Client: USACE Kansas City District
CTI was contracted by USACE Kansas City District to reduce contaminant mass from groundwater via in-situ remediation at the Former Hutchinson Naval Air Station (Former HNAS) FUDS. Following remediation of the disposal trench and impacted soils in 2013 by others, CTI performed soil and groundwater investigation followed by In-Situ Chemical Oxidation (ISCO) design and injection of catalyzed hydrogen peroxide (CHP) for remediation of the VOC-impacted groundwater.
Pre-design investigation activities included 60-foot soil borings to evaluate site stratigraphy and contaminant concentrations and monitoring wells to determine hydrogeology and establish baseline groundwater concentrations for long-term performance monitoring. The ISCO design included injection point spacing, injection parameters, and oxidant optimization for breakdown of the VOCs.
CTI’s engineering evaluation recommended replacing the required sodium permanganate injection event with a second CHP injection event due to the inability of permanganate to treat the carbon tetrachloride and chloroform. The CHP injection program under a KDHE Underground Injection Program permit included 10 direct push technology injection points to an average depth of 60 feet with an overlapping 15-foot radius of influence (ROI). Each ISCO event included approximately 3,150 gallons of a patented neutral pH chelated iron catalyst and 3,150 gallons of 12% hydrogen peroxide.
- Development of work plans (CQCP, APP/SSHP, UFP-QAPP, and FSAP)
- Site investigation activities to define site stratigraphy and groundwater flow characteristics
- Engineering evaluation to select oxidant and optimize injection strategy;
- Acquisition of the KDHE Underground Injection Program (UIP) permit;
- Implementation of KDHE approved ISCO injection program;
- Groundwater monitoring to assess the effectiveness of the ISCO injection program;
- Attained groundwater mass reduction of 90% for TCE; 89% for CTet; and 88% for chloroform.
- Removal Action Completion Report (RACR).
Under this cost reimbursable contract, CTI also performed 3-D modeling of contaminant concentrations and soil type physical characteristics to supported the USACE decision to reduce infiltration and vertical contaminant migration through the installation of a clay cap at the base of soil removal excavation.