Residential Onsite Systems

NSF/ANSI 40 is a standard for residential wastewater treatment systems with rated capacities between 400 and 1,500 gallons (1,514 and 5,678 liters) per day.

Septic worker inserts hose to pump sewage from residential septic tank.

We can evaluate any kind of system, regardless of treatment technology, in test facilities in the U.S., Canada and Europe.

To achieve certification, treatment systems must produce an acceptable quality of effluent during a six-month (26-week) test. Class I systems must achieve a 30-day average effluent quality of 25 mg/L CBOD5 and 30 mg/L TSS or less, and pH 6.0-9.0 spanning six months of testing. System service and maintenance are prohibited during the test period.

Testing Process

Wastewater of required strength is introduced to the treatment system at the rated system capacity in even doses at prescribed periods. Stress sequences simulate wash day, working parent, power outage and vacation scenarios.

The effluent criteria required of a Class I system is based on the U.S. EPA secondary effluent treatment requirements for municipal treatment facilities.

In addition to effluent performance, requirements also exist for product literature, including installation, operation, maintenance, troubleshooting and repair manuals. The system must also meet minimum requirements for structural integrity, leakage, noise, electrical certification, access ports, failure sensing and signaling equipment (visual and audible alarms), flow design, data plate and service labels.

Ready to Begin the Process?

Contact us with questions or to receive a quote.