SECTION 1. The first sentence of subsection (i) of section 6 of chapter 62 of the General Laws, as appearing in section 102 of chapter 140 of the acts of 2024, is hereby amended by inserting after the words “another taxpayer” the following words:- , who has not claimed a tax credit pursuant to subsection (i½) for the same residential property.

SECTION 2. Said subsection (i) of said section 6 of said chapter 62, as so appearing, is hereby further amended by inserting after the first sentence the following sentence:- The tax credit shall be refundable to the taxpayer.

SECTION 3. Said section 6 of said chapter 62, as most recently amended by section 13 of chapter 248 of the acts of 2024, is hereby further amended by inserting after subsection (i) the following subsection:-

(i½) Any owner of residential property located in the commonwealth who is not a dependent of another taxpayer and who has not claimed a tax credit pursuant to subsection (i) for the same residential property shall be allowed a non-refundable credit equal to 60 per cent of the expenditures for design and construction expenses for the repair, replacement or upgrade of a cesspool or septic system or connection to a sanitary sewer collection system, if such repair, replacement, upgrade or sewer connection is required pursuant to the provisions of Title 5 of the state environmental code, a watershed permit issued by the department of environmental protection or other requirements or conditions for implementation of the watershed permit imposed by the permittee or the department of environmental protection. Said expenditures shall be the actual cost to the taxpayer or $30,000, whichever is less; provided, however, that said credit shall be available to eligible taxpayers beginning in the tax year in which the repair, replacement, upgrade or sewer connection was completed; and provided further, that said credit shall not exceed $4,000 in any tax year and any excess credit may be applied over the following 5 subsequent tax years up to an aggregate maximum of $18,000. The department shall promulgate such rules and regulations as are necessary to administer the credit afforded by this subsection, including, but not limited to, a notification system by the commonwealth to recipients of said interest subsidy or grant of the amount of the total subsidy provided by the commonwealth.