Meet Us

The principals of CPF have over 80 years of combined experience helping clients with forensic, regulatory, and technical problems associated with the manufacture, use, regulatory approval, and disposal of chemicals, biological materials, physical agents and commercial products. We offer an effective scientific team that has been consulting together for more than 25 years in addition to our individual experiences in industry, government and academia. We have also established an extensive network of professionals in allied fields of science and engineering who can provide additional specialized services as members of the CPF team through flexible partnerships and teaming arrangements.

Paul C. Chrostowski, Ph.D, QEP


Ph.D. Environmental Engineering and Science, Drexel University, Philadelphia, PA (1981).

M.S. Environmental Science, Drexel University, Philadelphia, PA (Environmental Chemistry and Health Specializations, USPHS Traineeship) (1979).

B.S. Chemistry, University of California, Berkeley, California (American Chemical Society Certified, Honors) (1976).

Professional Certification

Dr. Chrostowski is a Qualified Environmental Professional (QEP) (#02970014)


Dr. Chrostowski is a founding member of CPF Associates, Inc. He is an environmental engineer, applied toxicologist, and chemist with more than 40 years’ experience in environmental science and engineering work on behalf of both government and private clients. Previously, he was Director of Environment, Health & Safety programs at The Weinberg Group, Vice President and Senior Science Advisor at ICF/Clement, Senior Scientist at EA Engineering, Science & Technology, Assistant Professor at Vassar College, a consultant in private practice and a pollution control/industrial hygiene technician in industry. He has specialized experience in the scientific and technical aspects of federal, state, and international regulatory programs including the CAA, CERCLA/SARA, RCRA, TSCA, FIFRA, OSHA, waste management technologies and ecological assessment. In addition, he has directed projects involving environmental chemistry, remedial investigation, pollution control, regulatory affairs, and quality assurance. In addition to EPA and OSHA programs, Dr. Chrostowski has developed substantial expertise in indoor air quality, the risk analysis of hazardous material transportation, and the risk analysis of FDA-regulated products. Dr. Chrostowski has conducted research into environmentally-friendly new product development and has directed registration and approval petition processes for the environmental and occupational aspects of new products, pesticides, and pharmaceuticals. Dr. Chrostowski’s research interests include the behavior of complex mixtures, pharmacokinetics, application of quantitative management tools to environmental strategy development and evaluation, biomonitoring, use of epidemiology in risk assessment, mass transfer phenomena, applied statistics, and mathematical modeling for risk management decision making. Dr. Chrostowski practices at the state-of-the-science frontier applying innovative tools such as compound specific isotope analysis, polymerase chain reaction, diagnostic genomics, and microbial fingerprinting to a broad array of environmental problems. Dr. Chrostowski is active in numerous professional societies and expert panels and has authored or co-authored about 100 publications or presentations in the environmental field. In addition to his technical work, Dr. Chrostowski has taught university-level environmental sciences and has presented expert testimony in litigation cases, regulatory, and permitting hearings and public meetings and has conducted technical negotiations on behalf of private and governmental clients.

Sarah A. Foster


M.S., Environmental Health Sciences, Air Pollution Control Program Harvard University School of Public Health, Cambridge, MA (1985).

B.A., Political Science (Environmental Law/Energy Policy), Williams College, Williamstown, MA (1981).


Ms. Foster is a founding member of CPF Associates, Inc. She has 30 years of consulting experience in environmental health sciences, with expertise in developing strategies for and conducting exposure and risk analyses related to environmental and public health issues. Previously, Ms. Foster was a Senior Consultant with The Weinberg Group, a Project Manager at the Clement Division of ICF/Kaiser, an Environmental Analyst with the U.S. Environmental Protection Agency’s Office of Policy Analysis, and a researcher for the Harvard Public Health School’s Six City Study. Her areas of specialty include the application of quantitative methods for evaluating potential risks, including multiple chemical, multiple exposure pathway risk assessments for air toxics sources and waste management technologies, Monte Carlo simulation, environmental epidemiology, and good risk assessment practice principles. She has managed and performed over 100 comprehensive risk assessment projects for combustion sources, waste sites and consumer and commercial products, with specialized knowledge in the conduct of risk assessments for municipal solid waste combustors, hazardous waste incinerators, landfills, and emissions from industrial facilities. She has developed and applied a wide variety of environmental fate and transport models, and critically analyzed and compiled a broad array of human activity pattern data for use in exposure assessment projects involving inhalation, ingestion and dermal pathways as well as the use of household tap water. She has also developed and applied innovative risk assessment methods to assess risks from combustion sources, indoor water use, waste sites, and pesticides and anti-microbial materials that include geostatistical kriging and stochastic simulation. Ms. Foster has also researched the historical state-of-knowledge of toxicological and environmental health sciences issues. In conjunction with many of her risk assessment and regulatory toxicology projects, Ms. Foster has provided risk communication and technical support for public, regulatory and permit hearings, and for litigation. Ms. Foster has numerous publications focusing on risk assessment, air toxics and emissions from industrial sources and is a member of several professional societies. She also has considerable experience in developing and conducting risk assessment training courses.

Lorraine J. Pearsall


M.A. Chemistry, Vassar College, Poughkeepsie, NY (1985).

B.A. Chemistry (Departmental and General Honors), Vassar College, Poughkeepsie, NY (1981).


Ms. Pearsall is a founding member of CPF Associates, Inc. She is an environmental scientist with over 20 years experience in environmental and analytical chemistry, exposure and risk assessment, and hazardous waste site investigation and remediation. Previously, she was a Managing Consultant at The Weinberg Group, a Project Manager at the Clement Division of ICF/Kaiser, a Senior Scientist at Martin Marietta Environmental Systems, and a Staff Scientist at Environ Corporation. Ms. Pearsall assists clients in developing risk-based remediation strategies that minimize liabilities under RCRA, CERCLA/SARA, TSCA, OSHA and at property transfer and acquisition sites. Her specialty is in the development of innovative approaches and creative solutions for approaching waste site problems, bringing to bear her extensive knowledge of cost recovery pitfalls in addressing these issues. Ms. Pearsall has worked under traditional Superfund programs, the Superfund Accelerated Cleanup Model (SACM), state hazardous site programs, and RCRA corrective action. She is an experienced negotiator with USEPA and state regulatory authorities on issues surrounding remedy selection and cost-effectiveness, exposure, risk, cleanup goals, divisibility of liability, cost allocation, and remedial strategies. During her career, she has performed hundreds of risk analyses for hazardous waste site projects on behalf of public or private sector clients. Her training in environmental and analytical chemistry has benefited her clients in matters pertaining to chemical fate and transport evaluations, source apportionment, testing strategies for the environmental behavior of new products, data validation and review, analytical laboratory problems, statistical interpretation of data, and the development of new analytical methods. Because of her practical experience and technical training, Ms. Pearsall is often retained to provide expert review of the quality of risk assessments, sampling plans, compliance programs, remedial designs, the need for remediation, and reasonableness of remediation costs. She also has served as a guest lecturer at Johns Hopkins University and has developed and conducted numerous risk assessment training courses.