Payson PCE | WQARF Site

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Payson PCE | Site History

2020: Groundwater sampling was conducted in February 2020

2016 to 2019: Sugar-based substrate injections were completed in September 2016 and February 2017. One bio-augmentation injection was completed in May 2017. In October 2017, a combination of vegetable oil and lactate was used in one monitor well. The other wells were injected with a solution of High Fructose Corn Syrup (HFCS). Early 2018 performance monitoring data demonstrated some effectiveness of treatment of the source area with enhanced reductive dechlorination (ERD). Additional ERD injections were completed in August 2018 and February 2019. Groundwater sampling was conducted in April and November 2019.

2015: In 2015, a total of 101 groundwater samples were collected. A new Sampling and Analysis Plan and a Remedial Optimization Evaluation and Recommendations Report were finalized.

2014: On May 14, 2014, TOP was instrumental in disassembling, removing and transporting the IGTS tanks to the Arizona Department of Administration surplus yard in Phoenix, Arizona. In January 2014, two additional monitor wells connected into the production well network, of the EGTS, started pumping water to the EGTS for remediation of contaminated groundwater. In May 2014, an evaluation to conduct a catalyzed hydrogen peroxide in-situ chemical oxidation (ISCO) pilot test was completed to determine feasibility of the project.

2013: Equipment and controls from the Payson PCE IGTS was permanently decommissioned. The groundwater remediation system was initially constructed for the Payson PCE WQARF site and was put in operation Oct. 1998. The IGTS was phased out with the construction of the EGTS which continues to remediate contaminated groundwater and supply drinking water to the town. On July 22, 2013, TOP was instrumental in disassembling, removing and transporting the IGTS to the Arizona Department of Administration surplus yard in Phoenix. During operation of the IGTS, 59.5 million gallons of water were treated and 218 pounds of VOCs were removed for disposal. On November 26, 2013, ADEQ issued the 2012 Periodic Site Review.

2012: The TOP continues to operate the groundwater extraction system.

2011: In September, groundwater samples were collected from 46 monitor wells at the site. PCE results ranged from ND to 23.5 µg/l. The highest concentration of PCE was detected in DMW-1B near the source area. Samples from 6 wells in the site area contained PCE concentrations that exceeded the AWQS. Since installation and through December, the ETGS has treated more than 865 million gallons of water and removed 498 pounds of VOCs.

2010: In late September and early October, groundwater samples were collected from 42 monitor wells at the site. PCE results ranged from non-detect (ND) to 16.3 µg/l. Samples from 5 wells in the site area contained PCE concentrations that exceeded the AWQS.

2009: ADEQ continued to fund the operation of the ETGS. Between October and December, 18,015,400 gallons of water were treated and 0.41 pounds of PCE were removed. As of Dec. 31, the EGTS removed a cumulative total of 497.56 pounds of PCE. A cumulative total of 832,781,500 gallons of water were treated.

2008: Groundwater samples were collected and water level measurements taken in March, June, September and December. The highest PCE concentration (32 µg/l) was detected in monitor Well DMW-1C. This well is located southeast of the groundwater treatment system and near the source area. PCE concentrations exceeding the AWQS were present in nine other monitor wells in the immediate vicinity.

2007: Semi-annual groundwater sampling was conducted in March and September. The highest PCE concentration detected during the September sampling event was 41 and 40 μg/l, respectively, in one well (DMW-1) in the Fractured Granite/Competent Granit Unit. In the Alluvial Unit, PCE concentrations ranged from non-detect to 21 μg/l. The ROD for this site was signed in June.