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Recommendations for arsenic in drinking water

Special Well Casing Depth Area for Outagamie and Winnebago Counties - Effective October 1, 2004

Special casing areas have been established by DNR for specific areas within the arsenic advisory area where naturally occurring arsenic contamination is affecting existing wells.

Well construction recommendations for homeowners

Recommendations for Homeowners [PDF] provides a simple overview intended for homeowners in the arsenic advisory area to more properly understand well construction requirements.

Well compensation

Well construction has a direct bearing on arsenic levels of the water drawn from the well. These recommendations have been developed to minimize arsenic concentrations by reducing the introduction of oxygen and isolating the primary arsenic bearing zones. These recommendations have been very successful in most situations at reducing arsenic concentrations to acceptable levels. How long this will last is dependent on water usage and local geology. Conservation of water is an important factor in keeping arsenic concentrations in wells low. Construction Specs and Conditions for Arsenic Replacement Wells [PDF].

Water treatment

The following list contains Treatment devices approved by the Department of Safety and Professional Services for the removal of arsenic. Two categories of devices are defined, Point of Use (POU) and Point of Entry (POE). POU devices are used to treat water at the point of use such as a single tap. Distillation units provide safe water in batches while Reverse Osmosis (RO) units can be installed on a single tap. POE treatment systems treat all the water entering the home. All types of systems must be properly installed and maintained to reliably remove the arsenic from your drinking water.  To access the DSPS list of water treatment devices go to, from the search dropdown, select products; then from the type of product dropdown, choose plumbing products and from the select product description dropdown, choose water treatment device.


Well chlorination in arsenic sensitive areas

Well Chlorination in Arsenic Sensitive Areas [PDF] answers a number of common questions regarding chlorination and how it relates to arsenic sensitive areas. The publication also provides a step by step discussion of how to chlorinate a water supply well.

Well and system maintenance

The DNR is currently formalizing recommendations for well maintenance. Until it is developed consult your local DNR water supply specialist for details on issues involving bacteriological contamination, iron bacteria and well rehabilitation.