A county staff member presented April monitoring‑well results to the Land and Water Conservation Committee, reporting that wells screened farther from the river showed higher nitrate concentrations than wells screened closer to the Wisconsin River.

"So this is just an update on our April, monitoring well sampling," the presenter said, describing the data as preliminary and part of an ongoing project.

Why it matters: groundwater nitrate concentrations can indicate nutrient inputs from agricultural land, septic systems or other sources. The county’s monitoring aims to track spatial and seasonal patterns and to identify likely sources so land‑use or mitigation work can be targeted.

What the data show
- Upgradient vs. downgradient patterns: Monitoring wells 1, 2, 6 and 7 — described as further from the river — generally showed higher nitrate values. Wells 3, 4 and 5, screened closer to the river, had much lower nitrate concentrations, with many samples near or below 0.1 milligrams per liter in shallow screens.
- Variability: Wells 1 and 7 showed relatively stable nitrate trends across samplings dating back to mid‑2023, while wells 2 and 6 displayed large seasonal fluctuations. The presenter noted monitoring well 6 as an outlier that will receive additional attention.
- Possible explanations: staff said the lower nitrates near the river could reflect denitrification, dilution from river water or other mixing processes; they said they may consult university researchers for analysis.

Next steps and testing: staff said additional sampling is scheduled (including a July sampling) and that future tests will include organic source tracers, pesticide/herbicide breakdown products and septic‑system tracers to help identify likely nitrate sources.

The presentation was framed as an interim update: the presenter emphasized that the sampling series is ongoing and that greater clarity should come with the next rounds of data.