Particular concern has been expressed over the composition of the additives to the fracking fluid.
For any one fracking operation, up to a dozen chemicals or additives, often fewer, are needed for the fracking process to work. The additives are required to be named, explained, and approved by the Environmental Protection Agency (EPA), under the Hazardous Substances and New Organisms Act 1996.
Information on additives may also be obtained from, e.g. PEPANZ or providers of fracking services such as Baker Hughes, a firm operating in 80 countries including New Zealand. For example lists of fracking chemicals, click here.
The main chemicals for a fracking operation typically comprise:
A friction reducer – for ease of pumping and evacuation of fluid
A natural gel – to hold the sand in suspension
A gel management system - to stabilise the gel until the sand is moved into fissures, and later weaken the gel to allow the fluid to come back up, followed by the gas
A clay stabiliser - to prevent any clay minerals in the reservoir rock from expanding on contact with water and plugging the reservoir
A bactericide – to prevent bacterial action underground corroding the well casing
The above chemicals are similar to many found in other commercial uses or in the household. For example: the natural gel is guar gum which is also used in ice cream manufacture; the gel breaker is similar to chemicals used in household detergents; and the bactericide is similar to those in hand-wash soaps and disinfectants, e.g. for sterilising medical and dental equipment.
In the concentrations used, the fracking chemicals are non-toxic to humans, and many are biodegradable. (That’s not an invitation to drink this any more than one would drink dish water.)
Additives used in modern fracking NO LONGER include BTEX - an acronym for benzene, toluene, ethylbenzene, and xylenes - compounds which can have harmful effects on the human central nervous system.
The media is fond of describing fracking fluid as a "cocktail of chemicals". That would make coffee a super-cocktail of chemicals, as would tea, beer, ... almost everything.
Humans have an innate fear of chemicals, going back to a time when our forebears took great care not to eat the wrong plant. Such fears are natural and legitimate but in today's context are not always rational.
For example, swimming pools contain toxic chemicals yet people swim in them safely. Sleeping pills can definitely kill a human but are fine if used safely; ditto for alcohol.
As a law of nature, chemicals that are toxic at high concentrations may be safe, or even beneficial, at low concentrations.
The National Toxics Network, an Australian non-governmental organisation, wrote a misleading report on fracking chemicals. The NTN identifies many chemicals not used in fracking in New Zealand. Secondly, the effects of these chemicals are discussed with no context presented. An example is volatile organic chemicals, such as petrol fumes and paint thinners. On the NTN's rationale, petrol stations and enamel paint should be banned. Of course, these are used safely every day.
More on fracking chemicals here.