Senate Bill No. 575 aims to expand the existing bioscience enterprise corridor zone in Plainville by including all of a specified census block, rather than limiting it to just 53 acres zoned for a technology park. The bill repeals the previous language regarding the 53 acres and replaces it with a broader designation of the entire census tract 420700, block 2000, as defined in the 2020 federal decennial census. This expansion allows more eligible businesses and commercial properties within the area to qualify for enterprise zone benefits, which are available to businesses engaged in bioscience, biotechnology, pharmaceuticals, or photonics research, development, or production.

The bill outlines that eligible businesses must have fewer than 300 employees and have been operational for at least 12 months, while eligible commercial properties must be owned or leased by these businesses or newly constructed or substantially renovated for their use. The enterprise zone benefits include significant property tax exemptions and fixed assessments for qualifying improvements, with the state providing reimbursement to municipalities for lost tax revenue. The bill is set to take effect upon passage, and its fiscal impact may result in a reduction of Plainville's grand list due to additional property tax exemptions, although this may be offset by state grants.