We took our third 2009 water samples Wednesday, July 8, at about 11 am.

#1 Dock 11 cfu
#2 Cedar Fork Creek 7 cfu
#3 Booker Creek 410 cfu
Caution level is individual reading above 400 cfu, or average above 200 cfu.

Lake water temp: 28-28.5C 82-83F

The SECCI clarity reading was 31 inches.

This is the first time since I began taking water tests that we had one reading in the caution zone and the other two at the lowest end of the safe range. The readings near the beach area and the Cedar Fork Creek forebay are completely OK.

If we got a 410 cfu reading at the dock, we would need to close the beach. At this time that is not necessary. In comparing this to recent beach closings at Falls Lake, this type of contamination is localized, so only specific areas are involved. The prudent response to this elevated reading is to avoid swimming in the long arm of the lake that originates at the Booker Creek inlet to the left of the beach. The main bay of the lake appears to be OK.

The high reading is probably related to the forebay excavation. That work displaced contaminated water from an area that attracts a lot of wildlife. There was not enough water involved to affect the entire lake, and this should dissipate in a couple of days. I think this behavior is comparable to that of a drop of food coloring in a bowl of water. We will need to run another test next week to make sure that there are no other problems. If the pattern persists, we should continue weekly tests until all counts are below 200.

The Fecal Coliform bacterium does not live or reproduce in water, so the lake does not “grow” it. It comes from the intestines of warm-blooded creatures. The beach and dock are near the dam at the “downstream” end of the lake. When the counts are elevated there, we use the two “upstream” sites to trace the origin. There are also springs in the main bay, and they are probably contributing as much water right now as the two tributary creeks. In this case, we did not get enough total contamination to make it all the way across the lake. The water from the springs stalled the progress of the displaced forebay water.

Of greater concern to me is the general lack of rain. If we were having regular rain, I would imagine the forebay work would make our lake very muddy, but any pulses of displaced contaminated water would be quickly diluted. If you are watering your lawn or garden near the lake margins to make up for this lack of rain, please take extra care not to flush any clippings or fertilizer into the lake or drainage creeks

Chuck Henage
chenagemht@aol.com