How safe is your grey water?

Posted on 4 December 2017

Increases in infectious diseases can be a direct result of droughts. As we head into a more severe water crisis in the Western Cape and outlying areas, we consider the safety concerns of using grey water.

Times of drought are synonymous with innovative ways of saving water. Whether showering with a bucket or flushing your toilet with bath water, “grey water” is becoming a buzzword in the drought-stricken Western Cape. And while being “water wise” is essential in this time of crisis, it is important to be aware of the potential health risks that accompany both drought and the grey phenomenon.

‘Grey water includes non-municipal and non-sewage water,’ says Dr Evert Bouwer, a Durbanville-based general practitioner. ‘All shower, bath and basin water fall into this category. Sewage and water from a kitchen basin is classified as black water, where the kitchen variety is characterised by its high fat content.’

Municipal water is treated with gas chlorine, thereby decreasing the pathogen count and being suitable for human consumption. Grey water, on the other hand, is effectively a cesspool of bacteria and it is just as important to be water aware as it is to be water wise.

‘A pathogen is any living organism that can cause disease,’ explains Bouwer. ‘For instance, consider the smell emanating from a bucket of grey water left unattended for a number days. The organic material in the grey water causes bacteria to multiply, hence the unpleasant aroma.’

Bouwer says there has been a notable increase in drought-related illnesses of late, the categories of which he outlines as follows:

– Low humidity consequences: ‘Dry air and low humidity tend to dry out the mucous membranes of the nasal cavity. People are therefore more prone to airborne pollen, which leads to allergic rhinitis and asthma-related chest conditions. Upper respiratory viral infections are also more prevalent under these circumstances due to viruses entering the mucous membranes.’

– Droplet-spread conditions: ‘Less water available means less water used for hand washing. This gives rise to contamination, either through accidental oral ingestion of grey water droplets, or through broken skin or sores. Influenza-like symptoms predominate, as do gastroenteritis and even hepatitis A or typhoid in more serious cases.’

– Dehydration: ‘Lowered water consumption is also evident in times of drought, where dehydration, renal disease and loss of cognitive function are often a result.

‘I would like to re-emphasise that grey water should never be consumed,’ continues Bouwer. ‘That said and given the current conditions, an increased awareness can go a long way towards a decrease in illness.

‘Do not store unfiltered grey water for more than two days. Using a waterless hand-cleaner after going to the toilet reduces the risk of faecal-oral contamination of pathogens. Additionally, never leave grey water unattended around children and pets. And keep up your clean drinking water consumption.’

Some municipalities offer services for treating grey water to make it safe to store and use. Contact your local municipality to discuss water treatment methods and avoid informal untested methods of treating water.