2024: Groundwater sampling was conducted in March and October.

2023: Groundwater sampling was conducted in March and October. Pulse operations of the soil vapor extraction (SVE) system at the East Plume were conducted from July to August and from September to October; shutdown rebound testing continues.

2022: Groundwater sampling was conducted in March and October. An upgraded blower was installed on the SVE system at the East Plume in February to increase VOC mass removal. The SVE system at the East Plume was shut down in November to begin rebound testing.

2021: Groundwater monitoring and sampling was conducted in March and October.

2020: The Feasibility Study (FS) report was completed by ADEQ in January. Groundwater monitoring and sampling was conducted in February/March and October. Additional soil gas assessments were conducted in the West and Central Plumes. The soil vapor extraction (SVE) system in the East Plume was expanded by installing and connecting an additional SVE well. The Proposed Remedial Action Plan (PRAP) was completed by ADEQ in December.

2019: Groundwater monitoring and sampling was conducted in April/May and October. A SVE system was installed in the East Plume and began operating in early 2019. A vapor intrusion evaluation was completed in March on eight sites to address data gaps in the RI Report. Revised Remedial Objectives were issued for public review and comment in December.

2018: Groundwater monitoring and sampling was conducted and the Feasibility Study (FS) Work Plan was completed in January. A 30-day SVE pilot test was also conducted in the East Plume as part of the Emergency Repsonse Action (ERA).

2017: The draft Remedial Investigation (RI) report was issued for public review and comment in May. In June, a 5-day SVE pilot test was performed in the East Plume to evaluate if this remedy is effective for addressing Volatile Organic Compounds (VOC) impacts within the vadose zone. ADEQ finalized the RI report in December.

2016: A deep groundwater monitor well and a shallow groundwater monitor well were installed. Additional soil and soil vapor sampling was conducted in the East Plume.

2015: Groundwater monitoring and sampling was conducted in February and November. A soil vapor partition test and limited passive soil-gas survey was conducted in the East Plume to evaluate the area for local sources of contamination.

2014: ADEQ monitored and sampled groundwater in February, monitored water levels in May and June to study effects on groundwater by the Salt River Project (SRP) wells, and conducted a passive soil gas survey along 33rd Avenue. Data indicate that trichloroethylene (TCE) concentrations in the vicinity of the former Triad property declined; the plume may be moving in a southern direction; and pumping SRP wells appears to effect water levels in the North Canal Plume (NCP).

2013: The well network (44 wells) was cleaned up for groundwater monitoring and sampling. Depth to water was measured in each well and groundwater samples were collected and analyzed for VOCs, chlorinated hydrocarbons and total chromium. Results indicated that the plume may be moving in a southern direction.

ADEQ Underground Storage Tank (UST) Program State Lead Unit installed 26 wells and an SVE/air sparge remediation system at the former TRIAD property.

2009: Worked on the draft RI report continued through the collection of information needed to compile the Land and Water Use report. Questionnaires were sent to various stakeholders, property owners and water providers.

2008: Soil vapor samples were taken across two areas at the site to aide in the placement of new monitor wells. As a result of samples taken earlier in the year, additional soil vapor samples were taken. Results of these sample events will be incorporated within the final RI report.

2007: An aquifer test was carried out in September at the former Southwest Metals facility to help determine potential groundwater treatment options for the regional groundwater plume. Additionally, ADEQ conducted a SVE pilot test in February at the former Osborn Products facility. Based on the concentrations from the pilot test, the results did not merit a soil remediation system at that time.

2006: The second ERA evaluation and technical report was issued in October. Several facilities were identified as likely sources of the groundwater contamination in the site. The facilities included, but were not limited to: the former Osborn Products facility, former Magic Metals facility, former Southwest Metals facility, and Precise Metal Products/Paraflex Tool & Machine (Precise/Paraflex). Other facilities were being investigated as potential sources of groundwater contamination at the site.

2005: An interim RI report documenting all activities was issued in August. 

1987 – 2000: In 1987, the West Central Phoenix (WCP) area was designated a WQARF priority list site. In 1997, ADEQ established the WQARF Registry, which replaced the priority list. The site was placed on the WQARF Registry in June 1998, with a score of 22 out of a possible 120. The site score was re-evaluated in 2000, with a revised score of 27.

1982 – 1989: VOCs were first detected in groundwater in the WCP area in July 1982. The City of Phoenix (COP) detected TCE in four municipal public supply wells, COP wells #70, #71, #151, and #152. The Arizona Department of Health Services, SRP, and the COP confirmed the presence of VOCs in the groundwater with sampling in 1983, 1985, and 1986. Groundwater from COP wells #70 and #71 contained the highest concentrations of TCE and, therefore, were immediately shut down. Wells #151 and #152 were monitored for VOC concentrations from 1982 until 1989. As a result of sampling conducted during February of 1989, COP elected to take both wells #151 and #152 off-line on March 7, 1989.

Field investigation activities for the site began in 1984. Several contaminants were detected in soil and groundwater samples collected during field investigations at the four facilities. The primary contaminants of concern found were tetrachloroethene (PCE), TCE, 1,1-dichloroethene (1,1-DCE) and chromium. 

1977 – 1989: The former Magic Metals facility was located near 36th Avenue and Whitton Avenue.   Magic Metals operated at the site until 1987 when the facility was abandoned by the company. Principal business activities of Magic Metals included electroplating for automobiles, custom restorations, industrial parts, and antiques. The facility generated waste electroplating baths and rinses containing cyanide, waste caustics and unspecified waste solvents from stripping tanks, and waste acids (sulfuric and chromic). Those tanks were excavated and removed from the facility in 1989.

1963: The Precise/Paraflex facility is located near 39th Avenue and Clarendon Avenue.   Precise/Paraflex and three subsidiary companies; Precision Marking, Paint Spray, Inc., and Perigee Metal Spinning, all operate at this facility.

1956: The former Osborn Products facility was located near 36th Avenue and Clarendon Avenue. Osborn Products operated at the site until 1984. Facility operations included chrome plating, machining, and grinding of parts for the aerospace industry. On-site processes included degreasing metal parts, chrome plating, and machining of parts to specification.

1952: The former Southwest Metals facility was located near 36th Avenue and Clarendon Avenue. Southwest Metals operated at this property until 1973. The manufacturing process at the site consisted of constructing sand casts to form magnesium, aluminum, and brass castings.