Editor's note: A previous version of this article incorrectly listed the Edwards Aquifer Authority as opposing the pipeline. The organization says it has not taken a formal stance on the issue.

A proposed natural gas pipeline that would slice through the Austin area poses a hazard to water and wildlife in the region, a new City of Austin analysis indicates. The analysis ratchets up mounting resistance to the project.

The city’s Watershed Protection Department produced the analysis after the Austin City Council unanimously approved a resolution June 19 expressing opposition to the planned 430-mile, $2 billion Permian Highway Pipeline and calling for ways to block it. Austin City Council members have joined a growing chorus of government officials and environmentalists raising concerns about the pipeline’s possible harm to the environment, including surface water and groundwater.

As envisioned now, the Permian pipeline would cut through 16 Texas counties, including Blanco, Caldwell, Gillespie, and Hays. More than 810 miles of energy pipelines already operate in those four Central Texas counties. In the Austin area, the Permian pipeline would sit just north of Wimberley, south of Kyle, and west of Lockhart.

“I am especially concerned about the pipeline’s undeniable threat to the Trinity and Edwards aquifers, and all of our natural resources,” says Austin City Council Member Leslie Pool, who sponsored the pipeline resolution.

The City of Austin analysis, dated August 28, says the pipeline presents a possible risk to Barton Springs and San Marcos Springs — two “significant, highly sensitive environmental resources” that flow from the Edwards Aquifer. Furthermore, according to the analysis, the pipeline could endanger the habitats of three federally protected creatures: the Barton Springs salamander, the Austin blind salamander, and the golden-cheeked warbler.

The Edwards Aquifer, which covers eight counties, is the primary source of water forthe San Antonio area; it also feeds into several bodies of water, including Austin's beloved Barton Springs Pool at Zilker Park. The Trinity Aquifer is a key source of water for a 61-county area stretching from the Red River to the Hill Country.

Government regulations currently on the books aren’t sufficient to ensure construction and operation of the Permian Highway Pipeline would not cause “adverse environmental consequences,” the analysis says.

One of those consequences could be the accidental release of dangerous contaminants like hydrocarbon liquids as the pipeline carries natural gas between the oil- and gas-rich Permian Basin in West Texas and the Texas Gulf Coast, according to the analysis. Hydrocarbon liquids, which are components of natural gas, can hurt people and damage the environment.

Houston-based oil and gas pipeline operator Kinder Morgan Inc., the primary company behind the project, says natural gas traveling through the pipeline would not turn into liquid unless it was exposed to extreme cold.

The City of Austin analysis notes that a lack of data about the “volume and characteristics” of contaminants that might be emitted by the pipeline prevents a complete forecast of any pipeline-triggered environmental threat.

Kinder Morgan points out that the pipeline will carry only natural gas, which it says is lighter than air and won’t seep into the ground or affect groundwater sources. “In the extremely unlikely event of a leak, the gas would rise into the atmosphere,” the company says.

Andy Sansom, director of environmental strategy at Texas State University’s Meadows Center for Water and Environment, pushes back against that assertion. Pipeline leaks “are more common than you might think and can be catastrophic to the surrounding area. With this specific pipeline and this specific route, there is no room for error,” Sansom says.

Kinder Morgan maintains that the proposed route of the pipeline would minimize its environmental impact, even though it would travel through the Hill Country. Its engineers and environmental specialists settled on this route after concluding that shifting the pipeline to the north of Austin or closer to San Antonio would create a greater environmental impact, the company says.

Several federal and state agencies are responsible for approving and overseeing the pipeline, including the Railroad Commission of Texas, Texas Commission on Environmental Quality, U.S. Fish and Wildlife Service, U.S. Army Corps of Engineers, and Texas General Land Office. Citing federal data, the operator says only 0.01 percent of U.S. transportation accidents involve pipeline.

A number of entities oppose the pipeline. Aside from the City of Austin, they include the Barton Springs/Edwards Aquifer Conservation District, Hays Trinity Groundwater Conservation District, City of San Marcos, City of Kyle, City of Wimberley, Texas Real Estate Advocacy and Defense (TREAD) Coalition, Save Barton Creek Association, and Wimberley Valley Watershed Association.

Robin Rather, a longtime environmental activist in Austin, complains that the City of Austin waited too long to enlist in the anti-pipeline battle.

“It’s an interesting case study where the small towns like Kyle and Wimberley have been leading the fight, and Austin has been far in the background,” Rather says. “It’s an indication of how our region has grown and how our tradition of water advocacy has grown regionally as well. This is a fight we need to fight together as a region.”

David Baker, executive director of the Wimberley Valley Watershed Association, has emerged as one of the most visible and vocal critics of the pipeline.

Potential pollution from the pipeline “is a direct threat to Jacob’s Well, San Marcos Springs, Barton Springs, and aquifer species, as the watersheds and water supply throughout the Hill Country are all interconnected,” he says. “This pipeline is the greatest threat to our groundwater aquifers in our lifetimes.”

The company, which says it’s collaborating with several aquifer agencies and advocacy groups along the proposed route, also says it will perform an environmental analysis of the project and promises to protect environmental and cultural resources along the route.

Customers of the pipeline would include Houston-based Apache Corp. and Fort Worth-based XTO Energy Inc., a subsidiary of Irving-based Exxon Mobil Corp. Construction is supposed to start this fall, with the pipeline set to begin operating in late 2020.