At such hearing, the selectboard shall assess each real estate owner outside such municipality benefited by the construction of such sewer, drain, or outlet, his or her proportion of the expense, according to frontage or the benefit received. When such assessment is made and signed by the selectboard or a majority of it, it shall be recorded in the office of the town clerk. When so recorded, it shall be a first lien except taxes and may be enforced, as a tax lien is enforced, upon the land described in the assessment until the same is paid.