System Design

The design of the septic system is based on the number of bedroom equivalents, the number of plumbing fixture units, and the conditions identified in the site and soils evaluation. Once the site and soils evaluation has been completed and approved, a report will be provided. The report will include a description of the soils and the soil absorption rate (SAR). Any limiting conditions will also be noted. 

Plan Submittal and Inspection Procedures


  1. Select, design, and lay out the septic tank and primary and reserve disposal areas on the site plan. Refer to the worksheets and sizing charts in the NOID application packet for instructions.
  2. Submit the NOID application (see below), along with all required supporting documentation.
  3. Maricopa County Environmental Services Division will review the application materials. Additional information or redesign of the system may be requested.
  4. Once the application is approved, a Construction Authorization Permit is granted.
  5. Install the septic system according to the approved plans.
  6. To initiate the final inspection, call the inspection line 602-506-1787. Complete the Request for Discharge Authorization Form (PDF) and submit the form to the On-Site Wastewater Treatment Facility Program. Have the permit/tracking number and address available and provide any special instructions or requests (e.g. call to meet at site, gate code).
  7. Once the construction inspection is approved, a Discharge Authorization will be issued.

Application Instructions


Phase II application instructions and forms, bedroom and fixture unit worksheets, sizing charts, setback requirements, example documents and online Permit Application Submittal instructions can be found on the Forms and Applications page.