Updated Guidance on Conducting Preliminary Endangerment Assessments in California

If you own property undergoing assessment, it is crucial that the most recent regulatory guidance be applied so that the information you obtain is consistent with all new regulations. Regulatory agencies regularly update clean up levels and action levels. If you are responsible for site or property that was assessed using prior guidance and levels, you may need to have that assessment updated.

---

The main guidance document for Preliminary Endangerment Assessment (PEA) investigations is the PEA Guidance Manual, published in January 1994 with a second printing in June 1999. Since 1999, the PEA process has been the main procedure to investigate public school sites, military properties, and contaminated sites that have the potential to impact the public and the environment. Since 1994, sampling and analytical procedures, assessment and investigation methods, risk assessment parameters, regulatory requirements, and supporting guidance have been developed and accepted in the environmental site assessment and risk assessment community, both by consultants and regulators.
​
In October 2015 the DTSC released a revised version of the PEA Guidance Manual. The revised version of the PEA manual included the most recent guidelines used by environmental professionals to evaluate the potential for contamination at various sites. The main difference between the older version of the manual and the current version is the inclusion of the most up to date information, such as new screening levels and technical recommendations as laid out by the ASTM Standards.

​The revised manual has also incorporated regulatory guidance documents and advisories, updated environmental sampling, environmental media, contaminants of potential concern (COPC), and consideration of contaminant background levels. Examples include the following:

• Investigation procedures for Soil Vapor and Indoor Air Sampling,
• Evaluation of arsenic concentrations against background levels,
• Evaluation of inorganic lead and updated cleanup levels,
• Inclusion of methane and hydrogen sulfides,
• Inclusion of naturally occurring asbestos, radon, and radioactive materials,
• Short term action levels for TCE for residential indoor air,
• Updated toxicity and potency factors,
• Updated cleanup process including Removal Action Workplan (RAW), Land use Covenant (LUC), and Operation and Maintenance Plan/Agreement, if required.

​
A PEA must be conducted under the supervision of a State of California Licensed Professional Geologist (PG) or Professional Engineer (PE) Civil. In addition, the environmental consultant that conducts a PEA must have experience in working with the DTSC and knowledgeable of guidance documents and advisories for soil vapor, including volatile organic compounds (VOCs), methane and hydrogen sulfide, inorganic metals such as arsenic and lead, evaluation of health risks, and residential standards.

Have questions? Contact Alta Environmental at 888-608-3010