The decisions that exposed thousands of Flint residents to lead and other contamination brought national awareness to the widespread problem of drinking water infrastructure badly in need of updates.
The Flint water crisis brought national attention to concerns about lead and other contamination in drinking water. The city has made great improvements in the last five years, including replacing lead pipes all over the city, but now other cities and states are grappling with the same issues and lack of resources to resolve them.
Advocacy groups like Food and Water Watch, which tracks issues about water infrastructure and affordability, say even if water is discussed in the debates the candidates need to give more specifics about how they will make their plans happen and who will pay for it.
Compromised drinking water systems can pose a public health risk through exposure to contaminants like chemicals or lead, as well as disease or bacteria. The CDC said in 2008 as many as 19 million people a year become sick from contaminated community or city water systems.
Mary Grant, campaign director with Food and Water Watch, told ABC News Americans all around the country are dealing with concerns over contamination in their water and rising costs of water as cities try to update aging infrastructure.
She said climate change impacts water infrastructure as rain events become heavier and more frequent, causing more flooding as sewer systems can't keep up. States like California could start seeing more issues with water scarcity and drought, per Grant.
She also said her organization has worked with Americans in rural areas who can't drink their water because of reported contamination from chemicals used in agriculture or mining that can leach into the system.
"Our next president needs to make sure everyone in this country has access to safe water so it should be a priority. If we can't provide access to safe water what are we doing?" she told ABC.
Sen. Amy Klobuchar was asked during Tuesday's debate what she would do as president to prevent another situation like the water crisis in Flint.
She connected the issue with broader infrastructure problems like roads and rural broadband, saying it's a "bread and butter" issue for people impacted by failing infrastructure every day and that President Donald Trump has failed to fulfill his campaign promise to get an infrastructure deal.
"I would put a trillion dollars into this, and I would pay for it by first of all, changing the capital gains rate, by doing something when it comes to that regressive tax bill that left everyone behind but really made his Mar-a-Lago friends richer as he promised and I would take that money and put it into rural broadband and green infrastructure so you won't have what you had in Detroit with the Jefferson Chalmers neighborhood, the African American neighborhood, that was most hit when you had those recent rain storms and I truly believe that if we're going to move on infrastructure in climate change, you need a voice from the heartland," she said.
Erik Olson, senior adviser to the Natural Resources Defense Council Action Fund, said there needs to be significant federal investment in helping states and cities improve water infrastructure, enforcing rules about drinking water quality, and regulating more chemicals that states have identified in the water supply.
"We'll be listening for whether they have real concrete plans and specifics on what they're going to do to fix the country's drinking water supplies because it's been a major public health concern and lack of investment," he said.
Olson said the federal government will need to spend a lot more to clean up drinking water, as groups that represent water utilities say it will take close to $1 trillion over the next 25 years to fix drinking water systems.
And even though the Trump administration has said it sees water quality around the world as a big environmental issue, Olson said he wants to see Democrats promise to reverse some of the administration's rollbacks of rules intended to protect water in the U.S.
"It's been a longstanding problem, it's not brand new the lack of investment, the lack of enforcement, it's something that we really need more than lip service to this we really need concrete plans," Olson said.
The list of costs facing water systems keeps going up as states and the federal government grapple with new information about contaminants like chemicals used in nonstick products and firefighting foam, known as PFAS, that have been found in drinking water and groundwater around the country. Americans in rural areas can also face water contamination from chemicals used in agriculture, for example.
Grant said federal investment in water infrastructure has fallen drastically since the '70s and cities pass on the cost of improvements to residents.
Some presidential candidates have also used the debate in Detroit this week to launch plans to tackle environmental injustice -- the idea that low-income and minority communities are exposed to more pollution and older infrastructure than other areas that may have more money or power to address the problems.
Marianne Williamson got one of the biggest audience reactions of the night at Tuesday's Democratic Debate when she addressed the influence of race in how majority nonwhite communities like Flint experience more issues with water and pollution.
"We need to say it like it is, it's bigger than Flint. It's all over this country. It's particularly people of color. It's particularly people who do not have the money to fight back, and if the Democrats don't start saying it, then why would those people feel they're there for us, and if those people don't feel it, they won't vote for us and Donald Trump will win," she said.
Washington Gov. Jay Inslee released a plan to protect vulnerable communities from climate change and Sen. Kamala Harris released a proposal in the Senate that would require any environmental proposals consider the impact on minority communities. Sen. Cory Booker released an environmental justice plan earlier in the race and former Housing and Urban Development Secretary Julian Castro released a plan to eliminate exposure to lead.
Grant said a problem that adversely impacts those communities is the cost of water as utilities have to raise rates to replace pipes or deal with other issues.
"The burden is falling on low income and working families across the country." Grant said, adding, "It's an issue that resonates with people. What we've seen in communities is that it's widely and deeply felt, the issues with water affordability."