WASHINGTON, DC -- A bipartisan group of lawmakers are asking the White House to pressure the military to hasten efforts to clean up toxic chemicals leftover from firefighting foam and expand access to clean water for people exposed to them.

Eight Democrats and six Republicans in the U.S House of Representatives signed the Aug. 1 letter to President Donald Trump, which argues the Defense Department has been "slow to provide safe drinking water to those areas with contaminated water."

The letter urges more be done about perfluoroalkyl substances (PFASs), also known as perfluorinated chemicals (PFCs), which have polluted groundwater on or near military bases around the country where PFC-laden firefighting foam was used in training and crashes.

In Michigan, Aqueous Film Forming Foam (AFFF) used at former Air Force and current National Guard bases has resulted in PFC plumes which have contaminated private wells in Oscoda and Grayling, and possibly the Grayling municipal water supply.

Preliminary assessments indicate the chemicals may be present at other bases in Michigan, including Selfridge Air National Guard Base near Mount Clemens, the Alpena Combat Readiness Training Center and the Battle Creek Air National Guard Base.

According to the letter, the Department of Defense (DoD) has identified and begun testing 664 sites for PFCs, which are a class of fluorocarbons that have been tied to developmental defects in children, cancer and diseases of the liver and thyroid.

However, the military refuses to pay for a long-term safe water supply unless a well tests above the Environmental Protection Agency's health advisory threshold of 70 parts-per-trillion (ppf) for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), which some public health researchers criticize as too high.

The Pentagon is disputing a Michigan law passed in January that sought to put the cost and cleanup burden on the military for the PFC contamination it caused.

The EPA has only established an advisory for PFOA and PFOS, but some wells in Oscoda are testing at extremely elevated levels for perfluorohexane sulfonic acid (PFHxS), a PFC which is closely related to PFOA and PFOS that was nominated in June for inclusion on the Stockholm Convention on Persistent Organic Pollutants.

The PFCs in Oscoda are coming from the former Wurtsmith Air Force Base. In Grayling, PFHxS was found in municipal wells. The Michigan National Guard is currently investigating PFC plumes near the Grayling Army Airfield, part of the Camp Grayling complex.

"We ask that the Administration hasten the DoD's response to the issue of PFC contamination," the letter read. "We have asked our service members to make critical sacrifices for our freedom and we must assure them that they, and their families, have access to safe drinking water."

Provisions attached to military spending bills in Congress would require the Pentagon conduct a national PFC health study through the Centers for Disease Control and Prevention (CDC), and report on progress toward developing a firefighting foam that does not contain PFOS or PFOA, which give AFFF its fire-retardant capabilities.

The bill would also authorize the Pentagon to sign agreements with local health departments for screenings in communities near bases with PFC problems in the ground or municipal water.

An amendment to provide $60 million for PFC cleanups at bases nationwide passed the full House last week. The fate of PFC provisions is uncertain as the chambers debate the spending bill, which includes funds for a U.S.-Mexico border wall that Democrats oppose.

A bill pending in the House energy and commerce committee would require the EPA establish enforceable standards for PFCs in drinking water. The present health advisory level is a voluntary guideline.

"PFCs are a dangerous chemical, the full impact of which is still unknown, and it is critical that DoD take immediate action to prevent further exposure," the letter read.

"Despite the danger PFCs present, DoD has been slow to provide safe drinking water to those areas with contaminated water. For more than a year, members of Congress have repeatedly requested that DoD prioritize investigations of contamination on its sites and provide safe drinking water for these impacted areas. Yet there are still veterans, their families and surrounding communities exposed to PFC-contaminated drinking water that the DoD has yet to address."

Lawmakers who signed the letter include:

Daniel T. Kildee, D-Michigan

Carol Shea-Porter, D-New Hampshire

Lisa Blunt Rochester, D-Delaware

Brendan F. Boyle, D-Pennsylvania

Brian Fitzpatrick, R-Pennsylvania

Patrick Meehan, R-Pennsylvania

Sean Patrick Maloney, D-New York

Elise Stefanik, R-New York

Lee Zeldin, R-New York

John J. Faso, R-New York

Donald McEachin, D-Virginia

Paul Cook, R-California

Salud Carbajal, D-California

Mark Takano, D-California