Gasonline spill contaminating well water.

There was an accident in front of our home involving an automobile and a gasoline tanker. The driver of the car turned in front of the tanker. The tanker hit and ran over the car. The driver of the car was killed. The tanker over turned onto the car. The tanker was punctured and spilled over 3,000 gallons of gasoline which was absorbed into the ground. As a result our well water has been contaminated. The insurance company for the tanker has installed a water filtration system in our home as well as some monitoring wells at different locations from the site of the accident. We have nothing in writing from them letting us know what they intend to do for us over the years. We are having to depend on bottled water for drinking, cooking, and brushing of teeth. What can we do legally as far as selling our home in the future or our health in the coming years. Who is liable for the bottled water and the upkeep of the water filtration system after the three year statue of limitation runs out?