Remediation Activities

Soil Vapor Extraction (SVE)

STATUS AS OF 9/1/2021 - FULLY FUNCTIONAL AND OPERATING

Soil vapor extraction, or “SVE,” extracts (removes) contaminant vapors from below ground for treatment above ground. Vapors are the gases that form when chemicals evaporate. SVE extracts vapors from the soil above the water table by applying a vacuum to pull the vapors out. The air is then filtered through a series of filtration tanks before being discharged. Discharged air meets all applicable air quality standards.

Since full scale start up in September of 2015, the SVE has extracted over 46,780 pounds of VOCs. It is currently estimated to be extracting approximately 200 pounds per month. Monitoring has indicated an overall decrease in TCE concentrations at all soil vapor depths.


Water Treatment System (WTS)

STATUS AS OF 9/1/2021 - UNDER CONSTRUCTION (see each phase for details)

Phase 1 GWTS Photo 1Phase I - Water Treatment System

The Water Treatment System is complete. Because the Phase 3 infrastructure is still in the process of being permitted and constructed, the treatment system is not operating at this time. As of 9/1/2021, this system is complete and ready for operation once the other phases are complete.


pipePhase II - Conveyance Pipeline (complete)

Construction is complete. The sub-grade, 8-inch diameter pipe has been installed from the Groundwater Treatment System (on the landfill property) to the injection well located on City of Phoenix property at 4050 Sleepy Ranch Road.


Phase III - Injection Well (under construction)

There are three sub-phases to Phase III

Phase III, Sub-phase A (complete) is the well itself. The well has been drilled and developed to a depth of 1,600 feet below surface level. Once the entire system is complete, clean water will be injected into the groundwater at a depth of greater than 1,000 feet below surface level. The pump will be submerged in the well approximately 1,000 feet below the surface.

Construction of the well itself is complete.


wallPhase III, Sub-phase B (under construction) is the well security and screening. Neighbors around the 4050 E Sleepy Ranch Road well site have worked with the County to ensure a decorative wall and landscaping. Site components will be kept below the wall height. The injection pump will be a submergible pump installed some 1,000 feet below the surface. (Note: picture is a rendering only and is not intended to show detailed features.)

Construction of the wall is complete and planting of trees and shrubs on three sides is complete. The last of the landscaping will be restored once the final utility work has also been completed.


Phase III, Sub-phase C (in permitting / contracting) is the equipment necessary for the injection process. It includes a submergible pump, an electrical vault, a partially underground tank, and piping. Some components must be custom designed and built to keep the equipment profile below the screening wall height. In an effort to minimize the impact to the residents, the electrical service will be bored rather than be installed using an open trench.

The design phase of the equipment for injection is complete and vendors are being selected. Work is expected to begin August 12, 2021. (Note: Larger picture is available in the images folder.)


New Well  Installations - 2021

STATUS AS OF 9/10/2021 - PENDING START OF CONSTRUCTION

Monitoring Wells (MW) 16 and 17 (pending start of construction)Well Locations

MW-16 and 17 have been approved for location on State Land to the south of the landfill. These wells are planned for areas that are believed to be free from contamination and will serve as "sentinels" to allow better tracking and modeling as the County steps up remediation activities. The schedule for drilling was modified following feedback received during the 6/16/2021 Public Meeting. MW-17 (closest to residents) will be drilled first beginning in late July with MW-16 coming at the end of the drilling project that includes two monitoring wells and two extraction wells (see below). See New Well Construction - 2021 map in the "Maps" tab.

MW-17 total depth was reached on 8/30/2021. Final development is anticipated to be complete around 9/15 after which the equipment will be moved to the EW-03 site.

Extraction Wells (EW) 2 and 3 (pending start of construction)

EW 2 and 3 will be part of a capacity expansion to the Water Treatment System that will allow the treatment of approximately 500 gallons per minute of groundwater. The strategic placement of these wells helps to ensure a speedier remediation phase and a more complete capture of the plume. EW 2 and 3 are a critical component of the County's more aggressive remediation plans. EW-03 (closest to residents) will be drilled after MW-17 is complete, followed by EW 2 and finally MW 16. See New Well Construction - 2021 map in the "Maps" tab. 

EW-03 setup is expected to start around 9/20/2021 with drill slated to start as soon as set up is complete. Set up includes a full sound barrier around the drilling site and an additional noise barrier surrounding the generator and compressor inside the enclosed site.