s of October, 1997, the State of California enacted four bills addressing MTBE and fuel oxygenates.  The SB 521 directed the University of California to assist the state on these issues by requiring it to conduct an independent study and assessment of the human health and environmental risks and benefits of MTBE and alternative fuel oxygenates.  The governor, state law-makers, regulatory agencies, and ultimately the public were able to use the SB 521 final project report for guidance on both the need and options for taking appropriate protective and remedial actions.

A multidisciplinary team of sixteen UCD faculty members and post-doctoral researchers developed an integrated workplan focusing on MTBE in aquatic environments.  The UCD MTBE research team was actively involved in the following areas:

  1. Sources and levels of MTBE in surface waters
  1. Modeling environmental fate of MTBE in reservoirs and groundwater
  1. Bioassay techniques applicable to ecosystems
  1. Ecological risk assessment
  1. Chemical/biological treatment technologies for MTBE removal from water
  1. Effects of MTBE on gasoline storage tanks
  1. Impacts of MTBE in the Lake Tahoe Basin

  1. Effects of alternative fuel oxygenates (e.g. ETBE, TAME, and ethanol)
  1. Technical and policy options

The focus of the UCD research was not on human health risks and toxicology of MTBE directly, rather the goal was to conduct an exposure assessment based on the frequency at which human and wildlife populations are or will be exposed to MTBE in drinking water at concentrations exceeding state action levels (35 ppb).  The costs and benefits of treatment options and prevention and control techniques were evaluated and compared to help inform state elected officials, agencies, and water managers about reducing risk of MTBE exposure.

The SB521 final project report includes an integrative review of the existing literature, assessment of available monitoring data, and original research performed by UCD, UCB, UCSB, and UCLA. The complete report as submitted to the Governor is available at the following link: Report to Governor 11/12/98

In addition to the work performed under SB521, a number of studies involving biological treatment were performed by researchers at UCD. References to that body of work are located at the following link: Chemical/biological treatment technologies for MTBE removal from water. These advances led to both ex situ and in situ remediation technologies. By collaborating with two privately owned businesses in California, These technologies are now commercially available and are being applied across the country. While not an endorsement of the companies involved, for the reader's convenience, links to the company websites are provided if you would like to learn more about their capabilities:

The USEPA Region I has a description of Environmental Resolutions Incorporated's ex situ treatment technology:

http://www.epa.gov/region1/assistance/ceit_iti/tech_cos/ERIBioreactor.html

Environmental Resolutions Incorporated ex situ treatment:

http://www.eri-us.com/bioreactor.html

Regenesis corporation in situ treatment:

http://www.regenesis.com//products/bioaug/pm1/default.aspx



To find out more about SB521 research at other UC campuses, visit the UC Toxic Substances Research and Teaching Program's (TSR&TP) website:  http://tsrtp.ucdavis.edu

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