and analysis of water at areas far away from the water treatment plant as well as the distribution stations to determine the concentrations of chlorine residual.
• We can deal with the problem of inevitable chlorine dissipation by substituting chlorine with Chloramines. Chloramines especially Monochloramines are known to last longer in water, has associated lowered disinfection byproducts and cost effective.
Besides these seven points, I also suggest that Ministry of Health (MOH), Environmental Protection Agency (EPA), and Food and Drugs Board (FDB) should coordinate to constantly monitor the safety of our potable water. For instance, MOH through doctors can capture health data of the patients and sort out waterborne disease cases. Data containing residence and work place addresses can be relayed to EPA and FDB for a follow up investigations on food and potable water sources patients consumed. If the source of the ailment is identified, actions should then be taken to correct it. A development of a nation demands healthy human resources and we should all help in one way or another in making Ghana a healthy place to be.
Douglas Oti, PhD (Civil & Environmental Engineering)