Chicago could face a drinking water crisis akin to the one in Flint, Michigan, unless the city halts main-line construction and embarks on a cost-sharing plan to replace lead service lines, two mayoral challengers warned Thursday.

“Rahm is basically telling our kids to pick a poison. Be poisoned by the lead from our water or the lead from bullets,” community activist Ja’Mal Green said at a City Hall news conference Thursday.

“I went to Flint when the water crisis happened. I went door-to-door giving out cases of water to people in public housing. … We don’t want to end up like Flint in the next 20, 30 years. We need to solve this problem now because Rahm Emanuel is basically ignoring the problem because he knows he won’t be around when the problem worsens.”

Former Chicago Public Schools CEO Paul Vallas said Chicago’s problem is “compounded” by its decision to allow lead water piping until 1986, “long after most cities had banned its use and many had started replacing lead service lines.”

“There are no safe lead levels,” Vallas said Thursday.

“If the city’s got enough money to give Wintrust Arena [$55 million] in TIF money or to build a $200 million park on the North Side or to suddenly, magically say that they’ve got $1 billion for school construction, I’m sure they can find some money to provide families with filtration devices.”

Shortly after taking office, Emanuel doubled water rates over a four-year period – followed by annual increases to match the cost of living – to modernize the water and sewer system.

Now, Green wants to halt that massive overhaul; he said it makes the lead problem worse by disturbing the protective coating inside lead pipes.

Instead of forging ahead with the replacement of century-old water mains and ignoring the impending drinking water crisis, Green and Vallas want the city to confront the inconvenient truth.

No city in America has more lead service lines than Chicago and they desperately need to be replaced at a cost that could range from $3,000 to $10,000 for each of the 380,000 impacted properties.

That can’t be done overnight. Nor can the cost be shouldered entirely by Chicago homeowners who have already endured more than $1.3 billion in property tax increases for police, fire and teacher pensions.

That’s why both candidates want to expedite distribution of water testing kits and supply water filtration systems — at a cost of up to $15 million — to those homeowners with high levels of lead in their drinking water.

Green wants to bankroll that cost with parking ticket revenue and the bonanza of funds generated by tax-increment financing (TIF) districts.

Vallas would also use “excess TIF funds” to subsidize filtration systems that can cost anywhere from $100 to $1,000.

The cost of filtration systems pale by comparison to the cost of replacing lead service lines.

Green would tackle that challenge by giving homeowners a choice. They could pick their own contractor to perform the work and assume the entire cost. Or, they could let the city do the work and share the cost; property owners would be able to pay their share over five to 10 years, through an additional fee added to their property tax bill.

For low-income homeowners, Green would establish what he calls a “Lead Be Gone Assistance Fund” that would accept private donations and draw revenue from the city’s $205 million vehicle tax fund. Eligible homeowners would get a 65 percent break.

Currently, that fund, generated by city sticker fees, is devoted exclusively to road repairs.

Vallas would bankroll lead service line replacement with a Neighborhood Conservation Fund that would provide grants, low-interest loans and partial subsidies, depending on income levels.

Seed money would come from excess TIF dollars, developer fees and by asking the state to “stop diverting corporate personal property tax replacement dollars.”

Water Management spokesperson Megan Vidis accused both candidates of sounding a false alarm.

“Public health is everyone’s top priority, but it is completely irresponsible to mislead and falsely alarm residents. Chicago’s drinking water meets or exceeds state and federal water quality standards,” Vidis wrote in an email.

The city has launched a study aimed at determining “what, if any, impacts water main construction has on water quality for residences with lead service lines,” Vidis said.

But, she said: “Replacing the city’s century old water infrastructure is not a luxury, it’s a necessity. It is also work that is helping protect the overall water system from contaminants and conserving water through greater efficiency.”

Last month, Emanuel got the go-ahead to issue $900 million more in bonds to refinance old debt and continue the massive rebuilding of Chicago’s crumbling water and sewer system.

Aldermen asked — but never got an answer — how much, if any of that borrowing would be spent on the lead problem.