Friday 28th August 2009
From the DEH media release, "Acidic water found in Lake Alexandrina region"
"About 200 hectares of acidic water has been discovered in an area adjacent to Lake Alexandrina.
Scientists have identified the acidic water in Loveday Bay, in the southern region of the lake. Testing by the Environment Protection Authority found pH levels of less than 3...."
Loveday Bay showing iron precipitate at pH 2.3
The Courier reports that "Acidic water strong enough to dissolve mussel shells has been discovered".
Click here for a map of the exact location of Loveday Bay. For comparison purposes, 200 hectares is approximately 1km by 2km in area.
Another site further up the river where the acid problem got out of control is at Bottle Bend Lagoon. View our information page on Bottle Bend Lagoon here.
Review the CSIRO acid soils map of the Lower Lakes (2MB) showing the extent of acid sulfate soils in the region at -1.5 AHD. See the sidebar at left for current AHD levels.
The diagrams below from the latest CSIRO report,(4MB), show the extent of ASS soils to be exposed at varying AHD levels. Current water levels in Lake Alexandrina are now lower (-0.69m AHD in lateAugust, 2009) than the -0.5m AHD in the middle map, labelled as "current",
and have been lower earlier in 2009.
The seriousness of the predicted levels of acid for -1.5m AHD can be better appreciated by looking at the pie chart, which shows that the area affected in Lake Alexandrina would be about one third of the total area, and over half for Lake Albert. Click on the image to enlarge.
Lake Alexandrina Lake Albert