Northwest Hillsborough County Reclaimed Water System

Transcription

1 Northwest Hillsborough County Reclaimed Water System Spring 2002 Quarterly Reuse Coordinating Committee Meeting Presented at the Hillsborough County Dale Mabry AWTP Tampa, FL May 15, 2002 Presented by: Ed Fox Nick LoPresti Bob Henderson Mike Lehigh Mark McNeal

2 Presentation Overview Background and Initial Planning Activities Reclaimed Water User Profile Reclaimed Water ASR Final System Planning System Design and Construction Real Time Monitoring and Control System System Start-up Lessons Learned

3 Major Objectives of the Reuse Program Maximize conservation benefit Don t over commit the resource Provide reliable service Provide efficient maintenance of system

4 System Statistics WWTP Facilities 6 Regional AWT Plants 1 Sub-Regional Advanced Secondary 35.4 MGD Permitted Capacity 2002 Reclaimed Water Facilities 80 miles of transmission mains 100 miles of distribution mains 115 MGD pumping capacity 81 MG of above ground storage ASR system under development

5 Who are our customers? Single Family Residential Commercial Golf Courses Industrial Agricultural

6 County-wide Reclaimed Water Usage by Customer August August 2001 Golf Course 25% Agricultural 1% 3.47 MGD 3.05 MGD Commercial 22% 3.11 MGD Industrial 23% 4.01 MGD Total AADF Reuse MGD Residential 29%

7 County-wide Customer Base and Reuse Demands Table 1 Customer Base Demands in MGD Customer Category Number of Reuse Number of Reuse Customers Demand Customers Demand Residential (single family) 6, , Commercial Golf Course Industrial Agricultural Total: 6, ,

8 Overall Water Conservation Success! TOTAL SYSTEM PRODUCTION (mgd) HILLSBOROUGH COUNTY WATER DEPARTMENT POTABLE WATER DEMAND 12-Month Avg No Conservation NO CONSERVATION (1989 PER CAPITA) 12.4 MGD SAVINGS CALENDAR YEAR

9 Economic Considerations Cost analysis to select projects Funding capital projects Approximately $116 million spent since 1978 SWFWMD funding contribution of $11 million Current reclaimed water rates based primarily on old effluent disposal mindset

10 Rate Structure Current Residential - $9.00 per month flat fee Commercial - $9.00 base charge $.60/1000gal for the 1st 100,000 gallons $.08/1000gal for the 2nd 29,900,000 gallons $.06/1000gal over 30,000,000 gallons Proposed Changes for Spring 2002 Inclining Conservation Rate for Commercial and Industrial Customers Metered rate for new residential customers not grandfathered in by BOCC

11 Hillsborough County Reclaimed Water Service Areas

12 Northwest Hillsborough County Reclaimed Water Service Areas

13 Background Significant development in Northwest Hillsborough County since the early 1990s Tampa Bay area drought-sensitive and freshwater resources limited Objective to expand beneficial use of reclaimed water in this area by interconnecting four water reclamation facilities Provide a tool to manage reclaimed water for the future

14 Reclaimed Water Use Projections Seasonal reclaimed water demand will outpace dry weather reclaimed water availability Dry weather peak demands limit the connection of new customers Dry season Peak Day Flow = 2 x AADF Dry season Peak Hour Flow = 4 x AADF Dry season supply 5 to 10 percent less as well Reclaimed water service will be limited until seasonal storage (ASR) can be implemented

15 Dry Season Reclaimed Water Availability With and Without ASR (NW Service Area) MGD W/O ASR With ASR A phased ASR program would boost reclaimed water availability during the dry season ASR will allow connection of >25% more customers

16 Water Conservation Benefits with ASR in Average Daily Flow (NW Service Area) Potable Ground MGD

17 Northwest Reuse Plan Existing Transmission Line New Transmission Line Proposed Transmission Line Potential Transmission Line Reuse Permitting Boundary Reuse Sites Wellfield Site Wastewater Treatment Plant Pump Station & Storage

18 System Design and Construction River Oaks 17 mgd effluent pumping station 3 high service reclaimed water pumping stations - total capacity of >20,000 gpm and 5 mg of storage 14 miles of 12-inch to 30-inch transmission lines Initial ASR pilot system 2 remote residential master metering sites 2 remote golf course metering sites A remote monitoring telemetry control system

19 River Oaks Effluent Pumping Station

20 River Oaks Reclaimed Water Storage and Pumping Station

21 River Oaks Reclaimed Water Pumping Station

22 Reclaimed Water ASR System ASR will allow optimizing the seasonal use of reclaimed water Initial well constructed and testing underway for nearly one year Cycle testing of initial well will lead to operational permitting and provide design criteria for construction of future ASR wells

23 ASR Site Compatible with Area Water Resources Hillsborough River Tampa Bypass Canal Alafia River ASR Well (typ.) Tampa Limestone Suwannee Limestone Ocala Limestone Avon Park Limestone

24 Construction of Initial ASR Well

25 Hillsborough County has Florida s s first reclaimed water ASR well First to receive UIC permit (Nov. 97) First well constructed (Spring 98) First to be granted permission to cycle test (Fall 98) First to begin cycle testing (July 2001) First to place ASR water into reuse system (Jan. 2002)

26 Significant issues addressed with Hillsborough County s s ASR System Reclaimed water ASR permittability confirmed 2-Diethylhexyl Phthalate (DEHP) issue resolved Native groundwater characterization and definition what defines an aquifer as less than 1,000 mg/l TDS? DBPs successfully controlled using chloramines will likely seek a variance for the long haul Total coliform presence in reuse system and MWs wet/dry cycles in open environments transmission system is not a drinking water system monitoring wells are not sterile Cycle testing discharges through permitted reclaimed water outfalls

27 Hillsborough County Cycle Test No MG successfully recharged and recovered DBP control during recharge Chloramination system reduced THMs from about 175 ppb to about 100 ppb Ammonia addition followed chlorination Recovered water quality met reuse standards without further treatment TSS, BOD, and fecal coliform standards met Presence of varying amounts of total coliform in recharged and recovered water Surface water discharge to waste

28 Additional Hillsborough County cycle testing is ongoing Cycle No. 2 recharged 45 MG and recovered approximately 13 MG to the reuse system TTHM control much improved during recharge by adding ammonia prior to chlorination Total coliform standards met in recharge water Increasing TDS limited recovery to about 30% Cycle No. 3 recharged approximately 45 MG Back-to to-back total coliform >4cfu/100ML caused recharge operations to cease short of 90 mg target Recovery began May 6, 2002 Alternative total coliform control considered Providing a beneficial use this year

29 Efficient Management and Operation of System Required Innovative Solutions County goal to merge operations of potable and reclaimed water systems The system includes over 30 individual treatment, pumping, storage, or bulk user monitoring points - > 500 I/O points Service area over 100 square miles Remote telemetry monitoring control system (RTMC) required

30 RTMC Planning and Design Criteria County merged the management and operations of potable and reuse systems to improve efficiency For the Northwest service area two central redundant sites were established for central control from two major water treatment plants System architecture utilizes a variety of com links - high speed PVC phone circuits, spread spectrum radio, dial-up cell phone Control system configured as a WAN with Ethernet LAN segments at major facilities

31 County Wide WAN (Fawn Ridge Node) Historical Manors User Phone 13 Fawn Ridge Phone 1 Lake Park Phone 12 Eagles WTP Server WTP Server User Westchase East User Phone 2 Northwest Regional RPS Source Cell Phone 7 Phone 6 Phone 3 River Oaks EPS Source Fiber 5 River Oaks RPS Source Radio 9 Phone 4 Van Dyke RPS Source Radio 10 Phone 5 Dale Mabry RPS Source Old Memorial User Radio 14 Radio 15 Radio 16 Radio 17 Radio 18 North Lakes RPS Source (Repumped) Northdale RPS Source (Repumped) Northdale Golf Course User Carrollwood Golf Course User RTMC System Monitoring and Control Architecture Westchase West User Cell Phone 8 Repeater Radio 11 Westchase Golf Course User NW Reclaimed Water RTMC WAN Block Diagram Abbreviations: EPS = Effluent Pump Station RPS = Reclaimed Pump Station WAN = Wide Area Network WTP = Water Treatment Plant General Notes: All Radio Links Spread Spectrum

32 RTMC System Network Communications

33 Key Operational Features and Benefits Central monitoring and control possible from two redundant sites Water plant monitoring and control utilizes the same software packages and screen systems County reclaimed management and planning staff ability to remotely access real time system operation through RAS connections Historical data base being developed along with potable water and reclaimed water reports system

34 NW Reclaimed Water Overview Screen

35 Typical Pumping Station Screen

36 Remote Station Control Panel CP-2

37 System Start-up Lessons Learned New linked regional system resulted in seasonally varying hydraulic conditions High speed phone line coordination critical when working with 21st century telecom providers PLC/field wiring - check and double check Working as a team - issues do not become problems

38 Northwest Hillsborough County Reclaimed Water System Spring 2002 Quarterly Reuse Coordinating Committee Meeting Presented at the Hillsborough County Dale Mabry AWTP Tampa, FL May 15, 2002 Presented by: Ed Fox Nick LoPresti Bob Henderson Mike Lehigh Mark McNeal