The Park-Euclid site is located east of downtown Tucson, Arizona and is bounded approximately by 8th Street on the north, Mountain Avenue on the east, 14th Street on the south and Park Avenue on the west. The site includes facilities located at both 299 and 301 South Park Avenue, where three companies have conducted laundry and dry cleaning operations since the late 1930s.
The plume geographic boundaries depicted on the site map represent the Arizona Department of Environmental Quality’s (ADEQ) interpretation of data available at the time the map was constructed. The map is intended to provide the public with basic information as to the estimated extent of known contamination as of the date of map production. The actual extent of contamination may be different. Therefore, the plume boundaries may change in the future as new information becomes available.
In March 2015, the P-E Group submitted to ADEQ its preliminary draft FS and modeling reports. In the summer of 2015, the P-E Group performed additional modeling. The P-E Group will be submitting its final revised draft FS report to ADEQ in fall 2015. Per the ADEQ/P-E Group working agreement, the final revised draft FS report will be issued for public comment.
In February 2015, the P-E Group started operation of a soil vapor extraction (SVE) Early Response Action to limit migration of volatile organic compounds (VOCs) from the lower vadose zone down to the regional aquifer. As of August 2015, this system has removed about 311 pounds of tetrachloroethene (PCE) and other VOCs from the lower vadose zone.
In November 2013 the community advisory board for this site was combined with the 7th Street and Arizona Avenue WQARF site. This combined CAB met for the first time in February 2014.
1990: During an early ADEQ investigation of diesel contamination in the area, a groundwater sample was collected from a well on the Mission Linen property. Analysis of the sample indicated that contamination was present in the well and was a combination of diesel product and VOCs, including tetrachloroethene (PCE), trichloroethene (TCE) and 1,2-dichloroethene (1,2-DCE).
1992: Mission Linen conducted a Phase I investigation which included soil gas sampling, groundwater sampling and the abandonment of an inactive water supply well.
1993: Mission Linen conducted investigations that focused on the perched aquifer and the installation of a short term pilot soil vapor extraction (SVE) system.
1994: Mission Linen began investigating the regional groundwater aquifer including the examination of potential hydraulic connections between the perched and regional aquifers.
1999: The site was placed on the WQARF Registry with an eligibility and evaluation score of 51 out of a possible 120. In October, ADEQ initiated an RI. As part of the investigation, ADEQ began sampling two U of A water supply wells located downgradient from the site.
2000 - 2001: In January 2000, three regional groundwater sentinel wells were installed south of U of A's Main Campus to monitor groundwater conditions upgradient of U of A’s wells. In February 2000, EPA informally delegated responsibility for the site to ADEQ through the RI/ FS stages.
In 2000, Mission Linen completed the installation of an SVE system beneath the facility at 301 S. Park Avenue. The pilot SVE system operated from June 2000 to August 2003 and removed approximately 6,000 pounds of PCE.
Since August 2000, monthly groundwater samples have been collected from the three sentinel wells. No PCE contamination above AWQS has been detected in U of A’s water supply wells.
From November 2000 to February 2001, ADEQ installed 12 additional groundwater monitor wells to further characterize VOC and diesel contamination in the two aquifers underlying the site. ADEQ conducted site investigation activities within the vadose zone and shallow aquifer.
2002 - 2003: ADEQ installed an additional eight groundwater and three soil vapor monitor wells from May 2002 to February 2003. In February 2003, ADEQ conducted site investigation activities that focused on the sewer near the Mission Linen property.
2004: In July, ADEQ released the draft RI report summarizing site characterization activities. Also, Mission Linen expanded the pilot SVE system and continued remediation of the shallow soils beneath the facility. An additional 420 pounds of PCE were removed from the shallow soils by the existing SVE system.
2006: In August, ADEQ completed the remedial objectives (RO) report following the completion of the public comment period. The RO for land use beneath Mission Linen is to restore soil conditions to the State’s non-residential soil remediation levels. The RO for drinking water use of groundwater from the regional aquifer is to protect the use of the groundwater supply of the U of A and the City of Tucson from contamination from the site.
2007: ADEQ selected a new consultant to perform site work. Periodic groundwater monitoring and sampling resumed along with monthly sampling of the UA production wells and ADEQ’s sentinel wells.
2008: Mission Linen completed construction of the multi-phase extraction (MPE) system to remediate contaminants including PCE in the perched aquifer and upper vadose zone. The MPE system became operational in April. Also in April, ADEQ installed a deeper sentinel well at the UAM-2 well location. This well is used for monitoring a deeper portion of the regional aquifer near the U of A wells.
2009: ADEQ continued to work on completing the RI. No sampling was performed in 2009. Mission Linen operated the MPE system at the facility until June. A report detailing system operations was released in November. In this pilot phase of the MPE system, approximately 1,396 pounds of VOCs and 750 gallons of diesel free-product were removed, while treating 38,851 gallons of groundwater.
2010: In 2010, some of the potentially responsible parties at the Park-Euclid site signed an agreement to form the Park-Euclid (P-E) Group to manage and fund remediation activities at the site with ADEQ oversight. The responsible parties at the site signed an agreement to form the P-E Group to manage and fund remediation activities at the site. Work plans were prepared and reviewed for groundwater monitoring and restarting the MPE system.
2011: The MPE system was restarted in October. Groundwater sampling occurred in November and December. The final RI report was completed in November.
2012: As of the end of March, the MPE system had treated 8,565 gallons of water and removed a total mass of 542 pounds of VOCs. The MPE system operated routinely through September, then was shut down for the remainder of the year awaiting additional permitting. Groundwater sampling occurred in January through March, and monthly from August to December.
2013: The MPE system was restarted in January and ran continuously through February, after which it ran intermittently due to maintenance and overheating issues. Through the end of June, the MPE system removed approximately of 400 pounds of VOCs and 1700 gallons of diesel free-product. Groundwater sampling of all the monitoring wells occurred in February, with repeated sampling of the majority of wells in May and August. The FS work plan for future cleanup for the site was completed and approved in June and plans were made to install an additional regional aquifer monitoring well, upper vadose zone soil vapor sampling wells and a pilot SVE system for the lower vadose zone.
2014: The P-E Group provided ADEQ with technical reporting concerning its groundwater modeling for the FS (site-wide) and SVE pilot testing for the lower vadose zone, sampled groundwater (perched and regional) and soil gas wells at the site, and installed two regional groundwater monitor wells to further delineate the toe and the eastern extent of the plume. The P-E Group completed its biotreatability bench-scale testing and determined that neither biostimulation (adding lactate) nor bioaugmentation (adding KB-1 microbial cultures) were viable for treating cis-1,2-DCE, which is the dominant contaminant of concern in the perched groundwater.
The results of the P-E Group’s human health risk assessment for the FS indicated that there is no unacceptable risk to onsite workers or offsite residences from the migration of VOCs in shallow soil gas into buildings. (Shallow soil gas samples were collected onsite and offsite.)
At the end of 2014, the P-E Group presented ADEQ with an interim update on its remedial alternatives screening for the FS.
The P-E Group shut down the MPE system in April 2014. From the pilot phase (October 2011) through April 2014, approximately 110,500 gallons of water were treated and a total mass of approximately 3,392 pounds of VOCs were removed, along with approximately 7,250 gallons of diesel free-product.
The current contaminants of concern include PCE; TCE; cis-1,2-DCE; trans-1,2-DCE; and vinyl chloride (contaminants of concern in groundwater are those contaminants exceeding the AWQS). Contaminants of concern at the site may change as new data become available.
A preliminary risk assessment was completed by the Arizona Department of Health Services (ADHS) in March 1995. Based on this ADHS assessment, there are no significant health risks associated with the site at this time.
In February 2004, ADEQ conducted soil gas flux testing and sampling of soils overlying the contaminant plume in the perched aquifer to assess potential risks to human health due to vapor intrusion into overlying businesses and residences. Results of a screening health risk assessment indicated that VOCs migrating upward from subsurface soils and groundwater did not pose a significant risk to current or future off-site residential structures, but could pose a significant risk to workers at the Mission Linen facility. Based on this risk assessment, Mission Linen performed ambient air quality sampling inside the Mission Linen facility that indicated vapor concentrations inside the building were significantly below applicable occupational health exposure limits. Also, in 2014, the P-E Group’s human health risk assessment for the FS indicated that there is no unacceptable risk to onsite workers or offsite residences from the migration of VOCs in shallow soil gas into buildings. (Shallow soil gas samples were collected onsite and offsite.)
U of A operates three active production wells downgradient from the regional aquifer contaminant plume. No PCE contamination has been detected in these water supply wells. No one is known to be drinking contaminated water from this site; however, if you are drinking water from a private well within the boundaries of the site, please contact the ADEQ project manager. The City of Tucson (aka Tucson Water) is the main municipal water provider at this site.
The site is located within the Tucson Basin, a northwest trending alluvial valley covering an area of about 750 square miles in the Santa Cruz River drainage basin of southeastern Arizona. The subsurface materials underlying the site are predominately of fine to coarse-grained sands and silts, interbedded with clay and gravel-sized sediments. A clay aquitard of variable thickness occurs at around 100 feet below ground surface (bgs), underlying the perched aquifer.
Depth to the perched aquifer is about 90 feet bgs, and depth to the regional aquifer is about 200 feet bgs. The current flow direction in the regional aquifer is to the north/northeast.
*In Arizona, but outside the Tucson area, call toll-free at (888) 271-9302.
Interested parties can review site information here on this page and at the ADEQ Record Center located at 1110 W. Washington Street, Phoenix, Arizona. Please contact (602) 771-4380 or (800) 234-5677 ext. 6027714380 for hours of operation and to schedule an appointment. To review site information at a location near you, please contact the designated Community Involvement Coordinator.