1 Notice Of Corrosion Risks In Underground Storage Tanks storing diesel fuel US Environmental Protection Agency, Office Of Underground Storage Tanks July 2016. EPA recommends that owners of Underground Storage tank (UST) systems storing diesel fuel check inside their Tanks for Corrosion , which research suggests is now appearing on equipment in most tank systems storing diesel fuel . Summary Recommendation Observations from EPA's 2016 research, which EPA recommends UST owners check for Corrosion in examined 42 operational UST systems storing diesel their tank systems storing diesel fuel ; this applies to fuel across the country, show a significant prevalence both systems with steel Tanks and systems with of Corrosion of metal components inside those Tanks . fiberglass Tanks . Owners reporting Corrosion The preliminary results categorized 35 of 42 or 83 sometimes find sludge or particles, which may look percent of the examined diesel fuel Tanks exhibiting like coffee grounds, clogging their fuel filters.
2 EPA. moderate or severe Corrosion . Less than 25 percent recommends all owners of UST systems storing diesel of USTs involved in the research reported Corrosion fuel conduct a visual inspection by checking in their prior to the internal inspection. Corrosion in the filters and inside UST system access points even if they upper vapor spaces inside USTs is a relatively new have not seen symptoms in the filter; severe Corrosion phenomenon and can cause equipment failure by may already be established before symptoms appear preventing proper operation of release detection and in the fuel filter and an owner becomes aware of a prevention equipment. In steel Tanks , Corrosion can severe Corrosion issue. Remember that this initial cause direct tank failure and releases to the diagnostic observation of UST equipment visible from environment. At this point, we do not think there is the surface may not show Corrosion even if it exists in an epidemic of releases and we cannot project the the UST system.
3 Actual percentage of USTs in a real world setting with advanced Corrosion . But we are sufficiently Owners should also contact UST servicing companies concerned about potential releases that we think it to further evaluate the extent of Corrosion inside prudent to alert tank owners of the problem and Tanks . These companies can remove and check further investigate the issue. If left unchecked, there equipment for evidence of Corrosion ; they may also could be a substantial number of new UST releases, sometimes use a specially designed video camera to which have historically been a leading cause of conduct a thorough visual inspection inside an UST. groundwater contamination. system. If observations show Corrosion , the company might remove more equipment and check to ensure We estimate there are at least 100,000 federally all equipment is functioning properly. The company regulated USTs storing diesel fuel .
4 However, the might suggest additional testing for the functionality number of potentially affected Tanks is significantly of overfill prevention equipment, leak detection higher when counting similar sized aboveground equipment, and automatic tank gauges. Testing the Storage Tanks and smaller unregulated USTs such as integrity of both single-walled and double-walled farm Tanks and home heating oil Tanks . Tanks for absolute tightness may also be warranted. Since studies to date have not definitively confirmed If owners or the servicing company finds Corrosion , the root cause of the Corrosion , there is no widely- equipment should be repaired or replaced as accepted solution to the problem. However, there are necessary to ensure proper functionality. Until the actions tank owners can take now to minimize the exact cause of Corrosion is determined and a long Corrosion and the associated Risks while stakeholders term solution is identified, EPA recommends owners look for a solution.
5 Office of Underground Storage Tanks , Washington, 20460 July 2016. refer to several industry Examples Of Industry suggest that taking action to address documents that suggest Maintenance Documents microbiologically-influenced Corrosion is very effective best currently available Coordinating Research at slowing and limiting negative impacts of Corrosion practices, technologies, or Council in USTs storing diesel . treatments available to Preventive Maintenance Guide for diesel Storage minimize the risk of release and Dispensing Systems and EPA's research does not supply conclusive findings of diesel fuel from Tanks . diesel fuel Storage And regarding the cause of Corrosion . Nonetheless, the Regularly checking for and Handling Guide number of Tanks in our research; the diversity of tank Clean diesel fuel Alliance . removing water found in Guidance For Underground type, operation, and maintenance practices; and the bottom of Tanks storing Storage Tank management nationwide locations of the 42 Tanks examined At ULSD Dispensing diesel fuel is widely provide an improved understanding of the probable Facilities recognized as a critical Steel Tank Institute extent and geographic spread of Corrosion .
6 The preventive method for Recommended Practice For research results and subsequent discussions also give Storage Tank Maintenance reducing the risk of R111 Revision us a broader understanding of the Risks to equipment Corrosion . Additional ASTM D6469 (available for integrity and functionality posed by Corrosion . The preventive practices may purchase) Standard Guide Coordinating Research Council is now developing a for Microbial be beneficial. Contamination in Fuels and third phase of research, which EPA is supporting by fuel Systems providing input and access to data collected during Background About our research. Corrosion In Tanks storing diesel fuel Beginning around 2007, owners reported to servicing Risks Of Corrosion In Tanks storing diesel fuel companies new incidents of severe and rapid Heavy Corrosion could potentially prevent proper Corrosion of internal metal components of Tanks functioning of various release prevention equipment, storing diesel fuel .
7 These reports usually described which is required in all Tanks . Equipment functions severe Corrosion of equipment in upper portions of range from detecting UST system releases should they UST systems in the regions generally not submerged in occur to minimizing the chance of overfilling Tanks and fuel . Prior to 2007, a Corrosion risk in diesel fuel Tanks releasing diesel fuel to the environment. was considered minor and, if it occurred, appeared in the wetted, or lower, portion of the tank. Corrosion also appears to present a risk to the integrity of Tanks , especially in the bottom of metal Industry and EPA are working together to understand Tanks where water and sludge may accumulate. the Corrosion issue and identify solutions. The Clean Corrosion of metal tank walls or metal bungs in diesel fuel Alliance, an organization represented by fiberglass Tanks could result in failure of that many industry members and supported by EPA, began equipment and could cause a release of diesel fuel to researching the Corrosion issue as reports became the environment.
8 More numerous. In 2012, the Clean diesel fuel Alliance produced the first research results about this Owners are responsible for the costs of cleaning up Corrosion issue. EPA worked collaboratively with releases to the environment when they occur, so it is industry and other agencies to develop the second important for owners to check their Tanks for phase of research, which built on the knowledge and Corrosion . Severe Corrosion without a release may questions from the 2012 research. In July 2016, EPA still result in higher costs due to the need for released the research results in a peer-reviewed increased maintenance or the premature replacement report. of equipment. Owners should check for Corrosion in addition to continuing to meet all applicable UST. Research to date has not been able to pinpoint a regulatory requirements. cause, but it appears microbiologically-influenced Corrosion could be largely responsible.
9 Many For More Information processes are occurring at the microscopic level in See EPA's Corrosion in USTs storing diesel website or USTs, but several industry maintenance documents contact UST implementing agencies. Office of Underground Storage Tanks , Washington, 20460 July 2016.