The goal of Phase 2 soil and groundwater investigations and subsequent remediation is to obtain environmental regulatory case closure. Closure of leak cases by regulatory agencies requires satisfaction of the following criteria:

  1. the source of contamination has been removed
  2. contaminant concentrations are decreasing with time
  3. the extent of contamination in soil and water is known
  4. there is no risk to human health and safety, sensitive receptors or the environment.

Recent conversations by ERAS with local regulators indicate that the State of California is allowing for and requesting local agencies to evaluate the possibility of risk-based closures.

Risk based analysis may involve evaluation of vapor intrusion into buildings. (see above for information on soil gas and indoor air risk) However, it also allows for case closure even with the presence of soil and groundwater contamination.

In areas of known soil and groundwater contamination by solvents (VOCs) such as dry cleaning solvents, the volatile chemicals can migrate into nearby buildings, crawl spaces or other enclosed space.

The vapor intrusion risk can occur as a result of contaminated groundwater which has migrated beneath the property from an up-gradient, off-site source. These vapors present a health risk to the occupants in high concentrations.

The affected property owner usually has no responsibility for the cleanup of contamination. However, owners and lenders face potential liability from the occupants of the building and may have to take steps for mitigation of contaminated vapors.

If soil or groundwater contamination is suspected, Phase 2 soil vapor sampling is conducted using specific procedures and specially prepared samplingcontainers. Results of laboratory analysis can be compared with Regional Water Quality Control Board (RWQCB) Environmental Screening Levels (ESL).

If soil vapor results exceed these levels, indoor air sampling should be conducted by a Certified Industrial Hygienist (CIH) to evaluate the risk to occupants and potential liabilities to owners.

ERAS has over 25 years of experience in performing Phase 2 soil and groundwater investigation services. Our low overhead and focus on clear efficient goals for our sampling and investigation projects provides a blend of quality and value unique in the industry.
ERAS has considerable experience with current environmental regulations and negotiating skills with environmental regulators.
We can provide sampling services for the following:

  1. waste characterization and disposal
  2. shallow soil sampling for redevelopment
  3. soil and groundwater investigation for due diligence
  4. workplan preparation, soil boring and monitoring well installation
  5. soil vapor and sub-slab sampling
  6. risk assessment and case closure
  7. monitoring well monitoring and sampling
  8. remediation planning and oversight

Key Conclusion: The main goal and purpose of a Phase 1 assessment is to determine the need for a Phase 2 subsurface investigation.
A Phase 1 ESA is an evaluation of environmental conditions based on available agency and other printed and published documents. There are some situations, based on current, previous or nearby uses that the conclusions of an ESA may recommend a Phase 2 project. In Phase 1 ASTM standard terminology these are referred to as recognized environmental conditions (REC).
REC may include 1) a current condition such as the presence of an underground storage tank (UST) or sump used for chemicals, 2) the current or historical documented spillage, leakage or dumping of hazardous substances, 3) a former UST or other underground oil or chemical storage device that was removed but there is not sufficient subsurface sampling data, 4) an adjacent or up-gradient site is already a known leak case

An adequate Phase 1 MUST identify specific problems in specific locations involving specific chemicals (i.e. why, where and what?). It is not possible to abolish all risk regarding subsurface environmental conditions. It is never possible to test all areas on a Property for all chemicals. The best a Phase 2 can accomplish is to minimize the risk of a specifically identified problem. It is not acceptable to recommend Phase 2 sampling and then miss the target area. Yet this is an example of a recommendation that is presented in poorly prepared ESA reports.
Imprecise statements in an ESA report such as “based on historical uses of the Property, there may have been releases of petroleum products and solvents to the subsurface” are essentially meaningless. That is because it does not identify why, where and what implies that any chemical contaminant could be present in any location on the Property. If a Phase 2 investigation is performed based on that recommendation, there will be questions about why, where and what?