Swimming pond water quality testing

Asked June 14, 2018, 9:46 PM EDT

Hello, We have a 1/3 acre man made swimming pond at the house we just purchased. It is 15 years old in good shape with an ecosystem of small bass, blue gill, frogs, several geese or ducks sometimes, and small patches of cat tails. We have been trying to figure out where to get water quality testing done. The DEQ test request sheet is confusing and I am not sure which test we need. I know we want an E-coli test, but I am not sure if nitrogen tests and stuff like that are needed. We want to make sure the water is safe for the kids to swim in and the chemistry is not creating any water quality issues that will harm fish and encourage scum growth. Could you recommend where we can take water samples for testing and which tests we should have done? Thanks! Todd Lukens Grand Ledge

Eaton County Michigan pond and water gardens

2 Responses

The MDEQ drinking water lab will do analyses including E. coli bacteria, but you need to tell them which tests you want, and also that the sample is lake water and not drinking water. There are also many private labs that will do the analyses. Links to certified drinking water labs are listed on the MDEQ website at: https://www.michigan.gov/deq/0,4561,7-135-3307_4131_4156-36940--,00.html. Before sending in a sample, make sure you call the lab to find out if they analyze lake water, and how the water should be collected. There are certain protocols to use when collecting water, particularly for bacterial analyses. In some cases you can do some of the tests yourself by purchasing a water test kit from a company like LaMotte or Hach. If kids are swimming in the pond, then an E. coli analysis taken near shore would be good. I probably wouldn't recommend a nitrogen test. It, alone, won't tell you too much. Phosphorus may tell you more, but a total phosphorus test can be expensive. Less expensive tests like hardness, alkalinity, conductivity, and pH may give you a decent picture of overall water quality. Dissolved oxygen is very important, but that's not a test you can send out to a lab. You'd need to call someone in, like a pond or lake consultant to take that measurement on site. I hope this is somewhat helpful. You may call me if you have further questions.

Thank you very much