Operation & Maintenance

The home owner is responsible for the operation and maintenance of the On-site Wastewater Treatment Facility (OSWTF), also known as the septic system.

Septic Tank & Disposal Field

The On-Site Wastewater Treatment Facility (OSWTF) consists of two components: the septic tank and the disposal field. Occasionally there are additional treatment components for other specific purposes for which an Operation and Maintenance Agreement should have been established and followed accordingly.

Tank Specifications

The tank itself may be concrete, fiberglass, or polyethylene. The tanks are sized according to a formula using the number of plumbing fixture units and/or bedrooms to determine the daily design flow that represents the gallons of wastewater the OSWTF must treat.

Disposal Field Specifications

The disposal field consists of trenches, drilled pits or other approved methods of water application to the soil. The size of the disposal field is determined by the soils absorption rate and the daily design flow.

Routine Maintenance

A major advantage of the septic tank is that it has no moving parts and therefore needs very little routine maintenance. The required maintenance is cleaning the effluent filter regularly, at least once a year, and pumping the entire septic tank every 3 to 5 years. The pumping must be done by a licensed, professional pumping company to remove all contents from all compartments of the tank(s).

Operation & Maintenance Recommendations

Read the Maricopa County Operation and Maintenance Recommendations (PDF) for an OSWTF.