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Residential Fire Sprinkler Concerns A Water Purveyors Perspective April 2013 Bill Kirkpatrick, Engineering Manager NFPA Home Fire Sprinkler Summit.

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Presentation on theme: "Residential Fire Sprinkler Concerns A Water Purveyors Perspective April 2013 Bill Kirkpatrick, Engineering Manager NFPA Home Fire Sprinkler Summit."— Presentation transcript:

1 Residential Fire Sprinkler Concerns A Water Purveyors Perspective April 2013 Bill Kirkpatrick, Engineering Manager NFPA Home Fire Sprinkler Summit

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

3 General Policy Issues Service –Reliability –Flexibility –Quality Balancing Competing Interests Cost –Home Rule –Affordable –Universal Liability –Supply –Operational

4 Service Reliability –24/7 x years

5 Cost Home Rule - California has it all –Private Individual Corporation –Municipal –Special District / Agency All agencys 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 R NFPA-13D Domestic allowance Pre-2011 practice vs. new code

10 Determining Meter Size Pre Practice New Code Fire Flow + Total Peak Domestic Flow EBMUD used 1.5 meter Fire Flow + 5 gpm Domestic Allowance What size meter & lateral?

11 EBMUD Meter Sizing Study Research on Domestic Flow Hydraulic Calcs 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 – gpm

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

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

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 Number of Sprinkler Heads Flow per Sprinkler Head (gpm) Total Sprinkler Flow (gpm) Domestic Demand (gpm) Total Flow (gpm) Required Meter Size (inch) Maximum flow though 1-inch meter = 50 gpm Maximum flow through 1.5-inch meter = 100 gpm

17 Hydraulics - Headloss

18

19 Backckflow Preventer Pressure Loss Backflow Device Pressure Loss at Given Flow (psi) 1-inch 26 gpm31 gpm34 gpm41 gpm Double Check Reduced pressure inch Double Check Reduced Pressure Data is from manufacturers' specifications sheets 1. Average of headlosses from 6 Febco, Watts, and Wilkins 1-inch double check valves. 2. Average of headlosses from 11 Febco, Watts, and Wilkins 1.5-inch reduced pressure valves. 3. Average of headlosses from 5 Febco, Watts, and Wilkins 1-inch double check valves. 4. Average of headlosses from 10 Febco, Watts, and Wilkins 1.5-inch reduced pressure valves.

20 Irrigation 18 to 41 gpm (5+13) (15+26) Fire Sprinklers Domestic Meter Main Pressure, psi Residual 1636 (1", 1") (1", 1.5") (m, lat.) Adding DCBP 1030(1", 1") 28848(1", 1.5") 1 or 2 (13-26 gpm) ~ 5 gpm appliance flow (15 gpm) 2 heads at 13 gpm + 5 gpm = 31 gpm M = 3 psi loss 50 gpm rated 1, 1 1, psi loss 7 psi loss Main Pressure Residual (assuming 41 gpm) 19 (1", 1") 29949(1", 1.5") Adding DCBP 12(1", 1") 2141(1", 1.5") Or 2 heads at 13 gpm + 15 gpm = 41 gpm M = 5 psi loss

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

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 + EBMUD Ten year PW = $12.60x12 mo x10 yr = $1,512 PW10 ~ $3,200 PW60 ~ $19,000 for a near zero risk

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

24 FY12 Monthly Meter Service Charges Meter Size Monthly Meter Charge (including Seismic) 1.5-inch Meter (current standard SFR combination meter size) $ inch Meter (proposed standard SFR combination meter size) $ /8- or 3/4-inch Meter (most SFR without fire sprinklers) $12.60

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) 26 gpm(FF = 2 13 gpm) + 15 gpm(Domestic Allowance) 41 gpm 1 meter 35 gpm(FF = gpm) + 15 gpm(Domestic Allowance) 50 gpm 1 meter

28 1.5-inch Meter Examples 1.5-inch tap and lateral 1.5-inch meter Examples (note: same meter for 5 gpm) 52 gpm(FF = 4 13 gpm) + 15 gpm(Domestic Allowance) 67 gpm 1.5 meter 68 gpm(FF = 4 17 gpm) + 15 gpm(Domestic Allowance) 83 gpm 1.5 meter

29 EBMUDs Backflow Preventer Requirements Backflow Preventer Type Property Description Double CheckCombo MeterReduced Pressure Well located on property, not cross- connected Well located on property, not cross- connected, installation area restrictions do not allow double check valve Well located on property is cross- connected

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

31 Cost No changes to EBMUDs Schedule of Rates and ChargesNo changes to EBMUDs Schedule of Rates and Charges One-inch meter = $14.05 reduction in monthly charge from 1.5-inch meterOne-inch meter = $14.05 reduction in monthly charge from 1.5-inch meter Installation = $106 less for new configurationInstallation = $106 less for new configuration

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 EBMUD –No change in Backflow requirements – be mindful of resulting lower service pressures


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