Water Ponds: All Lined Up

In a recent speech dedicated to Best Practice for Protection of the Local Environment at Fracking Sites, Stefan Baldauf, Director of Global Sales Engineering, GSE Consulting, spoke about what explorers could add to protect the environment - the extra protection to be had from linings.

He began his presentation by offering notes from a European Parliament plenary session from lat last year, which wrote "Each member state has the right to decide on whether to explore for shale gas, says the Energy Committee resolution... However, a robust regulatory regime is needed for all shale gas activities including hydraulic fracturing. Environmentally-friendly processes and best available techniques should be used to achieve the highest safety standards, say MEPs"

Showing that GSE's global operations entailed virtually every continent, and offering a glance of the company's products, like geomembranes and geosynthetic clay liners, which could be used at facilities like coal ash ponds or landfills, among others, Mr. Baldauf also provided information on best practice in the US in using such technologies.

He noted, "In the US there is no countrywide regulation of the containment works on shale gas sites; these come from each individual state, so the regulation is very diverse. Many times there is no clear regulation - many times these are made on a project specific basis."

The conditions at each shale play in North America were quite diverse, which led to very different solutions on the part of those operating shale gas sites. "Operators are concerned with freshwater, flowback water and of course the potential contamination of the ground at the site itself," he said.

Baldauf introduced delegates to what a typical operation looked like, mentioning concerns about fresh water, flowback water and concerns on the ground of the operation itself. He showed a Marcellus shale site with a freshwater pond in front of it that had a V shape and various ponds.

Among GSE's concerns at shale gas developments, he said, were: the big quantities of water used at a shale gas site - 15-40,000 cubic meters of water used per well; environmental contamination at the drilling site.

"Typically 10-30% of total water use comes back as flowback water, which is treated and reused, but also has to be contained," explained Mr. Baldauf. "This can contain hazardous chemicals, or components - surely the biggest issue of above ground to drillers."

Contamination of the groundwater aquifer, he said, was to be avoided.

The wellhead itself, he said, needed to be lined completely, and then there were liners for freshwater and flowback water ponds, some of which had to be lined.

Mr. Baldauf explained: "The lining of the well pad itself will be called a secondary containment liner, which typically is done with polyethylene geomembranes, which are the most widely used products for these kinds of applications, because of the very high chemical resistance, durability, long-term performance."

He said geomembranes had rough surfaces for safety reasons.

"These kinds of secondary containments should be installed in all areas, for chemical tanks and Untitled eventsimilar equipment, in case of damage or if any kind of hazardous liquid is released onto the ground."

Baldauf also spoke of geo-synthetic barrier pads/secondary containment, ponds/surface impoundments included mud/cutting pits, and freshwater ponds.

Regarding flowback water ponds, which he said were used to collect and store potentially contaminated flowback water, he showed an example from the Marcellus shale.

"They contain high quantities of salt, but sometimes, more importantly, traces of radioactive materials and some heavy metals," he explained. "And some even fall under specific regulation for hazardous wastes in the US, so there's more attention on the correct construction of the containment system for flowback water ponds.

"At a minimum, these ponds are lined with 1-1.5 of geomembrane, which is the minimum recommended. A lot of bigger an larger companies are concerned about the environment and double-lined systems are used."

Conductive Leak Location Liners, he said, could be used to continually check membrane integrity.

"Conductive geomembranes let you test directly after installation with small pinholes; you can also do that at anytime during maintenance," said GSE's Stefan Baldauf.