Today’s question: People are allowed to swim and go boating in our water supply reservoir. Should I worry about this?
Plain Talk answer: Swimmers and boaters do add some pollution, which is diluted by all the water in the lake or reservoir and doesn’t amount to much. Also, because the water is thoroughly treated before it is delivered at the tap, any contamination is removed. Wildfires, litter and stormwater runoff can cause far more disturbance to the water quality in the supply reservoir than recreational pollution.
Still, some water districts do limit the activity on their water supply reservoirs to nonmotorized boats and prohibit swimming and other body-contact activities. Problems with methyl tert-butyl ether (MTBE), a gasoline addictive, have been found in reservoirs that allow watercraft with two-stroke engines, such as Jet Skis, so some places have put strict restrictions on such craft. Prohibiting activities on a recreational water body can be an unpopular decision, so your water utility would need the support of its customers if such action were to be taken.
For more information on this and many other water-related topics, check out Plain Talk About Drinking Water by Dr. James M. Symons.