The UST Program's Purpose:
The Underground Storage Tank (UST) program is concerned with the assessment and clean-up of contamination from leaking USTs. In the past, petroleum, oils, and lubricants (POLs) - including gasoline, waste oil, diesel, heating oil, and jet fuel - were stored in unmonitored, single-walled USTs. Over time, the USTs rusted and leaked, thereby contaminating surrounding soil and groundwater.
Today's regulations, however, require that all USTs are double-walled with proper monitoring devices or are removed and replaced with aboveground storage tanks (ASTs). As older USTs are upgraded or removed, the excavation and related soils are visually inspected and sampled to determine if there has been a release to the environment. If contamination is detected, further site assessment is performed.
Assessment provides a detailed delineation of the extent of contamination at the site. Based on the risk ranking and the level of contamination, the site may require clean-up. A Corrective Action Plan (CAP) is then presented to the North Carolina Division of Environment and Natural Resources (NCDENR), which details remediation activities and clean-up goals. After the CAP is approved by the NCDENR, it is implemented at the site. Remediation can take the form of an active remediation system or natural attenuation with long term monitoring. Once the site is remediated to regulatory standards, the site is submitted to NCDENR for no further action.
During assessment and cleanup of a site, the UST program must comply with federal and state regulations. NCDENR’s Groundwater Section distributes guidelines for the remediation of soil and groundwater. This document details and outlines state requirements for site assessment and cleanup. One important aspect of this publication is that it lists required soil and groundwater sampling methods. Required methods include various EPA methods and the Massachusetts Department of Environmental Protection (MADEP) methods.
North Carolina also passed Risk-Based Corrective Action (RBCA) rules in 1998. These rules establish procedures for the risk-based assessment and corrective action of petroleum USTs, and they are meant to:
- protect human health and the environment;
- abate and control contamination of the waters of the State;
- permit management of the State’s groundwaters to protect their designated current usage and potential future uses;
- provide for anticipated future uses of the State’s groundwater;
- recognize the diversity of contaminants, geology, and characteristics of each individual site; and
- accomplish these goals in a cost-efficient manner to assure the best use of the limited resources available to address groundwater pollution within the State.
Vol II guidelines: http://gw.ehnr.state.nc.us/RBCA/default.htm
RBCA rules: http://gw.ehnr.state.nc.us/RBCA/default.htm
MADEP method info above link as well as: www.magnet.state.ma.us/dep/bwsc/vph_eph.htm
EPA Method index: www.epa.gov/epahome/index
Remediation Technologies we implement…
The UST program implements various remediation, or cleanup, technologies in order to restore impacted soils and groundwaters. The following list summarizes several technologies:
- Air sparge/soil vapor extraction (AS/SVE)
- Natural attenuation
- Aggressive Fluid Vapor Recovery (AFVR)
- Pump and treat
More information on the above technologies can be found on the Internet. One particular site is http://www.frtr.gov/. This is the Federal Remediation Technologies Roundtable website where one can view a remediation screening matrix, detailing various remediation strategies.
For more information on the UST Program, please contact the program manager at (910) 451-9017.