Mississippi Administrative Code
Title 11 - Mississippi Department of Environmental Quality
Part 5 - Underground Storage Tank Regulations
Chapter 2 - Mississippi Commission on Environmental Quality Underground Storage Tanks Regulations Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks (UST) (Adopted March 22, 1989; Amended August 25, 2011, Last Amended August 23, 2018)
Appendix 11-5-2-280.1 - GUIDELINES FOR THE EVALUATION OF UNDERGROUND STORAGE TANK CATHODIC PROTECTION SYSTEMS
Appendix 11-5-2-280.1-F
Universal Citation: MS Code of Rules 11-5-2-280.1-F
Current through September 24, 2024
| STRUCTURE-TO-SOIL TEST PROCEDURE FOR GALVANIC CATHODIC PROTECTION SYSTEMS |
| 1. Place voltmeter on 2 volt DC scale. |
| 2. Connect voltmeter negative lead to reference electrode. |
| 3. Place reference electrode in clean soil directly over the structure that is being tested to obtain local potential. At least one local potential is required for each tank - the preferred test point is at the approximate midpoint along the centerline of the tank. Piping may require measurement at each end of the pipe and at the middle depending upon anode configuration (see Section 6.10.2 of MDEQ guidance document). |
| * The reference electrode may not be placed on concrete or other paving materials. |
| * Ensure that the reference electrode is placed in a vertical position (tip down). |
| * Ensure that the soil where the reference electrode is placed is moist - add tap water if necessary. |
| * Ensure that the soil where the reference electrode is placed is not contaminated with hydrocarbons. |
| * Ensure that the reference electrode window is not exposed to direct sunlight. |
| 4. Connect voltmeter positive lead to structure that is to be tested. |
| * If a test lead wire is utilized to make contact with the tested structure you must ensure that continuity exists between the test lead wire and the structure. This may be accomplished by conducting a point-to-point continuity test as described in Appendix E. |
| * Ensure that good metal-to-metal contact is made between the test lead clip/probe and the structure. |
| * Ensure that no corrosion exists where the test lead makes contact with the structure. |
| * Ensure that your body does not come into contact with the electrical connections. |
| * Ensure that test leads are not submerged in any standing water. |
| * Ensure that test lead insulation is in good condition. |
| * sti-P3* tanks |
| * If the test lead wire is not continuous or is not present, contact with the inside bottom of the tank is necessary. This may be accomplished by connecting the voltmeter lead wire to a test prod mounted onto the bottom of a wooden gauging stick and lowering the stick into the tank fill riser. Be sure that firm contact is made with the tank bottom. Care should be taken to ensure that any drop tube that may be installed in the tank does not prohibit contact with the tank bottom. If a metallic probe bar is utilized to contact the tank bottom, ensure that the probe bar does not contact the fill riser or any other metallic component of the UST system. |
| * If a sti-P3 tank is equipped with a PP4 test station, the PP4 test station is disregarded and potentials must be obtained with a portable reference electrode placed in the soil (both local and remote) as described in Section 6.10.1 of the MDEQ guidance document. |
| 5. Obtain voltage and record in the local column on the MDEQ galvanic survey form. |
| 6. Place reference electrode in clean soil remote from the protected structure. (Refer to Section 6.10.3 for a discussion of remote reference electrode placement.) |
| 7. Obtain voltage and record in the remote column on the MDEQ galvanic cathodic protection form. (Note: if the fixed cell-moving ground method was used to conduct continuity survey, the potential obtained during the continuity survey for each corresponding structure may be transposed to the appropriate column.) |
| Data Interpretation (for a more complete discussion refer to Appendix C of this guidance document) |
| * If both the local and the remote potential are -850 mV or more negative, the 850 on criterion is satisfied and it is judged that adequate cathodic protection has been provided. |
| * If either the local or the remote potential is more positive than -850 mV the test result is inconclusive and further testing and/or repairs are necessary. Alternatively, a person qualified as a corrosion expert could evaluate/conduct the survey and declare a pass or fail based on their interpretation and professional judgement. |
Disclaimer: These regulations may not be the most recent version. Mississippi may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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