WATERBURY — In a broken and pitted parking lot next to a huge crumbling factory, U.S. Sen. Chris Murphy announced Wednesday a push to resurrect two federal tax breaks for redevelopment of polluted properties.

The former Anaconda Brass site is one of several along Freight Street that is being targeted for redevelopment with millions of dollars in local, state and federal grants and spending. Officials plan to inventory hazardous chemicals in the roughly 60 acres around Freight Street, cleaning and preparing sites for future development.

The area is flat, served by a rail line, and is nestled between Route 8 and Interstate 84. The Naugatuck River borders one end.

Mayor Neil M. O'Leary says the area is the most appealing development prospect the city has to offer. But fear of unknown pollutants and huge cleanup costs have kept developers away for decades. The city is working hard to strip away the mystery of potential costs and, eventually, clean up these areas.

Murphy, a Democrat, said his proposal could be a part of the formula that finally unlocks the potential of Freight Street, along with other urban centers where clean and undeveloped land is rare.

"We have spent a lot of time on this site and I feel we are closer than ever before to taking this symbol of the old Waterbury and making it the symbol of a new Waterbury," Murphy said.

Murphy said Connecticut will be unable to grow new jobs without creating more room for development.

WATERBURY HAS 27 POLLUTED sites on the state's inventory of polluted brownfield sites. Naugatuck has two. Cheshire and Watertown have one each. Torrington has five.

U.S. Rep. Elizabeth H. Esty, D-5th District, has introduced duplicate legislation in the House.

The most substantial of the two proposed tax breaks would allow companies to deduct the cost of brownfield cleanup off federal taxes in the first year of expense, rather than phasing that break over five years, Murphy said.

"That's a big deal because a lot of these developers need as much money and as much capital as they can in the first year, when they are doing the work," Murphy said.

To qualify, an entity would have to spend more than $550,000 or 12 percent of the property's value on cleanup.

This tax credit expired in 2011, according to Murphy's staff. Murphy or his staff could not immediately Wednesday point to examples of developers using the tax credit before it expired.

The second proposed revival is a tax break that expired in 2009. It would allow nonprofit entities that engage in a cleanup to collect revenue from the finished sites, such as lease payments, without becoming subject to taxes, Murphy said.

Murphy said they expired not from opposition. They aren't "budget busters," he said. They simply lacked a champion. Murphy hopes to secure these again late in the year, a time Congress generally considers relatively minor tax matters, he said.

WATERBURY MAYOR NEIL M. O'LEARY lauded Murphy as a champion of the city's brownfield's efforts, having helped secure $15 million for cleanup of the former Chase Brass complex along Thomaston Avenue in 2008. Today, the site hosts four companies employing hundreds, with a chemicals manufacturer building a $50 million plant.

O'Leary said the city has been approached by developers eager to consider the Freight Street area, but the city isn't likely to commit to any development until the sites are ready for development in three or four years. Officials want to make sure the valuable property is put to its most productive possible use, he said.

O'Leary supports Murphy's proposal as another tool in the crucial work of putting dormant industrial sites on the tax rolls and creating jobs.

"We believe this piece and other pieces in Waterbury are going to be key to the success of the city," he said.