As President Donald Trump continues to demand more than $5 billion in taxpayer funding for a border wall, a growing number of voices are calling for such funds to be diverted to a far more pressing issue: water.

The rapidly decaying infrastructure of water systems across the country is bringing dangerous levels of lead and other contaminants into homes, and action needs to be taken to upgrade them.

Newark Mayor Ras Baraka highlighted the issue in an open letter to Trump this week in which he urged the president to consider “a true emergency that puts millions of our citizens at risk.”

Besides Newark, more than 20 other New Jersey cities and towns have elevated lead levels in their tap water, as do many other municipalities, said the letter. And while Flint, Mich., is the poster child for poor water management, it’s not the only place suffering a crisis that demands immediate action.

“I join in solidarity with the 11-year-old girl known as Little Miss Flint who told you that spending $5 billion to make water safe is a much better way to protect Americans than building the wall,” said Baraka.

Don’t miss:Water stocks are a bargain for 2019 after selloff, analyst says

Also read:‘Sleepwalking into catastrophe’: Extreme weather is biggest global risk in 2019

U.S. infrastructure is reaching the end of its economically useful and serviceable life cycle, according to a new report from NACE International, a group created in 1943 by 11 corrosion engineers from the pipeline industry. The acronym stands for National Association of Corrosion Engineers.

“Today, bridges, pipelines, roads, power generation and transmission, and water treatment facilities [are] all are at risk of corrosion-related failure,” according to the association’s 2019 Spotlight on Corrosion Report.

The cost to repair infrastructure across the world is estimated at $2.5 trillion, the report found, but existing corrosion techniques could save up to $875 billion of that sum, or about 35% of the cost.

The report recommends an action plan that would remove contaminants from public drinking water and address ways to mitigate the external corrosion of buried steel and reinforced concrete pipes associated with water treatment.

See now: Absence of clear-cut climate-disclosure policies puts companies in peril: report

Also:PG&E bankruptcy: The first of many corporate casualties of climate change?

“While it is well known that the magnitude of the water crisis in Flint was caused by lack of action to counter the threat of corrosion, the case spotlights how financial avoidance influences the ongoing infrastructure crisis in the U.S. water sector,” said the report.

There are more than 151,000 drinking-water systems in the U.S., delivered through millions of miles of pipes. These systems experience roughly 240,000 leaks and breaks every year mostly due to third-party damage or corrosion, leading to the waste of more than 2 trillion gallons of drinking water, the report found.

That can be greatly reduced with a corrosion-management program that includes regular maintenance and inspections, but starts with system design.

See: How the Trump presidency ranks against prior administrations in links to lobbyists — in one chart

What most businesses and investors get wrong about risk

“A successful strategy includes a life-cycle cost analysis, which balances the cost of corrosion management over the life of an asset (from design to decommissioning) with the potential cost of corrosion,” said the report.

Most of all, the issue requires a change of attitude by those who manage water, who need to stop thinking of it as a cost and instead understand it’s an investment. It’s also a crucial one to avoid devastating, long-term health risks, such as the ones already seen in Flint.

“ ’[I]nstead of wasting billions of dollars to keep an ill-conceived campaign promise, I urge you to use our resources in a way that will truly save American lives.’ ” — Newark Mayor Ras Baraka

In Newark, Baraka is distributing 40,000 water filters and cartridges to affect homes, and it’s changing its corrosion control system. Long term, the only real solution is to replace lead service lines, at an estimated cost of $70 million. The estimated cost of replacing all of the lead service lines in the U.S. is $35 billion, said the mayor, and that would require help from the federal government.

Read also:Swiss startup that filters plastics out of water is eyeing U.S. and China markets

“You have been saying that a border wall will save thousands of American lives, but that’s simply not true, instead of wasting billions of dollars to keep an ill-conceived campaign promise, I urge you to use our resources in a way that will truly save American lives — help repair our nation’s deteriorated water infrastructure,” he wrote.

The Invesco Water Resources ETF PHO, -1.27% was up 1.1% Friday and has gained 7% in 2019 so far. The Invesco Global Water ETF PIO, -0.89% was up 1% and has gained 6% in 2019.

By comparison, the S&P 500 SPX, -1.11% and the Dow Jones Industrial Average DJIA, -0.87% have gained about 6%.

Read on:How to invest in water: A long-term bet on an essential commodity with limited supply