Remote Monitoring of Natural Source Zone Depletion Using Temperature Data to Support Long-Term Passive Management Strategies
Abstract
Many DoD sites are affected by historical releases of light non-aqueous phase liquids (LNAPL). Recently, natural source zone depletion (NSZD) has emerged as a passive remedy approach that offers the potential for greater rates of LNAPL destruction when compared to active remedies, a more sustainable remediation approach, and lower long-term costs. Analogous to the generation of heat from a compost pile, the biological degradation of petroleum in the subsurface generates heat. This heat signature allows use of an innovative temperature-based technology to quantify biologically-mediated depletion of LNAPL in the subsurface. Across 40 sites where NSZD rates have been measured by various parties, NSZD was documented to occur at all sites. The measured NSZD rates did not vary by fuel type. NSZD was also documented at the two demonstration sites under both paved and unpaved locations. Different methods used to quantify rates yielded a range of rates that were generally within an order of magnitude. While offering some clear advantages, additional work may be required to fully validate 2nd generation monitoring equipment and background correction methods, especially to resolve short-term NSZD rates (e.g., monthly or seasonal). The primary cost driver is the cost of the temperature sensor stations. While one-time measurements of NSZD, such as Carbon Traps, may be cheaper for single measurements, the temperature-based methods offer clear cost advantages at sites where long-term monitoring is required or advantageous.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 10, 2023
- Accession Number
- AD1219228
Entities
People
- Kayvan K. Askarani
- Kenneth L. Jr Walker
- Schuyler T. Robinson
- Thomas McHugh
- Thomas Sale
- Travis Lewis
Organizations
- Colorado State University
- GSI Environmental (United States)
- Naval Facilities Engineering Systems Command