There are around 60 different crops grown in the Barron River catchment area.According to the Australian Pesticides and Veterinary Medicine Authority corn on its own has 1415 products registered to be used.
After heavy rain events the Barron is quite easily transformed into an agricultural drain.
The water test suites which include heavy metals and pesticides are conducted twice a year by Mareeba Shire Council and only include a very small number of the possible active ingredients of those products.Council refuses to conduct an audit to actually find out what is used in the catchment area so the test could be adjusted accordingly.
On top of it, those tests are conducted in April and September when most chemical run off after the first big rain events will have long passed through our town water supply or been washed down the Barron.
We found when testing the Clohesy that the tests for heavy metals were clear in the dry season but in December after the first rains they showed a presence of Arsenic, Cadmium and Lead.
Other toxins, for example blue-green algae toxins, chlorination by products and herbicides are not tested for at all including widely used herbicides like Glyphosate and Atrazine.
In 2006 a JCU study found Atrazine in the mouth of the Barron. Glyphosate only narrowly escaped being banned in the European Union this year.
The town water filter system is such that it can not remove all of the many possible contaminants that drain into the Barron.
Considering the above Council is in no position to guarantee that the water is always safe to drink as they don’t really know what is in it.
In fact one might think, tests if they are conducted at all are timed so they produce good results rather than gaining an understanding of the forever changing water quality of the source water.
Council has responded to those allegation by saying that they are following the drinking water management plan. But on close examination of that documen,t it appears that the testing regime does not correspond with the risk assessment, proposed control measures or proposed verification monitoring program.
- blue green algae toxins,
- chlorination by products,
- heavy metals,
- pharmaceuticals and more in the water.
In December 2015 the State Department of Environment and Resource Management conducted 10 water tests on 5 different days in Myola on the Barron. The samples were tested for herbicides by QLD Forensic and Scientific services.
All the samples showed low levels of Diuron, Atrazine, 2,4D, Hexazinone and Fluroxypyr. Glyphosate was not included in the tests.
The Australian Drinking Water Guidelines say on page 401, 543, 606 and 642:
‘With good water quality management practices, pesticides should not be detected in source waters used for drinking water supplies. Persistent detection of pesticides may indicate inappropriate use or accidental spillage, and investigation is required in line with established procedures in the risk management plan for the particular water source.’
The Australian Drinking Water Guidelines also reveal on page 310 concerning Cryptosporidium that Council is not following the guidelines.
So, as already mentioned, Council should make residents aware that town water may not be safe to drink in Kuranda and Mareeba.
It seems Cairns City Council, despite needing an extra water source to meet growing demand, is more cautious and responsible about considering using the Barron as source water.
Apart from warning residents, Council should also test the source water frequently (twice a month at least) for all possible contaminants for at least a year to gain a comprehensive understanding of the Barron River water quality.
Based on the results of those frequent tests, Council should draw up a new risk assessment plan which is then followed through by proposed control measures and a proposed verification monitoring program.
If it proves impossible to guarantee that town water is always safe to use, an alternative safe water source should be found.