An estimated $1 billion price tag for the cleanup of contaminated former manufactured gas plants has experts and residents fearing for Long Island's economic health.

Cleaning up all 12 of the contaminated MGP sites could costs more than $1 billion, according to economist Marty Cantor. Cantor believes ratepayers will bear the financial burden, which could result in a 30 percent rise in electric and gas utility rates.

"This is an economic disaster for ratepayers to have to pick this up," Cantor said. "Long Island's economy is extremely fragile and this will crack it."

At the center of the dispute is whether or not ratepayers should foot the bill, a decision that rests with the Public Service Commission. Island lawmakers lodged a formal complaint with the PSC asking it reconsider staff recommendations to hold ratepayers responsible.

Also in dispute is the estimated cleanup cost. A spokesperson for KeySpan, which currently owns the sites, said until they know how extensive the contamination is, they can't accurately predict the price tag. KeySpan "will vigorously pursue third parties who should be responsible for parts of the cleanup costs, including insurance carriers...and will seek rate recovery for the remainder of the...cleanup costs," the spokesperson said.

Environmentalist Adrienne Esposito said the abandoned plants are a real health concern, and residents shouldn't be deterred from cleaning them up because of the intimidating costs.