Swimming is not advised at Lake Darling State Park in Brighton due to test results exceeding the Algal toxin action level. Algal blooms can be dramatic and are a result of excess nutrients from fertilizer, wastewater, and stormwater runoff, coinciding with lots of sunlight, warm temperatures, and shallow, slow-flowing water. Typically, Lake Darling goes under advisory for high levels of E. coli bacteria. Although there are relatively few documented cases of severe human health effects, exposure to algal toxins may produce allergic reactions such as skin rashes, eye irritations, respiratory symptoms, and in some cases, gastroenteritis, liver and kidney failure, or death.