Mass. Gen. Laws ch. 82 § 12
When a highway has been finally laid out, altered, relocated discontinued or maintenance discontinued, or when specific repairs are ordered on an existing highway by the county commissioners, the county shall be primarily liable for all damages thereby caused, or for all amounts awarded or assessed as indemnity. The commissioners shall determine what proportion if any of the expenses of the proceedings, cost of construction, damages and indemnity shall be assessed upon the land benefited under chapter eighty and whether the remainder, if any, shall be borne by the county, or by the towns in which the parts of the highway are respectively located. The commissioners shall notify each such town of any balance due from such town to the county under this section and may enforce payment as provided in section fifteen.
Mass. Gen. Laws ch. 82, § 12