VISTA, CALIF.—One of the many ways commercial facilities are reducing water consumption is to use greywater. Greywater is referred to as “gently used” water coming from restroom sinks, kitchen sinks, showers, etc.
These facilities are often “doubled plumbed,” with greywater going into storage tanks and water from toilets and urinals discharged into sewer systems.
While some greywater may look discolored, even “dirty,” it is usually safe, even beneficial to use to irrigate vegetation, even though it should not be used for human consumption.
Because facilities that are landscaped often use more water for vegetation than anywhere else, if water can be reused there, it can prove to be a significant water and cost savings.
Rules & Guidelines
However, according to Klaus Reichardt, CEO and Founder of Waterless Co. Inc., manufacturers of no-water urinals, there are some rules and guidelines to follow to use greywater properly. Among these are the following:
- Greywater should not be stored for more than 24 hours. After that, it will start to break down and odors may develop.
- Avoid touching greywater. While it is “gently used” water, it can contain pathogens that are harmful if consumed by people.
- Don’t let greywater “pool” on the surface. This can result in mosquito breeding grounds.
- While some plumbing will be required, as mentioned earlier, elaborate pumps and filters are usually not necessary. These extra systems require maintenance, can be costly, and need energy to operate.
- Don’t over water vegetation with greywater. Irrigate vegetation with the same amount of water as you would with freshwater.
- Install a valve system that makes it easy to switch from a greywater source to a freshwater source, just in case the greywater tank is dry.
“Building owners and managers should also switch to greywater friendly products,” says Reichardt. “For instance, many environmentally preferable cleaning solutions, laundry detergents, even dishwashing detergents will not affect the pH of water so they can be perfect for greywater.”