Greeley, CO., a city of about 70,000 people 60 miles northeast of Denver, this fall is considering a new water plan to allow developers to use untreated water delivered through a second system for lawns. Untreated water is safe to play in, but contains parasites such as giardi, that can make people sick if it swallowed. The practice is commonplace in AR and CA for years, but is new for Colorado. Greeley spent $3 million during the past two years on a system to use untreated water for its parks and ball fields.

Greeley's use of untreated water is saving an average of 3.6 million gallons a day, representing an 8% reduction. A 400-home subdivision in nearby Windsor already has a second system to deliver untreated water directly to a home's sprinkling system.