At the site following the removal of multiple Underground Storage Tanks, a release was discovered. GRI was contracted to assess the area. After performing a receptor survey, GRI recommended that the site risk be reclassified as low risk and the incident be closed with deed recordation of a Notice of Residual Petroleum. This request was denied because non-potable wells used for fish cleaning benches were located greater than 600 feet but within 1,000 feet of the site. In order to reduce the risk level, GRI advocated for the development of language in the general statutes that would further define high risk as sites where potable wells or irrigation wells were actually threatened, not just within a certain distance from the site.
In 1991, a release was discovered at the site following the removal of one (1) 6,000-gallon gasoline, three (3) 4,000-gallon gasoline and one (1) 4,000-gallon diesel Underground Storage Tanks (USTs). A total of 11 Type II monitoring wells and 1 Type III monitoring well were installed over the years at the site during previous ground water assessment and corrective action activities by previous consultants. Geological Resources, Inc. (GRI) was contracted to evaluate the site and conduct activities required by the North Carolina Department of Environmental Quality (NCDEQ).
Following a file review, GRI’s first request was to update the receptor survey and conduct a comprehensive sampling event. The previous receptor survey had identified numerous water supply wells within 1,000 feet of the site.
Based upon GRI’s updated receptor survey, no high or intermediate risk receptors, as defined by the NCDEQ’s risk-based corrective action guidelines, were identified within the appropriate search radii to warrant the high risk classification. In addition, ground water quality at the site was well below Gross Contamination Levels (GCLs). GRI recommended that the site risk be reclassified as low risk and the incident be closed with deed recordation of a Notice of Residual Petroleum. This request was denied because non-potable wells used for fish cleaning benches were located greater than 600 feet but within 1,000 feet of the site. According to the NCDEQ, the water supply wells used for fish cleaning were being considered as potable supply wells and the risk classification would remain high until the wells were abandoned. GRI sampled the site on a semi-annual basis and requested that the site risk be lowered again. The NCDEQ again stated that the site would remain high risk until the fish cleaning bench wells were abandoned.
This site was the impetus for GRI to contact the North Carolina Petroleum Marketers (NCPCM) to assist in developing language in the general statutes that would further define high risk as sites where potable wells or irrigation wells were actually threatened, not just within a certain distance from the site.
In addition GRI advocated for inclusion of non-UST source petroleum releases to be included in risk-based corrective action. GRI personnel spoke at a NC Senate subcommittee meeting in favor of this language on behalf of the NCPCM. The UST Section Chief at that time spoke against this language at the same meeting. This language was later codified as General Statute (G.S.) 143-215.94V(b).
Further, GRI spoke to NCDEQ regarding the fact that the Department had yet to allow implementation for risk reduction through modeling as stated in G.S. 143-215.94V(b). Following a meeting GRI had with the new UST Section Chief to discuss the non-implementation of the rule by the UST section, GRI completed a model at the site. The model helped determine that the plume would not impact the nearest supply well in the vicinity of the site. Subsequently, the risk classification was lowered and the incident was closed following deed recordation of a Notice of Residual Petroleum (NRP).
Actively promoting the change in law, codified as General Statute (G.S.) 143-215.94V(b), to further define high risks sites by addressing the threat of contamination to potable or irrigation wells within the site’s radius, as well as pushing for the State agency to follow laws more accurately to allow risk reduction through modeling indicates GRI’s dedication its clients and to the stewardship of the trust fund.