The maps are so old that the Acadiana town of Melville doesn't know the exact location of the pipes distributing drinking water to about 540 homes and businesses.

When he comes upon water bubbling to the surface — and that happens almost every day — Houston Sanders, the town’s fix-it guy, acts like one of those 18th-century dowsers who searched for fresh water with a Y-shaped stick. But his divining rod is a pair of wire coat hangers that, remarkably, quiver and spread to mark the alignment of the water pipes.

He digs a couple of feet down, attaches a clamp to the leak, then refills the hole.

“I’ll be out here again in a couple weeks, but I won’t have to use this,” Sanders said, tossing his improvised divining rod in the back of the pickup.

He now knows how the pipes lie. And since his temporary fix puts pressure at another point on the corroding pipe he knows about where to start looking for the next leak.

Melville really needs to replace its 60-year-old system. But like many other small Louisiana communities, Melville can’t afford to maintain, much less improve, the aging system that delivers drinking water to the town’s residents.

State officials are unsure just how many of the 1,366 water systems are having similar problems — Dr. Jimmy Guidry, the state’s health officer, estimates about 400 — but they’re struggling to find out.

A recent survey by the Louisiana legislative auditor, in which a little more than half the systems participated, found 301 systems had pumps, pipes and treatment facilities that were 30 years to 50 years old. Seventy-six more had infrastructure, like Melville, still in use after a half-century.

"Here I am thinking I was the only one," said Melville Mayor Erana Mayes, whose tenure has been clearing one hurdle after another to apply for the loans necessary to upgrade the town's infrastructure. "I don't want to become the next St. Joe."

Lingering over a problem the U.S. Environmental Protection Service estimated in 2011 would cost the state about $5.3 billion to fix, is the northeast Louisiana town of St. Joseph, which is about the same size as Melville.

St. Joseph struggled for years with its aged infrastructure. Shortly before Christmas, state health officials found lead and copper in the drinking water.

The leaks, health officials surmise, required additional chemicals, like chlorine, to the keep the water clean. But the town couldn’t keep up with the costs of the ever-increasing amounts of chemicals needed. Plus, leaks caused the water pressure to fluctuate, which stressed the pipes, causing iron and copper from past repairs to flake into the drinking water.

Those minerals cause severe health problems and they were turning up in samples in amounts far exceeding what’s necessary to trigger emergency intervention by the state.

Town residents started receiving bottled water from the state’s disaster reserves and will continue to get their water in gallon jugs into the fall when the project to lay new pipes, upgrade treatment facilities and install new water towers is completed. Residents, beginning in March, were implored to have their blood tested for lead contamination. (None has been found so far.)

The state taxpayer’s bill, when everything is fixed in St. Joe, will be roughly $12 million or about $25,000 for each customer of the town’s water system. And then the monthly water bills will dramatically rise in a town where more than half the residents live on a fixed income.

State authorities don’t know which town, parish, subdivision or community water service will be the next emergency. But they do know the symptoms, and they are taking steps to identify the most likely candidates: those with aging, poorly maintained infrastructure that have lots of leaks and rates too low to maintain the system.

Old pipes leak and 43 percent of the state’s water system doesn’t track water loss — Louisiana has no law compelling them to do so. But of those that do track water loss, 88 systems found that water leaking from their corroded pipes accounted for about 15 percent of their total water consumption.

Of the 212 governmentally controlled water systems, 87 had expenses that exceeded revenues in the fiscal year that ended June 30, 2015. About half of those systems also operated in the red for 2013 and 2014.

“If water systems do not generate enough revenue to properly maintain their infrastructure, they may also face issues similar to the Town of St. Joseph,” Legislative Auditor Daryl Purpera wrote in a report released in March.

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Additionally, Purpera’s office is preparing a list of local governments with financial problems.

When Mayor Mayes walked into the Melville town hall for the first time last year, she found boxes of paper along a wall stacked almost as high as she is tall. Despite the volume, the documents didn’t include key information state accountants need to verify how the town spent public dollars, which is necessary for a clean audit.

Without an audit — and Melville has not had one since 2012 — agencies are forbidden by law from releasing public dollars to the town.

Once Melville gets a clean audit, Mayes will apply for a federal grant to pay engineers to estimate the cost of upgrading the water system. Only then can she apply for the loan.

Since the town charges all its customers the same flat rate, the loans will require the installation of meters that will measure consumption for every customer.

“A lot of people are afraid of meters, but that’s the only way we’re going to save this little town,” Mayes said. “And they’re going to want us to raise rates. I don’t want to even contemplate that, at least right now.”

The American Society of Civil Engineers has rated Louisiana’s drinking water infrastructure as D+, meaning the state’s infrastructure is crumbling and needs an infusion of money.

Guidry, the state health officer, would like to see water infrastructure included in the debate to increase revenues for highways and bridges. “Being responsible to help systems meet the requirements, then being held accountable when they can’t, that’s a tough place to be,” he said.

For Russel Honoré, who became an environmentalist after retiring from the U.S. Army, there is no debate.

"Government has an obligation to ensure pure, safe drinking water for every citizen, period,” he said.

The issue is more complex for state Sen. Francis Thompson, the Delhi Democrat who has been instrumental in helping poor communities secure loans to repair their water systems. He says the locals need to look toward themselves first.

“It’s their water. They can’t always come to the state and expect us to solve it alone,” he said.

“It’s about communities not having the resources,” said Lady Carlson, an organizer with Together Louisiana, a coalition of clergy and community activists that is helping communities attract attention to their water problems.

“In terms of the cost of infrastructure, these towns simply can’t raise the kind of the money that’s needed. And even if they could raise it, the rates would be so high that the people couldn’t pay it,” she said.

Wilma Subra, a microbiologist from New Iberia, has been brought in by water systems to help bring them back into compliance after they are issued violations.

Of the 4,520 violations issued by the Louisiana Department of Health, 3,788 were issued to small systems that serve fewer than 3,300 customers. The smaller systems usually have few employees and often have trouble keeping up the testing regimes and paperwork, she said.

But, it’s not just the small systems and those that tap into underground reservoirs that have problems. Brain- eating amoebas, more precisely naegleria fowleri, showed up in the drinking water of St. Bernard, Terrebonne, Ascension and St. John the Baptist parishes in 2015. The reason is that the surface water used for drinking in those parishes was contaminated and not treated with enough chlorine.

But those communities are wealthier and have a larger population over which to spread the cost of addressing the needs of treatment systems and distribution lines, Subra said.

“Not to minimize their problems, but the real issue is in the municipal/community water systems that simply don’t have the resources,” Subra said. “As many as 300 communities cannot afford to maintain and improve their water systems.”

Follow Mark Ballard on Twitter, @MarkBallardCnb.