What exactly is greywater? You’ve probably heard the word.

Greywater is a term used in irrigation to identify used water coming from the home. It can be described as cleaner than sewage water (or black water), as it doesn’t usually come in contact with harmful substances. It’s the water that comes out of bathrooms, sinks, washing machines and dishwashers.

While greywater is relatively cleaner than sewage water, it doesn’t mean it’s automatically safe to dump back into the environment. Commercial water treatments have evolved to process greywater efficiently, instead of focusing only on black water. 

Why do we need to process and treat greywater?

It Can Make Soil Water Resistant

Oils and lipids, particularly from kitchen refuse, flow with greywater. When the greywater comes in contact with the soil, the latter can absorb the fats and lipids the water contains.  When it does, the soil becomes more resistant to water, preventing water from penetrating it. Other organic matter in greywater may also have the same effect. 

For households that process sink drain as black water, this might not be much of a problem. Natural Flow systems use a series of natural filtration methods to remove such contaminants from greywater.

Detrimental Effects on Plants

Phosphates, salt and other compounds can change the characteristics of the soil. From altering the pH levels to making it dry, these compounds can turn a good soil into a bad one when left unchecked.  Using greywater for direct soil application is possible, but without treatment, it is harder to draw the line.

Algal Blooms

Greywater, especially in large amounts, creates problems when it reaches ponds or lakes. The volume of phosphates it carries could trigger an algal bloom, an abnormal increase in algae growth. Consequently, sudden population spikes such as this can throw the local ecosystem off balance and create an adverse effect, such as fish kills.

Our systems take care of both grey and black water. Through an integrated, holistic approach, Natural Flow systems aim to reduce the environmental impact of households. By processing greywater to remove harmful components before release, there’s more potential for benefitting the surroundings and the environment at large.