Gray water, or greywater, is wastewater that is generated from a variety of sources in homes and commercial buildings through the use of water for showers, washing machines, bathroom sinks, dishwashers, or other uses. Greywater does not contain serious contaminants and does not include water from toilets or urinals. The Department of Health is responsible for developing standards, procedures, and guidelines, with input from technical experts, for the cost-effective reuse of greywater.
Nonpotable water is water that is not of drinking quality, but may still be used for many other purposes, depending on its quality. Nonpotable water is generally all raw water that is untreated such as from lakes, rivers, groundwater, natural springs, and ground wells. Nonpotable water sources also include rainwater, reclaimed/recycled water, and greywater. While nonpotable water is not appropriate for human consumption, it can be used in a myriad of other applications, such as doing laundry and toilet flushing.
On-site nonpotable water reuse systems capture and treat water sources generated from within, such as wastewater, greywater, stormwater, or roof collected rainwater. The treated water is then reused onsite or locally for nondrinking purposes.
The Department of Health (DOH) is required, in consultation with the Washington State Building Code Council (SBCC) and the Washington State Association of Plumbers and Pipefitters, to adopt rules by July 1, 2022 for:
At minimum, the adopted rules must address:
The rules take effect December 31, 2022. However, if any on-site treated nonpotable water systems are in operation before January 1, 2022, then such systems must be in compliance with the rules by January 1, 2024.
The permitting local jurisdiction may grant a permittee a waiver of compliance with the rules if the local jurisdiction finds that the permittee is unable to come into compliance with the rules because the engineering, repair, or replacement of the system is cost prohibitive.
The DOH may consult or contract with other public or private entities, including the SBCC and Ecology, for advice on state building code language, water rights, water quality, and other technical matters relating to adoption of the risk-based water quality standards.
The rules adopted by the DOH must provide property owners who are required to mitigate stormwater runoff a reduction in the amount of stormwater they must mitigate based on the amount of nonpotable water that is treated and reused onsite in conformance with the bill.
The substitute bill adds a requirement that the rules adopted by the Department of Health provide property owners who are required to mitigate stormwater runoff a reduction in the amount of stormwater they must mitigate based on the amount of nonpotable water that is treated and reused onsite in conformance with the bill.
(In support) The bill addresses climate change resiliency and would create a rule for the use of on-site nonpotable water. The process involves collecting wastewater, stormwater, rainwater, and other types of water and treating it for nonpotable reuse. The bill does not affect potable water. The bill creates consistent and safe statewide standards. No such regulatory framework currently exists in Washington. On-site nonpotable water reuse systems allow existing potable water to be used for potable purposes first, then, after treatment, reuse it for nonpotable uses. Businesses and companies that would like to utilize this system often cannot because no structure currently exists. Benefits include reducing stormwater impact and reducing energy consumption. The framework in the bill would be the basis for providing on-site nonpotable water reuse systems. The goal is to support the safe adoption of on-site nonpotable water reuse systems and to develop tools using research. On-site nonpotable water reuse systems are supported by leading water institutions, and a number of other places have already adopted rules; Washington is urged to follow. This bill represents the merging of many different sectors including water, health, and business. On-site nonpotable water reuse systems reduce the demand on central utility systems. The risk-based framework is a key part of the legislation. The system evaluates the number of pathogens from expected sources, and different levels of treatment are used to make any source safe for its intended use. On-site nonpotable water reuse systems that are in use now are primarily done through waivers from local governments. The bill provides standard regulation of these systems. Creating an on-site nonpotable water reuse system is optional. On-site nonpotable water reuse systems are good for use in new buildings that are environmentally built and will last a long time. Recycling of greywater can reduce the building's footprint on the climate.
(Other) The on-site nonpotable water reuse system rules provide a common sense solution to reduce the demand for water, and are being used in other states already. Conservation and reuse of greywater is a more economic way to reduce water supply and strains on rivers and streams. The only concern with the bill is that it includes the reuse of greywater from all domestic fixtures, which could be construed to include toilets. Toilets are not a source of greywater.