US EPA PUBLISHES REPORT – CORROSION IN ULTRA LOW SULFUR DIESEL (ULSD) UNDERGROUND STORAGE TANKS (UST).
The US EPA has just released a report of the results of a series of 42 UST inspections that were performed in January and February 2015. Despite the tiny percentage of ULSD UST inspected and sampled, the report highlights the considerable disconnect between observed corrosion (83% of the systems inspected had moderate to severe corrosion) and corrosion awareness (only 25% of site owners were aware of corrosion issues. The report also does a nice job of listing the different ways in which uncontrolled corrosion – particularly microbiologically influenced corrosion (MIC) – can increase operational costs and decrease profitability.
The investigators were able to collect bottoms-water (B-W) samples from only 11 of the 42 inspected UST. The pH of those B-W samples averaged 4.6, which is in the acidic range (neutral pH = 7.0). Moreover, many of the B-W samples contained mixtures of weak organic acids that are characteristic of microbiological activity. Unfortunately, no microbiological testing was included in the study.
The report’s greatest value is in its potential to improve awareness. I recommend that all fuel retail site owners and operators read at least the executive summary. You can find the EPA report at https://www.epa.gov/ust/alternative-fuels-and-underground-storage-tanks-usts#tab-5.
BCA’s Microbial Audit program is unique within the petroleum industry. It provides the total picture of both current and potential MIC risk. For more information visit the Microbiological Audit’s section of BCA’s Services listing (https://biodeterioration-control.com/microbial-testing-services/).