Beach monitoring in the Door County area, 2003

This page shows the results of water tests from Whitefish Bay Dock in the north to the Lily Bay Boat Ramp in the south, which includes Glidden Drive. This area is on Lake Michigan, just north of Sturgeon Bay, Wisconsin, USA. These tests were done in 2003.

The tests were done under the Adopt-A-Beach program administered by the Lake Michigan Federation and the Door County Soil and Water Conservation Dept. Some of these reports, and others, can be found on the the Adopt-A-Beach site. This monitoring is done by volunteers, and is not the official monitoring done by government bodies.
E. coli and other coli tests were done with Petrifilm, a disposable paper plate. A 1 ml water sample is taken with sterile equipment, deposited on the Petrifilm, incubated for 24 hours, then the blue (E. coli) & red (other coli) dots are counted manually. The ideal incubation temperature is 95°F.

What do the results mean?

Ideally, there would be no E. coli or other coli colonies formed after incubation time. Minor contamination from animal (primarily bird) waste is often inevitable, yet bird bacteria is not normally dangerous to human beings, so a non-zero count may be nothing to worry about unless you are a bird. Note that neither these tests nor the official ones are able to distinguish between animal waste (harmless) and human waste (harmful). Tests are available to do this, but have been declared too expensive. So the published numbers are of combined coli and should be interpreted with this information in mind.

A count of 235 colonies per 100 ml is sufficient to post a warning sign, and 1000 colonies will cause a beach to be closed to swimming.

Test Results

Date	Time	Location	I. Temp range	E. coli	Other coli	Comments
06/19/03	6PM	Sherman Bay	93°F-96°F	None	None
06/27/03	3PM	Whitefish Bay Dock	91°F-113°F	None	2
06/27/03	5PM	Lily Bay Boat Ramp	91°F-113°F	None	None
06/29/03	9AM	Sherman Bay	87°F-93°F	None	7	Many gulls in water and on beach before sample taken
07/13/03	1PM	Sherman Bay	87°F-98°F	None	None
07/27/03	1PM	Lily Bay Boat Ramp	92°F-110°F	None	None	Test done by Katie Giles
07/31/03	1PM	Lily Bay Boat Ramp	94°F-97°F	None	None	Test done by Katie Giles
08/02/03	2PM	Whitefish Bay Dock	80°F-99°F	2	15	Test done by Susan Mazza
08/06/03	2PM	Sherman Bay	88°F-101°F	None	None
08/10/03	Noon	Goldenrod Lane	~95°F	None	None	Test done by Mel Madel
08/21/03	5PM	Sherman Bay	88°F-93°F	None	None
09/21/03	1PM	Sherman Bay	89°F-95°F	None	None

NOTE: These tests were done with a 1 ml water sample. The official results are always shown at "N colonies per 100 ml." So the above figures should be multiplied by 100 to compare with the official tests. (Example: the 06/29/03 tests, which found 7 colonies per 1 ml, equates to 700 colonies per 100 ml.) BUT, multiplication by such a large factor also multiplies sample defects and errors, increasing inaccuracy.

Links of Interest

Chamber of Commerce Door County Beach map. Status, water temp and recent test results of each beach in DC.
How often beaches will tested
Door County Health Dept.
Map of DC beaches (but no test links)
Wisconsin Great Lakes beaches