Skip to main content

Residential Wastewater Treatment Systems

Discover different types of residential water 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.

How NSF Can Help You

Get in touch to find out how we can help you and your business thrive.

What’s New with NSF

  • Thomas Vyles Honored With 2026 Walter F. Snyder Environmental Health Award

    August 19, 2026
    The award honors Walter F. Snyder, co-founder and first executive director of NSF, and pioneers whose work advances environmental and public health.
    Read the Story
  • NSF Hosts First External Review Panel for ‘NSF/KWTC 555’ with Key Asian Water Authorities

    August 3, 2026
    Joint standard development gains momentum to enhance confidence in Asia’s water industry and advance drinking water safety.
    Read the Story
  • NSF Achieves European Accreditation for Drinking Water Product Certification Ahead of 2027 EU Deadline

    July 22, 2026
    The 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.
    Read the Story
  • Meet NSF at Fruit Attraction

    July 15, 2026
    NSF is excited to be exhibiting at Fruit Attraction, a leading international trade fair for the fruit and vegetable sector.
    Read the Story