Full article published by the Coffs Coast Advocate on 23/05/2018.
Republished here as a community service so locals can better understand, review and consider the water crisis on the Coffs Coast: (emphasis ours)
Study Into Agriculture Impacts
WATER quality investigations will be undertaken in a local creek catchment, after community concerns were raised over the impact of intensive plant agriculture.
Coffs Harbour City Council has engaged Southern Cross University to perform the testings within the Bucca Bucca Creek catchment.
“In this report, we describe the findings of observations performed during various flows to establish baseline data and identify whether water quality may be linked to agricultural practices in the Bucca Bucca catchment,” the report states.
During the investigation, detailed samplings were taken from 16 sub-catchments and included 16 samples of surface water sites and 10 groundwater bores on 11 occasions between February 7 and May 7.
In conclusion, the study found the main pathway of nutrient loss from farms was surface run-off rather than groundwater discharge.
The highest nitrogen oxides (NOx) concentrations were measured when surface run-off increased with a storm event after a period of dry weather.
There was a significant correlation between blueberry area and creek NOX concentrations and loads.
“There was a significant difference in NOx between sites downstream of blueberry farms and control sites,” the report states.
“We showed that 25 per cent of NOx samples downstream of blueberries were between 50 and 800 fold higher than the Australian and New Zealand Environment and Conservation Council (ANZECC) water quality guidelines trigger values, primarily after rain events.
“This report represents the first attempt to assess the impact of blueberry farms on creek water quality in the Coffs Harbour region.
“Several lines of evidence demonstrated a strong influence of blueberry farming on creek water quality, in particular nitrate.”