Most river runners in Canyonlands carry in all of their culinary water from an outside source. In the event all culinary water is not carried, all water consumed or used for cooking should be purified. Research on the Colorado River and its tributaries indicates that increased sediment from flooding or other causes may pose a high risk to river users. The following water purification steps should be followed:
- Use the main course of the river to collect water.
- Cloudy, sediment-laden water must be cleared before disinfecting. Settle overnight or use flocculating procedures (1 teaspoon alum per 5 gallons of water for drinking water). Decant the clear water into another container.
- On the basis of a recent literature review, the Center for Disease Control and the Environmental Protection Agency recommend that water be rendered safe for drinking by bringing it to a rolling boil for 1 minute, plus an additional minute for each 1,000 feet above sea level. (Elevation of the Green and Colorado rivers inside Canyonlands averages 4,000 feet, requiring 5 minutes of boiling.)
- Alternatively, filter water through an "Absolute" 1-micron filter or one labeled as meeting American National Standards Institute (ANSI/NSF) International Standard #53 for "Cyst Removal" followed by disinfection using household liquid chlorine bleach. Add 8 drops of bleach or 20 drops of tincture of iodine per gallon of water and let stand for 30 minutes.
- Water storage containers must be free of contamination when in use and washed and sanitized as needed.