Concern builds over chemicals left behind
FOR every “fracked” coal-seam gas well, between 10,000 and 35,000 litres of chemicals are injected into the ground, with up to 40 per cent remaining there.
The CSG industry has talked down the quantity of chemicals used in the process, repeatedly stating the chemicals represent roughly 1 per cent of fracking solution with the remainder comprised of water and “proppant” such as sand.
The Senate committee into CSG, which delivered an interim report this week, has examined the bulk of chemicals used in the hydraulic fracturing or “fracking” process. It states that because of the very large volumes of solution involved, “even 1 per cent is still a significant volume”.
Fracking is thought to be used at up to 40 per cent of the 18,650 CSG wells approved for development in Queensland.
The process involves injecting a large volume of water, proppant and chemicals under high pressures into coal seams, allowing gas to flow. While the amount of fracking fluid that returns to the surface varies widely, generally about 60 per cent resurfaces and 40 per cent of the solution stays underground.
CSG giant Santos has said it uses about one million litres of solution in a typical frack, which would equate to about 10,000 litres of chemicals per job.
Fellow CSG major QGC said fracking solutions “vary considerably” between wells, but provided an estimate showing 34,000 litres of chemicals would be injected in each frack.
The Senate committee raised concerns about a lack of information regarding the types and quantities of chemicals used in fracking and said the process had caused concern because of the “health risks posed by the chemicals used in fracking fluid”.
The committee also questioned the CSG industry’s statements that many of the chemicals used were also in “household products”.