Rock County, WI
Home MenuNitrates in Groundwater
Nitrates are found naturally in groundwater at very low levels due to decomposition of plant and other organic materials. Nitrate levels increase in the groundwater due to impacts by humans. Nitrates leach into our groundwater and drinking water supplies when nitrogen fertilizers are applied to crops and lawns are not completely used during the growing season. The excess nitrogen that leaches through the soil can result in high levels of nitrates in the groundwater. Septic systems are also a contributor to elevated nitrates as septic systems are not efficient in removing nitrogen.
The health advisory level for nitrates in drinking water is 10 mg/L. Nitrates at or above this level have been associated with an increased potential for methemoglobinemia or "Blue Baby Syndrome". This condition can cause a lack of oxygen in a fetus and infant up to 6-months of age. High nitrates have also been associated with possible increased risk of birth defects, thyroid disease, and certain types of cancer.
Nitrate Risk Mapping Tool
The Nitrate Risk Mapping tool was created by the Rock County Public Health Department to help citizens estimate the level of risk of nitrates reaching the groundwater that their private wells draw from.
Nitrate levels in your drinking water are also affected by groundwater flow and well depth. When using this map you should look at the risk level for your area, as well as, the surrounding area.
Access the Nitrate Risk Mapping Tool
About the Nitrate Risk Mapping Tool