Anthony Henage and I took our fifth 2009 water samples Wednesday, September 2, at about noon. Here are the “preliminary” results:
#1 Dock 6 cfu
#2 Cedar Fork Creek 11 cfu
#3 Booker Creek 17 cfu

These readings are at the low end of the “safe” range. As usual, I will not revise this posting unless the “official” results turn out to be something different.

Lake water temp: 24-25C, 75-77F

The SECCI clarity reading was 18 inches. That is the most turbid reading we have had this year, almost exactly the same as last year at this time

The water was pretty cool, although we have warmer days and nights predicted for the next couple of weeks. The lake warms up pretty quickly on a sunny afternoon and stays comfortable if the nighttime air temperature does not go below the low “60s”. This is our last regularly scheduled water sampling for 2009 unless we have an extended warm spell at the end of September.

Our water tests are the same as those taken at other open-water swimming locations in the state. The test looks for one type of “indicator organism” that is representative of water contamination from human and animal waste. The fecal coliform bacterium is present in almost all open water, and only represents a health risk at certain concentrations. It lives in our bodies and in the bodies of all warm-blooded animals. It does not grow or reproduce outside the body. Test readings in the safe range indicate bacteria that are being neutralized by dilution and by time outside the body in a normal process.

Our testing does not analyze all likely or possible types of contamination. Use common sense about showering or bathing after you swim, and about where and when you swim. Areas near the shore with little water flow, and the entire lake right after a rainfall are more likely to be contaminated or muddy.

We are fortunate to have an urban lake with good water quality. The three biggest hazards we face are surface contamination from animal waste and excess lawn chemicals, development (causing erosion and more impervious surfaces), and spills or overflows of wastewater. Our watershed is about 4 square miles mostly to the North and West of Lake Forest. It includes Lake Ellen, and the area around the airport. We get notices from OWASA whenever there is a sewage spill in this area. Fortunately, that is becoming rare. About a decade ago it was a regular occurrence

Chuck Henage
chenagemht@aol.com