Septic Tank Age Requirements

 Steel Tanks: What is required by age of tank?


0-20 years old:
Pump receipt


20-29 years old:
Inspect the tank and verify the liquid levels


Over 30 years old:
Expose 2 sides of the tank; preferably the outlet end and one side to look for leaks OR replace the tank 


Certificate of On-Site Systems Approval (COSA)

  • Issued by the Municipality of Anchorage (MOA) and serves as a confirmation to the buyer and lending institution that the well and/or septic system serving a single family or duplex home have been inspected/tested by a professioinal engineer and were found to be in compliance with the applicable standards established by the MOA.
  • Anchorage Municipal Code 16.65 requires a septic system to be sized based on the number of bedrooms in the dwelling unit(s) it serves, and assumes two occupants per bedroom.
  • For a summary of all that is included in the COSA testing process, feel free to visit the MOA's website at



Suggested Vendors for Water and Waste Systems










3801 Centerpoint Drive
Suite 200 Anchorage, AK 99503

(907) 230-7760