cost for radon mitigation
1 Ground water wells can also be tested for radon, then, if needed, can get a water radon mitigation system installed. 2  Installing a water radon mitigation system runs from $1,000-$4,500, and maintenance runs $0 to $150 annually. 3  To find out about radon content in a city water system, call the local water provider. Ventilating the home and crawlspace is a temporary and limited fix. 2  Passive and active suction systems cost $550-$2,500 depending on the size of the house. 3  These systems offer the best radon reduction available.