1.  Superfund Site.  Obtained a No Further Action for a Superfund site.  Developed a quantitative approach, using GIS, to demonstrate that chlorinated solvent contamination in groundwater beneath our client’s property was not part of the regional contaminant plume, even though it had some of the same chemicals.  Also demonstrated that the onsite contamination had been successfully cleaned up.  RWQCB concurred and issued a no further action letter.  This letter and our report were used to negotiate a de minimus cash out settlement with USEPA Region IX.  Our client’s liability at this Superfund site was previously estimated at over $1,500,000.

2.  Forensic analysis of fate and transport of molds within a dwelling.  Developed a statistical, risk-based approach to the evaluation of molds in indoor air and on surfaces within a residence.  Provided expert testimony that demonstrated that mold in different areas of the residence had different sources and did not result from the spread of mold from one source where the roof had been damaged.  Jury came back with an 11-1 verdict in favor of our client, an insurance carrier.

3.  Semi-conductor Manufacturing Site.  We developed and implemented a risk-based strategy and were instrumental in obtaining a No Further Action determination of the California Department of Toxic Substances Control (DTSC) and the RWQCB for a semi-conductor manufacturing site located upgradient of a municipal drinking water well.  The perched groundwater at the site had about 1,100 ppb TCE and some 500 ppb cis-1,2-DCE.  Prior to our involvement, the regulatory agencies had verbally approved a $1,000,000 Remedial Action Plan (RAP) for the site developed by a previous consultant. 

4.  Site adjoining harbor with chlorinated solvents and gasoline contamination.  We developed a risk-based evaluation of a site adjoining the ocean with chlorinated solvents (concentrations above 200,000 ppb) and gasoline contamination (free product) of soils and groundwater.  Spatial mapping of the data, chemical fingerprinting, and use of a 3D contaminant fate and transport model (Visual MODFLOW) were used to delineate the contamination and to quantify risks to marine organisms.  Based on our evaluation, only discrete “hot spot” remediation was recommended.  This risk-based evaluation was approved as written by the RWQCB with no comment. 

5.  Litigation support case involving arsenic.  On a litigation support case involving arsenic, our client said “…your achievements go beyond merely getting a good result for the clients.  There has been a nationwide impact.  USEPA has decided to withdraw its risk-based criterion for arsenic in water as a result of the litigation.”

6.  Groundwater flow and contaminant transport.  Used GIS mapping of soil gas sampling data and scientific visualization techniques, along with chemical “fingerprinting”, to illustrate two separate chlorinated solvent plumes, only one of which could be attributable to our client.  Developed 3D visualizations of the subsurface, using data from CPT logs, to delineate sand channels and clay barriers to groundwater flow and contaminant transport.

7.  Commercial strip mall site with PCE, TCE and BTEX in subsurface soils.  A risk-based approach was developed and used successfully to negotiate a No Further Action designation from the regulatory agency at a commercial strip mall site with PCE, TCE and BTEX in subsurface soils.  The entire process, including regulatory approval, was completed in less than six weeks to facilitate sale of the property.  The previous consultant had recommended a $500,000 cleanup of the site.

8.  High school built over a former gun club and skeet shooting range.  Site characterization and a risk assessment were conducted for a high school built over a former gun club and skeet shooting range.  GIS was used to map the spatial distribution of lead and pH in soils.  Also, the potential for migration of lead down to groundwater was evaluated.  The project involved communicating site-specific issues and health concerns to the School Board, the school community and to the general public.  The risk assessment was approved by the DTSC, which issued a No Further Action determination for the site.