Ngaere water is good, final tests confirm

13 March 2012

A second round of water sampling at Ngaere has confirmed the good quality of spring-water, surface water and groundwater surrounding Tag Oil (NZ) Ltd’s Cheal sites, the Taranaki Regional Council says.

The second round of sampling, from a spring and from a stream flowing beside the Cheal B exploration and production site, completes a testing programme designed to investigate concerns raised regarding a particular spring in the area. Earlier results were reported in February,

The Council’s Director-Environment Quality, Gary Bedford, says sampling sites and testing parameters were carefully selected in consultation with GNS Science (the Institute of Geological and Nuclear Science) to determine whether exploration or well development activities had indeed caused contamination. No trace of such contamination has been found.

Water from two bores, two shallow wells, three springs and the stream has been analysed, and found to be of high quality. Every single chemical parameter was found to meet New Zealand Drinking Water Standards, and no parameter showed any result out of the ordinary for typical Taranaki shallow groundwater.

“The only issue was that bacteriological counts, indicating faecal contamination from agricultural sources, didn’t meet the standard,” says Mr Bedford.

The analysis covered almost 50 parameters, including a wide range of compounds commonly associated with hydraulic fracturing (“fracking”) and other processes used in oil and gas exploration and well development.

The parameters included:

• The “BTEX” range of compounds – benzene, toluene, ethyl benzene and xylene
• Methanol
• Dissolved natural gas
• Aldehydes, which can be used as biocides (disinfectants)
• Glycols
• Total petroleum hydrocarbons
• Trace metals
• Conventional parameters widely used to characterise fresh waters

“In all cases, no contamination and nothing unusual was detected,” says Mr Bedford. “There was a trace of methane in a sample taken from one spring, where we had been expecting more given that the Ngaere area was originally swampy. But even that was dozens of times lower than natural levels of methane we’ve detected elsewhere.”

Mr Bedford says the analyses included tests for compounds which aren’t used by the industry in New Zealand, but which are the subject of concern overseas.

Laboratory results

Round 1 sampling results (154 KB)
Round 2 sampling results (151 KB)
Bacteriological results (49 KB)

ENDS

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