30-A M.R.S. §707: Illegal assessments

All assessments under this Part made by the county commissioners which include sums assessed for an illegal object are not void, nor shall any error, mistake, omission or inclusion of illegal sums in the assessment by the county commissioners void any part of the assessment that is assessed for legal purposes.

Any person paying a tax assessed for an illegal object may bring a civil action against the county in the Superior Court for the same county and may recover as much of the sum paid as was assessed for an illegal object, with 25% interest and costs and any damages which that person has sustained because of the mistakes, errors or omissions of the commissioners.