Monitoring Water Quality in Seasonal Storage Reservoirs – How Utilities Are Maximizing Recycling without Going Bright Green

Seasonal storage sites of four agencies were visited: Washoe County in Nevada; and Santa Rosa, Santa Margarita, and Irvine Ranch Water Districts in California to analyze the effects of the physical characteristics of the reservoirs on recycled water quality. Each agency developed its system based on varying driving forces and end users, storage capacities and levels of post treatment.In the sites surveyed, a clear difference in water quality was apparent between the deeper reservoirs and shallower reservoirs. Shallow reservoirs had no stratification and light penetrated to the bottom. As a result, algae caused significant problems for smaller reservoirs. Deeper reservoirs received less light penetration, and exhibited fewer algae problems.As recycled water purveyors expand their systems by providing seasonal storage, they can benefit from the experience of others. Ensuring that the storage facility is deep enough to minimize algae problems will ensure higher water quality.