How do you know if lake water is safe to drink?
How do you know if lake water is safe to drink? Never drink water from a natural source that you haven't purified, even if the water looks clean. Water in a stream, river or lake may look clean, but it can still be filled with bacteria, viruses, and parasites that can result in waterborne diseases, such as cryptosporidiosis or giardiasis.
How do you know if a lake is clean?
Look for signs of poor water quality, such as algal blooms and dirty or turbid water. Do not swim in water that smells like rotten eggs or sewage. Avoid swimming near pipes that drain into lakes or streams.