Disposal of drilling waste questioned

16:00, Dec 17 2013

Claims fracking waste is being disposed of on land farms are inaccurate, according to the Taranaki Regional Council.

Media reports yesterday said the TRC based their practice of allowing "fracking waste to be applied to farmland" on Canada's Alberta Energy Regulator (AER)'s guidelines.

They also stated the AER said it did not allow this practice.

A spokesperson from the Canada energy regulator told Radio New Zealand that Alberta's fracking waste was disposed of "in industrial waste facilities" and was not allowed to be spread on farmland in the process known as landfarming.

The spokesperson reportedly said waste from the hydraulic fracturing process was not suitable for agricultural land.

The TRC's director of environmental quality Gary Bedford said the disposal of fracking fluids had only been consented to on one landfarm in Taranaki.


"That landfarm is now closed.

"Its consent remains in force while comprehensive soil testing is carried out.

"This testing will continue until it demonstrates that the soil is within New Zealand and Canadian agricultural guidelines."

He said yesterday's media reports had confused drilling waste with fracking fluid.

"The majority of waste disposed of at landfarms is comprised of water and synthetic-based drilling muds and rock cuttings.

"The council's stance is that the landfarming of drilling muds, solids, and sludges is considered environmentally viable."

He said the council recommended disposal of the wastewater, which was produced by the fracking process, by deep well injection.

This meant injecting the waste into porous underground formations that were isolated from freshwater aquifers.

The method was used at a number of different well sites in Taranaki, according to a TRC report on the future management of oil and gas operations in the region, which was published in November.

But environmental activist Sarah Roberts said the difference between fracking fluid and the drilling mud that was spread on landfarms was irrelevant.

"Both types of waste are toxic. They are just different kinds of toxic."

Ms Roberts pointed to a report from consultancy company BTW, which managed two land farms near Waitara, that recommended research be carried out on the application of fracking wastes at landfarming sites.

The chemical composition of the wastes compared to synthetic and water-based muds needed to be clarified, as did their effect on soil nutrient levels, biodiversity and health, the report stated.

TRC guidelines for the disposal of drilling waste onto land were initially developed from Canada guidelines, due to an absence of any in New Zealand.

Based on international best practice, TRC guidelines evolved as experience was gained with Taranaki conditions.

Hydraulic fracturing, known as fracking, is the process of pumping fracking fluid into a well to create enough pressure to fracture the rock layer.

The typical composition of fracking fluid, according to Todd Energy, is 97 to 99.5 per cent water and proppant (silica sand or ceramic beads) and 3 to 0.5 per cent chemical (chemicals vary depending on company and can include guar gum, glutaraldehyde, ammonium, citric acid, and isopropanol.)

Once the fracking operation is complete, the pressure at the surface is reduced to enable the fracturing fluid, mixed with ground water and hydrocarbons, to return to the surface.

Taranaki Daily News