ES Projects

Status Updates

• 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.

• March, June, Sept., and December
  The City will conduct closed landfill site inspections quarterly. A report documenting site conditions will follow these events. These inspections are included with the annual report to ADEQ.

• March & September
  The City conducts groundwater monitoring semi-annually during these months at thirteen groundwater monitor wells and two privately owned irrigation wells. An annual report is sent to ADEQ documenting these results.

• April 2013
  Kolb Road: Connection to Sabino Canyon Road This project is part of the $2.1 billion, 20-year RTA plan approved by voters in May 2006. A new road is to be built that connects Kolb Rd to Sabino Canyon Road. A portion of the new road will pass over the Vincent Mullins Landfill. In April 2013, ADEQ approved the plan for geotechnical borings into the landfill in preparation for building the road.

• March 2013
  The city, with a consultant, completed an odor study. The study found that Vincent Mullins Landfill was not a source of significant odor. The report is available in the Reports/Attachments section of this website.

• November 2007
  ADEQ granted approval of landfill closure. This date marks the beginning of the 30-year post closure monitoring and management period.

• 2005-2006
  The City closed the landfill according to Federal and State regulations. Closure included construction of the landfill cover for the landfill, a graded earthen cap and landscaping to prevent erosion.

• January 2005
  The new and expanded landfill gas extraction system began operation at the Vincent Mullins Landfill. The system is the key element of the corrective action plan to clean up VOC vapor concentrations in the soil and eliminate potential sources in the landfill. The City previously operated two other landfill gas extraction systems which only had extraction wells along the western landfill boundary from 1986 - 2005.

• 2004-2006
  The City installed five additional groundwater monitor wells to delineate the PCE plume. These wells along with the other existing monitor wells are monitored twice a year.

• February 2004
  A new monitoring well (WR-453A) was installed downgradient from the landfill and monitoring results showed several detections of VOCs with PCE exceeding the Aquifer Quality Limit in the APP at a concentration of 5.4 ug/L. Up to this time, none of the other groundwater monitor wells at Vincent Mullins showed VOC detections. The City notified ADEQ and submitted a corrective action plan to address the issue.

• January 2002
  APP permit issued by ADEQ Solid Waste Unit. APP requires ongoing groundwater monitoring, capping the landfill and upgrading the landfill gas extraction system.

• 1986-2003
  Installed and monitored four groundwater wells (WR-115A, WR-116A, WR-117A, and WR-118A). The wells were monitored twice a year and results did not show any landfill impacts to the groundwater.

• 1987
  The City stopped accepting waste at the Vincent Mullins Landfill.

• 1984
  The City installed twenty landfill gas monitoring probes at the southern, western, and northern perimeters of the landfill. The probes were monitored for the off-site migration of landfill gases such as methane. Over the years, the City has installed and monitored new probes as necessary.