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Disposal of waste water

Much of what goes down a well during a fracking operation comes back up. Management of discharge of used fracking fluid is covered under the Resource Management Act 1991. This is the same as for management of used water or waste water in many businesses, such as farms, pulp and paper mills, mines and quarries, road and infrastructure construction, food processing plants.   

The first task is to collect all used fracking fluid that comes back up, as well as other water that was naturally in the rock formation deep underground. (For this reason, this water is sometimes called "produced water".)

The waste water is collected either in lined ponds/sumps or storage tanks. It is then treated to meet specified levels of purity required by regional or district councils. That can be achieved via dilution - the already very low levels of additives are further reduced by adding water. Alternatively, the water can be chemically or mechanically treated, e.g. in a water treatment plant. Diluted or treated water may be discharged into rivers or onto land, under an RMA consent for water discharge. As well, treated water can also be recycled for use in fracking.

Waste water may also be re-injected to deep rock formations (via a well where the deep formations are isolated from shallow aquifers). Until now there has been little or no regulation in New Zealand for pumping water underground. That is changing with resource consents now required by Taranaki Regional Council, with other councils either likely to follow suit, or develop regulatory requirements of their own. 

Well sites

Well sites require resource consents for their construction and part of this requires containment of surface run-off. Any products deemed hazardous are covered under the Hazardous Substances and New Organisms Act 1996. Appropriate surface storage and containment facilities will be required, as is the case for any material covered under the HSNO Act.

Insofar as water in storage is concerned, skimmer pits and drainage systems are built so that any surface run-off flows through the system and can be trapped and cleaned. This is much more stringent than, say, construction sites where only silt and sediment traps are required.

Visual impacts, roading impacts

Visual impacts of fracking can be reduced by drilling multiple horizontal wells from the same site. Wells would then be drilled roughly 1.5km apart. Piping water to single pond sites also keeps trucking on local roads down. In the US, companies put up bonds to cover any damage to roads. In New Zealand, the industry has traffic management plans, and can be required to remedy damage caused to roads by trucks.