Summary of Portage County Groundwater Conditions

Portage County

Wisconsin

Summary of the Portage County Groundwater Conditions Report

The Portage County Groundwater Conditions Report was produced as an educational outreach tool for the general public by the Groundwater Management Plan & Implementation Subcommittee and the Public Involvement & Education Subcommittee of the Portage County Groundwater Citizens Advisory Committee. (January 2000)⁷

Groundwater is a valuable resource to people, as well as the environment. Groundwater supplies Portage County with 100% of its drinking and water needs and feeds many lakes, streams, and rivers. Since groundwater belongs to the public, we need to protect it, so we can pass this resource onto future generations.

This document summarizes available groundwater information and identifies the challenges that need to be addressed in a new planning effort. These challenges include:

Nitrate Pollution: 20% of wells tested in Portage County exceed the Drinking Water Maximum Contaminant Level (MCL) of 10 ppm (parts per million) for nitrate-nitrogen. In addition, nitrate levels in Portage County have been steadily increasing. Most nitrate pollution is from agriculture with smaller amounts from septic systems, lawn fertilizers, and other sources.

Pesticide Pollution: Atrazine has been detected in 40% of wells tested in Portage County with 3% exceeding the MCL. Sufficient testing has not been done for all the pesticide residues that may be present in the groundwater. Also, limited information is available on the impacts of pesticides on health.

Quantity: Groundwater challenges arise when pumping lowers the water table so that users are unable to get sufficient water for their needs, and when pumping diverts water away from streams, lakes, and wetlands.

To view this 32 page document containing text along with supporting maps and charts, click here.

To view proposed goals and strategies to address these concerns, click here.