|The Nebraska Department of Environment & Energy (hereafter referred to as Department or NDEE) developed this guidance in response to concerns regarding potential Air Quality Construction and/or Operating Permit requirements. It also addresses risks of exposure to air emissions generated by the remediation of soil and ground water contaminated with petroleum hydrocarbons (hereafter referred to as petroleum) through the use of air strippers (AS) or vacuum extraction systems that discharge pollutants to the air. For the purposes of this guidance, the term ‘vacuum extraction’ includes any remedial technologies (e.g., soil vapor extraction, bioventing, dual phase pump and treat) that remove petroleum vapors from the subsurface and emit them to the atmosphere.
When followed, this guidance serves as a pre-approved workplan for compliance with air emissions requirements, and no separate workplan is necessary. It also assures that actions taken as explained in this document will be considered for reimbursement under Title 200 for eligible remediation projects. Petroleum remedial systems designed, operated, and sampled/monitored as described in the guidance will not need Construction and Operating permits from the Department’s Air Quality Division. Alternative actions and methods other than those presented in the guidance may also be acceptable, but they will require a workplan and need Department approval prior to implementation.
This guidance is applicable to any petroleum remediation site, including those contaminated by leaking underground storage tanks, leaking aboveground storage tanks, pipelines, or other petroleum storage and/or conveyance vessels. Unless approved by the Department, this guidance is not to be used to assess exposure risks for other hazardous substance or hazardous waste remediation sites (e.g., CERCLA, RCRA, landfills, etc.), nor is it to be used to evaluate risks for routine air emissions associated with stationary sources (e.g., factories, industries, etc.). This guidance is not applicable to situations determined by the Department to be emergencies until the emergency conditions have been mitigated.
Utilizing this standard guidance and the accompanying Emissions Calculation Workbook reduces review time for NDEE personnel. If the responsible party or their consultant wish to propose evaluating air emissions using alternative methodologies, the proposal must be submitted in detail and in writing for review by the Petroleum Remediation Section prior to development of the Remedial Action Plan for the site. At a minimum, the proposal must justify that any emission alternative methodology will provide equal or better data than the methodologies presented in the guidance and, at the same time, be of cost benefit. The Department will review alternative proposals on a case-by-case basis.
The AS portion of this document was developed in accordance with EPA document “AIR/SUPERFUND TECHNICAL GUIDANCE STUDY SERIES: Estimation of Air Impacts for Air Stripping of Contaminated Water” (EPA-450/1-91-02). In addition, much of this guidance is a collaborative effort of the Department’s Air Quality Division and Petroleum Remediation Section and its contractor. NDEE would also like to recognize the Nebraska Health and Human Services Environmental Health Section for its assistance in developing the guidance for assessing risks posed by carcinogenic contaminants.