There are no state regulations specifically for radon mitigation businesses in Wisconsin. The link to the proficiency lists is combined from two national certifying organizations, whose web sites carry the most up-to-date information:
To be listed by them, a person has to pass a national exam, meet continuing education requirements, and follow radon mitigation standards. (For information on radon mitigation proficiency training to be held in Wisconsin, please contact the Indoor Air and Radon Program, 608 267-7199.)
Being listed is not endorsement by the State of Wisconsin, the Department of Health Services, or Fond du Lac County. The lists are given as another resource for anyone interested.
Professional measurement contacts: