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
Section 11-5-2-280.1-1 - GENERAL
Section 11-5-2-280.1-1-1.1 - Introduction
The purpose of this document is to establish the policy of this office regarding the evaluation of cathodic protection systems operating on underground storage tank (UST) systems in the State of Mississippi. While conducting structure-to-soil potential surveys is the primary means of testing cathodic protection systems, other aspects related to the evaluation, installation, operation and repair of cathodic protection systems are also addressed in this document where necessary.
Evaluation of cathodic protection systems to ensure they are functioning as intended has proven to be one of the more problematic areas that has led to a great deal of confusion and various practices among individuals engaged in the field of cathodic protection. Because the applicable regulations contain no specific criteria and instead defer to industry standards, a large degree of latitude has historically been provided for interpretation of what constitutes an acceptable evaluation.
Since there are many factors that can affect cathodic protection, there is understandably no standard test method or "cookie-cutter" approach that will work at every site that has a cathodic protection system in operation. Therefore, the primary intent of this policy is to create a level playing field in which everyone engaged in the field of UST system cathodic protection in the State of Mississippi understands what is expected. The second focus of this policy is to provide that documentation sufficient to reproduce the results generated by a cathodic protection tester must be established in order to conduct a valid cathodic protection evaluation. To this end, forms that must be utilized when evaluating cathodic protection are included in Appendix K and L of this document.
It is further necessary to understand that the creation of this policy has necessitated a compromise to some degree. Every effort has been made so as not to place an unduly harsh burden on the tank owners and contractors who operate in the State of Mississippi. At the same time, it is necessary to be protective of human health and the environment to the degree required to achieve the charge of the Mississippi Department of Environmental Quality (MDEQ). This document represents the best efforts of the MDEQ to assure that cathodic protection systems operate as intended and effectively mitigate corrosion while being mindful of the economic constraints that must be considered.
Some of the more important points established with this guidance document are:
> Access to the soil directly over the structure that is being tested must be provided.
> Both "local" and "remote" structure-to-soil potentials must be obtained on galvanic systems.
> "Instant off' potentials must be obtained on all impressed current systems.
> Continuity/isolation must be established whenever a cathodic protection survey is conducted.
> Under certain conditions a "corrosion expert" must evaluate the cathodic protection survey.
> A person must meet certain minimum qualifications in order to conduct an effective evaluation.
Simply conducting a structure-to-soil potential survey does not adequately evaluate a cathodic protection system. Other considerations that may need to be addressed are outlined in the text of this document and include: continuity measurements; evaluation of rectifier operation; current distribution among an impressed current anode ground bed; consideration of voltage drops; assurance of wiring integrity; continuity bonds; as built drawings and others.
This policy is not intended to replace any statute or regulatory requirement concerning the installation, repair, operation or testing of cathodic protection systems. Rather, it is intended to state the interpretation of the MDEQ with regard to the implementation of those rules and regulations applicable to UST cathodic protection systems.
