Water reuse has become important in many parts of the country. The less that has to be treated in a metropolitan wastewater center, the more capacity there is and the less spending a city has to do to expand processing.
Don't think that graywater is something icky concept only used in down-market projects. The Waldorf Astoria Beverly Hills recently began the implementation of a water reuse system. Using Epic Cleantec's OneWater technology, the hotel will recycle an estimated 95% of its collected graywater — 438,000 gallons of water.
The graywater will go to landscape irrigation, saving the cost of potable new water use in the desert, saving money and improving environmental activity and standing.
More broadly, graywater can replace the need for more expensive potable water for multiple uses. Treatment can include filtration and disinfection. It can reduce the need for chemical fertilizers for plants, decrease energy use, and help take pressure off municipal efforts to provide potable water in drought-prone areas.
According to the Environmental Protection Agency, the EPA has no governance over water reuse. Instead, regulations are primarily through state legislation over water resources. Tribes and local authorities can also control aspects of water use.
The Yale School of the Environment says that by processing and reusing gray water, whether by a single property or on a campus or neighborhood basis, the process of "driving down demand for potable water, which is costly to filter, treat, and distribute, the units will help manage water more efficiently."
According to an article in the Journal AWWA (American Water Works Association), data collected from 2017 to 2023 showed residential sewer prices increasing from $79.39 for 6,200 gallons a month to $95.02. Commercial rates tend to be higher and vary greatly depending on the metropolitan area.
Graywater includes wastewater from such uses as clothes washers, bathtubs, showers, and bathroom sinks, as the EPA points out. However, that's only part of the entire picture. There is also blackwater — which comes from toilets, dishwashers, kitchen sinks, and utility sinks — rainwater, air conditioning condensate, stormwater, and foundation drainage.
A fuller approach to recycling water would include a broader approach to more of the water sources. Capturing rainwater on a roof and stormwater at below grade can add to irrigation capabilities.