Code of Maine Rules
06 - DEPARTMENT OF ENVIRONMENTAL PROTECTION
096 - DEPARTMENT OF ENVIRONMENTAL PROTECTION - GENERAL
Chapter 695 - RULES FOR UNDERGROUND HAZARDOUS SUBSTANCE STORAGE FACILITIES
Appendix 096-695-F - Requirements for Cathodic Protection Monitoring
Current through 2024-38, September 18, 2024
1. All cathodic protection monitoring required by this rule must be performed by a cathodic protection tester as defined in Section K.
2. All measurements must be made by placing a saturated copper or copper sulfate reference electrode in direct contact with the soil electrolyte.
3. The copper or copper sulfate electrode must be placed over the center line of each tank and each piping run.
4. All measurements must be recorded using a direct current voltage measuring device with a minimum of 10 megohms input impedence, accurate to at least plus or minus 1% at 1 volt.
5. A negative voltage of at least 0.85 volts must be recorded for each metallic tank and piping run.
6. The tank owner must maintain, repair or replace the system in accordance with the recommendations of the National Association of Corrosion Engineers, Recommended Practice #RP-0295, Corrosion Control of Underground Storage Tank Systems by Cathodic Protection, 1995, whenever the system does not register a negative voltage reading of at least .85 volts for each tank or piping run, except as provided for in 18, below.
7. Alternate methods of monitoring, as described in RP-0295 may only be used with written approval of the commissioner.
8. The frequency of cathodic protection monitoring must be consistent with the requirements in section 9(C) of this rule.
9. When a negative voltage of at least 0.85 volts is not achieved upon installation, the measurement must be repeated within 6 months. Upon failing to achieve a negative voltage of at least 0.85 volts after the 6 month period, the tank owner must comply with paragraph 6 above.
NOTE: Structure to soil potentials measured when the soil Is frozen may be inaccurate because of the increased resistance of the soil electrolyte. Cathodic protection monitoring schedules should be planned to avoid frozen soil conditions.
