A week ago when the city of Corpus Christi ordered its 320,000 residents to avoid tap water because of a potential industrial chemical leak, the first thought many of them had was, “Not again.” 

It was the fourth time in 17 months the city had made such an announcement and, for residents, it was just another example of its failure to deliver the most basic and crucial of municipal services. With a total usage ban in place for much of the city for four days — it wasn’t just a boil-water notice this time — the impacts went far beyond a mild inconvenience, shuttering local school districts and water-dependent businesses and requiring residents to scrounge up bottled water and forego showering. 

But the latest incident and its root cause are clearly different from the others, according to a municipal water systems expert and a former city mayor whom voters ousted last month amid ongoing water problems. While the signs suggest the most recent problem stemmed from inadequate industrial safeguards to prevent a chemical leak, they attribute the three previous water problems to a long-neglected water delivery system and operational complications created by a decrease in usage during a recent drought. 

The city had put off replacing old cast-iron water pipes for some 40 years, said former Corpus Christi Mayor Nelda Martinez, who concedes the city’s persistent water issues were “a strong variable” in the outcome of her re-election bid last month. (They also inspired a city manager to resign.) 

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Most of the 225 miles of cast-iron pipe installed beneath Corpus Christi between 1950 and 1959 need to be replaced, according to the Corpus Christi Caller-Times. 

“A basic service is providing water to your citizens, and when that is compromised — I understand” why residents would respond the way they did, Martinez said, adding that the city executed more improvements to the system during her four years as mayor than it had in the previous 25 years. It clearly wasn’t enough, she acknowledged. 

“If it takes you 40 years to get to this point, it’s going to take awhile to dig out of it," she said.  

The city’s current mayor, Dan McQueen, who was sworn into office the day before the most recent water notice, declined an interview request through a city spokeswoman amid an ongoing state investigation into the incident. Local and state officials have zeroed in on a plant run by Mississippi-based Ergon Asphalt & Emulsions Inc., which leases its complex from a subsidiary of Valero Energy Corporation. (A local hair salon and other businesses that had to shut down during the water ban, which the city lifted Sunday, are suing the companies.)

Corpus Christi's myriad water woes aren't unique. Along with aging infrastructure — a challenge for many cities across the United States — municipal water utilities also can experience quality problems when they see a decline in usage, said Ben Hodges, the research director of the Center for Infrastructure Modeling and Management, a new, federally funded venture at the University of Texas at Austin that is studying ways to improve beleaguered municipal water systems. Such declines occur due to shrinking populations or usage restrictions, the latter of which Corpus Christi employed during the recent drought. 

When water usage goes down, the amount of time it takes water to get from treatment plants to faucets can change and “dead zones” in the system can materialize. The goal is to ensure that water still contains some bacteria-killing chlorine — but not too much — by the time it reaches its destination.

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Last year, the city lifted watering restrictions to help improve chlorine levels.

“It’s a balancing act,” said Hodges, noting that Corpus Christi’s three previous water emergencies were due to “a lack of chlorine residual" and involved bacterial contamination. (All prompted boil-water notices.) 

“It’s not so much that anything new was introduced,” he said.

That’s the opposite case with the latest incident, in which an asphalt emulsifier reportedly escaped a mixing tank at Ergon's plant and potentially ended up in the water supply. That prompted the city to enact an all-out usage ban rather than a boil-water notice.

City officials initially said they discovered some amount of Indulin AA-86 in the city water system, although tests of several water samples collected from around the city have come back clean, according to information posted on the Texas Commission on Environmental Quality (TCEQ) website. More samples will be tested in the coming days.

The agency said during a press call Monday that some kind of chemical leak “absolutely” occurred. 

“Duration, the quantity, where did it go — that's what's under investigation,” said TCEQ Executive Director Richard Hyde.

The U.S. Environmental Protection Agency and at least two other state agencies have been involved in the investigation, including the Texas Attorney General’s Office, which is “assisting TCEQ in evaluating appropriate legal action,” according to a spokeswoman.

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Ergon is cooperating fully and is glad the water is back on, said Bill Miller, a well-connected, Austin-based political consultant working as a spokesman for the company. He declined further comment. (Valero has blamed Ergon for the leak.)

Industrial plants are supposed to install equipment to prevent the "backflow" of chemicals and other hazardous materials into municipal water systems when pressure gets too high, said Hodges, of the Center for Infrastructure Modeling and Management. It’s a tall order for any city to prevent backflow totally, he said, noting it can occur even from residential lines if water pressure gets high enough.

“What happened in Corpus Christi has the potential to happen almost anywhere,” Hodges said, adding that it probably got even more attention because it came on the heels of so many other water-related issues in the city.

“As a practical matter, regulators can’t simply be looking over the shoulder of every industry with every move," he said.

At a city council meeting Tuesday night — the first since the incident — City Manager Margie Rose said she would expedite a review of a backflow prevention program that had been scheduled for early next year, noting there are "a lot" of non-compliant commercial and residential properties.

Martinez, the former mayor, said the city should be asked and willing to answer hard questions for accountability's sake as authorities work to figure out what exactly went wrong.

"I would insist those questions be asked because that way they are able to show their accountability and ability to run a very complicated water distribution system," she said. "Who knew, when did they know and what could we have done differently?"

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