May 25, 2012
GOOD NEWS: We received our NPDES permit from DEQ for the application of Diquat dibromide to our weeds. If all goes as planned we should have a reasonably weed free lake for the summer.
There are certain conditions for the use of this herbicide. Diquat is a contact herbicide with a very short half life of about 6 hours. The contacted plants show results in a week or so. As they die the bacteria etc. that break them down will require oxygen from the water, so by EPA label requirements we can only treat 50% of the lake at a time, requiring two treatments. The first will be to treat the edges of the lake (shallow); however, we must stay 6 feet from the shoreline. This will insure safety for fish and wildlife. The lake will be lowered by 18 inches to half pool and then refilled during the treatment which will contain all of the herbicide until it is fully degraded and none of it is discharged downstream. Refilling with take 7 – 14 days. Water quality testing will occur throughout the treatment period and with test results below our design limits we will lower the lake a second time and repeat the treatment process in the center of the lake (deep). Once the lake refills it will remain at full pool for the remainder of the summer. Boating will be restricted only on the two treatment days along with cautions for swimming, drinking, and keeping pets away from the water.
