Phase III Environmental Cleanup & UST Closure in California
Encon Environmental manages Phase III cleanup and UST cleanup fund site closures for contaminated properties across California, with a strong focus on the greater Los Angeles region and other industrial corridors.
Building on Phase I and Phase II findings, we use a multi-tiered remediation approach to move sites toward low-risk closure, efficient use of budgets, and alignment with State and Regional Water Board expectations.
- Closure-focused strategies for LUST and UST cleanup fund sites.
- Aggressive yet targeted remediation to reduce risk and shorten cleanup timelines.
- Support for property sales, refinancing, and redevelopment throughout California.
From Phase I & Phase II to Phase III Cleanup
Phase III cleanup brings together everything learned during Phase I and Phase II and turns it into a focused plan for remediation and closure.
Phase I Site Assessments identify potential environmental concerns. Phase II investigations use subsurface sampling to confirm whether impacts are present in soil, soil vapor, or groundwater. Phase III then uses those results to design and implement cleanup actions that reduce risk to acceptable levels for current or planned land use.
Encon’s staff includes engineers, geologists, and field crews who understand both the technical requirements of California regulatory programs and the practical realities of working at active facilities and redevelopment sites.
- Phase I ESA: identification of recognized environmental conditions (RECs).
- Phase II investigation: confirmation and delineation of subsurface impacts.
- Data evaluation and conceptual site model development.
- Phase III cleanup planning and workplan development.
- Implementation of remedial actions and monitoring toward closure.
Multi-Tiered Remediation and Low-Risk Closure Strategies
Since the mid-1990s, Encon has helped close many LUST and UST cleanup fund sites by using a multi-tiered remediation approach. We match the level of effort to the level of risk—focusing on actions that materially change risk and support low-risk closure determinations where appropriate.
For sites that have been in cleanup for more than five years, we often find that incomplete site characterization, ineffective remedial technologies, or underfunded budgets are slowing progress. Encon reviews historical data, identifies gaps, and develops a realistic action plan that moves the site toward closure rather than simply repeating past efforts.
- Independent review of historical soil and groundwater data.
- Identification of data gaps and targeted supplemental investigation.
- Evaluation of current cleanup progress versus closure criteria.
- Development of a practical UST cleanup action plan.
- Coordination with State and Regional Water Boards on low-risk closure paths.
Phase III Cleanup Services for Contaminated Properties
Encon works with owners, operators, and buyers of contaminated properties to design and implement cleanup programs that prepare sites for continued use or redevelopment. We consider your end use goals—whether that is continued industrial operations, conversion to retail, or development of more sensitive uses such as schools or housing.
Our cleanup programs are designed to be technically defensible, budget-conscious, and compatible with ongoing facility operations wherever possible.
- Remedial excavations and off-site soil disposal or treatment.
- Bio-remediation and chemical injection programs.
- Soil vapor extraction and other vapor control systems.
- Lead, PCB, and arsenic soil remediation strategies.
- UST / waste oil tank, hydraulic lift, and clarifier removal and closure.
Restarting Stalled Cleanup and UST Fund Sites
Many California sites have been in a “cleanup” phase for years without a clear path to closure. Sometimes investigations were never fully completed; in other cases, remediation systems have produced diminishing returns without a change in strategy.
Encon takes professional pride in closing challenging UST cleanup fund sites. We focus on what is needed to move a site from long-term status to closure eligibility, balancing technical requirements, regulatory expectations, and real-world budget constraints.
- Review historical reports, data, and agency correspondence.
- Determine why closure has not yet been achieved.
- Refine the conceptual site model and closure strategy.
- Propose focused actions with defined end points.
- Coordinate directly with regulators to align on a closure path.
Need Phase III Cleanup or UST Closure Support in California?
If your site has been in assessment or cleanup for years without a clear end point, or you are planning redevelopment of an impacted property, Encon Environmental can help design a Phase III cleanup program that targets closure.
