2024: The early response action (ERA) and pilot testing continued at the site, while the Proposed Remedial Action Plan (PRAP) is being drafted.

2023: A pilot test was installed near the potential source area to evaluate the proposed remedy for the PRAP. The downgradient ERA system continued operation.

2022: The final Feasibility Study (FS) report was released, with the recommended remedy being the more aggressive remedy, whereby the groundwater is treated with in-situ bioremediation, the soil vapor extraction (SVE) and capping for the impacted soils and soil gas at the site. 

2021: ADEQ is evaluating possible remedial technologies for the site, and is drafting the FS report.

2019 – 2020: ADEQ worked on and released the Draft Remedial Investigation (RI) report in February 2020. After soliciting remedial objectives (RO) from the public, ADEQ released the draft RO report in May. The final RI/RO report and FS Work Plan were released in December.

2017 – 2018: ADEQ listed the Lake Havasu and Holly WQARF site and began the RI. ADEQ sampled soils in the area of the former facility and installed additional monitoring wells to fully characterize the groundwater plumes.

2014: ADEQ conducted groundwater monitoring and sampling, documenting chromium, nitrate, tetrachloroethene (PCE) and trichloroethene (TCE) all exceeding the corresponding Aquifer Water Quality Standards (AWQS).

2003 – 2008: Shop Vac installed additional monitoring wells and conducted soil and groundwater sampling.

2003: Shop Vac conducted an in-situ calcium polysulfide pilot test for hexavalent chromium was conducted in the former plating area.

2002: Palo Verde Investments, LLC, entered into a Prospective Purchaser Agreement for the property at 900 N. Lake Havasu Ave.

2001 – 2002: Shop Vac installed a soil-vapor extraction and air sparge system in the area of the former leaking underground storage tank (UST) to remediate hydrocarbon-related soil and groundwater contamination. Groundwater sampling continued to detect concentrations of chromium, nitrate and TCE above their corresponding AWQS.

1998 – 1999: McCulloch filed for bankruptcy in January 1998 and ceased operations. Shop Vac, McCulloch’s parent company, continued investigative and remedial activities at the site, including soil-gas investigations and the installation of additional monitoring wells.

1995 – 1998: McCulloch installed multiple groundwater monitoring wells to further characterize the extent of contamination.

1995: Groundwater sampling at the site detected volatile organic compounds (VOCs), petroleum hydrocarbons (benzene, toluene, ethylbenzene, and xylene [also known as BTEX]), dissolved chromium, and hexavalent chromium. Chromium was detected in soil samples to depths of 165 feet below ground surface (bgs), the approximate depth to groundwater at that time.

1992: A leaking UST was removed from the facility. An investigation detected chromium-contaminated soil up to depths of 15 feet bgs beneath the plating shop. Total chromium concentrations exceeded the non-residential soil remediation level of 65 mg/kg.

1990: Approximately 20,000 pounds of soil contaminated with chromic acid was excavated from under the floor of the plating building.

1960s – 1980s: Manufacturing occurred at the former McCulloch facility at 900 N. Lake Havasu Ave. This facility manufactured sewing machine motors, gyrocopters and small gasoline-powered equipment.