Ms. Zemo is an experienced expert witness and
confidential litigation consultant. She has been deposed, prepared declarations
and expert opinion reports, and has testified in binding arbitration hearings, jury
trial and bench trial. A complete listing
of Ms. Zemo’s expert witness testimony is available upon request. Representative
Witness for Defendant, Diesel/Bunker Fuel Remediation, Former Railyard. Ms. Zemo was an expert in the case City Parkway v. UPRR (U.S. District
Court, District of Nevada) in which she rendered written opinions and deposition
testimony regarding whether defendant had met regulatory requirements for
investigation and remediation even though “TPH” was found in shallow soil
during property redevelopment after remediation was complete. Her opinions addressed areas including
regulatory compliance, the uncertain nature of the “TPH”, and health-protective
Witness for Plaintiff, Age-Dating of Diesel Release. Ms. Zemo was
an expert in the case Blech v. Oceano
Packing (case was arbitrated) in which she rendered written opinions,
deposition testimony and hearing testimony regarding the age-dating of a diesel
release to surface soil.
Consultant for Defendant, Dry Cleaner Litigation. Ms. Zemo
is retained as a confidential consultant to a dry cleaner equipment
manufacturer on a portfolio of several sites.
Services include assessment of: the fate and transport of PCE, release
sources, and cost estimates for site remediation.
Witness for Joint Defendants, Diesel Release. Ms. Zemo was an expert in the case Stockton Redevelopment Agency vs. BNSF and
UPRR (U.S. District Court, Eastern District of California) in which she
rendered written opinions and deposition testimony regarding the age-dating of
the diesel release, the source of diesel and other chemicals found in site
soil, and the appropriateness of the remedial actions performed by
plaintiff. Ms. Zemo testified at the
■ Fact Witness
and Non-Retained Expert for Defendant, and Testimony at Jury Trial, Chlorinated
Solvent Plume. Ms. Zemo testified in
the case Clark vs. UPRR, et al
(Sonoma County Superior Court) regarding her previous work characterizing a
chlorinated solvent plume that plaintiffs alleged had migrated to their
properties. She explained to the jury about the techniques used in her work,
her evidence that the data were representative, and that the plume had not
migrated as alleged. Her testimony was
essential to the jury’s finding for the defense.
Witness for Defendant, Marine Sediments Offshore of Creosote Facility. Ms. Zemo was an expert in the case Pacific Sound Resources v. Burlington
Northern Santa Fe Railway Corporation (U.S. District Court, Western
District of Washington) in which she rendered written opinions and deposition
testimony regarding her forensic evaluation of the sources (petrogenic v.
pyrogenic, and “urban background” v. site specific) of PAHs in sediments of
Elliot Bay, Seattle, Washington.
Consultant for Joint Defense Group, MTBE Litigation. Ms. Zemo was retained as part of a
confidential consultant team for a large case focused on MTBE releases in the
Central Valley of California. Ms. Zemo
provided input regarding the timing, magnitude and migration of releases from
multiple facilities, and the efficacy of remedial actions at each facility.
Consultant for Defendant, Mixed Releases: MGP Tar, Heavy Fuel Oils and Diesel. Ms. Zemo was engaged to distinguish among
impacts caused by MGP tars and heavy fuel oils that migrated downgradient into
a separate diesel plume. It was alleged
that these fuels and tars had also impacted near-shore sediments. Forensic interpretations of soil and
sediments were primarily centered on previously-existing “TPH” and PAH data,
and included evaluating chromatograms and constituent ratios. The evaluation was successful in
distinguishing the sources and costs were allocated accordingly.
Witness for Defendant, Dry Cleaner Litigation. Ms. Zemo was retained as an expert in the
case Adobe Lumber v. Taecker et al
(U.S. District Court, Eastern District of California) in which she provided
written opinions and deposition testimony regarding PCE impacts to soil and
groundwater, and remediation cost estimates.
Witness for Cross-Defendant, Co-Mingled Dry Cleaner and Gasoline Station
Plumes. Ms. Zemo served as a
technical expert in the case Clark v.
Boyett et al (Sonoma County Superior Court) for a property owner impacted
by both a PCE plume emanating from a dry cleaner and a BTEX plume from a former
service station. Ms. Zemo provided
remedial alternatives and cost estimates for her client’s property and assisted
during mediation among all the parties so that a comprehensive remedial
strategy was selected.
Witness for Defendant, Solvent Storage Terminal Litigation. Ms. Zemo was retained as an expert in the
case Richmond Redevelopment Agency v.
Petromark, Inc, et al (U.S. District Court, Northern District of
California) in which she was to render opinions regarding impacts of PCE, TCE,
and other chlorinated solvents to soil and groundwater and the appropriateness
of remedial alternatives and cost estimates put forward by the plaintiff. The case settled one day before submittal of
Witness for Joint Defense Group, State-Wide Proposition 65 Litigation. Ms. Zemo was
retained by a joint defense group of eight oil companies in the case Communities for a Better Environment v.
Tosco Corp., et al. (San Francisco County Superior Court). This case
centered on the timing of gasoline releases to the subsurface at hundreds of
service station sites within California.
She submitted to the Court a technical declaration that explained the common
factors that influence analytical results and product thickness at fuel release
sites, and the challenge of distinguishing between a new release and
site-specific variability caused by non-release factors. In opposition to
plaintiff’s expert, Ms. Zemo’s declaration included site-specific opinions
about timing of release and factors causing concentration changes in monitoring
Consultant for District Attorney.
Ms. Zemo provided confidential consulting to the Santa Clara County (CA)
DA’s Office Environmental Enforcement Group in the prosecution of a case
focused on the timing of releases from a retail service station and the delay
in remediating an MTBE plume and source area.
Consultant for Defendants, Port and Other Redevelopment Properties. Ms. Zemo has been engaged on several matters
for industrial clients in which Port authorities or other local government
entities have claimed damages for remedial costs associated with property
redevelopment under either the Polanco Act or other laws. Her services have focused on environmental
forensics (either product/material identification and attribution, or timing of
the release) and/or appropriateness of the remedial action contemplated or
undertaken by the Port or redevelopment agencies. Constituents include petroleum, lead, tars,
and chlorinated solvents.
■ Member of Neutral Consultant Team. Ms. Zemo was
part of a neutral consultant team engaged by counsel for four parties (three
major oil companies and a county department) to collect and evaluate data from
four adjacent former bulk fuel storage facilities for developing remedial cost
allocations among the parties. The project included performing a CPT/LIF
investigation for further source delineation (residual NAPL) and developing a
3-D visualization model to display all site data. Ms. Zemo evaluated the
correlation between the new CPT/LIF results and historical soil TPH data in
defining source areas. Ms. Zemo was
subsequently engaged as the neutral technical assistant to the mediator during
cost allocation deliberations.
■ Expert Witness for Defendant, Product Identification
Based on “TPH”. This case
focused on TPH data that plaintiff claimed proved hydraulic oil contamination to
plaintiff’s soil and creek water. After
reviewing the chromatograms and other lab data, Ms. Zemo concluded that the
“TPH” detections resulted from organic interferences to the measurement, and
that no petroleum was present in the samples.
She collected site-specific samples of organic material (twigs, pine
needles, leaves) that produced a fingerprint that matched plaintiff’s
Technical Consulting for Settlement Discussions. This
assignment centered on the timing and migration of multiple fuel releases at an
operating bulk storage terminal that changed ownership. Ms. Zemo argued to
USEPA Region 9’s in-house counsel and project officers that the previous owner
should be added to the site cleanup order because they were responsible for
fuel releases prior to the property transfer date. Ms. Zemo presented the
forensic chemistry basis for age-dating the gasoline, which relied on comparing
ratios of key constituents that reflected changes in local refining practices
over specific time periods.
Witness and Testimony at a Jury Trial. Ms. Zemo served as a testifying
expert on the case Wine World v. The Beverage Source, et al (Sonoma
County Superior Court). Her opinions focused on the development and discovery
of a “smear zone” in the site subsurface subsequent to a fuel oil release, and
using site physical and hydrogeologic data to estimate when the release
occurred. Ms. Zemo also provided an opinion about the appropriateness of the
remediation completed by the site owner. Ms. Zemo was deposed and later
testified at the jury trial.
Witness for Arbitration of Service Station Portfolios. This case centered on the transfer of 200 retail service
station properties between two major oil companies and allocation of
environmental cost liabilities at each property. Ms. Zemo developed expert
opinions regarding the source and timing of releases, site-specific vs.
regional sources of MTBE in groundwater, interpretation of analytical data
(including interferences to “TPH” and MTBE quantification), and
appropriateness/efficacy of remedial solutions. Ms. Zemo submitted expert
technical opinion reports for six sites. In addition to opinions on the
source/timing of the release(s), each report contained a recommended cost
allocation between the two parties. She provided expert testimony to a panel of
three arbiters, including direct and cross-examination, at two arbitration
■ Other Expert Witness and Confidential Consulting
Assignments. Ms. Zemo has been engaged on several other
matters either to render expert opinions or to provide confidential technical
support centered on the issues of the interpretation of analytical data (in
particular, detailed evaluations of “TPH” data), forensic chemistry of product
composition, timing and magnitude of releases, site-specific vs. background
sources of chemicals, fate and transport of groundwater plumes, and
appropriateness/efficacy of remedial solutions.
These have included sites affected by petroleum hydrocarbons (crude oil,
refined products, and residuals), oxygenates (MTBE, TBA, etc.), tars,
chlorinated solvents, and PAHs. Sites have been in
California, Texas, Louisiana, Washington, Oregon, Wyoming, South Dakota, Utah, Idaho,
Canada, and Ecuador.