The controversial oil and gas extraction process known as hydraulic fracturing, or "fracking", is capable of being managed sustainably and without serious risk of groundwater contamination or inducing damaging earthquakes, the Royal Society has found.
One of the world's most respected independent scientific bodies, the society worked with the Royal Academy of Engineering to produce a report sought by the UK's chief scientific adviser, John Beddington.
The report comes ahead of a report due before the end of this year from New Zealand's Parliamentary Commissioner for the Environment Jan Wright, and is far from a complete bill of health.
It warns that faulty well construction is the greatest risk for groundwater contamination, rather than the fracking process itself.
"Well integrity is the highest priority," the report concludes. "More likely causes of possible contamination include faulty wells."
"Attention must be paid to the way in which risks scale up should a future shale gas industry develop nationwide."
The UK's "unique" system for examining offshore oil wells "must be made fit for purpose for onshore activities," the society's report says. Several companies with onshore exploration licences in New Zealand have indicated fracking is a likely choice for some exploration activities.
A Canadian/Texan joint venture between TAG Oil and Apache Corp. has promised not to frack before Wright's report is released. TAG has used fracking for onshore Taranaki oil and gas finds which lifted the company onto the main board of the Toronto Stock Exchange.
The Petroleum Exploration and Production Association of New Zealand chief executive David Robinson welcomed the report, saying "if the practice in the UK is safe, people in New Zealand should feel confident that hydraulic fracturing here is just as safe, if not safer."
The Royal Society said "health, safety and environmental risks can be managed effectively in the UK" and "operational best practices must be implemented and enforced through strong regulation."
Groundwater contamination caused by the fracturing process itself was unlikely, "provided that shale gas extraction takes place at depths of many hundreds of metres or several kilometres."
"Even if fractures reached overlying aquifers, the necessary pressure conditions for contaminants to flow are very unlikely to be met given the UK's shale gas hydrogeological environments," the report says.
Robust monitoring should be carried out before, during and after shale gas operations and an Environmental Risk Assessment "should be mandatory", based on the entire lifecycle of operations, from water use through to the disposal of wastes and the abandonment of wells, and include seismicity.
"Seismic risks are low," the report says. "Seismicity induced by hydraulic fracturing is likely to be of smaller magnitude than the UK's largest natural seismic events and those induced by coal mining."
While fracking requires significant quantities of water, this could be managed sustainably.
The report also identified the need for more research on the carbon footprint created by shale gas extraction, the main use to which fracking is put in the UK.
"Further benefit would also be derived from research into the public acceptability of shale gas extraction and use in the context of the UK's energy, climate and economic policies," the report says.By Patrick Smellie