Pennsylvania's senators and local members of Congress are pressing the Navy to fund blood testing for residents affected by water contamination around former naval air bases in Bucks and Montgomery Counties.

That request Tuesday - prompted by health concerns over chemicals that leaked into water supplies, and are linked to cancer and reproductive issues - came on the same day that the consumer advocate Erin Brockovich and a New York-based law firm announced that they would investigate the drinking-water issues in the area.

It is also two weeks after a Navy representative told reporters that the military was not planning to fund health screenings.

Since 2014, 16 public drinking wells and dozens of private wells have been shut off due to contamination with chemicals used at military bases in Horsham and Warminster.

In a letter to the Navy, a group of lawmakers said testing for the chemicals, known as PFOA and PFOS, in residents' bloodstreams is necessary to allow them to seek medical treatment if needed.

"As the responsible party for the groundwater contamination, we believe the Navy has an obligation to take further steps to address ongoing health and safety concerns," they wrote.

The Pennsylvania Department of Health is now looking into the cost of blood screenings.

"We are hopeful that the federal government will cover the costs for testing any affected residents," department spokesman Wes Culp said in an email Wednesday.

Also Wednesday, the Pennsylvania House passed a resolution urging the federal government to do more to address water-related health concerns.

State Rep. Todd Stephens (R., Montgomery) said blood testing for 70,000 residents in the area could cost about $8 million, which he said he hopes the federal government should pay.

Lawmakers' letter to the Navy, sent Tuesday and made public Wednesday, was signed by U.S. Sens. Robert P. Casey Jr. and Patrick Toomey, and U.S. Reps. Patrick Meehan, Brendan Boyle, and Mike Fitzpatrick. Casey and Boyle are Democrats; Toomey, Meehan, and Fitzpatrick are Republicans.

A spokesman for the Navy did not return a request for comment Wednesday.

Gregory Preston, director of the Navy's base realignment and closure program management office in Philadelphia, said at a meeting with local and federal officials last month that residents concerned about health effects should speak with doctors.

While the Navy will continue paying to clean up the water supply and remediate the contamination, he said, there were no plans to fund health testing. "There is no blood sampling . . . and I'm not sure if there will be," he said at that meeting.

Although officials say public water is now safe to drink and private well owners are being moved onto the public supply, residents worry about the years they spent drinking the water - and many say the government and military have failed to give them all the answers they are seeking.

The law firm Weitz & Luxenberg decided to get involved after residents contacted it "in large numbers," said Robin Greenwald, head of the firm's environmental and consumer protection unit. The firm, which has a Cherry Hill office, has done PFOA investigations in New York, Vermont, and New Hampshire, and filed a class-action suit in February in a similar case in Hoosick Falls, N.Y.

"Nobody wants to drink a chemical," Greenwald said. "You have people who are really uncertain about what all this means."

Brockovich, who was portrayed by Julia Roberts in an eponymous 2000 film, takes on environmental, pharmaceutical, and personal injury issues.

"It is time to give this community a voice and make sure those responsible are held accountable for this issue," Brockovich said in a statement.