What are the potential benefits of greywater reuse for landscaping and irrigation in a building?

1 Water conservation

One of the main benefits of greywater reuse is that it can reduce the demand for potable water, which is often scarce and expensive in many regions. By using greywater for watering plants, flushing toilets, and washing cars, a building can save up to 50% of its water consumption, according to some estimates. This can also lower the pressure on the municipal water supply and the wastewater treatment facilities, which can reduce the energy use and greenhouse gas emissions associated with water provision.

3 Landscape enhancement

A third benefit of greywater reuse is that it can improve the quality and diversity of the landscape around a building. Greywater contains nutrients such as nitrogen and phosphorus, which can act as natural fertilizers for plants. This can enhance the growth and health of the vegetation, as well as the soil structure and moisture. Additionally, by using greywater for irrigation, a building can support a wider range of plants that are adapted to drought and salinity conditions, which can increase the biodiversity and aesthetic value of the landscape.

5 Greywater reuse systems

To benefit from greywater reuse, a building must install a system that can collect, store, treat, and distribute greywater for various uses. The exact system type depends on the source and quality of the greywater, the intended use, and local regulations. Common components of a greywater reuse system include a filter or screen to remove solids and debris, a tank or basin to store the water temporarily, a pump or gravity-fed system to transport the water to its destination, a disinfection or treatment unit to reduce microbial and chemical contaminants, and a distribution network for delivery to irrigation or plumbing fixtures.

6 Best practices

In order to ensure the safety and efficiency of greywater reuse, it is important for a building to use biodegradable and low-phosphate detergents and cleaners that won't harm plants or soil. Hazardous substances like bleach, paint, and oil should be avoided. Greywater pipes and faucets should be labeled clearly to prevent confusion and misuse. The greywater reuse system should also be monitored and maintained regularly to avoid leaks, blockages, or malfunctions. Lastly, local codes and standards that regulate greywater reuse must be followed.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?