Report: Compatibility Considerations for UST Systems

In October of 2015, the Emerging Fuels Task Force Tank Subcommittee of the Association of State and Territorial Solid Waste Management Officials (ASTSWMO) issued a new report discussing compatibility issues regarding underground storage tanks (USTs) and biofuels, ethanol, and ultra-low-sulfur diesel. The report is titled Compatibility Considerations for UST Systems, and it was prepared with assistance from the EPA’s Office of Underground Storage Tanks. Explore the report’s central themes below.

Report: Compatibility Considerations for UST Systems

The Compatibility Considerations for UST Systems report is meant to serve as a resource for UST owners and operators, equipment manufacturers, State and Territorial UST program staff, contractors, consultants, and more. Although we can’t review every detail of this 40+ page document, we would be happy to provide summaries and citations:

Overview & Introduction

As a result of new state and federal mandates, the production and use of biofuels has increased, causing the number of facilities storing biofuels to increase as well. In addition, on October 13, 2015, the new federal UST regulation became effective, requiring owners and operators of UST systems to notify the relevant agency before switching to biofuel storage, keep certain vital records, and demonstrate that their system is compatible with biofuel storage through one of three methods:

• Certification or listing by a nationally recognized independent testing laboratory;
• Equipment or component manufacturer approval; or
• Another method determined by the applicable agency that must be no less protective of human health and the environment.

The report contains a variety of informational resources as well as a compatibility search tool and case summaries to help owners and operators understand (1) how to demonstrate compatibility and ensure compliance and (2) the potential risks that arise when you use incompatible equipment.

Product Operational Compatibility

Compatibility refers to the ability of two or more substances to maintain their physical and chemical properties whilst in contact with each other. These days, we have refined and improved compatibility testing methods to accurately represent the real-world conditions of the intended usage. To ensure compatibility, owners and operators of UST systems must use equipment appropriate for the operational environment. This may be tougher in hot and humid areas, where corrosion is more common.

Properties of Biofuel Blends

Biofuel blends are known for their high solubility, capacity for water absorption, and conductivity, especially when compared to conventional fuel. View pages three and four of the report for more information.

Properties of Ultra-Low-Sulfur Diesel

With the word ultra in its name, it should come as no surprise that ultra-low-sulfur diesel is notably different from its predecessor, low-sulfur diesel. The greatest difference, of course, is its reduced sulfur content. To view its other properties, including lower lubricity and oxidation stability, view page four of the report.

Checklist and Search Tool for Compliance Evaluation

An evaluation is required to convert and install storage and dispensing systems, and modifications may be needed to maintain compatibility with biofuels. Additional concerns may arise when you add ethanol or biodiesel. Tailor the report’s provided checklist to fit your state’s specific requirements and the review process. View Appendix A of the report to see the checklist.

In addition, you may wish to view the Task Force’s compatibility evaluation search tool, which allows you to search for “documented manufacturer compatibility certifications” based on fuel type or equipment components. From time to time, the search tool will be reviewed and revised to account for regulation updates. This feature will be available in early 2016 on the ASTSWMO website.

Storage Considerations for Biofuel Blends and Ultra-Low-Sulfur Diesel (ULSD)

• Consider utilizing a checklist (such as the checklist in the report) for organization during the evaluation process.
• Evaluate older equipment to ensure it is compatible with biofuel storage, as existing equipment can present a challenge due to corrosion.
• Understand that inadequate water management can harm UST systems storing biofuels or ULSD.
• Water can enter UST systems through leaks or loose fittings, but one can check for it using ATG probes or a tank-gauging stick and water-finding paste. In addition, of course, use a watertight UST system if possible.
• Microbial activity can be a concern, as microbes may consume and degrade the biofuels and contribute to corrosion. Detect microbial growth using a field detection kit and remove excessive microbes with a thorough tank cleaning.

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If you need assistance with UST compliance tasks, contact Environmental Works, a full-service environmental consulting and contracting firm. We can help you file Change of Ownership documentation, implement a UST closure, and assist with monthly and yearly walkthrough inspections. Plus, you can use our Virtual Task Manager (VTM) software to schedule inspections and tests. To learn more about our services, please give us a call at 417-890-9500 (Springfield, MO), 816-285-8410 (Kansas City, MO), 479-250-4947 (Springdale, AR), or contact us online.