Utility Partner Data Report

Transcription

1 Utility Partner Data Report Project Title: Studying Distribution System Hydraulics and Flow Dynamics to Improve Water Utility Operational Decision Making Water Distribution System: Nicholasville, Kentucky Project No.: UK Grant No.: HSHQDC Organization: University of Kentucky Principal Investigator: Field Support Lindell Ormsbee Signature Date L. Sebastian Bryson Signature Date City of Nicholasville Water Tom Calkins Water Utility Director Signature Date

2 TABLE OF CONTENTS LIST OF TABLES... II LIST OF FIGURES... II 1.0 INTRODUCTION KEY PERSONNEL MAJOR COMPONENTS DISTRIBUTION PIPING WATER TREATMENT PLANT History Current Facilities and Operations Pumps Water Treatment Plant Discharges TANKS VALVES HYDRANTS WATER QUALITY MONITORING SYSTEM DEMANDS WORKS CITED APPENDIX A: PUMP CURVE DATA APPENDIX B: NICHOLASVILLE 2010 WATER QUALITY REPORT. 15 LIST OF TABLES Table 1. Pipe Materials... 4 Table 2. Pump Information... 7 Table 3. Nicholasville Tank Information... 9 Table 4. Summarized Water Quality Report... 9 Table 5. Customer Base for Nicholasville Table 6. Wholesale Purchasers of Nicholasville Water LIST OF FIGURES Figure 1. Nicholasville Location Map... 1 Figure 2. Schematic of Nicholasville Water Distribution System... 3 Figure 3. Aerial View of Water Treatment Plant... 5 Figure 4. Nicholasville Average Day Water Production... 8 Figure 5. Nicholasville Maximum Day Water Production... 8 ii

3 1.0 INTRODUCTION The City of Nicholasville is located southwest of the City of Lexington in Jessamine County, Kentucky. The population was 28,015 for the 2010 census making it the 12 th largest city in the state. According to the U.S. Census Bureau, the City has a total area of 8.5 square miles which is serviced by the Nicholasville Water Treatment plant. In the census of 2000, the median income for a household in the city was $37,462, and the median income for a family was $42,978. The majority of the racial makeup of the city was 91.5% white, 4.3% African American, 0.5% Asian. Figure 1 below displays a location map of the Nicholasville area. Louisville Frankfort Lexington ^_ Nicholasville Richmond Bowling Green Miles Ü Figure 1. Nicholasville Location Map 1

4 2.0 KEY PERSONNEL The water distribution system is provided by Nicholasville Utilities. Nicholasville Utilities also provides electric and sewer services within and adjacent to the city. Mr. Tom Calkins Public Utilities Director Nicholasville Water Department 517 North Main Street Nicholasville, Kentucky (859) Mr. Danny Johnson Water Distribution Superintendent Nicholasville Water Department 517 North Main Street Nicholasville, Kentucky (859) Mr. Jim McDaniel Nicholasville WTP Shift 1 Operator 595 Water Works Road Nicholasville Water Department Nicholasville, KY (859) Mr. Kevin Baker Nicholasville Fire Chief 1022 South Main Street Nicholasville, KY (859)

5 3.0 MAJOR COMPONENTS The Nicholasville water distribution system consists of an intake pumping facility, a water treatment plant, a high service pumping facility, and transmission and distribution systems. The treatment plant serves approximately 13,000 retail customers and two wholesale customers. The treated water transmission and distribution system consists of a grid of mains ranging from 2 to 24 inches in diameter and has a total elevated storage of 3 million gallons (3 Tanks). The topography of the area varies from a maximum elevation of ~1042 feet to a minimum elevation of ~560 feet. Despite the changes in elevation, the Nicholasville system consists of only one pressure zone (Nicholasville, ). 3.1 Distribution Piping The City of Nicholasville s water distribution system is comprised of pipe sizes up to 24- inches in diameter. The transmission mains from the water plant to town consists of two 10-inch lines for the entire route and a 16-inch line installed approximately 2/3 of the distance from the water plant to town. The 16-inch line becomes a 24 inch line which continues directly into town. In town distribution consists of 4 through 12 inch water mains. The majority of the system is looped with a combination of 10, 12 and 20 inch pipes. Figure 2 shows the layout of the Nicholasville Water Distribution System. Figure 2. Schematic of Nicholasville Water Distribution System 3

6 There are pipes of several different materials installed within the system. Table 1 below displays the material, the different size diameters and the total length of each material. The ages of the pipes typically range anywhere from 55 years old to less than 5 years old. There are ductile and cast iron pipes that are 55+ years old. Generally the asbestos cement pipes are around 40 years old. PVC pipes and ductile iron pipes tend to be newer than the cast iron and asbestos cement pipes. Material Table 1. Pipe Materials Diameters (in) Total Length of Pipe (ft) Percent of Total Length (%) Asbestos Cement 4,6,8, Cast Iron 4,6,8,10, Ductile Iron 6,10,12,16,20, PVC 2,3,4,6,8,10, Polyethylene 1,2,6, Galvanized 1, Water Treatment Plant History The Nicholasville Water Treatment Plant was originally constructed as a.75 MGD facility in The original plant consisted of a river intake pumping station, chemical mix facilities, flocculation/settling basin, filtration, finished water storage and pumping. In 1967, the plant was expanded to 1.5 MGD with the addition of a second intake pumping station and raw water main along with an additional flocculation/settling basin, two additional filters, and a second finished water storage tank. In 1975 the plant underwent a "high rate" expansion, which increased treatment capacity to 3.6 MGD. This project included intake pumping improvements, the addition of "tube settlers" to existing settling basins, high rate expansion of existing filters with the addition of dual media (anthracite and sand), and construction of a third finished water storage tank. Continued growth of Nicholasville and Jessamine County resulted in the expansion of the plant to a capacity of 6.0 MGD. The expansion addressed concerns about the adequacy of the existing intake pumping stations during low river pool levels, which were experienced during the 1988 drought. The plant expansion included a new river intake pumping station (with deeper intakes), a new 24-inch raw water transmission main, new chemical feed facilities and a chemical mix basin, additional flocculation basins, additional settling basins, two additional filters, a new treated water storage tank, new high service and backwash pumping station, new sludge lagoons, and an upgrade of 4

7 the computer plant instrumentation system for the monitoring and control of treatment plant operations. In 2009, the capacity of the system was increased to 9.0 MGD. In 1993, at the annual convention of the Kentucky/Tennessee chapter of the American Water Works Association, the Nicholasville Water Treatment Plant was presented the "Award for Excellence in Operations" for treatment plants in the capacity range of 5-10 million gallons per day. This award was given, in part, in recognition of the superior quality water produced at the Nicholasville Water Treatment Plant. Figure 3 displays an aerial view of the current water treatment plant facilities. Figure 3. Aerial View of Water Treatment Plant Current Facilities and Operations Nicholasville s water treatment plant draws surface water from Pool 8 of the Kentucky River for treatment. The existing plant is a conventional turbidity removal plant that utilizes chemical coagulation, flocculation, settling and filtration to remove suspended particles from the raw water. The following is a brief and simplified description of the various treatment processes, which are utilized within the Nicholasville Water Treatment Plant. Raw Water Pumping Untreated water is pumped from the Kentucky River (approximately 330 feet vertically) to the plant for treatment. Raw water pumping facilities consist of three intake/pumping towers, each of which supports two vertical turbine pumps. The newest tower, constructed in the expansion, has the capability to withdraw water at a depth of 10 feet below river pool stage (allowing maximum utilization of pool storage during a drought). Chemical Mix Basin The raw water enters a high energy-mixing chamber where it is treated with several chemicals for a variety of purposes. Since these solids by themselves, are too small to be removed from the water by gravitational settling within a practical period of time, a coagulant is added to increase particle size and weight, thus improving solids removal during the sedimentation and filtration processes. The primary coagulant, 5

8 which is added to aid in the removal of fine suspended solids, is polyaluminum chloride or PAC, which has a specific gravity of A liquid polymer is also added as a coagulant aid to increase the efficiency of the coagulation process, and to help remove Total Organic Carbons, or TOC s. Potassium permanganate can also be added as an oxidant to reduce taste and odor form several naturally occurring organic formations found in the Kentucky River such as algae growth during the summer months. Powdered activated carbon is also available to be fed for occasional taste and odor problems or possible chemical spills in the Kentucky River. The plant has the capability to feed either chlorine or chloramines for disinfection. These chemicals are used to destroy or inactivate potentially harmful bacteria and other microorganisms in the water, and also to provide residual disinfection within the distribution system. Flocculation Basins The PAC reacts with the natural alkalinity of the water to form a gelatinous precipitate. As the water passes through the flocculation mixing chambers, this gelatinous precipitate entraps the fine suspended solids and forms larger and denser masses called floc. Water is gently mixed in the flocculation basins with stirring paddles which facilitate the creation of larger floc particles as the suspended solids come into contact with each other. Settling Basins From the flocculation basins, the water flows to settling basins where quiescent settling conditions permit the floc to settle out of the water. To facilitate more efficient settling, each basin is equipped with tube settling modules. The clarified water is collected in weir troughs and is conveyed to the filters. Filtration After the treatment process of coagulation and sedimentation, the clarified water flows into dual media filter beds to remove any remaining solids. The filter beds are constructed of layers of anthracite, filter sand, and supportive gravel. Twenty inches of anthracite having an approximate diameter of 1.0 mm rest over ten inches of fine sand with an average diameter of 0.5 mm. As the water passes down and through the filters, the remaining suspended solids become entrapped in the interstices of the filter media. At routine intervals, the filters are cleaned of the entrapped solids by forcing clear, finished water in the reverse direction at high velocities. This reverse flow is called backwashing, and is required to remove the build-up of captured solids within the upper levels of the filter media. The Nicholasville Water Treatment Plant has six filters. The four older filters each have a rated capacity of.75 MGD and the two newest filters have a rated capacity of 1.5 MGD each. After filtration, fluoride is added to the treated water to improve dental hygiene. Chlorine is added after filtration for disinfection. Corrosion Control After filtration, zinc orthophosphate, a corrosion inhibitor, is added to inhibit the leaching of lead and copper from pipes in homes by creating a thin film on the pipes. 6

9 Finished Water Storage and Pumping Following filtration, the treated water is temporarily stored in concrete reservoirs called clearwells. The Nicholasville Water Treatment Plant has four clearwells with a combined storage capacity of over 900,000 gallons. From the clearwells, the treated water is pumped directly to the Nicholasville water distribution system. Instrumentation Plant operations are monitored and controlled by a computer based Supervisory Control and Data Acquisition (S.C.A.D.A.) system. The S.C.A.D.A. system monitors and controls pumps, chemical feeds, treatment equipment, flow rates, water levels, etc Pumps Nicholasville uses 6 pumps for collection of raw water from the Kentucky river. They have 5 high service pumps available for water distribution. Table 2 contains the capacity and the horsepower of each pump. Refer to Appendix A for pump curve information for the 5 high service pumps. Table 2. Pump Information Pump Type Pump Use Capacity (GPM) Horse Power TURBINE RAW WATER TURBINE RAW WATER TURBINE RAW WATER TURBINE RAW WATER TURBINE RAW WATER TURBINE RAW WATER TURBINE HIGH SERVICE TURBINE HIGH SERVICE TURBINE HIGH SERVICE TURBINE HIGH SERVICE TURBINE HIGH SERVICE Water Treatment Plant Discharges The average daily demand in 2010 for the Water treatment plant was 4,349,000 gallons. The maximum daily demand in 2010 was 5,782,237 gallons. Figure 4 and Figure 5 illustrate the average daily demand and maximum daily demands between 1989 and As can be seen from the figures, the total capacity of the system was increased from 6.0 MGD to 9 MGD in

10 Figure 4. Nicholasville Average Day Water Production 3.3 Tanks Figure 5. Nicholasville Maximum Day Water Production The City of Nicholasville contains 3 elevated storage tanks; Lake Street, Stephens Drive and Capital Court Tank. These three tanks were constructed in 1965, 1974 and 2005 respectively. All three tanks are pressure tanks. Telemetry data is recorded using a 8

11 SCADA system located at the Nicholasville Water Treatment Plant. Table 3 shown below displays some general characteristics of each tank. 3.4 Valves Table 3. Nicholasville Tank Information Nicholasville Utilities has approximately 3505 valves installed within its system as of A total of 90 valves serve as air relief valves, 70 valves serve as blow-off valves, 32 valves serve as domestic service valves and a total of 28 valves serve as fire service valves. Approximately 1114 valves serve as hydrant valves, 2170 valves serve as line valves and 1 valve serves as a meter bypass valve. 3.5 Hydrants Elevated Storage Tank Identification, and Elevations* Name Lake Street Capital Court Stephens Drive Size (gallons) 750,000 1,500, ,000 Elevation of Bottom of the Tank Minimum Level (ft) Max Level (ft) Shape Ohlatoid Composite Ovaloid Inside Diamter (ft) 60 ft 86 ft 68 ft *Data from Nicholasville Water Utility Department Nicholasville Utilities currently has 1279 hydrants within its distribution system. The hydrants vary in use. The majority of hydrants are used for fire protection, while 53 hydrants used routinely for flushing of the system. Hydrants are located off of water mains ranging in diameter from 4-inch to 12 inch. 3.6 Water Quality Monitoring Continuous water quality testing is performed at the Nicholasville Water Treatment Plant. Water is tested for turbidity, alkalinity, hardness, iron, manganese, fluoride, ph, corrosiveness, and disinfectant residual. Table 4 summarizes Fluoride and Chlorine levels in the 2010 Water Quality Report. Table 4. Summarized Water Quality Report Contaminant MCL (mg/l) MCLG (mg/l) Report Level Range of Detection Fluoride to 1.23 Chlorine to 1.9 9

12 4.0 SYSTEM DEMANDS The design capacity of the Nicholasville Water Treatment plant is 9 MGD. The average daily production is approximately 4.3 MGD with a high daily production of 6.09 MGD. The total annual volume produced is about 1320 MG. The estimated water loss is about 13.17% of the total annual volume. According to the Kentucky Infrastructure Authority (KIA, 2012), Nicholasville directly serves the following customer base as shown below in Table 5. Table 5. Customer Base for Nicholasville Wholesale Customers 2 Wholesale Usage (MG) Resident Customers Resident Usage (MG) Commerical Customers 619 Commerical Usage (MG) Industrial Customers 25 Industrial Usage (MG) 95 Total Customers Total Water Usage (MG) A breakout of the wholesale customers that purchase water from Nicholasville are summarized below. Table 6. Wholesale Purchasers of Nicholasville Water Purchaser Annual Connection Serviceable Purchaser Name Volume (MG) Meters population Jessamine County Water District # Jessamine South Elkhorn Water District Totals

13 5.0 WORKS CITED EPA. (2005). Water Distribution System Analysis: Field Studies, Modeling and Management. Cincinnati: Office of Research and Development. Kentucky Administrative Regulations. (n.d.). Surface water standards. 401 KAR 10:031. Frankfort: Kentucky Administrative Regulations. Kentucky Infrastructure Authority (2012) McDaniel, J. L. (2010). Nicholasville Water Treatment Plant Water Quality Report for year Nicholasville: City of Nicholasville. Nicholasville, City of. ( ). Utilities. Retrieved May 11, 2011, from Nicholasville: Scott, D. (2011, May 18). Operator WTP Shift 2. (J. Goodin, Interviewer) 11

14 APPENDIX A: PUMP CURVE DATA The figures shown below display the pump curves for the 5 high service pumps used in the Nicholasville Water Treatment Plant. Figure A.1 High Service Pump #1 12

15 Figure A.2 High Service Pump #2 Figure A.3 High Service Pump #3 13

16 Figure A.4 High Service Pump #4 Figure A.5 High Service Pump #5 14

17 APPENDIX B: NICHOLASVILLE 2010 WATER QUALITY REPORT 15