Estimating Cleanup Times Associated With Combining Source-Area Remediation With Monitored Natural Attenuation

Abstract

Under suitable conditions, monitored natural attenuation (MNA) can be a cost-effective strategy for restoring contaminated aquifer systems either as a stand-alone technology or in combination with other engineered remedial actions. However, USEPA guidance specifically requires MNA to achieve site-specific cleanup objectives within a reasonable time frame. Thus, it is necessary to provide estimates of cleanup times whenever MNA is proposed as part of a cleanup strategy. In response, the Natural Attenuation Software (NAS) was co-developed by the Naval Facilities Engineering Command (NAVFAC), U.S. Geological Survey (USGS), and Virginia Tech. NAS is a screening tool designed for estimating time of remediation (TOR) for MNA with varying degrees of source area remediation. Conventional screening tools for MNA are not designed to address source zone remediation options or simulation of plume reduction. The NAS consists of a combination of computational tools implemented in three main interactive modules to provide estimates for: 1) target source concentration required for a plume extent to contract to regulatory limits, 2) time required for contaminants in the source area to attenuate to a predetermined target source concentration, and 3) time required for a plume extent to contract to regulatory limits after source reduction. Natural attenuation processes that NAS models include are advection, dispersion, sorption, non-aqueous phase liquid (NAPL) dissolution, and biodegradation of petroleum hydrocarbons, chlorinated solvents, or any user-specified contaminants or mixtures. NAS can also be used to determine the equilibrium concentrate at any given location following source-zone remediation and when this will occur.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2008
Accession Number
ADA501191

Entities

People

  • Clifton Casey
  • Francis Chapelle
  • Mark A. Widdowson
  • Mark Kram

Tags

Communities of Interest

  • Biomedical
  • Ground and Sea Platforms
  • Human Systems
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force Facilities
  • Alkenes
  • Base Closures
  • Chemical Properties
  • Chemical Synthesis
  • Chemistry
  • Ecotoxicology
  • Environmental Monitoring
  • Environmental Pollutants
  • Environmental Protection
  • Environmental Restoration And Remediation
  • Groundwater
  • Materials
  • Medical Personnel
  • Organic Chemistry
  • Waste Disposal Facilities
  • Waste Products

Fields of Study

  • Environmental science

Readers

  • Computational Modeling and Simulation
  • Groundwater Contamination Remediation.