In Massachusetts, in order for the landlord to charge for water and sewer, there are a number of specific steps that have to be taken. There has to be water conserving fixtures installed and the water has to be separately metered. A plumber has to certify as to the installation of water conserving fixtures. A document has to filed with and approved by the board of heath concerning the water conservation fixtures. These steps have to be taken before the issue of changing the lease can be reached. If a landlord has not complied with these steps a tenant should be able to call the Board of Health who should notify the landlord that he can't charge for water and sewer charges.
This can be a complicated area of law and a landlord should consult and experienced real estate attorney to comply with the law.