Hydraulic Modeling, PUDs & Managing Water System Growth

Transcription

1 Hydraulic Modeling, PUDs & Managing Water System Growth American Water Resources Association Intermountain Section October 9, 2013 Utah Division of Drinking Water Ying-Ying Macauley Presentation Topics I. Hydraulic Modeling Overview II. What Water Systems Can Do to Improve the Quality of Hydraulic Modeling III. Utah s Hydraulic Modeling Requirements and Off-Ramps IV. Refining Public Water System Definition V. Planned Unit Development (PUD), New Development & Impact on Water System VI. Manage Water System Growth 1

2 Not Today s Topics I. Becoming an Engineer II. Using the hydraulic modeling software III. Becoming an Expert in Utah s Rules IV. Statutes, Plat and Subdivision Laws V. City s or County s Ordinance VI. Planning and Zoning Process Presentation Topics I. Hydraulic Modeling Overview II. What Water Systems Can Do to Improve the Quality of Hydraulic Modeling III. Utah s Hydraulic Modeling Requirements and Off-Ramps IV. Revising Public Water System Definition V. Planned Unit Development (PUD), New Development & Impact on Water System VI. Manage Water System Growth 2

3 Tank Reservoir Pump Pipe Valve Node Water Distribution System Modeling Steady-State Represents a snapshot in time under static conditions Extended-Period Represents system behavior over a period of time 3

4 Visualize Pressure and Velocity Results Pressure Fluctuation at a Connection 4

5 Level Fluctuation at a Tank Understand Water Quality Patterns 5

6 Uses for Water Distribution System Models Master Planning Design Tool System Rehabilitation Daily Operations Fire Protection Assessment Water Quality Assessment Asset Management Vulnerability Assessment Meeting Regulatory Requirements Demand Flow Source Flow 60,000 50,000 Peak Instantaneous = 49,500 gpm FLOW (gpm) 40,000 30,000 20,000 Peak Day Average = 32,500 gpm 10,000 Total Peak Day Volume = 46.8 MG Volume above Peak Day = 6.9 MG Volume from Storage = :00:00 AM 10:00:00 PM 8:00:00 PM 6:00:00 PM 4:00:00 PM 2:00:00 PM 12:00:00 PM 10:00:00 AM 8:00:00 AM 6:00:00 AM 4:00:00 AM 2:00:00 AM 12:00:00 AM TIME 6

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8 Water System Optimization by Hydraulic Modeling Examples Using Tank Equalization Storage Using Lower Cost Water First 8

9 Eliminate Re-pumping of Water by Hydraulic Modeling Is the water recirculating or leaking through a PRV, relief valve, or surge protection device? Predict how much water should be pumped Trace where the pumped water is going Improve Pressure Management by Hydraulic Modeling 9

10 Presentation Topics I. Hydraulic Modeling Overview II. What Water Systems Can Do to Improve the Quality of Hydraulic Modeling III. Utah s Hydraulic Modeling Requirements and Off-Ramps IV. Refining Public Water System Definition V. Planned Unit Developments (PUD), New Development & Impact on Water System VI. Manage New Water System Growth Things a Utility Can do to Prepare 1. Update system inventory & facility map Pipe location, diameter, material, and length Valves (altitude/prv/isolation) location, elevation, and setting Tank location, volume, elevations, and setting Pump size, pump curves, and specifications Pressure zones location, elevation, and setting Source capacity, location Fire hydrant location and elevation 20 10

11 More Things a Utility Can Do to Prepare 2. Collect System Operation Data Settings & controls SCADA data Water use data and demand pattern Fire flow demand Fire flow testing and pressure data Feedback from system manager/operator 3. Prepare for model calibration 21 Engineering Contract Issues Who does what data gathering & data entry An electronic copy of the physical facility data will be provided to the water system Professional Engineer s certification & hydraulic modeling report 22 11

12 Other Issues Identify the true cost of providing water to a new development Who pays for the cost of providing water to the expansion area? Consider having an ordinance dealing with growth (Rural Water Assn of Utah can help) Academic institutes may be able to help small water systems 23 Poll Question #1 Does your water system conduct hydraulic modeling or capacity assessment before serving a new development? 1) Yes 2) No 3) Not applicable 24 12

13 Presentation Topics I. Hydraulic Modeling Overview II. What Water Systems Can Do to Improve the Quality of Hydraulic Modeling III. Utah s Hydraulic Modeling Requirements and Off-Ramps IV. Refining Public Water System Definition V. Planned Unit Development (PUD), New Development & Impact on Water System VI. Manage Water System Growth Utah s Hydraulic Modeling Rule R Community water systems Non-Transient Non-Community water systems with high water demands Demands higher than required by R Significant fire suppression demands 26 13

14 Utah s Hydraulic Modeling Rule R Rule Elements Hydraulic model Professional Engineer s certification Hydraulic Model Design Elements Report (or System Capacity and Expansion Report ) The water system s acknowledgement of receipt of the model findings (for Community PWS) 14

15 Utah s Hydraulic Modeling Rule Purpose Water systems can reliably supply sufficient water to all customers at adequate pressures Fine tune the design Properly managed growth Engineering based decisions 29 Drinking Water Projects That Should Include Hydraulic Modeling Water system expansion New Construction expected to have hydraulic impact Master Plan 30 15

16 Hydraulic Modeling & New Development Existing deficiencies versus new development A new construction project may be allowed as long as the new construction project: is located in a hydraulically separated area, and does not adversely impact the existing deficiencies or does not create new deficiencies within the water system. Hydraulic Modeling Off-Ramps R (1)(a) i. No negative hydraulic impact ii. iii. iv. A part of a pre-approved master plan Systems maintains a hydraulic model & designates a Professional Engineer who oversees the hydraulic analyses. Real time data indicative of modeled hydraulic conditions 16

17 Hydraulic Modeling Off-Ramps R (1)(a)(i) No Negative Hydraulic Impact (A) New sources without adding any new connections (B) Treatment/Chlorination/Fluoridation (C) Tank repair or re-coating (D) Water main addition without new connections (E) Transmission line addition without new connections (F) Pump stations upstream of distribution system (G) Projects involving minimal hydraulic impact Engineer s Certification Not Required Hydraulic Modeling Report Not Required Hydraulic Modeling Off-Ramps R (1)(a)(ii) Waterline projects as a part of a preapproved master plan Master Plan supported by hydraulic analyses Meeting master plan definition Master Plan submitted to DDW for review/approval Hydraulic Modeling Report Not Required Engineer s Certification Required 17

18 Hydraulic Modeling Off-Ramps R (1)(a)(ii) Systems maintains a hydraulic model & has a designated Professional Engineer (PE) overseeing the hydraulic analyses. Water system notifies DDW in writing has and maintains a hydraulic model identifies the model method and version identifies the name of the PE (and affiliation) Hydraulic Modeling Report Not Required Engineer s Certification Required Presentation Topics I. Hydraulic Modeling Overview II. What Water Systems Can Do to Improve the Quality of Hydraulic Modeling III. Utah s Hydraulic Modeling Requirements and Off-Ramps IV. Refining Public Water System Definition V. Planned Unit Development (PUD), New VI. Development & Impact on Water System Manage Water System Growth 18

19 Public Water System Threshold 15 service connections Under the same ownership or control OR Average 25 people daily for 60 days a year Equivalent to 8 service connections Count heads? Whatever the physical facility capacity is. Monitor days of usage? When the water is available for use. 37 Sub-Metered Properties Property owner bills tenants and pays water bills from a Public Water System (PWS) Examples Subdivisions Condominium Complex High Rise Buildings Mobile Home Park Campus Military Facilities Industrial or Commercial Complex Planned Unit Development (PUDs) 38 19

20 Sub-Metered Property Issues Having a large distribution system (>500 feet, pipe size larger than typical service lateral), serving a large popula on, or serving a mixed popula on PWS Is the master meter treated as the PWS boundary? Beyond the master meter Design and Construction Standards? Distribution System O & M (fire hydrants, waterlines, cross connection control)? Water Quality Sampling? Which party is responsible for protecting public health? 39 Refining Utah s PWS Definition Work Group Internal and External Stakeholders Chaired by Patti Fauver of DDW Initiate Rule Revision in 2014 Scope Clarify PWS Threshold & Definition Address Sub-metered Properties Clarify PWS Categories 40 20

21 Poll Question #2 Does your water system require the design and construction standards for the distribution system in a new subdivision or PUD? 1) Yes 2) No 3) Not applicable 41 Presentation Topics I. Hydraulic Modeling Overview II. What Water Systems Can Do to Improve the Quality of Hydraulic Modeling III. Utah s Hydraulic Modeling Requirements and Off-Ramps IV. Refining Public Water System Definition V. Planned Unit Development (PUD), New Development & Impact on Water System VI. Manage Water System Growth 21

22 Managing PUDs & Developments Issues 1. Master meter allowed? 2. Design & construction standards 3. Hydraulic modeling and capacity assessment 4. Fire hydrant O & M and fire truck access 5. Distribution system O&M, repair, replacement 6. Cross connection control 7. Water quality sampling 8. Easement 9. Who pays for what? Existing New 43 Poll Question #3 Does your water system operate, maintain, and repair the waterlines beyond the PUDs master meters? 1) Yes, completely 2) No, hell no 3) Have a cost-sharing arrangement 4) Not applicable (PUDs or master meter not allowed; not a water system; etc.) 44 22

23 Presentation Topics I. Hydraulic Modeling Overview II. What Water Systems Can Do to Improve the Quality of Hydraulic Modeling III. Utah s Hydraulic Modeling Requirements and Off-Ramps IV. Refining Public Water System Definition V. Planned Unit Development (PUD), New Development & Impact on Water System VI. Manage Water System Growth Case Study Logan City 23

24 Case Study Logan City Existing Sub-metered Properties or PUDs City Code amended access to PUD fire hydrants O&M, flushing, testing, and assessing a fee Not including waterline O&M, replacement or repair beyond the master meter Authority to implement cross connection control & shut the water until the PUD waterline is repaired In a few PUDs, City monitors chlorine residuals & Bear River Health Department monitors bacteriological samples PUDs must meet existing codes before City takes over New Developments Private Water Agreement required when water or fire lines installed on private properties (prior to plat recording / building permit) Or becoming a new PWS and deal with DDW Access for cross connection control Design and construction per City standards 47 Poll Question #4 Does your water system operate, maintain, and repair the fire hydrants beyond the PUDs master meters? 1) Yes, completely 2) No, hell no 3) Have a cost-sharing arrangement 4) Not applicable (PUD or master meter not allowed; not a water system; etc.) 48 24

25 Case Study St. George City Case Study St. George City Existing Sub-metered Properties or PUDs City Standards amended in 2003 master meter not allowed City took in all existing PUDs distribution system in 2013 Deed of Dedication must be recorded with the County Recorder City Owns, operates, and maintains water infrastructure within PUD roadways, or within 6 feet from the edge of the roadway asphalt New Developments PUDs allowed; master meter not allowed Design and construction per City standards Pre-qualified consultants Waterlines in PUDs or Subdivisions treat as extension of City s distribution system Record final plat with public utility easement in PUD open roadways 50 25

26 Acknowledgements Steve Jones, P.E., Principal, Hansen, Allen & Luce Bill Young, City Engineer, Logan City Mike Roundy, Water Services Director, Logan City Scott Taylor, Water Services Director, St. George City Patti Fauver, Rules Section Manager, Division of Drinking Water 51 Questions? Ying-Ying Macauley (801) Utah Division of Drinking Water 26