Hartford — It's questionable whether Gov. Dannel P. Malloy's administration will borrow $50 million to help fix aging drinking water infrastructure across Connecticut, funds some public water systems have been counting on to make needed repairs.

State and federal officials estimate Connecticut has nearly $3.6 billion worth of infrastructure improvement needs. About $2.6 billion of that amount includes repair and replacement of water mains, some of which are 100 years old. The U.S. Environmental Protection Agency projects it will cost $384 billion over 20 years to maintain the nation's existing drinking water infrastructure, while replacing pipes, treatment plants and other needs to handle a growing population could cost as much as $1 trillion.

Gian-Carl Casa, spokesman for the state Office of Policy and Management, said the budgetary agency "continues to consider the policy implications" of legislation passed in 2014 requiring the state to borrow money to fund the grant program. Under the initiative, grants would be provided to certain small and large public water systems that participate in the state's Drinking Water State Revolving Loan Fund, which is federally funded.

"It might not make sense to take on the expense of what would be a new entitlement when we already have a very good loan program in place," Casa said in an email. "We encourage water companies to avail themselves of the revolving loan funds."

Connecticut receives about $8.5 million annually from the federal EPA to finance the existing revolving loan fund. It makes low-interest loans available to the state's 2,500 or so public water systems, which can vary greatly in size. While a review of national data by The Associated Press determined more than $1 billion from the EPA's federal aid program is sitting unspent in government accounts, Connecticut officials contend the state's record for doling out the money bests the national average.

"We are in very good shape," said Lori Mathieu, the Department of Public Health section chief who manages drinking water matters. In Connecticut, she said, about 6 percent is not liquidated. But the revolving loan fund is never zeroed out because it is a continuous program, she said. Meanwhile, the state has made strides in moving out the money quickly, she said.

But Mathieu said some water systems may want to take out a loan to fix their aging infrastructure but can't afford to do so. That's why the General Assembly in 2014 decided to create a special grant program to supplement the loan program and essentially wipe out some of the principal.

"When you have that age of infrastructure, it takes a lot to maintain it," said Mathieu, adding that every water system that has participated in the loan program has been looking forward to the possibility of getting the grant money since the legislation passed.

Betsy Gara, executive director of the Connecticut Water Works Association, said "it's going to be a blow" if the state doesn't follow through with the grant program.

"There are utilities counting on it to move forward with important infrastructure projects," she said.

Norwich Public Utilities is among those hoping to see the funding placed on the agenda for the State Bond Commission, which Malloy chairs. Besides Norwich, the public utility serves water customers in Lebanon, Bozrah, Franklin, Montville, Preston, Lisbon and the Mohegan Tribe.

Chris Riley, NPU spokesman, said the utility has a number of projects that will be affected by the availability of the additional money, including a $4.65 million project that includes a million-gallon water storage tank, transmission lines and treatment plant infrastructure improvements. Riley said NPU hoped to receive $690,000 in additional funding, "which would have lowered the costs of this project and allowed us to make additional investments in our aging water infrastructure."

Without the grant funds, he said, NPU will have to adjust schedules and the size and scope of projects.