Universal Propulsion Company, Inc. (UPCO) Corrective Action Facility
U.S. EPA ID No. AZD 980 814 479
25401 North Central Avenue
Phoenix, Arizona 85085
Southeast ¼ of Section 5, Township 4 North, Range 3 East of the Gila and Salt River Meridian, Maricopa County, Arizona.
The UPCO facility is a former aerospace manufacturing facility in operation from August 14, 1972 until January 9, 2010. It was located on a 160 acre site, leased from the State of Arizona, about 25 miles north of central Phoenix, Arizona.
Manufacturing began in 1972 and ceased in January 2009. UPCO designed, developed and manufactured military aircraft ejection seats and related components for emergency escape and survival, including the required propellants. UPCO provided pyrotechnic devices for NASA's Space Shuttle program and also developed, marketed and produced automotive safety products. The plant consisted of administrative buildings and structures, and was separated into seven operational areas: A - Complex, B - Complex, C - Complex, D - Complex, E - Complex (i.e. the Storage Magazine Area), F - Complex, and the Open Burn Unit.
In 2009 and 2010 UPCO removed all of the operational areas, demolished most buildings and closed the Open Burn Unit. Currently, the facility is vacant land with groundwater monitoring wells onsite and offsite, and security fencing.
On March 23, 2004, officials from UPCO informed ADEQ that recent groundwater monitoring tests conducted at the facility revealed the presence of perchlorate ranging from 43 to 130 micrograms per liter (g/L) or parts per billion in their on-site groundwater monitoring wells.
On October 12, 2004 ADEQ and UPCO entered into two Consent Orders requiring UPCO to clean up contaminated soil and groundwater at the company's north Phoenix facility and cease the open burning of hazardous materials at the facility.
At ADEQ's direction, UPCO has installed a network of on-site and off-site groundwater monitoring wells, conducted additional testing and sampled the drinking water wells of nearby residents.
Hydrogeological Characteristics of the Site
The UPCO site is located within the Basin and Range Physiographic Province. The basin and range is characterized by northwest trending bedrock mountain ranges separated by gently sloping alluvial valleys (basins). The UPCO site is located between the southern flanks of the Union Hills, a northwest trending bedrock mountain range, and the northern margin of the West Salt River Valley within the Union Hills USGS 7.5' Quadrangle. Topographic relief near the facility ranges up to 800 feet within the Union Hills and slopes southward and westward towards the West Salt River Valley.
Depth to groundwater in the vicinity of the UPCO site ranges from approximately 150 to 250 feet below surface. Regional groundwater flow direction in the vicinity is generally considered to be southwest. Well yields are low from the bedrock aquifer at and near the facility. Private wells to the north pump groundwater from the bedrock and are being monitored semi-annually. Sixteen groundwater monitoring wells have been installed on the site as of August 1, 2010.
Summary of Corrective Action Activities
In December 1993, U.S. EPA contracted with Science Applications International Corporation (SAIC) to conduct a RCRA Facility Assessment (RFA). The RFA identified and assessed 22 Solid Waste Management Units (SWMUs) and other areas of concern at the facility.
RCRA Facility Investigation Work Plans
RCRA Facility Investigation (RFI) Work Plans were written for operational areas after a detailed review of facility operational history. These RFI work plans were used to guide soil characterization efforts which included numerous subsurface borings and surface samples. Surface and subsurface borings advanced during 2004 and 2005 provided initial sample results. Supplemental sampling in 2004, 2005, and 2008 provided additional characterization data.
RCRA Facility Investigation Reports
Draft RCRA Facility Investigation Summary Report – The Draft Report was submitted to ADEQ in July 2006. It described historic operations at the facility, described the study area, summarized the results of previous investigations and the results of the investigations described in the RFI Work Plans, described the hydrogeologic investigations at the site, discussed the nature and extent of contamination in soils and groundwater, described the physical characteristics of the study area, presented the Permittee’s conceptual site model, and presented a report summary with conclusions and recommendations for future work.
Interim Remedial Investigation Summary Report – The Interim Report was submitted in February 2009. The report includes much of the same information as the July 2006 Facility Investigation Summary but was revised extensively in response to additional data and ADEQ comments.
Final Remedial Investigation Summary Report - After installation of supplemental wells and in response to ADEQ comment in August, 2010 and August 2011, a Final Report was submitted on August 23, 2011. ADEQ approved the Report on August 29, 2011.
Based on investigation activities conducted at the facility, it has been determined that perchlorate has been released to the environment from historic operations at UPCO. The primary source is considered to be the refurbishing of rocket motor tubes at the Waterbore Area, with secondary sources related to propellant production activities, including cleaning activities in the C-Complex and open burning of waste energetic materials at the former-Open Burn Unit in the New Burn Area. (See Potential Perchlorate Source Areas - Figure 5)
The Waterbore source area is thought to be the primary contribution of perchlorate observed in soil and groundwater beneath the site. Perchlorate concentrations detected in monitor wells MW-1 and MW-2 downgradient of C - Complex and the New Burn Area, may also indicate some contribution from potential secondary sources (e.g., impacted soils in the C - Complex and New Burn Area). Based on the concentration of perchlorate detected in soil at the Waterbore Area, a historic driver (infiltration of wastewater from waterbore operations) and the apparent direction of historic groundwater flow (southwest), the former evaporation ponds in the Waterbore Area are assumed to be the primary source of perchlorate impacts. A potential third minor source of perchlorate detected in groundwater may possibly be attributed to recharge of impacted surface water from historic F - Complex, D - Complex, and/or Old Burn Area operations in the wash along the west side of the site. This potential third source may explain the low level perchlorate impacts (15 to 20 ug/L ) in groundwater at MW-6.
Since at least 1983, a high pressure water spray wand operation was used to remove solid propellant and binders from rocket motor tubes so that the tubes could be reused. This process was referred to as the waterbore operation. The Waterbore Area consisted of the waterbore water wand station, fiberglass and polyethylene above ground waterbore wastewater evaporation tanks, and two fiberglass evaporation tanks used for the evaporation of non-hazardous mop/rinse water generated throughout the facility.
Prior to use of the water wand station, an out-of-service water wand (i.e., former water wand) was located approximately 30 feet north of the water wand station. The former water wand was decontaminated and demolished concurrently with the closure activities conducted for the New Burn Area and the Thermal Treatment Unit. The former water wand was located in a fiberglass containment tank and in November 2002, the wand was shielded with plastic sheeting to limit horizontal water spray. In mid-2003, the former water wand was decommissioned and replaced with the fully-contained water wand station.
The wastewater generated by the waterbore operation contained suspended solids and dissolved oxidizers. The wastewater was filtered to remove the solids and the remaining solution containing the oxidizers was piped to the open-top evaporation tanks.
Prior to 1988, waterbore wastewater was collected and diverted into two earthen containment ponds lined with plastic. The former ponds covered a surface area of approximately 2,000 square feet and were located in the same area as the fiberglass evaporation tanks. The wastewater in the ponds was allowed to evaporate and the remaining solids were removed for treatment or disposal. The ponds were excavated and removed from service in the fall of 1988 and replaced with the open-top tanks (i.e., fiberglass evaporation tanks). In 2003, inner open-top polyethylene tanks were added so that the fiberglass tanks functioned as secondary containment. Additional containment was also provided by a 40 mil polyethylene liner underlaying the six-inch sand layer beneath the tanks.
The mop/rinse-water evaporation tanks were utilized for the evaporation of non-hazardous process rinse water and mop water generated throughout the UPCO operation. The resulting solution/solids were transported off-site for disposal.
C - Complex
The C - Complex Area consisted of various buildings/structures used for manufacturing of castable propellants including material weigh-out, oxidizer grinding, propellant mixing and casting. The C - Complex also served as a research and development area to improve and refine products and performance. The research and development activities included development of new castable propellants and energetic powders. Historically, Buildings C-2, C-9, and C-11 were used for the quality assurance/quality control laboratory activities that occurred in the F - Complex Building F-10 QC Laboratory. Oxidizers, binders, and metallic powders were also stored in the C - Complex Area.
During the manufacturing process, dry oxidizer materials were mechanically ground to the desired particle size distribution, sieved to break up agglomerates, and weighed out for a particular batch size. Polymeric binders consisting of polyurethane or polybutadiene and carbon black were then evenly applied to the interior of the motor tubes. At times, solvents may also have been used to fluidize the binder for ease of application during the lining process. These solvents included methylene chloride and, previously, Trichloroethane. After the lining was cured, the tubes were placed into the casting fixture. Tooling was inserted into the tubes to form the appropriate annulus space that was then filled with the propellant mixture. Polymeric binder and fuels (magnesium or aluminum powders) were added to the oxidizer to form a raw propellant blend. The propellant was then vacuum-cast into the lined tubes and cured in ovens. After curing, the tooling was removed and the propellant tubes were prepared for further assembly.
During research and development activities, new castable propellants and powders were generated in smaller quantities using the same techniques described for the manufacturing process.
The chemicals predominantly used in the C - Complex included ammonium perchlorate, potassium perchlorate, lead nitrate, ammonium nitrate, potassium nitrate, iron oxide, polymeric binders (e.g., polyurethane or polybutadiene-based materials), magnesium or aluminum-based powders, methylene chloride, acetone, and isopropyl alcohol.
New Burn Area
The Open Burn Unit (OBU) was operated at the New Burn Area, located south of the C-Complex near the south central property boundary. Open burning of waste and off-specification solid propellant materials were performed in this area from 1980 until 2004. Originally, wastes were burned on bare soil. In 1986 the OBU was upgraded with a burn pad consisting of 25 feet by 75 feet of four-inch steel-reinforced concrete covered with six inches of sand. In 1989, a 10-foot wide outer concrete apron, sloped towards the center, was constructed around the perimeter of the burn pad. Open burning activities were discontinued in December 2004. Closure of the OBU, associated open burning devices (OBD), and the Thermal Treatment Unit (TTU) was conducted in December 2007 and January 2008 in accordance with the hazardous waste closure Plan. Removal of some impacted soil in the New Burn Area was conducted in September 2008. A hazardous waste closure report for the OBU was submitted to ADEQ on December 19, 2008. ADEQ acknowledged partial closure of the OBU on February 23, 2009.
Groundwater Modeling Work Plans
A groundwater flow model has been created for the site. Work plans and technical memoranda on the creation of the groundwater flow model were submitted to ADEQ between June 2009 and June 2010. These documents discuss the conceptual site model, the modeling code, summarize the data requirements and the parameter development process for the groundwater flow model, and discuss the model calibration process.
Development of the Groundwater Protection Level (GPL)
A work plan was submitted to ADEQ on September 3, 2008 (Proposed Approach for Developing Groundwater Protection Level for Perchlorate in Soil at the Universal Propulsion Company, Inc.), amended by letter on June 18, 2009. UPCO proposed a site-specific GPL of 16.2 milligrams per kilogram for perchlorate in soil. This level was accepted by ADEQ on October 22, 2009 (REF: HWP-2186).
Results of Groundwater Monitoring
UPCO has installed a network of groundwater monitoring wells, conducted quarterly sampling and has sampled the drinking water wells of nearby residents semi-annually. Sampling to date shows that perchlorate levels in all drinking water wells remain less than the Arizona Health-based Guidance Level (HBGL) of 14 micrograms/liter.
Groundwater Monitoring Results conducted at the facility for the years 2006 - 2015:
- 2015 Annual Groundwater Monitoring Report
- 2014 Annual Groundwater Monitoring Report
- 2013 Annual Groundwater Monitoring Report
- 2012 Annual Groundwater Monitoring Report
- 2011 Annual Groundwater Monitoring Report
- 2010 Annual Groundwater Monitoring Report
- 2009 Annual Groundwater Monitoring Report
- 2008 Annual Groundwater Monitoring Report
- 2007 Annual Groundwater Monitoring Report
- 2006 Annual Groundwater Monitoring Report
Corrective Action Permit
On June 30, 2011, ADEQ issued to UPCO a renewal to its hazardous waste Permit. Because UPCO completed closure of their Open Burn Unit in December, 2008, the renewed permit no longer contains operating permit conditions for open burning. Instead, the Permit requires performance of corrective action at the site. This Corrective Action Permit authorizes UPCO to continue to perform corrective action at the former-manufacturing site and to continue to monitor groundwater at the site and at resident wells north of the site. After a remedy is selected, the Corrective Action Permit will include permit conditions on the operation and maintenance of the remedial units. The Corrective Action Permit has a term of 10 years. If UPCO has not completed Corrective Action at the end of the 10 years they will be required to apply for a renewal to the Permit.
Arizona Hazardous Waste Management Act Permit -- (PDF)
- Attachment A – Facility Description -- (PDF)
- Attachment B – Security Plan -- (PDF)
- Attachment C – Contingency Plan -- (PDF)
- Attachment D – Groundwater Monitoring Plan -- (PDF)
- Attachment E – Quality Assurance Project Plan -- (PDF)
- Attachment F – Quality Assurance Project Plan Addendum -- (PDF)
- Attachment G – Corrective Action Financial Assurance -- (PDF)
- Attachment H – Corrective Action Approved Plans and Reports -- (PDF)
- Exhibit H-1 - Final Remedial Investigation Report (June 2011)
- Exhibit H-2 - Corrective Measures Study Work Plan (December 2011) -- (PDF)
- Attachment I – Arizona Administrative Code -- (PDF)
Status of Corrective Action At UPCO
On December 22, 2015, ADEQ approved UPCO's Corrective Measures Study Report. The report describes the methods that UPCO will use to remediate the site. The remedy recommends excavation and offsite disposal, capping, and deed restrictions for contaminated soil. Ground water will be remediated by source area groundwater extraction, ex-situ treatment with an anaerobic bioreactor, reinjection, and alluvium in-situ biological reduction. UPCO recently purchased the site from the Arizona State Land Department and remedy implementation will begin in 2016.
- UPCO CMS Report, revised 10-30-2015 -- (PDF)
- UPCO CMS Report, revised 10-30-2015 Tables -- (PDF)
- UPCO CMS Report, revised 10-30-2015 Figures -- (PDF)
- UPCO CMS Report, revised 10-30-2015 Appendices -- (PDF)