D. B. G R A Y E N G I N E E R I N G I N C.

Transcription

1 SERVICING BRIEF Crichton Street Ottawa, Ontario Report No SB July 28, 2010 Revised November 3, 2010 D. B. G R A Y E N G I N E E R I N G I N C. Stormwater Management - Grading & Drainage - Storm & Sanitary Sewers - Watermains 1052 Karsh Drive, Tel: (613) Ottawa, Ontario. Fax: (613) K1G 4N1 dbgray@rogers.com 1

2 SERVICING BRIEF Crichton Street Ottawa, Ontario The following Servicing Brief is a description of the services of a proposed 32 unit three storey stacked townhouse building development with underground parking located on 1686 sq.m. of land Crichton Street in Ottawa. Refer to drawing SG-1 & SG-2 (Revision 1: Jul 28-10), prepared by D. B. Gray Engineering Inc. Water Supply for Fire Fighting: There are two existing fire hydrants near the subject property on the municipal right-of-way for Crichton Street on the opposite side of the street. One is located approximately 39m from the south-east corner of the proposed building (and proposed fire department connection). The other is located approximately 47m from the south-west corner of the proposed building. A fire demand of 9,000 L/min is required as per "Required Minimum Water Supply Flow Rate" as calculated using the Ontario Building Code - Appendix A - Article A "Water Supply For Fire Fighting". Field measurements by the City of Ottawa has recorded the actual flow from one of these hydrants at 5,014 L/min (1,103 ipgm) at a dynamic water pressure of 496 kpa (72 psi). The calculated the flow at 138 kpa (20 psi) is 14,884 L/min (3,274 ipgm). As such, there is an adequate water supply for fire fighting. Water Service: The proposed water service will connect to an existing 300mm municipal watermain in Crichton Street. Field measurements by the City of Ottawa have recorded the static water pressure in the municipal watermain to be 80 psi (552 kpa). The AWWA plumbing fixture value of the proposed development totals Based on the AWWA water flow demand curve, an estimated water pressure at the meter of 80 psi ( 552 kpa) and one external hose bib operating, the peak domestic demand is expected to be 292 l/min (70 USgpm). To meet fire fighting requirements a 150mm diameter water service connection is being proposed. A water service of this size will also meet the domestic demand. Based on 67 people at 75 litres per person per day, the daily average flow is expected to be 3.5 l/min (0.9 USgpm). Sanitary Service: The post development peak flows are calculated to be 1.41 l/s. The proposed sanitary sewer service 2% l/s capacity) will connect to an existing 300mm municipal sanitary 0.508% l/s capacity) in Crichton Street. The 1.41 l/s peak flow contributing to the existing 300mm sanitary sewer is expected to have a negligible impact on the existing municipal sewer. City staff at Infrastructure Approvals has advised that there may be sanitary sewer capacity issues in the area and has advised us to contact city staff at Infrastructure Services. Several attempts have been made to contact staff but contact has yet to be made. 2

3 Stormwater: The release rate for post-development storm events is designed to be equal to or less than the flow produced by a five year storm using a runoff coefficient of 0.50 and a 20 minute time of concentration. To restrict the flow to the maximum release rate each of four roof drains in the upper roof area will be flow control causing the storm water to pond on the upper roof. An inlet control device (ICD) located at the outlet pipe of a manhole will control the release of stormwater off the site. The ICD will restrict the flow and force the stormwater to back up into the upstream sewer pipes, catch basins and manholes. (Refer to Stormwater Management Report No SWM, July prepared by D. B. Gray Engineering Inc.) During the five year event stormwater released through the ICD will be restricted to a maximum flow of 7.54 l/s and will be conveyed off the site via the proposed 250mm storm sewer connection (@ 0.43% l/s capacity) to an 450mm municipal storm sewer (@ 0.728% l/s capacity) in Crichton Street. The restricted flow is expected to have a negligible impact on the existing municipal sewer. The unrestricted flow produced by a one in five year storm event at a 10 minute time of concentration will produce a peak flow of 30.0 l/s. A second storm sewer service connection will serve only trench drain at the ramp down to the underground garage. The flow will be unrestricted. The flow produced by a one in five year storm event at a 10 minute time of concentration will produce a peak flow of 2.1 l/s. The proposed storm sewer connection 0.43%) has a capacity of 40.7 l/s. 3

4 RE: 280 Crichton St - 'Yahoo! Mail' Page 1 of 2 29/07/2010 RE: 280 Crichton St Note: the computed flows are approximate and performed for hydrant colour coding purposes, thus these values are not intended for design purposes. ` Douglas Gray Company: D. B. G R A Y E N G I N E E R I N G I N C. Tel: (613) Fax: (613) Location: Electric Request_dt: :39:04 dbgray@rogers.com Inspection Flow Residual Pressure (psi) Flow (igpm) Date Hydrant Hydrant Static Dynamic Pitot 20 psi 2009/05/ Murray Crowder Technical Support Drinking Water Operations Branch Environmental Services Department City of Ottawa 951 Clyde Avenue, Ottawa, On K1Z 5A6 Mail Code Tel: (613) x Fax: (613) murray.crowder@ottawa.ca From: DOUGLAS GRAY [mailto:dbgray@rogers.com] Sent: June 22, :35 AM To: Crowder, Murray Subject: 280 Crichton St Hi Murray I am working on a project at 280 Crichton St (see attached map). Please send me water supply / pressure information in this area. Thanks, Doug D. B. G R A Y E N G I N E E R I N G I N C. Stormwater Management - Grading & Drainage - Storm & Sanitary Sewers - Watermains 1052 Karsh Drive, Tel: (613) Ottawa, Ontario. Fax: (613) K1G 4N1 dbgray@rogers.com This originates from the City of Ottawa system. Any distribution, use or copying of this or the information it contains by other than the intended recipient(s) is unauthorized. If you are not the intended recipient, please notify me at the 4

5 RE: 280 Crichton St - 'Yahoo! Mail' Page 2 of 2 29/07/2010 telephone number shown above or by return and delete this communication and any copy immediately. Thank you. Le présent courriel a été expédié par le système de courriels de la Ville d'ottawa. Toute distribution, utilisation ou reproduction du courriel ou des renseignements qui s'y trouvent par une personne autre que son destinataire prévu est interdite. Si vous avez reçu le message par erreur, veuillez m'en aviser par téléphone (au numéro précité) ou par courriel, puis supprimer sans délai la version originale de la communication ainsi que toutes ses copies. Je vous remercie de votre collaboration. 5

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7 Crichton Street, Ottawa Ontario Water Supply for Fire-Fighting Calculations: A fire demand of 9,000 L/min is required as per "Required Minimum Water Supply Flow Rate" as calculated using the Ontario Building Code - Appendix A - Article A "Water Supply For Fire Fighting". Fire Protection Water Supply Q = KVS Tot S Tot = S Side1 + S Side2 + S Side3 + S Side1 + S Side4 Spatial Coefficient Exposure Distance m S Side (to center line of road) S Side (to west property line) S Side (to north property line) S Side (to east property line) S Tot 2.5 Building (except garage): K (Water Supply Coefficient) 18 As per A Table 1 (Group C Occupancy / Combustible construction with fire separations and fire resistance ratings as per OBC ) V (Building Volume) Average Area Height Volume sq.m. m cu.m. Basement ,626 Ground ,809 Second ,900 Third ,743 3,772 sq.m. 11,078 cu.m. Q = Q 1 = KVS Tot 498,532 L Garage: K (Water Supply Coefficient) 22 As per A Table 1 (Group F3 Occupancy / Combustible construction with fire separations and fire resistance ratings as per OBC ) V (Building Volume) Q = Q 2 = Average Area Height Volume sq.m. m cu.m. 1, ,222 KVS Tot 177,223 L Q Tot = Q 1 + Q 2 Q Tot = 675,755 L Required Minimum Water Supply Flow Rate 9,000 L/min (As per A Table 2) Available Water Supply: Flow Residual Pressure Flow Hydrant Hydrant Static Dynamic 20 psi psi psi igpm igpm , kpa kpa kpa L/min L/min ,014 14,884 7

8 28-Jun Crichton St 32 Units WATER FIXTURE VALUE No. F.V. Total Bathtub Tiolet - tank Tiolet - flush valve Lavs Urinal - pedestal flush valve Urinal - wall flush valve Shower K. Sink Dishwasher Clothes Washer Commercial Sink J. Sink Commercial Dishwasher 0 Commercial Washer 0 Hose 1/2 in Peak Demand (fig 4-2 or 4-3) 60 Usgpm Meter 552 kpa 80 psi Pressure Factor (table 4-1) 1.17 Peak Demand 70 Usgpm Irrigation - hose 1/2 in 1 7 Usgpm (includes pressure factor) (assume one hose bib operating) TOTAL PEAK DEMAND 292 l/min 77 Usgpm Nominal Size 5.9 in 150 mm 0.9 ft/s 0.3 m/s DAILY AVERAGE 32 Units 2.1 Persons / unit 67.2 persons 75 litres / person / day 3.5 l / min 0.9 Usgpm 8

9 D. B. G R A Y E N G I N E E R I N G I N C. SANITARY SEWER DESIGN FORM Stormwater Management - Grading & Drainage - Storm & Sanitary Sewers - Watermains Average Daily Flows: Peaking Factor: PROJECT: Crchton St Residential: 350 l / capita / day Residential (Harmon Equation): P.F. = Karsh Drive Tel: (613) Commercial: 50,000 l / ha / day P = Population / P 0.5 Designed By: DBG Ottawa, Ontario. Fax: (613) Instituational: 50,000 l / ha / day K1G 4N1 dbgray@rogers.com Light Industrial: 50,000 l / ha / day Infiltration Allowance: 0.28 l / s / ha 28-Jul-10 Heavy Industrial: 50,000 l / ha / day Page: 1 of 1 Section Cumulative Section Cumulative SEWER DATA LOCATION Single Semi / Duplex / Apartments Apartments Apartments Apartments Residential Non-Residential Residential Sewage Infiltratio Total Family Townhouse Triplex (average) (1 Bed.) (2 Bed.) (3 Bed.) Area n = Area Peaking Area Flow Peaking Flow n Flow Flow STREET FROM TO ppu = 3.4 ppu = 2.7 ppu = 2.3 ppu = 1.8 ppu = 1.4 ppu = 2.1 ppu = 3.1 Pop. Type of Dia. Actual Dia. Nom. Slope Length Capacity Velocity Ratio Factor Factor No. of Units No. of Units No. of Units No. of Units No. of Units No. of Units No. of Units ha ha l/ha/day ha l/s l/s l/s Pipe (mm) (mm) (%) (m) (l/s) (m/s) Q/Qfull COMMENTS BUILDING EXIST PVC SDR mm SAN EXISTING MUNICIPAL SANITARY SEWER IN CRICHTON ST

10 D. B. G R A Y E N G I N E E R I N G I N C. Stormwater Management - Grading & Drainage - Storm & Sanitary Sewers - Watermains STORM SEWER COMPUTATION FORM PROJECT: Chrichton St, Ottawa 1052 Karsh Drive Tel: (613) RATIONAL METHOD Q = 2.78 A I R FIVE YEAR EVENT Designed By: DBG Ottawa, Ontario. Fax: (613) K1G 4N1 dbgray@rogers.com n = Date: 28-Jul-10 Page: 1 of 1 Time of Rainfall SEWER DATA LOCATION AREA (ha) Individual Accum. Peak Flow Conc. Intensity Type of Dia. Actual Dia. Nom. Slope Length Capacity Velocity Time of Ratio 2.78 A R 2.78 A R Q (l/s) STREET FROM TO R = 0.9 R = 0.70 R = 0.2 R = 0.9 (min) I (mm/hr) Pipe (mm) (mm) (%) (m) (l/s) (m/s) Flow (min) Q/Qfull COMMENTS CB-6 CB/MH PVC SDR CB/MH-4 CB/MH PVC SDR CB/MH-3 CB/MH PVC SDR ROOF CB/MH PVC SDR CB/MH-2 CB/MH PVC SDR CB/MH-1 exist 450 ST PVC SDR Trench Drain exist 450 ST PVC SDR EXISTING 450 MUNICIPAL STORM SEWER IN CRICHTON ST