A Natural Swimming Area is defined as an area where there is a fee or membership required to gain access to a natural freshwater location where swimming is promoted, or a natural freshwater location where improvements have been made to promote swimming. Natural Swimming Areas are required to take two water samples per month during the swimming season. These samples are analyzed for E. Coli. If the sample is greater than 349 colonies/100 ml, the area must be closed until a satisfactory sample is taken. Natural Swimming Areas are issued annual permits based on pre-season bacteriological samples.