Approved by the Energy, Environment, and Water Policy Committee on December 12, 2017
Approved by the Public Policy Committee on May 6, 2018
Adopted by the Board of Direction on July 13, 2018
The American Society of Civil Engineers (ASCE) supports treated wastewater and graywater reuse as a water supply source for the beneficial uses of industries and communities, including agricultural, industrial, and municipal uses. ASCE recommends the following:
- Encouraging use of treated wastewater and graywater as part of any plan to develop water supplies where legally, technically and economically feasible to do so and protective of public health, safety and welfare;
- Encouraging reuse of non-potable water when it can be provided cost effectively;
- Providing funding, such as federal or state loans or grants, to local utilities for implementation of treated wastewater and graywater reuse;
- Updating or establishing requirements by state and local agencies that promote water reuse projects, educate the public to the benefits of water reuse, and specifically limiting discharges near sensitive water bodies; and
- Furthering research and development into expanded applications of water reuse and agricultural, industrial, and municipal uses.
Sound water management consists of a variety of strategies to maximize the sustainable use of limited water resources. Water management strategies include water conservation, water reclamation and reuse, and graywater reuse. The demand for water is increasing, including the need for water to preserve in-stream uses such as aquatic habitat and water-oriented recreation. According to the Environmental Protection Agency (EPA), publicly owned treatment works (POTWs) treat 32 billion gallons of wastewater every day. Some of this wastewater could be reused where legally, technically and economically feasible. Water reuse should be an integral part of a water supply strategy. Public health and environmental requirements on the use and treatment of these waters must ensure water quality appropriate for the use.
Graywater is generated from water use in bathtubs, showers, sinks, washing machines, and dishwashers. Graywater accounts for a large portion of the outflow produced in homes, and it is generally of higher quality than black water, or water from sewage systems. Historically, the potential for high concentrations of organic waste and other water quality concerns have been barriers for reusing graywater safely. Building Codes that allow for separate graywater systems should address these concerns.
Use of reclaimed wastewater for irrigation is an accepted use for reclaimed water in many locations where legally permitted. Increasing public acceptance of wastewater reclamation through education in many communities makes it a viable component of a community's water supply portfolio.
Proven treatment technology is already available, and in some cases fully implemented, to provide safe, reliable non-potable water supplies that can be developed from graywater reuse.
Wastewater reclamation refers to the reuse of domestic and industrial wastewater that has been treated to specific standards set by state, federal or local agencies that can be beneficially reused for industrial, commercial, agricultural and municipal uses. Wastewater reclamation has been successfully used in many areas of the country.
ASCE recognizes the need for water recycling through the reuse of treated wastewater for agricultural and landscape irrigation, industrial processes, toilet flushing, and replenishing a groundwater basin (groundwater recharge), and public water supply. Water recycling offers resource and financial savings, and wastewater treatment can be tailored to meet the water quality requirements of a planned reuse. Through wastewater reclamation and reuse of graywater, the total water resources available can be utilized sustainably to meet water needs.
ASCE Policy Statement 332
First Approved in 1987