Transmission line herbicide testing returns negative results

Plant and soil samples collected under NB Power transmission lines in Wirral tested negative for pesticides and herbicides, a year after the area was sprayed for foliage control.

Resident near area treated still calls for eradication of spraying under transmission lines

The herbicide Vision Max was used around NB Power lines in Wirral. (CBC)

Plant and soil samples collected under NB Power transmission lines in Wirral tested negative for pesticides and herbicides, a year after the area was sprayed for foliage control.

CBC News collected the samples in July, following complaints from residents about the spraying.

Several dozen samples of soil, leaf litter and shrub branches were collected along a one-kilometre stretch of transmission line that residents said had been sprayed in late summer, 2014.

The samples were then sent to RPC Labs in Fredericton for analysis.

The lab ran two different tests, one for glyphosate, which is the main ingredient in the herbicide NB Power is approved to use on the lines, plus another test checking for six other pesticides or herbicides. The results showed none of the seven as being present.

Deborah Nobes, spokesperson for NB Power, said in an email Wednesday the results "appear to be consistent with our previous comments regarding how little actual herbicide is applied to control regrowth of hardwood trees."
NB Power has targeted areas underneath high electrical lines with plant-killing chemicals, such as Vision Max. The spraying has angered residents in Wirral, Tracy, Hoyt and Fredericton Junction. (Shane Fowler/CBC)

"These results appear to be consistent with the information we've previously shared about the minimal residual effects of glyphosate herbicide, the active ingredient in Vision Max," said Nobes

Vision Max, a glyphosate-based herbicide, is used by NB Power to stem growth of foliage under its transmission lines in rural areas.

The chemical is approved for use by the Department of Environment and NB Power says their application is diluted heavily with water. The company says it is "essentially non-toxic to humans."

Shane Kelly, a resident of Wirral and a community organizer protesting the use of herbicides by NB Power, says these results do not change his stance on the spraying program.

"Not at all," said Kelly.

"The herbicides themselves certainly need to be eradicated from our environment."  

Three possibilities exist for the negative test results in a treated area, the most likely being that plant and soil materials sprayed with chemicals did not retain any detectable levels of spray chemicals a year after being treated.

It is also possible that samples collected by CBC did not include any materials that were sprayed with herbicides. Or, chemicals other than what was tested for were used on the foliage.

Leaf litter samples were tested for glyphosate. Soil and branch samples were tested for the series of other common pesticides and herbicides.  

Glyphosate was not detected in a gas chromatography/mass selective detection test. The test can only accurately detect the presence of glyphosate greater than 0.1mg/kg.

The results do not prove the absence of glyphosate, but that the level of the chemical in the samples is lower than what is detectable by this test.

Soil and branch samples were tested for cycloxydim, fluazifop-p-butyl, flumioxazin, hexazinone, linuron, and metribuzin.

The method of testing used a dispersive solid phase extraction with analysis by liquid chromatography and analysed with a mass spectrometer. In all cases the tested samples provided to the RPC laboratory did not show detectable levels of these chemicals.

In August, NB Power apologized over its handling of the spraying program and said it will spray further away from residencies and provide more warnings about where and when spraying will occur in the future.   

About the Author

Shane Fowler

Reporter

Shane Fowler has been a CBC journalist based in Fredericton since 2013.