What are the safe uses for recycled water?
Recycled water requirements in Oregon make it safe to use for any non-drinking water purpose. If desired, it can be treated to drinking water standards as well; however, currently the MWMC does not treat recycled water to drinking water standards. Depending on the level of treatment (Class A, B, C, or D) and other water quality characteristics, the most basic levels of recycled water are safe for non-food crop agriculture, while the highest level of treatment (Class A) is safe for publicly-accessed areas and food crops. Recycling water is a safe way to conserve our natural water resources. At a minimum, wastewater treatment ensures water returned to the Willamette River meets strict standards to protect human health and the environment. Recycled water meets or exceeds those standards.
How is recycled water produced?
Modern wastewater treatment uses processes of solids settling, biological action, aeration, and filtering, along with final disinfection, to clean reclaimed water quickly and effectively. These are largely the same processes of the natural water cycle. Untreated wastewater arriving at the treatment plant contains less than 1% pollutants – it is over 99% water. Of that 1%, the treatment process removes more than 97% of the solids and other pollutants, producing recycled water that is over 99.97% pure.
The MWMC’s standard processes result in reclaimed water deemed suitable for many agricultural and industrial uses that is rated as Class C recycled water. To produce the highest quality of recycled water, the MWMC passes the initially treated water through additional filtration and ultra-violet light disinfection to provide ultra-clear, clean water for reuse as Class A recycled water.
Is recycled water regulated?
All recycled water use is regulated and registered by the State of Oregon through the Department of Environmental Quality and the Oregon Water Resources Department. The Department of Human Services also reviews plans for use of Class C and D recycled water uses to ensure the protection of public health. Oregon has specific rules covering recycled water use defined by Oregon Administrative Rules Chapter 340 Division 55 (OAR 240-055).
How do we know where recycled water is used?
All approved recycled water use sites have signs informing workers and the public that recycled water is in use and is not to be used for drinking. Nationally, all recycled water piping, including spigots and irrigation heads, is marked or painted purple (known as “purple pipe” in the water resources field). In Oregon, all recycled water producers operate under permit and a Recycled Water Use Plan filed with the Oregon Department of Environmental Quality and the Oregon Water Resources Department. These records are publicly accessible.
Is recycled water drinkable?
While recycled water is increasingly used for replenishing drinking water supplies around the world and in the U.S., Oregon’s current recycled water classes do not include drinking water quality standards. National standards have been developed for “direct potable reuse” of treated wastewater, and in Oregon and other regions, beer has been made from potable recycled water to celebrate the ability to do this. The MWMC’s recycled water does not go through the same level of treatment and testing done for drinking water. “Indirect use” applications do allow for recycled water to replenish drinking water aquifers, much the same way rainwater and streams do naturally. However, in the Eugene-Springfield community, the MWMC is evaluating opportunities for recycled water where drinking water quality is not required, such as for agricultural, commercial, and industrial applications.
Why not treat recycled water to drinking water standards?
The Eugene-Springfield area has extremely high-quality drinking water sources, even before treatment which is performed by other agencies in our area. Additionally, while other regions can and do treat reclaimed wastewater to drinking water standards, it is not necessary, cost-effective, or energy-efficient to do so here. The benefit of recycling water in this area is that it helps conserve our drinking water and other water resources while reducing temperature and other impacts to the river. Therefore, our recycled water is cleaned to be safe for use and the environment, but is not purified for human consumption.
What IS in recycled water?
Recycled water is reclaimed from wastewater and cleaned for safe use by removing harmful toxins and bacteria. All water contains trace minerals and salts, and different water sources have different mineral characteristics. Some waters have high levels of iron, sulfur, or calcium that make them unsuitable for any purposes. Recycled water can contain chlorides or other salts that may make it unsuitable for certain types of irrigation, but certain nutrients retained in recycled water can be beneficial to plant growth. Increasingly, our water sources also contain traces of pollutants from the air and surface runoff – or in the case of recycled water, from substances washed down the drain. Water resource specialists call these trace chemicals “micro-constituents” due to their extremely small, but still detectable, presence.
Detectable micro-constituents include everything from caffeine to fire retardants. The good news is that only a few micro-constituents of concern are regularly found in treated wastewater (based on a statewide study). Class A recycled water processing decreases their presence even further. Studies have also shown that irrigation use can improve the breakdown and removal of micro-constituents through natural soil processes. In fact, vegetated wetlands and planters are used around the world as natural filtration systems to clean water – and they are increasingly used to treat urban stormwater runoff before it flows to our streams.
What can community members do to protect recycled water quality?
We are more aware of particulates and substances in our environment today because modern technology allows us to identify them in extremely low concentrations, not only in water, but in household dust and in the polar ice caps. These trace chemicals are a result of our use of medications, antibacterial soaps, health and beauty products, and other commonly used flame retardants, water repellents, plastics, and pesticides.
To reduce their presence, state and local governments have imposed regulations and launched public awareness campaigns to ban or reduce the use of certain products, call for collection and disposal stations (for unused medications and other items), and avoid pouring hazardous waste down drains or toilets. To reduce the amount of unwanted chemicals in the environment, consumers can look for safe product labels (such as the EPA’s Design for the Environment label), reduce the use of disposable products and plastics, and properly dispose of household chemicals and wastes.