The Greenville Water System provides water to nearly 400,000 people through 140,000 accounts through two water treatment plants. The Adkins Plant is a modern conventional filtration plant with a current capacity of 45 MGD and a projected capacity of 60 MGD by the year 2004. The Adkins Plant draws water from Lake Keowee, which is owned by Duke Energy. The water system has an agreement with Duke to withdraw up to 150 million gallons per day (MGD) from Lake Keowee to supplement the supply for the Table Rock and North Saluda (TR & NS) Plant. The TR & NS Plant is a new state-of-the-art filter plant that was placed in service on July 8, 2000. The TR & NS Plant (from now on referred to as the DAF Plant) has a capacity of 75 MGD and is the largest in the United States to use Dissolved Air Flotation (DAF) in the treatment process. The DAF Plant draws water from Table Rock and Poinsett Reservoirs, which are located in the foothills of the Blue Ridge Mountains in northern Greenville County. The Greenville Water System owns 100 percent of both watersheds (nearly 30,000 acres), meaning the water system exercises more control over its pristine source water than any other water system in the world. For over 70 years the source water from the Table Rock and Poinsett Reservoirs was unfiltered; it was treated onsite only with chlorine and ammonia for disinfection and caustic for pH adjustment. Historical water quality data demonstrates the pristine nature of both reservoirs. However, due to the ever-tightening regulations and the growth of Greenville County, it was decided that a filtration plant should be constructed to complement the water quality delivered by the Adkins Plant. The objective of this paper is to highlight the effects filtration has had on the water quality coming from the Table Rock and Poinsett Reservoirs. In particular, the paper addresses the water quality leaving the treatment plants and in the distribution system before and after filtration. Includes 4 references, tables, figures.