Waterford — The proposal to develop the former tuberculosis hospital in Waterford into a state park and a lodge-style hotel will now face the test of the private market.

State officials released the request for proposals Wednesday, hoping to entice developers to bid on the chance to transform the former Seaside Regional Center, a collection of aging buildings, sea walls and landscaped lawns, into a destination hotel.

It calls for at least a 50-year lease of the buildings for a hotel with up to 100 rooms, and leaves the rest of the park and beach open to the public.

The ideal proposal would "offer amenities such as dining, meeting space, and a spa, and make the site an attractive destination that works in harmony with adjacent neighbors, the community, and nearby park properties," according to the request.

The responses from developers, which are due to the state July 27, will be the first test of whether the Department of Energy and Environmental Protection's plan to turn Seaside into a privately run hotel on the state park property could be a success, amid skepticism from Waterford and state officials.

The release of the request for proposals comes weeks after state Sen. Paul Formica, R-East Lyme, launched a legislative effort to call into question Gov. Dannel P. Malloy's decision four years ago to establish Seaside as a state park.

Malloy's 2014 surprise announcement cut off a private developer's yearslong bid to buy Seaside from the state and use it for purposes that varied from a nursing home to a high-end hotel similar to the concept DEEP would later decide on as its vision for Seaside's future.

The announcement appeased neighbors concerned about the potential effects of private development and preservationists hoping to ensure the protection of Seaside buildings designed by architect Cass Gilbert in the early 1930s and listed on the National Register of Historic Places.

Since 2014 DEEP officials have held public hearings, hired consultants and commissioned reports on multiple options for the property, finally landing in January on the final decision to partner with a private developer to run a lodge there.

Formica proposed the bills that were taken up by the Environment and the Government Administration and Elections committees to question the state's plans for Seaside, saying he believes state officials should reconsider selling the property to a private owner instead of leasing the buildings and keeping Seaside as a state park.

Both bills were the subject of hearings but appear to not be destined for a vote either at the committee level or in the General Assembly as a whole.

Susan Whalen repeated her support for the state park concept and her optimism that the hotel plan would generate high-quality proposals from bidders.

"You can never have enough state parks, in my view," she said. "Connecticut in particular doesn't have an awful lot of shoreline access, and so we think this property is especially important for ... visitors to have access to the Long Island Sound. We think that these buildings can attract a private investment that will essentially pay for the bulk of the adaptive reuse that needs to be done. We think these buildings have a future."

Renovating the buildings could cost up to $35 million, she said. Several developers have unofficially expressed interest in the property, she said.

The request for proposals stipulates that any successful bidder would have to keep the beach and grounds of Seaside open to the public.

In the request for proposals released Wednesday, DEEP officials have left many of the details — including the precise number of hotel rooms and the level of state investment — up to the bidding developers.

"We make it clear...that we will favor those proposals that have the least amount of state investment," she said. "But in exchange for that we offer a very long lease."

Whalen said Wednesday that the development could resemble anything from Watch Hill's Ocean House to the privately run inn at New York's Bear Mountain State Park.

"We're simply interested in someone who has both the financial resources and the right team in place. And that team can be constructed in any number of ways — whether it's a large company or a small company."

DEEP officials will host an open house at Seaside on May 7 for prospective bidders. Whalen said because asbestos abatement in the buildings is ongoing, anyone who registers for the open house will need to wear protective gear and register with DEEP beforehand.

A state-designated evaluation committee comprising staff at DEEP, the Office of Policy and Management and the Department of Administrative Services will review the proposals and interview the bidders.

The developer the committee chooses as its finalist then will present a proposal at a public meeting.

m.shanahan@theday.com