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 http://www.muni.org/Departments/OCPD/development-services/wells-septic/Pages/COSA.aspx