Well 8 Sentinel Well
About the Project
Madison Water Utility will be installing a “sentinel” groundwater monitoring well between Well 8 (in Olbrich Park) and Madison Kipp Corporation (MKC). The groundwater beneath MKC is contaminated with a chemical called PCE (tetrachloroethylene) and low levels of PCE have been detected in shallow groundwater 600 feet from the well. PCE has never been detected in the water at Well 8, and this sentinel well will act as an early warning if the contaminants are moving toward our well. This will give the utility time to act.
This $120,000 project will determine a location and install a deep monitoring well about 6 inches in diameter. The exact location will be identified using computer modeling to determine horizontal and vertical groundwater flow characteristics, so the well is positioned where it can intercept contamination pathways. It will also be deeper than any of the other monitoring wells around the MKC site, extending into the lower aquifer beneath the Eau Claire Shale. Well 8 draws water from this lower aquifer. After the well is installed, samples from there will be collected and tested regularly for PCE and other Volatile Organic Compounds present in the groundwater plume around MKC.
A local consultant has been hired to help with determining the location of this well and overseeing its installation. The Wisconsin Geological and Natural History Survey is assisting with the computer modeling. Several possible locations have been identified and a well depth proposed.
Located in Olbrich Park on Madison's east side, Well 8 is 774 feet deep and has an attached underground reservoir, which forms the basis of the sledding hill at Olbrich Park.
Well 8 is a “seasonal” well that only operates during the high-demand summer months. It contains naturally occurring iron and manganese, which can cause discolored water. You can learn more on our Well 8 webpage.
This monitoring well is critical in determining Well 8’s future. Combined with the computer modeling predictions, the sentinel well will provide water quality information along potential flow paths to Well 8, and inform utility managers of potential future risks to the well.
Well 8 was drilled in 1945, and the Capital Improvement Plan currently recommends reconstructing the facility and adding an iron and manganese filter.