LANDHOLDERS at Polda on Lower Eyre Peninsula are seeking answers from SA Water after a customer sampled water from the Polda-Lock pipeline late last year and found its pH levels to be 11.8 - above the level that can cause eye and skin irritation.
This was just before SA Water removed health warnings from mains water bills, declaring the water potable after four years of telling customers not to use it for drinking, cooking or cleaning teeth.
The people were further incensed when it was later revealed SA Water was not undertaking sampling anywhere along the 37-40 kilometre pipeline earlier this year despite stating it was undertaking "regular monitoring" of the water supply in new notices classifying it as "drinking water" in April.
Local queries to the SA Department of Health found that the water was only being sampled from a point near Lock, and the section between Lock and Polda was not part of the monitoring program.
Cattle farmer Scott Linsell says he was advised by the department not to drink the water and to tell his neighbours not to drink it either.
SA Water organised sampling to verify the data shortly afterwards, and has since flushed the pipeline, but this drew criticism as well because it led to the dumping of about 1.3 megalitres above an aquifer.
Mr Linsell wants answers from the Environment Protection Authority because there is no permit issued for what he considers a "water affecting" activity.
"The pH level was 11.8 while the Polda basin is about 8.7," he said.
"That's a lesser quality of water and makes it a water affecting activity.
"You can't do that, but when I spoke with the Natural Resources Management board they said it would never make it into the aquifer.
"Well that aquifer starts at ground level, and the water disappeared over night."
An EPA spokesperson said discharges were necessary for supply network "optimisation" and that the Polda event was reviewed.
"The EPA is satisfied that appropriate risk-based decisions were taken to minimise environmental impacts," he said.
"There is no evidence of any environmental impacts to land, vegetation or groundwater."
SA Water says its own sampling from near the customer's water meters in May, which was undertaken after issuing new notices that declared the water to be potable in April, found pH levels to be 8.29 and 9.71 respectively.
"The higher pH water was detected only in a dead end section of the Polda main, which is not supplied to customers," an SA Water spokesperson said.
SA Water flushed the last 10km of the Polda Main, which was completed on May 22 and brought pH levels down to 8.13 at the deadend of the Polda Main.
SA Health principal water quality advisor Dr David Cunliffe says the confirmed pH level of 9.7 that was being supplied to customers was higher than usual, but below the level that would cause skin or eye irritation.
He said SA Water had now introduced weekly testing to monitor pH and keep it below pH 9, and was continuing upstream testing for "microbiological and chemical" parameters.
* Full report in Stock Journal, September 5 issue, 2013.