South Carolina: Greenville Watershed Land Ownership Protects Greenville, SC Water Supply Background The City of Greenville, in the foothills of the Blue Ridge Mountains, obtains its drinking water from three surface water supplies: Table Rock Reservoir, North Saluda Reservoir, and Lake Keowee. The City of Greenville owns the Greenville Water System (GWS) which is governed by the Commission of Public Works. The Table Rock Reservoir in Greenville County is a man-made lake, created in 1930, along the South Saluda River. The watershed to the reservoir covers approximately 9,000 acres and is completely owned by the Greenville Water System. The North Saluda Reservoir, located on the North Saluda River, is a man-made reservoir that was brought on line in 1961. It has a watershed area of approximately 19,000 acres, which is also entirely owned by the Greenville Water System. In July of 2000, the Greenville Water System began using a new filtration plant that uses state-of-the-art Dissolved Air Flotation (DAF) technology for particle removal of the combined raw water from Table Rock and North Saluda Reservoirs. Before this new plant was brought into service, the water from these two reservoirs was unfiltered. The new DAF facility is the largest plant of its type in the United States. At the Table Rock and North Saluda Treatment Plant, the raw water is filtered, chloraminated and fluoridated. Small amounts of caustic soda are added for pH control, and a corrosion control agent is added to protect the integrity of the pipes in the distribution system. Lake Keowee, built by the Duke Power Company (now Duke Energy) in the 1960's, is located in western Pickens County. The Greenville Water System has an agreement with Duke Energy to withdraw up to 150 million gallons of water per day to deliver to the residents of Greenville and Pickens counties. The current capacity of the filtration facility is 60 million gallons per day. Water from Lake Keowee undergoes traditional sedimentation, is filtered, and then receives the same chemical treatment as the Table Rock and North Saluda Treatment Plant. Lake Keowee is a popular recreation destination that supports camping, swimming, fishing, and boating. Duke Energy has a hydroelectric station at the Jocasse Dam a few miles upriver from Lake Keowee, as well as a hydroelectric station and nuclear power plant (the Oconee Nuclear Station) approximately midway down the lake, at the Keowee Dam. Duke Energy does not own land within the Lake Keowee watershed, except for the immediate areas around its power generating facilities. Priority Contamination Threat Outdoor recreation is the priority contamination to one of the three water supplies, Lake Keowee. North Saluda Reservoir and Table Rock Reservoir are located in completely undeveloped watersheds and no activities threaten them. Local Involvement and Developing the Protection Plan Office of Water (4606M) 816F10046 January 2010 ------- The Friends of Lake Keowee Society (FOLKS) is a nonprofit organization founded in 1993 for the purpose of preserving the quality of the natural resources and economic benefits of the lake. FOLKS publicizes information on the condition of the lake and trends in water quality and usage, and encourages the use of Best Management Practices (BMPs). They provide forums for the exchange of information between land owners, lake users, educators, businesses, and others, promote policies that facilitate lake and river management, and sponsor local conservation projects. FOLKS creates public awareness and support of conservation of the lake and its watershed. The membership of FOLKS includes residents in the Lake Keowee area and representatives from the Greenville Water System (GWS), the Duke Power Company, and the South Carolina Department of Health and Environmental Control. The GWS has owned and protected the watersheds of the Table Rock and North Saluda Reservoirs since these water sources were brought into service. For this reason, community input on the management and protection of the drinking water source has been minimal. However, the public is always welcome to attend the monthly meetings of the Commissioners of Public Works, and the GWS's annual Consumer Confidence Report provides information on the sources and quality of the local drinking water. Management Measures Because the Greenville Water System owns all the land within the watersheds of the Table Rock and North Saluda Reservoirs, it maintains control over the activities that occur within the vicinity of the lakes. The watersheds are completely undeveloped, and the GWS employs full-time staff to patrol the watersheds and ensure that there are no activities occurring that could contaminate the public water supply. Public recreation is prohibited within the watershed. The Commissioners of Public Works signed a conservation easement with The Nature Conservancy in 1995 to offer even greater protection to the watersheds and the public water supply. Lake Keowee is designated as a No Discharge Zone by the U.S. Environmental Protection Agency. This determination was published in the Federal Register on March 4, 1999, after the State of South Carolina requested that the EPA determine that "adequate and reasonable" pump-out facilities exist for boaters on several lakes, including Lake Keowee. The No Discharge Zone designation prohibits the direct discharge of sewage from any vessel into the lake. Contingency Planning Given the exceptional protection afforded to the Table Rock and North Saluda Reservoirs and watersheds, it is highly unlikely that these two sources of drinking water would experience a contamination emergency. Regular testing will detect deteriorating water quality in time for corrective measures to be implemented before the water poses a threat to public health. Lake Keowee, however, is at risk from several sources including nonpoint source contamination from increasing development in its watershed, a large amount of boat traffic on its waters, the presence of power generating plants on its shores, and two highway crossings that convey traffic directly over the lake. Office of Water (4606M) 816F10046 January 2010 ------- The three reservoirs are connected by GWS infrastructure to deliver drinking water to the City and County of Greenville. In the event that the water in one of the three reservoirs becomes contaminated and may not be used as a public drinking water source, the GWS can disconnect the affected reservoir and utilize water solely from the remaining two lakes. Depending on weather patterns and water system demand, Greenville could function using water from just two reservoirs for an extended period of time. If the third water source were rendered unusable for a longer period of time, the Greenville Water System would institute water rationing until the water source could be restored. Measuring Program Effectiveness The most significant measure of program effectiveness has been comparison of current water quality monitoring data with historic water quality data. Water quality records for both Table Rock and North Saluda have been kept since the reservoirs were first put in service (in the 1930s and the 1960s, respectively). A comparison of those records with current testing indicates virtually no change in the water quality of these two lakes over the history of their use as a water supply, showing that Greenville's efforts to maintain the quality of its drinking water have been highly successful. Lake Keowee has been in use by the GWS since 1985, and water quality records over the last 15 years likewise indicate no change in the quality of water obtained from that source. However, in 1985, there was very little development of the area. Since then, development has increased at a rapid rate, and the GWS expects some degradation in water quality in the future. Comprehensive testing, in excess of the compliance monitoring mandated by federal and state requirements, helps to monitor the water quality in all three reservoirs and will give the water supplier advance notice in the event that just such a decline does occur. For further information, contact: Lyndon B. Stovall, General Manager Greenville Water System (864)241-6155 lstovall@greenvillewater.com Office of Water (4606M) 816F10046 January 2010 ------- |