HARRISON LANDFILL Project
|Objectives:|| To ensure the safety of the public and the environment by monitoring, managing, and controlling landfill gas and groundwater quality. ||
|Location:|| 9245 & 9475 E. Irvington Rd.|
|Waste Acreage:|| 64.7|
|Operation Dates:|| 1972-1996|
|Status:|| Active Clean-up Site|
|Annual Maintenance Budget:|| approximately $140,000|
|Project Contact:|| City of Tucson - Environmental Services 520-791-3175 |
|Description:|| The Harrison Road Landfill accepted municipal solid waste from 1972 until it closed in 1997. Data indicates soil vapor contaminated with volatile organic compounds (VOCs), specifically tetrachloroethene (PCE), migrated from the waste to the groundwater table and caused groundwater contamination of PCE at levels above regulatory standards. The City operated a deep soil vapor extraction (SVE) system to remove the source of the groundwater contamination. Today, the City is operating a groundwater pump and treat system to control and clean up the PCE contaminated groundwater. In addition, a landfill gas flare system was constructed to control the migration of methane and VOCs from the waste. The site is regulated under the Arizona Department Environmental Quality (ADEQ) Solid Waste Unit. The groundwater pump and treat system requires additional reporting to the Arizona Department of Water Resources (ADWR) because of the amount of water extracted each year.|
|Additional Info:|| Although groundwater contamination has been detected above regulatory standards, there are no nearby Tucson Water drinking water wells. The City monitors a downgradient private drinking water well semiannually for landfill impact.|
|Activities:|| Inspections, Landfill Gas Monitoring, Groundwater Monitoring, Landfill Gas Control System, Landfill Gas Remediation (soil vapor extraction), Groundwater Remediation|
|Last Update:|| Friday Sep. 5, 2014|
View this project on the Environmental Management Projects Map
- January, April, July, & October
The City conducts quarterly landfill gas monitoring at perimeter probes during these months every year to monitor for methane migration at the property boundary.
- May & November 2014
The City is scheduled to complete semiannual groundwater monitoring of site wells and a downgradient private production well. Monitoring reports will be prepared documenting the results.
- April & October 2014
The City is scheduled to conduct closed landfill site inspections. A report documenting site conditions will be prepared after the inspections.
- February 2014
The Arizona Department of Environmental Quality (ADEQ) provides approval to turning-off the groundwater treatment system. The remediation system has successfully cleaned-up the groundwater for tetrachloroethene (PCE) and trichloroethene (TCE) to concentrations below regulatory standards. The city will develop a work plan prior to shutting down the system for continued monitoring of the groundwater. Should concentrations in the groundwater rebound, the system can be turned back on.
- January 2014
A semiannual report describing the progress of the groundwater treatment system was sent to ADEQ and ADWR. The City of Tucson has treated more than 373 million gallons of groundwater, and removed 88.2 pounds of total VOCs. This semiannual report is available for download in the Attachments/Reports section of this website.
- February, May, August, & November 2014
The City is scheduled to complete quarterly groundwater monitoring of the pump and treat system’s carbon canisters, extraction wells, two downgradient monitoring wells, and one private production well.
- February 2013
The City submitted the annual groundwater withdrawal report for the pump and treat system to ADWR. The latest report should be available for download in the Reports/Attachments section of this website.
- May 2011
The city installed the new downgradient groundwater well HLM-550 along Wingate Road. The well is monitored quarterly and all VOC results are below the AWQS.
- January 2005
An existing groundwater monitoring well was converted to an extraction well to better contain the plume.
- June 2001
Groundwater pump and treat system began operation. The sytem is designed to remove and treat groundwater impacted with volatile organic compounds (VOCs), primarily tetrachloroethene (PCE) and trichloroethene (TCE). The treatment system consists of two 4,500 pound granular activited carbon (GAC) vessels. The treated water is re-injected into the groundwater.
- 1999-2002 & 2005-2006
Operation of the deep SVE and air injection system (AI) began in order to remove and treat VOCs from the deep soil vapor. The system removed and treated 18,034 pounds of VOCs. This system is currently not operating, but the City monitors the vapor wells periodically and will return the system to operation if needed.
The City acquired land rights and installed groundwater extraction wells, monitoring wells, injection wells, infrastructure and piping for the groundwater extraction and treatment system.
ADEQ Solid Waste Unit approved the use of an SVE system to remove the source of the contamination, and a groundwater extraction and treatment system to contain and clean up the PCE plume.
A landfill gas extraction and flare system was installed and is still in operation today. From 1995-1998 a temporary emergency flare was in operation.
- October 1998
The City closed the landfill according to Federal and State regulations. Closure included construction of the landfill cover for the landfill, including a graded earthen cap and landscaping to prevent erosion. This date marks the beginning of the 30-year post-closure monitoring and management period.
The City stopped accepting waste at the Harrison Landfill.
- July 1996
Groundwater investigation completed to characterize the aquifer properties and extent of the contamination.
The City installed shallow landfill gas monitor probes to monitor methane concentrations between the landfill and nearby homes and businesses and began routine monitoring.
Groundwater contamination of PCE was first discovered in monitoring wells that were not used to provide drinking water supply. Additional groundwater monitoring wells were installed to characterize the extent and migration rate of the contamination. The City commissioned studies to determine the best method of groundwater remediation.
Project Photos and Maps
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The soil vapor extraction system (SVE/AI) was designed to remove vapor phase contaminants between the waste and the groundwater table to prevent groundwater contamination. Soil vapor is extracted from three extraction wells, cleaned by carbon, and re-injected into the subsurface.
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Landfill gas extraction system and flare. System helps to control landfill gases.
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Groundwater treatment system carbon canisters. Water is extracted from three groundwater extraction wells, treated by two carbon canisters and then re-injected into the groundwater.
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Site Map includes the approximate landfill boundary, the groundwater and soil vapor monitoring points, and landfill gas extraction piping and well positions.
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Figure 2 map from the latest monitoring report. Map shows site, well locations, latest tetrachloroethene (PCE) concentrations and trends.
- Closed Landfills Inspection and Maintenance Report
The City of Tucson - Environmental Services owns and maintains fifteen closed regulated and non-regulated landfills. This guidance report provides the procedures for inspecting and maintaining those landfills. The text portion of this report is available at this link. To review the full document contact the Environmental Services office at 520-791-3175.
- 2011 Soil Vapor Testing Results
Remedial System Status, 2011 Soil Vapor Testing Results and Landfill Gas Extraction System Operational Recommendations. The text, tables, and figures to the report are available at this link. To review the full document contact the Environmental Services office at 520-791-3175.
- Harrison Landfill Monitoring Report, 2nd Half 2012
Report summarizes and discusses groundwater monitoring and treatment system performances during July - December 2012. The text, tables, and figures to the report are available at this link. For the full document contact the Environmental Services office at 520-791-3175.
- 2012 Annual Water Withdrawal Report
2012 Annual Water Withdrawal and Use Report for the Poor Water Quality Permit No. 59-583889.0001. The City of Tucson extracted, treated, and re-injected 57.9 acre-feet of groundwater in 2012. Cover letter date should be February 7, 2013.
- Post Closure Care Inspection
This memo documents the April 2013 post closure care landfill inspection for the Harrison Landfill.
- ADEQ Approval to Shut Down Pump and Treat System
Letter from ADEQ approving to turn-off the groundwater treatment system. The remediation system has successfully cleaned-up the groundwater for tetrachloroethene (PCE) and trichloroethene (TCE) to concentrations below regulatory standards. The city will develop a work plan prior to shutting down the system for continued monitoring of the groundwater. Should concentrations in the groundwater rebound, the system can be turned back on.
- Rincon Country RV Park Resort Groundwater Results
The City of Tucson - Environmental Services collected a sample from the private groundwater well located at Rincon Country East Mobile Home Park in November 2013. There were no detectable concentrations of volatile organic compounds (VOCs) in their water. This letter was sent to the park notifying them of the results.
- 1st Half 2014 Report
This report summarizes and discusses groundwater monitoring and treatment system performances during January - June 2014. The text, tables, and figures to the report are available at this link. For the full document contact the Environmental Services office at 520-791-3175.