DRC/Barron Ludlum

Workers erected a gas rig Thursday off North Bonnie Brae Street near the planned King's Ridge Estates housing development. The Denton City Council approved plans for the housing development in June, despite fears that construction could rupture underground gas lines.

As if tracing out a colossal connect-the-dots game, miles of high-pressure pipelines link more than 2,000 gas wells along Denton County roads and under prairies and pastures, pushing the gas mined from the Barnett Shale toward scrubbers or refineries and on to market.

Trouble is, no one person, or office, knows quite where the underground pipes are, officials said.

“Where they may lie, we don’t know the locations,” said Chris Steubing, director of Denton County’s planning department. “We have no authority whatsoever. It bothers us.”

When property owners sign over their mineral rights, the energy companies also ask for easements so they can come back over the lifetime of the well for servicing.

After the well is dug, the company builds flow and gathering pipelines to take the gas from the wellhead to an interstate transmission line.

The U.S. Department of Transportation enforces the rules for transmission lines, and the Texas Railroad Commission enforces some of the gathering lines.

The Railroad Commission writes no rules for on-shore flow lines, but a number of area cities have tried to write a few rules for both flow and gathering lines.

Most cities that have written rules for gas development have required the energy companies to build their pipelines to accepted industry standards and provide a specific map where the lines are laid. As an added safety measure, several cities have limited the amount of pressure that can be in the pipelines. Argyle expressly prohibits the transmission of highly toxic hydrogen sulfide gas, sometimes called sour gas, through its town limits.

But the county cannot make such requirements, Steubing said. The best the county can do is buy the Railroad Commission’s data and include it in its GIS maps.

Low-probability, high-impact

Experts agree pipelines gather and distribute natural gas safer and more efficiently than trucks on the freeway would. They also agree that while pipeline incidents are relatively infrequent, they cause a big commotion when they happen.

About two dozen homes in Wise County were evacuated Wednesday after a 24-inch transmission pipeline ruptured, leaving a 30-foot wide hole in the ground. That incident is still being investigated.

Denton County has recently had its share of pipeline leaks. A construction worker punched a 2-inch hole in a seamless steel, underground Atmos Energy transmission pipeline west of Krum in January. Another construction worker hit a gathering pipeline near Krum in May, prompting evacuations.

Anxiety has been building for some time, as some Denton officials question whether growth to the west — over the top of this web of pipelines — is an accident waiting to happen.

The issue arose in Denton in June, when the City Council approved plans for the 194-acre King’s Ridge Estates housing development in northwest Denton, despite one council member’s concern that construction activity there could rupture existing gas gathering lines.

Council member Bob Montgomery voted against the plans, saying he was concerned the gas lines weren’t clearly marked.

Marking the spot

Officials with EnCana Oil & Gas said anyone doing excavation is supposed to use the one-call system before they dig. This clearinghouse helps protect all kinds of buried utilities, including telephone and power lines, water and sewer pipes, in addition to gas and oil pipelines. Once the excavator makes the call, energy officials are required to come out to mark where pipelines are.

Quentin Hix, Denton’s oil and gas inspector, said the city has access to a Railroad Commission database that provides information on the location of gas gathering lines, although the database may be up to six months behind current conditions.

Gathering lines, which must meet federal pipeline safety standards, are more closely regulated than flow lines, which connect wellheads to gathering lines, Hix said.

“There’s no oversight or regulation of the flow line installation at the state or the local level,” he said. “On the flow lines, we have no record at all unless it’s been provided through our local platting process.”

Denton requests that operators detail the location of flow lines when they present a plat, or map, of the property for city review, Hix said. But if the operators can’t provide the information at that time, they can do so once the line is installed. 

The city also studies the location of gathering lines on an affected property before approving any surface development plat, Hix said.

Absent a city’s requirement, it’s unclear why energy companies are not required to record their pipelines with the county as they are built. Denton Fire Marshal Jody Gonzalez said one problem is that it’s not always immediately clear who owns a particular pipeline, since the energy companies often buy each other’s pipelines.

To improve its effect, Gonzalez and area firefighters regularly meet with energy companies and often train with them at well and pipeline sites. In addition, he said energy companies are adding odorant to gathering and transmission lines, as they have done for years with distribution pipelines, so that people aren’t standing, unaware, in the middle of a gas leak.

Steubing said the county has required energy companies to present engineering plans and meet minimum requirements when a pipeline crosses under a county road.

But without more authority from the Texas Legislature, that’s about all the county can do, he said.

Impact setback

Montgomery has called on the Denton City Council to adopt distance requirements from gas-gathering lines to any structure.

Denton requires gas wells to be at least 500 feet from homes, businesses and other occupied buildings — or at least 250 feet from certain structures when the property owner consents to the drilling. But the city has no distance requirements between gas lines and structures, nor do most other area cities.

In addition, most other area cities, if they included pipeline provisions in their ordinance at all, simply prohibit structures from being built over the top of pipelines. But if the energy companies recorded their easements properly, no permanent structure would be permitted.

Steubing said that a few developers have been able to build subdivisions around gas wells and their network of gathering pipelines in western Denton County, but it’s hard for many of them to make any money once they start factoring what they need to build around, with so many easements already in place.

“They are having to make do with these issues,” he said. 

Denton resident Joyce Poole spoke publicly in June against the King’s Ridge Estates development going forward until gas lines on the property were clearly identified, since she said their positioning should affect the placement of property lines and structures.

She also expressed concern with the city’s lack of ordinances applying to homes under development near existing gas wells. The city’s setback limits apply to new wells being built near homes, but there is no setback, other than the fire code requirement of 100 feet, for homes being built near wells.

She said the city could do more, since it’s charged with protecting the health and safety of its residents.

The key for people buying homes near gas wells and pipelines is to know how far away it is, what kind of line it is, and what to do in the event of an emergency, Gonzalez said.

“After Wednesday’s explosion [in Wise County], they evacuated people from three miles away,” he said. “No one would expect that, living three miles from a gas line.”

Poole said she would favor a 30-foot buffer between gas lines and neighboring property lines, allowing operators to service their gas lines without disrupting other people’s property. Currently, the distance between gas lines and other property varies based on the width of the easement.

“We need to get regulations in yesterday,” Poole said. “Get them on the books before any more development goes on around these wellheads, so we all know where we stand.”

PEGGY HEINKEL-WOLFE can be reached at 940-566-6881. Her e-mail address is  pheinkel-wolfe@dentonrc.com.

LOWELL BROWN can be reached at 940-566-6882. His e-mail address is lmbrown@dentonrc.com.