Collecting and analyzing Wisconsin landfill environmental monitoring data
The DNR's Waste and Materials Management Program has collected environmental monitoring data from licensed landfills since the mid-1970s. These data are captured in the Groundwater and Environmental Monitoring System (GEMS) database. Program staff use information in GEMS extensively to evaluate the performance of landfills and determine their impact on the environment.
Environmental monitoring data submitted to the DNR are also used to evaluate the effectiveness of remedial actions taken at landfills. We receive and review a wide variety of environmental monitoring data from more than 600 landfills, including the results from analysis of groundwater, air and leachate samples, methane gas readings and water table measurements.
Information contained in GEMS and its integrity
The records contained in GEMS cover analytical data for groundwater samples from monitoring wells at solid waste facilities, private drinking water supply wells around landfills, and a few hazardous waste facilities that have monitoring wells. In addition, the database contains records for gas, leachate and surface water monitoring from landfills.
The environmental monitoring data for older licensed landfills can be very extensive. In some cases, data has been collected since the late 1970s from groundwater monitoring wells (water table observation wells and piezometers), leachate tanks and head wells, gas probes, gas extraction wells, sedimentation ponds and surface water sampling points.
To maintain the integrity of the GEMS database, it is critical that facilities, consultants and laboratories work with the DNR to ensure that environmental samples are collected and analyzed properly with the resulting data transferred accurately to the DNR.
Public access to GEMS
The GEMS on the Web system is an interactive application used by DNR staff to view and analyze environmental monitoring data in a variety of ways, including generating more than 20 different reports. The public can access GEMS on the Web to find landfill environmental monitoring data.
Examples of guidance documents and a link to the documents are listed below. These documents and additional publications may be found on our searchable Publications system.
To locate a document in the Publications System, go to the "Standard Search," enter a topic of interest such as "monitoring," "leachate" or "gas" in the "Description" field and press the "Find" button. The title of the publication and the publication number will be listed. To view the publication, click on the publication number. You can also use the "Keyword Search" and enter key words such as "groundwater," "monitoring," "landfill" or "gas."
- Implementing Assessment Monitoring (WA-1008)
- Monitoring Water Supply Wells for VOCs Around Solid Waste Disposal Facilities (WA-1009)
- Inspecting Monitoring Wells at Landfills (WA-1796)
- Volatile Organic Compound Parameters for Landfill Gas Monitoring at Municipal Solid Waste Landfills (WA-1701)
- Reducing or Terminating Groundwater Monitoring at Solid Waste Landfills (WA-1013)
- Guidance for Review of NR 140 Requirements at Landfill Expansions (WA-1010)
- Problems Associated With bis(2-ethylhexyl)phthalate Detections in Groundwater Monitoring Wells (WA-1011)
- How to Calculate Preventive Action Limits (PALs) and Alternative Concentration Limits (ACLs) for Solid Waste Facilities (WA-1105)
- PAL/ACL Calculation Guidance for Solid Waste Facilities