Residential Wastewater Treatment Systems
Alternative residential wastewater treatment systems are designed to treat all liquid waste a residence generates. They are installed like a traditional septic tank and commonly have a similar-sized treatment tank. The primary difference between a septic tank and an alternative residential wastewater treatment system is the internal design and associated mechanical and electrical components that enhance treatment.
These systems are like miniature municipal treatment plants designed for a single family rather than an entire city or community. Their unique design and components accelerate the treatment process by creating optimum environments for microorganisms that digest the waste and for collecting and storing the resulting byproducts. The effluent generated by the tank is significantly superior in its treatment level to that of a septic tank, which allows for greater flexibility in disposing of the treated effluent.
Before deciding to use any wastewater treatment system, contact your local health department or other regulatory authority to ask about the requirements for such systems. Most communities require alternative residential wastewater treatment systems certified by applicable national public health standards, such as NSF/ANSI 40: Residential Wastewater Treatment Systems.
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What’s New with NSF

Thomas Vyles Honored With 2026 Walter F. Snyder Environmental Health Award
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July 22, 2026The ISO/IEC 17065 accreditation from BELAC complements NSF’s testing capacity, enabling end-to-end support for EU Drinking Water Directive (DWD) readiness ahead of the January 2027 deadline.
Meet NSF at Fruit Attraction
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