ARCADIS' responsibilities entail directing all aspects of negotiation and developing responses to a Correction Action Order on Consent (CAOC) from the State, to address indoor air, soil, and groundwater impacted by TCE, 1,1,1-TCA, 1,1-DCE, and xylene within a residential area resulting from past operations at the Materials Testing Laboratory.  Responsibilities include designing and managing the construction of an in-situ cometabolic biological remediation system for the treatment of groundwater impacted with chlorinated hydrocarbons. 

System construction included serving as the General Contractor, managing vertical and horizontal drilling, building, HVAC and electrical contractors while performing much of the piping and equipment installation and PLC programming activities.

Through our initial involvement, we redirected the scope of remediation by presenting the regulatory agency evidence documenting the presence of an alternative groundwater plume and chlorinated hydrocarbon source through groundwater finger printing and mass flux studies.  These changes in the site characterization and remediation effort saved the client more than $4 million.  Additionally, we developed and implemented a hydro-fracturing process resulting in a 100 percent increased injection well efficiency at a lower cost resulting in a $380,000 savings during construction.

Major project accomplishments include:

• Preparation of interim groundwater corrective measures plan (GWCMP) to demonstrate that upgrading the existing interim remedial measure (IRM) was a more cost-effective containment alternative than implementing a new funnel and gate system (at 60 feet bgs in bedrock).
• Design upgrades for existing IRM system to increase groundwater capture and system operational reliability (90 percent uptime) to ensure compliance with the CAOC.
• Preparation of a final GWCMP to demonstrate installation of an enhanced biological remediation system as the most cost-effective groundwater remediation alternative.
• Permitting, private property access negotiations, and construction of the enhanced biological remediation system.

Development of an improved relationship with Colorado Department of Public Health and Environment (CDPHE) and maintained compliance with CAOC.
ARCADIS continues to provide a wide variety of services for this complex, multi-media impacted site, including:

• Implementation of indoor air corrective measures including indoor air monitoring, data analysis, public protection, sub-slab depressurization systems at six apartment complexes and 32 residential homes, monitoring, and maintenance.
• Implementation of groundwater corrective measures including O&M of the groundwater remediation systems and completion of performance monitoring and analysis.