Earlier today, the state Environmental Facilities Corporation unanimously approved a $511 million loan from the state’s federally-funded clean water program to the Tappan Zee Bridge construction project, using funds intended for clean water initiatives in New York City.

In its press release, the board of Cuomo appointees said the loan, which will help the Thruway Authority save at least $17 million over three years, will go to pay for projects that mitigate the negative impact of the highway and “will help keep tolls on the new bridge as low as possible.”

The state says the highway qualifies for the loan — half of which is low-interest, the other half interest-free — because it is an estuary protection project that helps implement an EPA-approved estuary plan. The state claims the Tappan Zee project helps implement an estuary plan dating from 1996 focused on New York Harbor. While the bridge is just outside the plan’s core area, it does fall within its “watershed-based” boundaries.

Advocates aren’t buying it. According to their calculations, only $12.5 million of the $511 million loan would go to “genuine environmentally beneficial projects,” all of which the state agreed to as part of mitigation for the highway. In addition, the Tappan Zee environmental impact statement, completed two years ago, never mentions the estuary plan once. If the bridge project is related to protecting the estuary, why was that never mentioned before the state set out to get a clean water loan?

Robert Pirani is program director for the New York-New Jersey Harbor and Estuary Program, the EPA-funded initiative that created the 1996 plan. “They’re not projects that are discussed in the comprehensive management plan,” he said of the Tappan Zee loan.

Pirani noted that it’s up to the state to determine whether its own highway qualifies for the clean water loan. “There’s a lot of stuff we just don’t know,” he said. “They need to justify to themselves that this is an appropriate use of the funding.”

Advocates are also worried that the state could snap its fingers and turn this loan into funding with no expectation of repayment.

Since 2009, Congress has given state clean water funds broader latitude to issue both grants and “principal forgiveness,” which essentially converts part of a loan into a cash grant. Since 2009, EFC says it issued has more than $466 million worth of principal forgiveness to qualifying financially-disadvantaged communities.

Peter Iwanowicz, executive director of Environmental Advocates of New York, says that with the state providing so little information about the loan since it was announced two weeks ago, this mechanism opens up the possibility of turning at least some of the Tappan Zee loan into a cash grant. ”Since the full application and terms of the loan have not been provided,” he said, “I don’t think anyone should think that the loan will ever be repaid.”

The next step in the loan process is a vote before the Public Authorities Control Board, which has appointees from the governor and the legislature and next meets on July 16.