Doug MackayDoug Mackay retired from UC Davis on 7/1/17, but not from research, which continues, albeit at a more leisurely pace.  Past research by a host of students and staff has addressed many aspects of groundwater contamination and decontamination, often utilizing highly detailed field studies of existing groundwater contamination and/or highly controlled field experiments.   Both were conducted with resolution approaching that of laboratory studies but at scales and often including processes impossible to represent in laboratory studies.   In recent years, research has focused on:

  • highly controlled field experiments on fate of methane and ethanol-blended gasolines released into the vadose zone (now complete)
  • evaluation of natural source zone depletion (NSZD) at petroleum hydrocarbon release sites with lingering contamination (ongoing)
  • full-scale application of sulfate release for enhancement of in situ biodegradation of petroleum hydrocarbons in source zone (ongoing)

Contaminants investigated to date include:

  • petroleum hydrocarbons (e.g. gasoline, ethanol-blended gasolines [gasohol], oil, crude oil)
  • fuel oxygenates (e.g. in reformulated gasolines)
  • ethanol
  • chlorinated solvents
  • pesticides
  • complex mixtures

Topics that we've have addressed via field research in the past include: 

  • transport, sorption and degradation of various organic contaminants in sandy aquifers
  • factors limiting pump & treat remediation of contaminated groundwater
  • comparison of pulsed and continuous pumping for groundwater remediation by pump & treat technologies
  • pesticide transport and sorption in groundwater
  • remediation of groundwater via various configurations of permeable reactive biobarriers
    • aerobic PRBs using diffusive oxygen releasers or solid oxygen sources
    • anaerobic PRBs using diffusive hydrogen release, zero valent iron, gypsum as sulfate source
  • flushing of a high-concentration, multi-component organic/inorganic contaminant plume from a granular aquifer overlying a fractured aquitard
  • vulnerability of Mexico City's aquifer to contamination

Douglas M. Mackay

Adjunct Professor, Retired, Department of Land, Air & Water Resources
650-324-2809 office
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