NSF/ANSI 350 and 350-1: Onsite Water Reuse

  • Overview
  • Benefits of Certification
  • Why Work With NSF?
  • Certification Process

More than 97% of water on earth is salty and nearly 2% is locked up in snow and ice. That leaves less than 1% of water to grow crops, cool power plants and supply drinking and household water. Governments, NGOs, residential and commercial builders and architects are turning to onsite wastewater reuse systems as a solution to increasing water scarcity and energy costs associated with the treatment and distribution of municipal water and wastewater.

NSF/ANSI 350 and 350-1 establish material, design, construction and performance requirements for onsite residential and commercial water reuse treatment systems. They also set water quality requirements for the reduction of chemical and microbiological contaminants for non-potable water use. Treated wastewater (i.e. treated effluent) can be used for restricted indoor water use, such as toilet and urinal flushing, and outdoor unrestricted water use, such as lawn irrigation.

Benefits of Certification

NSF certification distinguishes your product in the marketplace by delivering confidence to consumers and assurance of performance to public health officials. The U.S. Green Building Council's LEED (Leadership in Energy and Environmental Design) green building rating system includes criteria that recognize NSF/ANSI 350-certified products.

Certification also provides:

  • Independent validation of system performance by a respected third-party organization
  • Proof of your company’s voluntary effort to demonstrate the performance and reliability of your product, including unannounced manufacturer audits and comprehensive test reports for distribution to customers, specifiers and public health officials
  • Listing of your product and company in the NSF web-based directory of certified treatment systems
  • Use of the respected NSF certification mark on your certified systems and promotional materials

Certification also helps position your product to these critical market drivers:

  • State, county and country legislation for water reuse systems
  • Green building and plumbing codes
  • Government specifications for sustainable products/systems
  • Green design and specification by architects and designers

Why Work With NSF?

NSF International is one of the most recognized and trusted names in onsite wastewater systems certification. We create standards and protocols, test and certify products and provide inspector accreditation. Our services deliver confidence to consumers, assurance of performance to public health officials and market access for product manufacturers in the onsite wastewater treatment industry.

Widely recognized for our scientific and technical expertise, we have collaborations with the World Health Organization, the U.S. Environmental Protection Agency, the National Environmental Health Association (NEHA) and the National Onsite Wastewater Recycling Association (NOWRA).

With a key focus on public health and appropriate water quality criteria for reuse applications, NSF/ANSI 350 and 350-1 are the first standards of their kind for comprehensive evaluation of water reuse technologies.

The NSF mark symbolizes the only third-party certification with over 40 years of commitment and service to the onsite treatment system product manufacturing industry and the regulatory community. When people see the mark, they know the product has met our stringent initial and continued certification requirements for safety and environmental quality standards.

Certification Process

NSF verifies that all design and performance requirements of the standards have been met, and confirms through testing that effluent reuse water meets stringent quality criteria for designated uses.

The certification process involves:

  • Twenty-six weeks of continuous testing with regularly scheduled sampling throughout. This lengthy testing time with high sampling volume is designed to assess the reliability of the treatment system over time.
  • No routine service and maintenance of the system during the test period. This rigorous test protocol favors reliable systems designed for reduced service and maintenance frequency.
  • A review of compliance with design specifications and literature.
  • Annual audits of manufacturing facilities and evaluation of design changes to determine if retesting is required.

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  • Open What types of systems are included in the standards?

    The NSF/ANSI 350 and 350-1 standards apply to residential or commercial (non-industrial) onsite graywater and blackwater treatment systems that serve single or multiple buildings within the same property. Residential systems are defined as those that treat wastewater from a single residence, while commercial systems treat wastewater from multi-family dwellings and from businesses.

  • Open Where can onsite treated water be reused?

    Treated water meeting the requirements of NSF/ANSI 350 can be used for toilet and urinal flushing, irrigation, decorative fountains, car washing and other non-potable water applications.

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