Since the discovery of potentially harmful chemicals known as per- and polyfluoroalkyl substances, or PFAS, in drinking water in communities in Bucks, Montgomery, and Gloucester Counties beginning in 2014, The Inquirer has provided award-winning coverage of the issue. Follow this timeline, which will be updated as our coverage continues, to catch up on the latest.

Just getting caught up? Check out these stories first:

Tainted: How Navy bases contaminated Pa. drinking water (June 18, 2016)

Nearly 400 military bases must be tested for drinking water contamination — and it will take years (April 21, 2017)

Toxins found in water near Bucks, Montco military bases more harmful than previously reported (June 20, 2018)

‘Is this really happening?’ Chemicals that tainted water on military bases spreading to other towns in Bucks, Montco (December 22, 2018)

Setting clean-water standards is the EPA’s job. Pa. and other states are doing it instead. (June 6, 2019)

Timeline

2020

Air Force to give more than $2 million to stop contaminated water flowing from former Montco base

2019

EPA offers first guidance on PFAS in groundwater

PFAS regulation plan gets weakened by Congress in latest spending bill

New funding ahead for PFAS drinking water cleanup as legislature passes bill that will help Montco, Bucks

Actor Mark Ruffalo calls for federal action on PFAS as the chemicals come to the big screen

Pa. regulators identify source of drinking water contamination in Bucks neighborhood

For Bucks families living on bottled water, a frustrating wait for contamination cleanup

Relief is coming for some Bucks County residents with tainted tap water. But others are still waiting.

Camden County town discovers water contamination, putting to use a state limit for PFAS

As Congress debates PFAS measures, lawmakers press 3M, DuPont, Chemours on chemicals they used

The goal? Clean water. The issue? Philly-area towns and state officials at odds over treatment system

How three towns outside Philly became ‘trailblazers’ on clean drinking water

Before DuPont and 3M hearing in Congress, activists highlight companies’ history with PFAS

Gov. Wolf pledges $3.8M for PFAS-tainted water in Philly suburbs

Bottled water tainted with PFAS? New England testing raises alarm

Here are some of the latest steps states are taking to deal with PFAS water contamination

A dozen homes in Bucks County are confronting their own water contaminant crisis. And not because of military bases.

Threatening veto of spending bill, White House opposes two PFAS cleanup measures

This Pa. neighborhood with tainted wells has been on bottled water for three years. No end is in sight.

After tests showed PFAS chemicals in food, FDA says it’s fine

Chemicals that tainted Bucks, Montco drinking water found in lettuce, beef, even chocolate cake

June 2019 » State after state is working to create drinking water standards for PFAS as state and federal lawmakers alike criticize the Environmental Protection Agency’s response to the crisis.

'Nobody should go through what we went through’: Congress discusses water contamination

PFAS water-contamination bills will get a hearing in Congress. Read up on what’s proposed.

‘We have a serious problem’: Congressional task force visits Montco, pushes for action on tainted water

May 2019 » Pennsylvania begins testing to find out if contamination in Bucks, Montco is ‘a problem across the entire state’

Pa. officials plan to regulate and test for PFAS — but residents want faster results

New Jersey moves to enact tougher drinking water standards for PFAS

February 2019 » The EPA, visiting Philadelphia, unveiled a plan to address PFAS contamination nationwide. It came under swift criticism from activists.

EPA says it has a plan to address PFAS in drinking water — and will announce it in Philly tomorrow

Navy searching for new landfill to take contaminated soil from site of Willow Grove base

N.J. landfill backs out of plan to accept contaminated soil from Willow Grove military base

Members of Congress will ‘put pressure on the EPA’ to address PFAS-contaminated water

‘Is this really happening?’ Chemicals that tainted water on military bases spreading to other towns in Bucks, Montco

December 2018 » Test results from Bucks and Montgomery County residents indicate the affected communities have above-average levels of PFAS in their blood.

First blood tests in Bucks, Montco show above-average contamination after tainted water

Health officials prepare findings from blood tests of Bucks, Montco residents with contaminated water

Feds meet with Montco, Bucks residents on water contamination at bases

June 2018 » A federal report that EPA and White House officials initially sought to block shows that PFAS chemicals pose a greater potential hazard to human health than previously indicated by the federal government.

Pa. moves ahead with blood tests of residents near tainted Bucks, Montco bases

Bucks and Montco towns with water contamination chosen for blood testing

Report: EPA, White House wanted to block report on military water contamination

Pa. senators propose health screenings near bases with tainted water

Federal cash could go to cleanup of tainted water

Tainted water, bigger bills for residents near bases

Funding deal requires Pentagon to report water contamination at bases

April 2017 » An Inquirer analysis revealed that the military planned to test nearly 400 military bases for PFAS contamination, offering an early indication of how widespread the problem could become.

Feds may back health studies in Montco, Bucks water contamination

Tainted water: Foam fight goes to federal court

Federal officials tell Horsham residents their water is safe — but questions remain

Montco town begins water-contamination tests near closed Navy bases

Air Force alone in halting use of foam that tainted wells

Pa. to kick in $10 million for Willow Grove water cleanup

June 2016 » The effects of the EPA’s more stringent drinking-water recommendations cause concern and confusion in local communities as residents seek answers and cleanup measures.

Naval base employees concerned about their health in the wake of tainted water issues

Navy pressed to fund blood tests for water contaminants

DEP probing tainted drinking water near Doylestown

Water worries tap frustration near former bases

May 2016 » The EPA establishes stricter guidelines for PFAS in drinking water, significantly expanding the drinking-water crisis and prompting the closure of public wells.

Free water offered to residents near tainted air stations

Montco town officials vow steps to ensure water safety

State board recommends water regulation on PFNA

January 2015 » Gloucester County residents who were among the first to deal with PFAS contamination related to a plastics company are still dealing with the fallout.

Paulsboro strikes deal to address water contamination

In lieu of agreement with plastics company, DEP to test more private wells

Paulsboro's free bottled water coming to an end

Contaminants in water affect Gloucester County families

Tests find high levels of contaminant in some West Deptford wells

Water contamination latest blow for Paulsboro