Runyan Lake - Water Quality

RLI monitors water quality by annual water testing and periodic water quality studies. Our annual water testing only tests for E. coli bacteria. Our less frequent water quality studies (every 5 - 10 years) include a much more detailed water analysis.

General Runyan Lake water use statement:

Exposure to any recreational water can be a potential health risk. Gastrointestinal and dermatological illnesses have been associated with recreational water exposure. Rain and subsequent runoff can dramatically increase E. coli bacteria levels in lakes and other surface waters. Therefore, it is advised that caution be exercised with total body contact in area surface waters after rain events. That said, Runyan Lake offers what most consider to be excellent water quality, both from a clarity aspect and a general health and safety aspect.

How do we sample the water?

RLI collects samples in areas of about 3 feet of water, and takes the actual sample at a water depth of approximately 2 feet. A map showing the sample locations can be accessed below. These samples are taken from areas of inflow into our lake (creeks), and therefore represent what is flowing into the lake as well as the total lake result after the inflow has mixed with the lake water in the immediate area.

How to interpret the results:

We deliver water samples to the Genesee County Health Department for analysis. The Genesee County Health Department utilizes the following rules to interpret the E. coli test results. (By authority conferred on the director of public health by section 12544 of Act No. 368 of the Public Acts of 1978, as amended, being §333.12544 of the Michigan Compiled Laws):

R 325.2102 Sanitation and safety determinations. Rule 2. (1) Bacterial concentrations in water at a bathing beach, as determined by standard methods, shall contain not more than 130 Escherichia coli (E. coli) per 100 milliliters, as a 30-day geometric mean. Compliance shall be based on the geometric mean of all individual samples taken during 5 or more sampling events representatively spread over a 30-day period. Each sampling event shall consist of 3 or more samples taken at representative locations within a designated sampling area. Bathing beach waters shall not contain more than a maximum of 300 E. coli per 100 milliliters. Compliance shall be based on the geometric mean of 3 or more samples taken during the same sampling event at representative locations within a defined sampling area.

The current State of Michigan public health standard for total body contact recreation (e.g., swimming) for a single sampling event requires that the number of E. coli bacteria not exceed 300 per 100 milliliters of water. A reading of less than 300 can be interpreted as water safe to swim in.

Keep in mind we also collect our samples from areas of inflow into our lake. These creeks may contain bacteria counts which become diluted as they disperse within the lake, but may result in somewhat elevated levels not representative of the bulk of our lake water. Our intent is to verify water flowing into Runyan Lake is not unsafe, and that water within Runyan Lake is safe.

Annual Water Quality Test Results - Total Bacterial Concentrations of Escherichia coli per 100 milliliters

	Test Locations
Date	Ostrowski Creek	Ramp Creek	Denton Creek	Hicks Creek	Sporer Creek	Middle of Lake	Comments
Date	Ostrowski Creek	Ramp Creek	Denton Creek	Hicks Creek	Sporer Creek	Middle of Lake	Comments
6/1/2006	33	9	186	n/a	11	n/a	Ramp sample taken in middle of cove. L. Johnson location instead of Sporer.
10/9/2006	12	12	16	0	2	n/a	Ramp sample taken in middle of cove. L. Johnson location instead of Sporer.
8/13/2007	6	50	1	2	5	n/a	Ramp sample taken off Fishwick lot
8/5/2008	236	8	186	40	224	n/a	Ramp creek sample taken off Fishwick lot
							In 2006 & 2007 samples obtained two foot below surface of water.
							In 2008 Otrowski, Denton, Hicks, Sporer samples obtained directly from creeks.
							Higher Ecoli counts may be due to obtaining samples directly from creeks.
2009							Sampling not done
6/1/2010	53	23	81	3	204	n/a	Ramp sample taken near the Polakowski / Fishwick property line
9/31/2010	3	8	74	3	3	n/a
6/14/2011	6	224	4	4	8	n/a	Ramp sample may have been taken in water too shallow or disturbed
8/9/11	12	204	25	6	14	0	Ramp sample may have been taken in water too shallow or disturbed

Reference Materials:
Map showing sample locations

Water Quality Studies:
2005 Progressive AE Water Quality Update 2008 Fish Study