Kristin Robrock
Kristin R. Robrock, Ph.D., P.E.
Managing Engineer
Environmental & Earth Sciences
  • Oakland

Dr. Robrock is an environmental engineer and microbiologist who specializes in biodegradation and the fate and transport of chemicals in the environment. Her expertise is on emerging chemicals, such as the flame retardants polybrominated diphenyl ethers (PBDEs) and triclosan. She has extensive experience working with chlorinated solvents, specifically PCE and TCE, perchlorate, metals, PCBs, and petroleum hydrocarbons in soil and groundwater. Dr. Robrock works largely on environmental forensics cases, determining timing and locating sources of contaminant releases, quantifying contaminant releases, conducting historical site reconstructions, and identifying other potential sources of contamination.

She provides technical consulting on effectiveness of remediation activities and costs. In addition, she is a California licensed civil engineer. 

Dr. Robrock’s research has focused on the degradation of the flame retardants PBDEs by aerobic and anaerobic bacteria that are capable of degrading chlorinated solvents and aromatic hydrocarbons. She delineated the degradation pathways using two-dimensional gas chromatography (GCxGC) and determined the conditions necessary for these biological processes to occur.

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Environmental Engineering, University of California, Berkeley, 2008
  • M.S., Environmental Engineering, University of California, Berkeley, 2003
  • B.S., Earth and Environmental Engineering, Columbia University, 2001
  • Tien Scholar for Environmental Science and Biodiversity, 2007–2008

    University of California Toxic Substances Research and Teaching Program Fellowship, 2003–2005

    Civil and Environmental Engineering Graduate Student Fellowship, 2002–2003

    Tau Beta Pi Honor Society, 2000

LICENSES & CERTIFICATIONS

Licensed Professional Engineer, California, #77047

LANGUAGES

  • Italian
  • French

Publications

Shields WJ, Ahn S, Pietari J, Robrock K, Royer L. Atmospheric fate and behavior of POPs. O’Sullivan, Sandau C (eds), Environmental Forensics for Persistent Organic Pollutants. Chennai: Elsevier, pp. 199–290, 2014.

Robrock KR, Coelhan M, Sedlak DL, Alvarez-Cohen L. Biodegradation of polybrominated diphenyl ethers by aerobic bacteria. Environ Sci Technol 2009; 43(15):5705–5711.

Zeng X, Robrock KR, Simonich SL, Alvarez-Cohen L, Korytár P, Barofsky DF. Application of a congener specific degradation model to study photodegradation, anaerobic biodegradation, and Fe0 reduction of polybrominated diphenyl ethers. Environ Toxicol Chem 2009; 29(40):770–778.

Robrock KR, Coelhan M, Sedlak DL, Alvarez-Cohen L. Aerobic biotransformation of polybrominated diphenyl ethers (PBDEs) by bacterial isolates. Environ Sci Technol 2009, in press.

Zeng X, Simonich SL, Robrock KR, Korytár P, Alvarez-Cohen L, Barofsky DF. Development and validation of a congener specific photodegradation model for PBDEs. Environ Toxicol Chem 2008; 27(12):2427–2435.

Robrock KR, Korytar P, Alvarez-Cohen L. Pathways for the anaerobic microbial debromination of polybrominated diphenyl ethers. Environ Sci Technol 2007; 42(8):2845–2852.

He J, Robrock KR, Alvarez-Cohen L. Microbial reductive debromination of polybrominated diphenyl ethers (PBDEs). Environ Sci Technol 2006; 40(14):4429–4434.

Presentations

Mesard PM, Robrock KR. Forensic evaluation and allocation of heavy metals in surface water runoff from multiple sources to an urban lake. Battelle Sediment Conference, New Orleans, LA, January 2015. 

Robrock KR. Is human activity a good predictor for polybrominated diphenyl ether (PBDE) concentrations in the Pacific Northwest? Groundwater Resources Association of California, Emerging Contaminants Conference, Concord, CA, February 2014.

Robrock KR, Cushing C, Kierski M. Polybrominated diphenyl ether concentrations in Columbia River sediment and fish compared to other areas in North America. Poster presentation. SETAC, Long Beach, CA, November 2012.

Robrock KR. Biotransformation of polybrominated diphenyl ethers by aerobic bacteria. IWA/GRA Micropol & Ecohazard, San Francisco, CA, June 2009.

Robrock KR. Aerobic biodegradation of Polybrominated Diphenyl Ethers (PBDEs) by PCB-degrading bacteria. Norcal SETAC Conference, Berkeley, CA, May 2008.

Robrock K, Alvarez-Cohen L. Degradation of polybrominated diphenyl ethers by aerobic PCB-degrading organisms. Poster presentation, NIEHS Superfund Basic Research Program Meeting, Durham, NC, 2007.

Robrock KR. Biodegradation of Polybrominated Diphenyl Ethers. California Water Environment Association Student Night, Oakland, CA, March 2007.

Robrock KR, Korytar P, Alvarez-Cohen L. Anaerobic microbial degradation pathways for seven environmentally relevant PBDE congeners. Poster presentation, 107th General Meeting for the American Society for Microbiology, Toronto, Canada, 2007.

Robrock KR, He J, Korytar P, de Boer J, Alvarez-Cohen L. Degradation of Polybrominated Diphenyl Ethers (PBDEs) by Dehalococcoides Species. Poster presentation, Groundwater Resources Association Emerging Contaminants in Groundwater, Concord, CA, 2006.

Robrock KR. Anaerobic Microbial Debromination of Polybrominated Diphenyl Ethers. Association for Environmental Health and Sciences West Coast Conference, San Diego, CA, March 2006.

Robrock KR, He J, Korytar P, de Boer J, Alvarez-Cohen L. Degradation of Polybrominated Diphenyl Ethers by Dehalococcoides Species. Poster presentation, 106th General Meeting of American Society for Microbiology, Orlando, FL, 2006.

Robrock KR. Anaerobic Microbial Debromination of Polybrominated Diphenyl Ethers. Dioxin 2005 Conference, Toronto, Canada, August 2005.

Robrock K, Alvarez-Cohen L. Effect of triclosan on denitrifying bacteria. Toxic Substances Research & Teaching Program Annual Conference, Sacramento, CA, 2005.

Robrock K, Alvarez-Cohen L. Triclosan: Should we worry? Effects of triclosan on environmental microbial communities. Toxic Substances Research & Teaching Program Annual Conference, San Diego, CA, 2004.

Project Experience

Microbiology

Conducted a mass balance calculation for a gasoline release from an underground pipeline into a fractured bedrock aquifer. Calculated biodegradation rates for BTEX compounds from field data and estimated the mass of gasoline that had biodegraded since the release. Using VENT2D modeling, estimated the mass of gasoline that had evaporated from the soil shortly after the release.

Compiled anaerobic biodegradation rates for a cap design of contaminated lake sediments, and calculated the range of expected half-lives. The contaminants of interest included BTEX, PAHs, chlorinated benzenes, phenol, and PCBs.

Reviewed chemical and biological data at a TCE-contaminated site undergoing enhanced bioremediation. Based on 16S Dehalococcoides and dechlorinating enzyme gene counts, assessed the progress of the remediation and recommended additional substrate injection.

Conducted a literature review of bacteria associated with foot odors in healthy people for an FDA 510K submission for anti-embolism stockings treated with the antimicrobial triclosan. Devised a testing protocol for determining the antimicrobial effectiveness of the stockings against appropriate odor-causing foot bacteria. Oversaw antimicrobial testing of stockings and determined appropriate odorous chemicals to analyze during a sniff test.

Environmental Engineering

Prepared a soil management plan for the demolition of a former coastal power plant in California. The plan was meant to assist with identifying, sampling and disposing of soils contaminated with PCBs, heavy metals, TPH and PAHs during removal of demolished structures at the site. Prepared sampling plans for PCB-impacted concrete following EPA guidance in 40 CFR 761 and coordinated with the EPA to obtain approval for disposal of PCB-impacted concrete. Prepared a soil sampling plan for determining any residual contamination after completion of demolition activities.

Prepared a soil management plan for the demolition of a former coastal power plant in California. The plan was meant to assist with identifying, sampling and disposing of soils contaminated with PCBs, heavy metals, TPH and PAHs during removal of demolished structures at the site.

Reviewed remediation work conducted at a former dry cleaner in northern California to assess whether it was conducted according to the standards of the practice at the time. Reconstructed historical release information and evaluated quantities of PCE present in the sub-surface to determine whether PCE vapors in indoor air at an adjacent facility originated from PCE left in the sub-surface after remediation activities were completed.

Investigated causes of flooding at a residential development from a stormwater system consisting of an underground stormwater sewer and a natural drainage channel. Oversaw topographic surveying and sewer surveying. Developed hydraulic grade lines and calculated volume of sediment to be removed to restore conveyance of stormwater through the channel.

Conducted a Reasonable Potential Analysis (RPA) for stormwater runoff at a site in Southern California as part of an NPDES permit renewal. The RPA included metals, chlorinated organics, and phthalates. Reviewed and identified problems with an RPA conducted by the local RWQCB. 

Conducted an RPA for metal-containing effluent discharged during ship building and ship launching activities at a facility in Southern California as part of an NPDES permit renewal. 

Oversaw daily dredging activities of PCB-contaminated sediment in a ship-loading channel in New York harbor for a metal recycling facility. The sediment was chemically stabilized and used for an experimental project involving stabilization of mining-impacted hillsides in Pennsylvania. Oversaw construction of a golf course on a brownfield using the stabilized sediment. Handled an extension of the dredging permit and performed field sampling. Assisted with design of the dredged channel. 

Modeled the fate and transport of pesticides and herbicides sprayed at a Christmas tree farm in Washington State that were claimed to have impacted an adjacent cattle ranch. Modeled aerial transport, deposition of liquid droplets, and transport to an adjacent stream via stormwater runoff. Using biodegradation half-lives, estimated residual pesticide concentrations in downgradient vegetation and surface water runoff six months after spraying. 

Investigated chemical compounds likely historically present in stormwater runoff from a variety of industries with stormwater outfalls that discharged into a canal. Determined the historical time frames in which stormwater runoff could have discharged to the canal and the specific discharge locations for each industry. Developed an allocation matrix for remedial design costs and an allocation method for contributions from stormwater runoff based on surface area for each property as a proxy for historical stormwater flow rates. 

Compiled water quality data, specifically hardness and sodium levels, for drinking water in major metropolitan cities throughout the United States. The data were to be used by a consumer project manufacturing client to determine the appropriate water quality to use in product testing.

Chlorinated Solvents

Investigated sources of chlorinated solvents to a VOC plume in Orange County, California. Evaluated the impact of a former transducer manufacturer to the groundwater VOC plume from post-remedial residual PCE concentrations in soils compared to other industrial sites in the region. Calculated potential PCE mass contribution to the VOC plume.

Investigated potential sources, including sewer releases, contributing to a large commingled PCE plume originating from three adjacent dry cleaners in Northern California. Determined strategies to allocate remedial costs between the parties. 

Analyzed contamination scenarios for PCE in dry cleaning facilities, determining the quantities of PCE that could be released to sewers from various disposal methods. Quantified potential releases to the subsurface through leaking sewer pipes.

Conducted a cost estimate for remediation of a PCE plume at a dry cleaner facility in Oakland. Analyzed data to determine extent of contamination and possible remediation strategies.

Investigated the timing of release of PCE at a dry cleaner facility in northern California. Evaluated costs for the on-going remediation activities.

Conducted a National Contingency Plan (NCP) compliance study for remediation activities and costs conducted at a large former manufacturing site in New York impacted with chlorinated solvents in a CERCLA cost recovery litigation.

Conducted a source and timing investigation at a former dry cleaning operation in northern California destroyed by a fire. Evaluated potential release mechanisms of PCE due to the fire.

Evaluated whether a Phase I Environmental Site Assessment met the standards of the practice at the time in a case involving vapor intrusion from a PCE-plume into an adjacent residential apartment building.

Other Contaminants

Conducted an assessment of PBDE concentrations in fish and sediments in the Columbia River near a consortium of industrial facilities in Trail, British Columbia, Canada. Calculated doubling times and compared concentrations to fish and sediments in other areas of the Pacific Northwest. Compared PBDE concentrations to human health effect and ecological screening levels to assess potential risks from local fish consumption and exposure to sediments for humans and animals. Evaluated potential sources contributing PBDEs to the region.

Investigated a PCB release associated with a vandalism event at a building undergoing demolition in Northern California. Using PCB fingerprints, determined the extent of PCB contamination associated with the vandalism event and previously existing PCB contamination. 

Investigated the sources of heavy metals for an urban lake contaminated with lead and other metals. Quantified the amount of lead present in the lake and yearly depositional patterns. Calculated the lead contamination from direct urban runoff and aerial deposition from an adjacent roadway from historical and present automobile use. Investigated other potential sources of lead from nearby residential, military, and industrial uses, and determined the total lead input from all sources of runoff in the watershed.

Investigated sources of heavy metals, particularly copper, nickel and zinc, at a ship building facility to assist with NPDES compliance for water discharged to the San Diego Bay from the graving dock. Determined quantities of heavy metals in the storm water drainage system at the site draining to the graving dock. Conducted water sampling to determine rates of heavy metal leaching from ship hulls and other surfaces in the graving dock. Assisted with creation of a water quality model to compare predicted copper loadings into the graving dock with actual measured quantities. Based on modeling results, determined the most important sources of copper to the graving dock. Determined several readily-implementable recommendations for the ship builder to reduce copper loadings to achieve compliance with NPDES permit requirements.

Conducted an assessment of historical hexavalent chromium concentrations in groundwater for a drinking water dose reconstruction case in California.

Determined the mass allocation to the groundwater contamination from evaporation ponds at a coal-burning power plant in Nevada. Modeled seepage of salts into the underlying groundwater for each evaporation pond. Calculated environmental cleanup costs owed by the two co-owners of the power plant.

Evaluated investigation and remediation activities for a perchlorate groundwater plume for a CERCLA cost recovery litigation. Evaluated investigations, remedial activities and removal actions conducted at the site for compliance with National Contingency Plan (NCP). Determined costs associated with past environmental investigation and remedial activities and evaluated and critiqued proposed costs for future remediation activities. Investigated other potential sources of perchlorate in the area that could be impacting groundwater. Evaluated groundwater data and regional hydrogeology to assess the extent of the groundwater perchlorate plume and potential migratory pathways within the regional aquifer system. Assisted with groundwater modeling to determine future migration pathways and to reconstruct historical migration pathways for the groundwater plume. Oversaw vacuum dust sampling in homes for dioxin contamination of residential dust.

Devised a sampling plan and conducted sampling of a hydrocarbon sheen on an urban estuary using a sheen-specific Teflon® net sampling device. Oversaw chemical fingerprinting of the collected sheen for source identification.

Devised a sampling plan and conducted sampling of soils and hydraulic fluids in 55-gallon drums for chromium, dioxins, and VOCs from a former metal-plating facility.

Knowledge

News & Events

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Environmental Engineering, University of California, Berkeley, 2008
  • M.S., Environmental Engineering, University of California, Berkeley, 2003
  • B.S., Earth and Environmental Engineering, Columbia University, 2001
  • Tien Scholar for Environmental Science and Biodiversity, 2007–2008

    University of California Toxic Substances Research and Teaching Program Fellowship, 2003–2005

    Civil and Environmental Engineering Graduate Student Fellowship, 2002–2003

    Tau Beta Pi Honor Society, 2000

LICENSES & CERTIFICATIONS

Licensed Professional Engineer, California, #77047

LANGUAGES

  • Italian
  • French