7th Street and Arizona Avenue | Site History : Page 2 of 2

2011: In October and November, five nested soil gas probes and two groundwater monitoring wells located on the former Oliver's Cleaners property and in the COT right-of-way immediately adjacent to the property were sampled for soil gas. Soil gas data were converted to soil matrix concentrations. No SRLs were exceeded for contaminants of concern. 

2009: In June, the SVE system was permanently turned off because the system had reached the appropriate cleanup criteria. Through June, approximately 770 pounds of volatile organic compounds (VOCs) were removed by the SVE system. Perched well locations were investigated to define the farthest limits of the contaminant plume and to determine limits of the perched aquifer.  In late 2009 all work at this site was temporarily suspended until further funding was available.

2007: In February, five additional wells were installed to further investigate the boundary of PCE and trichloroethene (TCE). Two more wells were installed in November. An air sparing pilot test was conducted in October to evaluate the feasibility of air sparging as a remedial method.

2006: In June, ADEQ began operating an SVE system at the former Oliver's Cleaners located at 300 E. 7th Street. 

2005: ADEQ conducted two groundwater monitoring events which indicated that elevated concentrations of PCE and TCE existed in the surrounding perched groundwater monitor wells. No contaminants were detected above regulatory standards in the regional aquifer. 
2003: In July, a report of the findings and recommendations for a potential ERA under the WQARF was completed. Investigations showed that while a release of PCE, and possibly TCE, had occurred at the property at 300 E. 7th Street, there appeared to be no route for human exposure. 
2000: On April 27th, the site was placed on the WQARF Registry with an eligibility and evaluation score of 40 out of a possible 120.

1992: An assessment of soil and groundwater beneath the site was conducted. Soils near the heating and waste oil tanks were found to contain petroleum hydrocarbons. Analysis of a groundwater sample from a water supply well on the site revealed the presence of PCE and TCE in the regional aquifer underlying the site but below Arizona AWQS.

1991: Seven underground storage tanks (USTs), five solvent, and two heating and waste oil tanks were removed from the property. 

1957 - 1989: From approximately 1957 to 1989, dry cleaning businesses were located on the property at 300 E. 7th Street. The building was destroyed by fire in 1989, and now the property is vacant and used for parking. PCE used in the dry cleaning process was stored in USTs.