SAN ANTONIO -- Dennis Spencer said he never gave fiber optic cable much thought until installation crews showed up in his northwest-side neighborhood.

He said when they told him they would be coming inside his back yard, he began to have questions about the safety of the materials he saw them using and the process itself. Spencer said boring crews seem to be forcing liquid into the ground. He asked if the process was like fracking.

“I want to know what chemicals they're using. They have bags of stuff here called Bore Gel,” Spencer said. “What is the Bore Gel?”

The product being used by many local contractors is Wyoming Sodium Bentonite.

Product safety websites describe it as a fine clay with a small amount of lubricant to keep the mixture free-flowing. Drilling crews sometimes mix Bore Gel with water. Contractors said the mud-like solution is forced into the bore hole to help the drill bit pass through the dense material and to help carry drilled material out of the hole.

They said once the mud comes out of the ground, it is collected and taken to an authorized, safe disposal site.

Spencer said he also wonders if the process is safe for the children who play nearby and the homes close to the drilling zones.

“How do we know how this will impact the soil beneath the surface,” Spencer said.

One contractor working in the area said all the companies involved in this type of work are licensed and bonded and they must have proper permits from the city. They must also ensure that a utility locator service maps out where another infrastructure is buried to prevent damage to electrical, natural gas, water, sewer and cable service lines.

Contractor representatives said if they made a mistake work would stop, money would be lost and damages would have to repair, all scenarios they work to avoid.

From the City of San Antonio Transportation and Capital Improvement Division:

“In horizontal boring operations, which are done approximately 36”-42” below the surface, a drilling fluid primarily comprised of water is necessary to aid in transporting cuttings to the surface and to reduce drilling torque but oftentimes, boring operators include bentonite, which is approved for use by the EPA (reference below), as an additive to the water to increase stability of the bore hole and to aid in lubricating the passage of the drill bit and the pipe that is to occupy the bore hole. In boring operations, there is a direct relationship between the amounts of additive that is used and the harder the soils meaning that if bentonite is used as an additive, a higher content will be used in rock versus sand or clays soils. While it is understood that the makeup of drilling fluids used in boring operations will vary because of the diverse soils found across the city, the City of San Antonio does not provide regulatory oversight or testing of how much additive is used in drilling fluids associated with horizontal boring.”

From AT&T:

“We are currently working to install high-speed internet access in…San Antonio. We are committed to ensuring our work is completed safely, professionally and with the least amount of disruption as possible. While installing equipment, our contractors obtain all of the proper permitting and follow all safety and environmental regulations. While installing fiber at this location, technicians are using water for boring purposes. Following the installation, we clean up any remaining mud and replace top soil to restore the area to the condition it was when we got there. We have already placed 1 gigabit per second internet connections to nearly 150,000 San Antonio area homes, apartments and small businesses.”

From Google Fiber:

“Fiber contractors do not use any chemicals in drilling. They use an environmentally friendly water and clay based fluid to keep the drill bit cool and form the walls of the bore hole. Construction is ongoing, and there are no further updates at this time.”

For the EPA description of bentonite, click here.

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