Risk-Based Decisions, Inc.
Environmental Cleanup Consulting Company
Sacramento, California: (916) 923-0570 |
Investigation and Remediation of
Contaminated Soil and Groundwater from a former Dry
Risk-Based Decisions, Inc. undertook
characterization of the release of contaminants,
primarily PCE, from a former dry cleaner located in
a strip mall adjacent to a school and residential
properties. A statistically predictive
sampling plan revealed PCE in soil gas at:
several tens of millions of micrograms per cubic
meter near the source.
tens of thousands of micrograms per cubic meter as
far as 300 feet away from the former dry cleaner.
Groundwater was at about 60 feet below ground
surface and impacted at about 200 ppb PCE.
RBDI reasoned that if the contamination had spread
so far laterally within the soil column, the
judicious placement and screening of soil vapor
extraction (SVE) wells should remove the PCE from
the soil. Some SVE wells were screened to see if PCE
in groundwater could also be reduced using just the
In five years, both soil and the groundwater
have been cleaned up to residential standards.
Vapor intrusion modeling followed by confirmatory
Indoor air testing showed no risks to tenants at the
strip mall. The California Water Boards has issued a
Further Action letter (June 2017)
This is our second successful cleanup of PCE
in both soil and groundwater using just a SVE system
among many other successful chlorinated solvent site
cleanups. Site investigation through regulatory
site cleanup was
achieved at about 60% of the approved budget.