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Residential Fire Sprinkler Concerns

NFPA Home Fire Sprinkler Summit. Residential Fire Sprinkler Concerns. A Water Purveyor’s Perspective April 2013 Bill Kirkpatrick, Engineering Manager. Water Supplier Reliability Issues. Water Supply Water Facilities Water Quality Cost. General Policy Issues.

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Residential Fire Sprinkler Concerns

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  1. NFPA Home Fire Sprinkler Summit Residential Fire Sprinkler Concerns A Water Purveyor’s Perspective April 2013 Bill Kirkpatrick, Engineering Manager

  2. Water Supplier Reliability Issues • Water Supply • Water Facilities • Water Quality • Cost

  3. General Policy Issues Balancing Competing Interests • Service • Reliability • Flexibility • Quality • Cost • “Home Rule” • Affordable • Universal • Liability • Supply • Operational

  4. Service • Reliability • 24/7 x 150+++ years

  5. Cost • Home Rule - California has it all • Private • Individual • Corporation • Municipal • Special District / Agency All agency’s issues include political considerations

  6. Liability • Supply Reliability Need to build redundancy and reliability • Operational Risk • Issues with maintaining • pressurized water pipe and appurtenances

  7. Cost • Affordability Essential service - public health - economic development - recreation - public fire supply • Universal • Responsibility to serve • equitably without administrative burden

  8. Fire Sprinkler Discussion • Background • EBMUD Meter Sizing Study • Recommendations • Service Configuration • Costs

  9. Background • 2010 CRC, Section R313.1-5 • NFPA-13D • Domestic allowance • Pre-2011 practice vs. new code

  10. Determining Meter Size

  11. EBMUD Meter Sizing Study • Research on Domestic Flow • Hydraulic Calc’s • Shut-off Risk: $$ • Cost

  12. Research – Domestic Allowance “the 5 gpm???” • Toilet – 4 gpm • Sink – 2 gpm • Shower – 3 gpm • Washing machine – 4 gpm • Dishwasher – 3 gpm • Irrigation – 10-15 gpm

  13. Research – Domestic Allowance • Only 20% of flows ≤ 5 gpm • 90% of flows ≤ 15 gpm American Water Works Association Research Foundation sponsored study: Residential End Uses of Water, Report No. 90781, 1999

  14. Research – Domestic Allowance 48% Home fires NFPA, March 2010 American Water Works Association Research Foundation sponsored study: Residential End Uses of Water, Report No. 90781, 1999

  15. Why 15 and not 5 gpm? • No study/data to support 5 gpm • 5 gpm captures only 20% peak flows from water main to meter • Code language • Typical fixture flows do not seem relevant • Irrigation controllers • Human Reaction • Estimate for 5 gpm or 15 gpm ~70% 1-inch meter 30% 1.5-inch meter

  16. Hydraulics - Meter Size Based on Flow Maximum flow though 1-inch meter = 50 gpm Maximum flow through 1.5-inch meter = 100 gpm

  17. Hydraulics - Headloss

  18. Hydraulics - Headloss

  19. Backckflow Preventer Pressure Loss

  20. Meter Main Pressure, psi (m, lat.) 40 20 60 Residual 36 16 (1", 1") 1”, 1.5” (1", 1.5") 54 34 14 7 psi loss Main Pressure Adding DCBP (1", 1") 30 10 (1", 1.5") 48 28 8 Residual (assuming 41 gpm) 1”, 1” 19 (1", 1") (1", 1.5") 49 29 9 24 psi loss Adding DCBP (1", 1") 12 (1", 1.5") 41 21 Fire Sprinklers 1 or 2 (13-26 gpm) 50 gpm rated Domestic Irrigation (15 gpm) 18 to 41 gpm (5+13) (15+26) 2 heads at 13 gpm + 5 gpm = 31 gpm M = 3 psi loss ~ 5 gpm appliance flow Or 2 heads at 13 gpm + 15 gpm = 41 gpm M = 5 psi loss

  21. Water Shut-off Risk • What is fireprobability given statistical opportunity?? • Probability off = #houses off / total #(EBMUD) = ~5% • Probability fire = Chance is < 1 in 300 per year(NFPA) = 0.33% • Probability = Pox Pf = 0.0165%

  22. Water Shut-off - Cost vs. Risk • Cost of two service configuration, no shut-off • Additional service lateral (unpaved) and BFP ~ $1,700 • Monthly cost would increase + $12.60/mo. @ EBMUD • Ten year PW = $12.60x12mox10yr = $1,512 • PW10 ~ $3,200 • PW60 ~ $19,000 for a near zero risk

  23. Final Configuration 1.5” x 1” reducer 1” 1.5” • Minimum 1.5-inch lateral with 1-inch meter for flows ≤ 50 gpm • Size based on FF + 15 gpm or the Total Peak Domestic Demand, whichever is greater

  24. FY12 Monthly Meter Service Charges

  25. A Water Purveyors Perspective Thank you

  26. Background • SFM Task Force (08-09) • Phase I – Water Supply • Phase II – Installation • Phase III – Training and Education • Meter sizing

  27. 1-inch Meter Examples • 1.5-inch tap and lateral • 1-inch meter • Examples (note: same meter for 5 gpm)

  28. 1.5-inch Meter Examples • 1.5-inch tap and lateral • 1.5-inch meter • Examples(note: same meter for 5 gpm)

  29. EBMUD’s Backflow Preventer Requirements

  30. Surveys • Water purveyors – typical meter size • Fire departments – typical sprinkler flow requirement

  31. Cost • No changes to EBMUD’s Schedule of Rates and Charges • Installation = $106 less for new configuration • One-inch meter = $14.05 reduction in monthly charge from 1.5-inch meter

  32. EBMUD Combination Meter Sizing • State code requires fire flow plus 5 gpm for simultaneous domestic flow • Meter Study found fire flow +15 gpm • Staff studied SFR daily peak flow: Over 90% of recorded SFR peak flow were 15 gpm or less • 1" meter with 1.5" tap/lateral up to 50 gpm flow (typical 2 sprinkler head systems) • A lower system requirement than past @ EBMUD • No change in Backflow requirements – be mindful of resulting lower service pressures

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