Fort Worth

Contaminated groundwater seeping into the Trinity River from this spot needs costly fix

Fort Worth is working on a plan to contain benzene and arsenic from seeping into the Trinity River from the Brennan Avenue Service Center. City environmental authorities are looking at an underground barrier that would also act a water filter and clean the water before it goes into the river. This is a culvert on the south end of the property at the river.
Fort Worth is working on a plan to contain benzene and arsenic from seeping into the Trinity River from the Brennan Avenue Service Center. City environmental authorities are looking at an underground barrier that would also act a water filter and clean the water before it goes into the river. This is a culvert on the south end of the property at the river.

It’s been nearly a year since environmental consultants provided the city with a report on the long-known issue of groundwater contamination seeping into the Trinity River at the south end of its Brennan Avenue Service Center, but fixing the issue is not likely to happen anytime soon.

Whenever it does, taxpayers can expect to foot an expensive bill to solve an environmental issue that no one can completely pinpoint the source of or when it started happening. The city’s land was, and the surrounding properties have been, used by oil refineries for more than a century.

This bill will be on top of the money the city has already spent to remove contaminated soil and leaking oil storage tanks on its property since the 1990s. Groundwater monitoring has been done since, but levels didn’t start exceeding acceptable regulated levels until a few years ago, triggering this latest review.

City staff continues to work with consultants on a possible solution, one that could involve the placement of a filtration barrier that would clean the water, contaminated with benzene and arsenic, before it goes into the river just north of downtown. Project costs could run into the millions of dollars. City staff says it has a good deal of evaluating to do before that work can be done.

It will be, though, one of the larger and more complicated environmental projects for the city, and one that will require years of remediation monitoring, said Cody Whittenburg, Fort Worth’s environmental manager.

State law requires the remediation work because the contaminated groundwater is impacting the surface waters of the Trinity River.

“I don’t want to spend any money, especially at that magnitude, until we know we have a solution,” Whittenburg said. “We are going to move as quickly as possible.”

In September 2016, Fort Worth hired Dallas-based Enercon Services for $589,500 to look at soil and groundwater contamination at six city properties that will become part of a larger environmental capital improvement plan. The Brennan Avenue site is one of those projects. It is where the city operated a landfill for 22 years, before it was closed and capped in 1997.

“When we get into a long history of industrial uses ... it’s very, very difficult to assess blame and to find a responsible party to hold accountable,” Whittenburg said. “This is a greater area than just the actual Brennan Service Center. It goes back a long time. That’s one of the things that makes this project very complicated.”

The location now houses city facilities, among them the Police Department’s auto impound lot, Transportation and Public Works street services division, and a resident recycling and solid waste drop-off center. Although there are concerns about leaking automotive fluids from cars on the impound lot, the operations are not believed to be contributing to the groundwater contamination, Whittenburg said.

Cancer causing contaminates

The cancer-causing contaminates apparently are not all coming from the city’s property, but are believed to also be seeping into the groundwater from adjacent and nearby properties that over years housed tank farms for oil refineries and other industries, some that date to the early 1900s.

Groundwater, which takes years to seep through soil, flows through the city’s property in that area to reach the Trinity River. The spot in the river is in the path of the massive $910 million Trinity River Vision flood control and economic development project that spans 1,800 acres on the city’s north and east sides. The project is creating the 800-acre Panther Island on the north side that includes an urban lake.

Because the city owns the property where the contaminated groundwater goes into the river, it is responsible for tackling the issue. The city bought about 70 acres, a former large-scale oil storage area, in the mid-1970s and opened the landfill in 1975. It’s not likely the city will sell the property anytime soon, a city report says.

“We don’t know any specifics as to who might have caused what,” Whittenburg said. “We do see historical use of petroleum products in that area. There’s evidence to suggest we may be experiencing some groundwater pollution from those historical uses.”

Whittenburg said the fix that’s chosen will be the most efficient and least-costly method. In the meantime, he stresses the public is not in danger even though the amounts of benzene (which comes from petroleum products) and arsenic, are above acceptable levels.

Contamination discovered years ago

Benzene and arsenic contamination from leaking tanks on the city-owned property was discovered several years ago. In 1991, soil and underground tanks were removed and the issue cleared from the city’s property. However, from August 2013 to December 2015, benzene, arsenic and other chemicals were detected in most of the 21 monitoring wells in the area.

In late 2016, Enercon conducted the environmental review, which includes a historical look at the site and investigates whether “recognized environmental conditions” exist. The report gives the city a better understanding of what it is up against.

As a result, in 2017, a culvert for a stormwater outfall on the south end of the city’s property where it meets the Trinity River has been sealed to prevent contaminated groundwater from seeping in and mixing with the rainwater. Visible staining, which the city said could be the result of several things, such as iron oxidation or algae growth, has been removed from the one side of the outfall. Groundwater is still seeping from the other side.

Geological studies of the site are being done to watch the flow of the groundwater and to decide where the ground can best support a barrier. The consultants suggested that barriers also be placed in spots to prevent the groundwater from seeping to the city’s property.

The proposed barriers would contain a filter that is changed every so often. The filters effectively treat the water before it goes into the river.

“Overall our goal is to limit the groundwater that is impacted with the benzene and arsenic from entering into the surface water of the Trinity River,” said Roger Grantham, Fort Worth’s environmental supervisor.

People float in the Trinity River while enjoying the music of the Wayne Garner Band at Rockin' the River live on the Trinity River in Fort Worth, TX, Saturday, July 1, 2017. (Video by Max Faulkner/Star-Telegram)