TIMELINE: How Newark's water lead contamination crisis unfolded

NEWARK, New Jersey -- Newark, New Jersey is experiencing a water contamination crisis, as several neighborhoods have dangerous amounts of lead in their water supplies, and government-distributed faucet filters appear to be only marginally effective.

This is not a new problem for New Jersey's biggest city. Tests showed that portions the city's water supply far exceeded the legal limit of lead contamination in 2017. Even Senator Cory Booker, the city's former mayor and a presidential hopeful, had his name associated with a 2015 investigation involving mismanagement of the agency that oversees Newark's water treatment.

Here's a timeline of key events:

2014: The New Jersey state comptroller published an investigation, which found that the Newark Watershed Conservation and Development Corporation, the agency responsible for keeping the city's water safe, "recklessly and improperly spent millions of dollars of public funds with little to no oversight by either its Board of Trustees or the City" between 2008 through 2011. Both the BOT and city were led by then-mayor Cory Booker.

2015: City officials decided to adjust water treatment chemistry in an effort to comply with new EPA regulations. The pH levels in the treatment facility are lowered in an effort to reduce cancer-causing chemicals in the water supply, sources told ABC News.

A civil suit in filed in that same year also names Booker as a responsible party in the watershed scandal. In June 2016, Booker was dismissed, as a judge ruled that he served on the board only in his capacity as a public servant.

READ MORE: ABC News details the watershed scandal

2017: The watershed's executive director Linda Watkins Brashear was sentenced to eight years in prison for accepting nearly $1 million in kickback payments for awarding no-show contracts.

June 2017: Newark exceeded the federal action level of 15 parts per billion for lead in drinking waters. Approximately 10% of households had twice that amount.

June 2018: The Newark Education Workers (New) Caucus and the Natural Resources Defense Council (NRDC) file a lawsuit against the City of Newark and State of New Jersey, alleging that their violations of the federal Safe Drinking Water Act have resulted in dangerous lead levels in Newark's drinking water.

October 2018: Officials find that lead contamination in the city's drinking water presents a serious public health concern.

October 12, 2018: The city of Newark announced that water filters would be distributed to 19,000 homes.

August 9, 2019: Following recent tests that showed elevated levels of lead in the drinking water of two houses using the filters, the EPA recommended that local officials in Newark distribute bottled water to residents.

August 10, 2019: Newark Mayor Ras Baraka announced that new tests indicate dangerous levels of lead remain amd that water filters may not be working as effectively as anticipated.

August 13, 2019: An initial shipment of bottled water for Newark residents affected by potentially high lead levels was found to be past its "best by" date. State officials said no one is at risk.

August 14, 2019: New Jersey Governor Phil Murphy visited Newark to address the water crisis and called for federal help.

August 15, 2019: The groups who filed the June 2018 lawsuit appeared in court to demand that the city provide safe drinking water for residents.

Cory Booker's press secretary also released a statement that alleged no connection between the watershed scandal and Newark's 2019 water crisis.

Anyone concerned about lead poisoning in themselves or their children can get their blood tested.

CLICK HERE for more information about lead testing.

ABC News and the Associated Press contributed to this story.