ALBANY — Comptroller Thomas DiNapoli said Wednesday that some polluted parcels statewide including several on Long Island have taken 10 to 25 years to clean and redevelop for commercial use and housing under a state program.

In Nassau County, five of 20 active sites being redeveloped for companies and homes are taking more than 10 years to complete and one has taken more than 25 years. In Suffolk County, one of four active brownfields sites has been unfinished for 25 years, according to DiNapoli’s report.

Statewide 17% of the 518 active brownfield projects have been in the program for more than 10 years with 25 projects still underway after 25 years, according to the report. The brownfields program under the state Department of Environmental Conservation is funded in part by the polluters of the properties that are often located in potentially productive areas.

"The Brownfield Cleanup Program can transform contaminated sites into community assets, but only if there is strong oversight," said DiNapoli, a Great Neck Plaza Democrat. "Long Island residents deserve assurance that sites in Nassau and Suffolk are not languishing in the program or posing threats to the health and safety of residents."

He said the Department of Environmental Conservation must set clear deadlines and establish accountability and transparency measures "so these sites are actually cleaned up."

DiNapoli said the Department of Environmental Conservation is considering regulations to improve oversight and progress faster at "high-risk sites." A public database on the project is also planned, DiNapoli said.

A spokesman for the department didn’t immediately respond to a request for comment.

Properties on Long Island that have taken more than 25 years to clean and redevelop are:

Properties taking more than 10 years to clean and redevelop are:

The state’s brownfields program is intended to rid parcels of pollutants and toxic contaminants that must be removed before the property can be redeveloped to create housing and jobs. The program encourages private companies to voluntarily clean up the properties in exchange for tax credits, relief from liability and the benefit of technical expertise from the state.

The program is an alternative to the state and federal Superfund programs that mandate companies to clean their most contaminated sites and eliminate public health threats.

The DEC’s written response to DiNapoli’s auditors notes that the concerns involve just 6% of 699 active projects. But the department agreed with the findings of DiNapoli’s report on the delayed projects he highlights.

"DEC will take appropriate action to implement recommendations cited in the report," the department stated.