15A NCAC 02L .0405      REQUIREMENTS FOR LIMITED SITE ASSESSMENT

(a)  If the required showing for a commercial underground storage tank cannot be made or if the Department determines that a release from a noncommercial underground storage tank represents an unacceptable risk under Rule .0404 of this Section, the responsible party shall submit within 120 days of the discovery of the discharge or release, a report containing information needed by the Department to classify the level of risk to human health and the environment posed by a discharge or release under Rule .0406 of this Section.

(b)  The responsible party may submit a written request for an extension to the 120 day deadline set forth in Paragraph (a) of this Rule to the Department for the Department's consideration prior to the deadline. The request for deadline extension by the responsible party shall demonstrate that the extension, if granted by the Department, would not increase the risk posed by the release. When considering a request from a responsible party for additional time to submit the report, the Department shall consider the following:

(1)           the extent to which the request for additional time is due to factors outside of the control of the responsible party;

(2)           the previous history of the person submitting the report in complying with deadlines established under the Commission's rules;

(3)           the technical complications associated with assessing the extent of contamination at the site or identifying potential receptors; and

(4)           the necessity for action to eliminate an imminent threat to public health or the environment.

(c)  The report shall include:

(1)           a location map, based on a USGS topographic map, showing the radius of 1500 feet from the source area of a confirmed release or discharge and depicting all water supply wells, surface waters, and designated wellhead protection areas as defined in 42 U.S.C. 300h-7(e) within the 1500-foot radius. 42 U.S.C. 300h-7(e), is incorporated by reference including subsequent amendments and editions. Copies may be obtained at no cost from the U.S. Government Bookstore's website at http://www.gpo.gov/fdsys/pkg/USCODE-2010-title42/html/USCODE-2010-title42-chap6A-subchapXII-partC-sec300h-7.htm. The material is available for inspection at the Department of Environmental Quality, UST Section, 217 West Jones Street, Raleigh, NC 27603. For purposes of this Section, "source area" means the point of release or discharge from the underground storage tank system;

(2)           a determination of whether the source area of the discharge or release is within a designated wellhead protection area as defined in 42 U.S.C. 300h-7(e);

(3)           if the discharge or release is in the Coastal Plain physiographic region as designated on a map entitled "Geology of North Carolina" published by the Department in 1985, incorporated by reference including subsequent amendments or editions and may be obtained electronically free of charge from the Department's website at https://deq.nc.gov/about/divisions/energy-mineral-land-resources/north-carolina-geological-survey/ncgs-maps/1985-geologic-map-of-nc, a determination of whether the source area of the discharge or release is located in an area in which there is recharge to an unconfined or semi-confined deeper aquifer that is being used or may be used as a source of drinking water;

(4)           a determination of whether vapors from the discharge or release pose a threat of explosion due to the accumulation of vapors in a confined space or pose any other serious threat to public health, public safety, or the environment;

(5)           scaled site maps showing the location of the following that are on or adjacent to the property where the source is located:

(A)          site boundaries;

(B)          roads;

(C)          buildings;

(D)          basements;

(E)           floor and storm drains;

(F)           subsurface utilities;

(G)          septic tanks and leach fields;

(H)          underground and aboveground storage tank systems;

(I)            monitoring wells;

(J)            water supply wells;

(K)          surface water bodies and other drainage features;

(L)           borings; and

(M)         the sampling points;

(6)           the results from a limited site assessment that shall include:

(A)          the analytical results from soil samples collected during the construction of a monitoring well installed in the source area of each confirmed discharge or release from a noncommercial or commercial underground storage tank and either the analytical results of a groundwater sample collected from the well or, if free product is present in the well, the amount of free product in the well. The soil samples shall be collected every five feet in the unsaturated zone unless a water table is encountered at or greater than a depth of 25 feet from land surface in which case soil samples shall be collected every 10 feet in the unsaturated zone. The soil samples shall be collected from suspected worst-case locations exhibiting visible contamination or elevated levels of volatile organic compounds in the borehole;

(B)          if any constituent in the groundwater sample from the source area monitoring well installed in accordance with Part (A) of this Subparagraph, for a site meeting the high risk classification in Rule .0406(1) of this Section, exceeds the standards or interim standards established in Rule .0202 of this Subchapter by a factor of 10 and is a discharge or release from a commercial underground storage tank, the analytical results from a groundwater sample collected from each of three additional monitoring wells or, if free product is present in any of the wells, the amount of free product in such well. The three additional monitoring wells shall be installed as follows: one upgradient of the source of contamination and two downgradient of the source of contamination. The monitoring wells installed upgradient and downgradient of the source of contamination shall be located such that groundwater flow direction can be determined; and

(C)          potentiometric data from all required wells;

(7)           the availability of public water supplies and the identification of properties served by the public water supplies within 1500 feet of the source area of a confirmed discharge or release;

(8)           the land use, including zoning if applicable, within 1500 feet of the source area of a confirmed discharge or release;

(9)           a discussion of site-specific conditions or possible actions that could result in lowering the risk classification assigned to the release. The discussion shall be based on information known or required to be obtained under this Paragraph; and

(10)         names and current addresses of all owners and operators of the underground storage tank systems for which a discharge or release is confirmed, the owners of the land upon which such systems are located, and all potentially affected real property owners.

 

History Note:        Authority G.S. 143-215.2; 143-215.3(a)(1); 143-215.94A; 143-215.94E; 143-215.94T; 143-215.94V; 143B-282; 1995 (Reg. Sess. 1996) c. 648,s. 1;

Recodified from 15A NCAC 02L .0115(c)(4);

Amended Eff. December 1, 2005;

Temporary Amendment Eff. September 29, 2017;

Readopted Eff. June 1, 2019.