Troubled waters

DFW Airport officials were warned years ago that they had a problem with water pollution. So why are fish still dying?

Jim Crites takes off his suit jacket to give himself relief from the 100-plus-degree heat. For more than an hour, the director of operations at Dallas/Fort Worth International Airport has driven and walked around the airport grounds, giving a nosy reporter and photographer a tour of DFW's drainage system.

It's dull, miserably hot work, and Crites is becoming peevish. Chewing gum furiously with a frown on his face, Crites has reason -- besides the heat -- for his growing irritation. He and his guests have arrived at Trigg Lake.

Stagnant, blackish, about the size of four football fields, and wholly unappealing, the lake at the airport's southeast corner is nevertheless protected by the same pollution regulations that apply to rivers and lakes elsewhere. So last February, when an anonymous tipster told state inspectors about the dead fish, airport officials knew trouble was brewing.

A broken sewer line sent pollution rolling into Trigg Lake at Dallas/Fort Worth International Airport, killing hundreds of fish.
Peter Calvin
A broken sewer line sent pollution rolling into Trigg Lake at Dallas/Fort Worth International Airport, killing hundreds of fish.
Seventeen large drains like this one discharge runoff -- some of it polluted -- from DFW's storm-water system into surrounding streams.
Peter Calvin
Seventeen large drains like this one discharge runoff -- some of it polluted -- from DFW's storm-water system into surrounding streams.

In a letter to the airport board, Texas Natural Resource Conservation Commission inspectors wrote that they had found some 150 dead fish of all sizes -- bass, crappie, and catfish among them. Those still alive "were swimming on their sides and flopping intermittently." The lake smelled like sewage, and "a sewage-like substance [was] lining the northwest shore...A type of sewage mold was observed," inspectors reported.

What, they wanted to know, had the airport allowed into the lake?

Airport officials told them that a few weeks earlier a sewer line had broken outside a building about a mile from the lake, at the site of a company that prepares food for airlines.

Sewage from a place that makes airplane food certainly would explain the elevated levels of fecal material in the lake. But how, the inspectors asked, did jet fuel and chemicals used to keep ice off jets' wings make it into other nearby bodies of water they tested?

All told, the TNRCC says it is investigating eight alleged unauthorized discharges of pollutants at various lakes and streams on DFW property.

Because of the apparent seriousness of these violations, enforcement action has been initiated, Samuel Barrett, the TNRCC's waste section manager in the Arlington regional office, wrote to the airport board in June. Regulators asked the airport board to investigate the cause of the discharges so the state and airport can iron out an agreement to prevent them.

But dirty water at the airport has drawn the attention of others. Last October, the U.S. Environmental Protection Agency told the airport board that the EPA was investigating possible environmental law violations. Such a review could lead to criminal charges, though an EPA spokesman says the agency never comments if that kind of probe is taking place. Six months earlier, an EPA field officer observed water flowing from 17 airport storm sewers and found all sorts of industrial waste -- road material, jet fuel, and car-wash runoff among it.

"These fish probably shouldn't be here to begin with," Crites says as he scowls at the dark water of Trigg Lake. Fish attract birds. Birds and airplane safety don't mix. Some airports intentionally lace surrounding bodies of water with chemicals to eliminate fish.

But the dead fish at DFW weren't part of a coherent game plan. Instead, they reflect a troubling lack of planning.

According to DFW's own documents and sources inside and outside the airport, DFW officials have long known -- or should have known -- about severe inadequacies in the airport's system for containing and cleaning water pollution. An antiquated, overburdened drainage system has been allowed to overflow, sending potentially hazardous pollutants flowing into nearby lakes and streams. In the long run, TNRCC's Barrett says, the discharges could further taint the already dirty Trinity River or, in the case of jet fuel, result in explosions at the airport.

Fundamentally, the airport's industrial-waste system is too small and too old to provide properly for the needs of DFW, among the busiest airports in the world. (The more than 2,000 daily flights from DFW consume 798 million gallons of fuel annually.)

Built shortly before the airport opened in 1974, the industrial-wastewater system is similar to one that might be found at a truck stop. Buried beneath at least 17 inches of concrete, it consists of a series of drainage pipes that capture rain rolling off the runways and aprons and carry the water to streams, lakes, and fields surrounding the airport.

Theoretically, the system has mechanisms to remove spilled jet fuel, de-icing chemicals, and other pollutants. Dozens of containers called diversion boxes capture the water, allowing industrial waste to settle. The waste is sent down separate lines to the airport's pre-treatment plant, cleaned, then transported through the sewage system to the Trinity River Authority's central wastewater treatment plant in Grand Prairie for further cleaning. Other outlets in the diversion boxes discharge the remainder of the supposedly cleaner rainwater to the nearest creek, stream, or lake on the airport's 18,000 acres.

But the system does not work as smoothly as anticipated by its original designers, who created it when the airport was half the size it is today.

For starters, it backs up. According to a half-dozen internal airport board documents as well as one former and one current airport employee, the drainage pipes are too small to carry the volume of water from a sizable rainstorm. Consequently, the system overflows, the diversion boxes fill, manhole covers fly off, and contaminated water spreads over the surface and into the storm sewers. Within an hour of a storm at DFW, industrial waste could easily be on its way to lakes and streams. Compounding the problem, many of the aircraft-maintenance hangars built in the early '70s have floor and trench drains tied directly into this inadequate system.

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