PROPOSED THREE STOREY RESIDENTIAL APARTMENT BUILDING SITE LOTS 187 AND 188 R PLAN DONALD STREET CITY OF OTTAWA SERVICEABILITY REPORT

Transcription

1 PROPOSED THREE STOREY RESIDENTIAL APARTMENT BUILDING SITE LOTS 187 AND 188 R PLAN DONALD STREET CITY OF OTTAWA SERVICEABILITY REPORT REPORT No. R A REV. 1 MAY 2018 T. L. MAK ENGINEERING CONSULTANTS LTD. NOVEMBER 2017 REF. FILE No

2 1.) INTRODUCTION The developer of the property under consideration is proposing to construct a three storey residential apartment building on site. It is situated on the south side of Donald Street, west of Lola Street and east of Edith Avenue. The three storey apartment building will consist of a ground floor, second floor, third floor and basement. Typical floor space per floor is approximately 4, sq. ft. (436.4 sq. m). Therefore, the total gross floor area of the building is ±18,800 sq. ft. (±1, sq. m). There are (4) bachelor units, (12) one bedroom and (9) two bedroom units proposed in this building. Area of the development combined lots is ± ha. In addition to the apartment building, the other development features will comprise of a semi permeable access road along the west side of the property, rear semi permeable parking lot, landscape area, etc. to meet City of Ottawa site plan requirements. This report will serve to provide the City of Ottawa with our serviceability brief to address the proposed servicing scheme for this site. 2.) EXISTING SITE CONDITIONS AND SERVICING Presently, the two (2) single residential lots under consideration for the apartment building development site are referenced as 324 and 326 Donald Street. A one (1) storey dwelling unit currently occupies each of the (2) lots with an asphalt driveway linking Donald Street to the rear yard parking area along the east side of each property. Terrain of the property is relatively flat and slopes predominantly from back to front or south to north across the site. As for the availability of underground services, there are existing municipal services along the Donald Street road right of way consisting of the following main sizes: a 1050 mm diameter storm sewer, a 600 mm diameter sanitary sewer and a 400 mm diameter watermain. 3.) PROPOSED RESIDENTIAL APARTMENT BUILDING SITE One vehicle entrance located at the northwest corner of the site is proposed to serve this property along with an access roadway along the west property limit to direct vehicular traffic in and out of the site. Parking will be at the rear semi permeable parking lot and situated south of the apartment building. 2

3 A.) Water Supply Based on previous discussions with the owner, the building will not be installed with a sprinkler system. The building is proposed to be serviced via a 38 mm diameter water service pipe copper type K to the building from the city main. Based on the City s current boundary conditions provided from an e mail dated November 6, 2017 for hydraulic analysis (refer to Appendix A) in which the three storey residential building development is being serviced from a 400 mm diameter watermain, the calculated boundary conditions (HGL) are as follows: Minimum HGL = m Maximum HGL = m MaxDay (0.42 L/s) + Fire Flow (267 L/s) = m The ground elevation at street level at the location of the connection is approximately 60.4 m. The City has indicated that for the calculated Fire Underwriter Survey (FUS) fire flow of 267 L/s (attached) the resulting hydraulic grade line is m. This corresponds to a residual pressure of 479 kpa (70 psi) at this location and is well above the minimum residual pressure requirement of 140 kpa (20 psi). During peak hour flow conditions, the resulting minimum hydraulic grade line of m corresponds to a peak hour pressure of 484 kpa (70 psi). This value is above the minimum pressure objective of 276 kpa (40 psi). With respect to the maximum pressure check during average day demands, the resulting maximum hydraulic grade line of m corresponds to a pressure of 568 kpa (82 psi). This value is slightly above the maximum pressure objective of 552 kpa (80 psi). The Ontario Building Code (OBC) Section states that a pressure reducing valve shall be installed in areas that may be occupied where the static pressure exceeds 550 kpa (79.8 psi). The City s Water Distribution Design Guidelines technical bulletin (ISDTB ) further states that for areas that exceed 552 kpa (80 psi), pressure reducing valves should be installed immediately downstream of the isolation valve in the home/building. In conclusion, based on the boundary conditions provided, the 406 mm diameter watermain on Donald Street provides adequate fire flow capacity as per the Fire Underwriters Survey and provides anticipated demand flows above the minimum pressure objective during peak demand. However, during basic demand conditions, the maximum objective pressure of 552 kpa (80 psi) will be exceeded. Pressure reducing valves will be required to service the proposed building. B.) Sanitary Flow Peak sanitary flow for this proposed development site is estimated at Q = 0.70 L/s with an infiltration rate of 0.03 L/s. This flow will enter the existing 600 mm diameter sanitary sewer via the 3

4 proposed apartment building 150 mm diameter PVC sanitary service lateral sloped at 1% (min.). Refer to Appendix B for details. The peak sanitary flow estimated for the combined (2) existing lots occupied by a total of (2) residential dwelling units is Q = 0.14 L/s with an infiltration rate of 0.03 L/s. Therefore, the estimated net increase in peak flow from this proposed development is 0.56 L/s. The existing Donald Street sanitary sewer size is 600 mm diameter in front of this property, an increase in sanitary flow to this sanitary sewer system by 0.56 L/s from this residential site is not expected to negatively impact the existing sanitary sewer. C.) Storm Flow Stormwater outlet for this proposed property will be the existing 1050 mm diameter storm sewer located on Donald Street. The proposed residential apartment building rooftop is flat and will be able to provide on site stormwater management (SWM) storage. Roof water from the building will be drained and controlled by two roof drains each with a release rate of 0.63 L/s (10 US gal/min.) which then discharges onto a concrete splash pad and then surface drains onto the Donald Street road right of way. On site drainage shall be graded from rear to front and surface drained to the Donald Street road right of way. Based on the site plan from the architect, the average post development runoff coefficient is estimated at C = 0.63 and A = ± ha. An estimation of the pre development flow condition was carried out using the criteria accepted by the City of Ottawa. Pre development 5 year allowable flow rate for this residential area is estimated to be approximately Q = L/s using C = 0.5 (max.) runoff value and tc = 10 min. for this proposed development site in which flow ultimately outlets to a 1050 mm diameter storm sewer on Donald Street. Therefore, based on this calculation, on site retention is required for this proposed development site. Storage volume for the 5 year and up to 100 year event will be stored by means of flat rooftop of the proposed apartment building. The 5 year net allowable release rate off site was determined to be 3.17 L/s. For development of this residential site (±0.1085ha.) and in controlling the five (5) year storm water release rate off site to an allowable rate no greater than 3.17L/s, a site storage volume of approximately 8.11m 3 minimum is required during the five(5) year event. For this site, two (2) flat rooftop storage areas will be used for storm water management attenuation. 4

5 During the five year storm event for the flat rooftop storage, the ponding depth on this rooftop is estimated at 110mm at the drain and 0mm at the roof perimeter, assuming a 1.4% minimum roof pitch to the drain. The rooftop storage available at Roof Area 1 is 4.27m 3 and the rooftop storage available at Roof Area 2 is 4.08m 3, for a total of 8.35m 3, which is greater than the required storage volume of 8.11m 3. To control the 100 year storm water release rate off site to be less than the net allowable rate of 3.17L/s, calculated at 2 x 0.63L/s = 1.26L/s, a site storage volume of approximately 19.23m 3 minimum is required during the 100 year event. During the 100 year storm event for the flat rooftop storage, the ponding depth on this rooftop is estimated at 150mm at the drain and 0mm at the roof perimeter, assuming a minimum roof pitch to the drain. The rooftop storage available at Roof Area 1 is 10.19m 3 and the rooftop storage available at Roof Area 2 is 9.97m 3, for a total of 20.16m 3, which is greater than the required storage volume of 19.23m 3. Therefore, by means of flat building rooftop storage and grading the site to the proposed grades as shown on the Proposed Grading, Servicing and Stormwater Management Plan Dwg G 1, the desirable five(5) year storm and 100 year storm event detention volumes of 8.35m 3 and 20.16m 3 respectively will be available on site. It is proposed that the roof drain outlet for this building be discharged onto a concrete splash pad located at the front east corner of the building and then be surface drained onto the Donald Street roadway for storm water outlet. It is proposed that the building weeping tile drainage of the proposed residential site be collected in a sump pit complete with duplex sump pumps. The sump pit water will in turn be pumped up and discharged onto a concrete splash pad located at the front northwest corner of the building, and then surface drained onto the Donald Street roadway for storm water outlet. Because the shallow buried depth of the existing 1050mm diameter Donald Street storm sewer, there shall be no storm laterals or sewers to be connected to this sewer due to frost issues. For this site, based on the latest revised site plan dated April 23, 2018 including comments set out by the Rideau Valley Conservation Authority (RVCA), from their March 14, 2018 comments, Best Management Practices (BMPs) are proposed to be implemented for this site from details of the revised site plan. In comparison to the original proposed site plan, the revised site plan reflects a larger roof area for SWM, drive aisles and parking area using semi permeable material to promote infiltration that result in the site s stormwater being collected and represents similarly to the existing development conditions for TSS treatment on site and are considered clean for the purpose of quality control mitigation. Vegetative area proposed at both the front and rear yard would allow for infiltration, in addition to being considered clean. 5

6

7 PROPOSED THREE STOREY RESIDENTIAL APARTMENT BUILDING SITE LOTS 187 AND 188 R PLAN DONALD STREET CITY OF OTTAWA APPENDIX A CITY OF OTTAWA WATER DATA BOUNDARY CONDITIONS AND FUS FIRE FLOW CALCULATIONS

8 From: Wu, John To: TL Mak ; Subject: RE: Donald Street Date: Monday, November 06, :38:39 PM Attachments: 324 Donald November 2017.pdf Here is the result: ****The following information may be passed on to the consultant, but do NOT forward this directly. **** The following are boundary conditions, HGL, for hydraulic analysis at 324 Donald (zone 1E) assumed to be connected to the 406 mm on Donald (see attached PDF for location). Minimum HGL = m Maximum HGL = m Max Day + Fire Flow = m These are for current conditions and are based on computer model simulation. Disclaimer: The boundary condition information is based on current operation of the city water distribution system. The computer model simulation is based on the best information available at the time. The operation of the water distribution system can change on a regular basis, resulting in a variation in boundary conditions. The physical properties of watermains deteriorate over time, as such must be assumed in the absence of actual field test data. The variation in physical watermain properties can therefore alter the results of the computer model simulation John From: TL Mak [mailto:tlmakecl@bellnet.ca] Sent: Thursday, November 02, :52 AM To: Wu, John <John.Wu@ottawa.ca> Subject: Donald Street Hi John, The proposed multi-unit residential building located at Donald Street is a 3-storey building with a basement. There is a total of 25 units and are comprised of bachelor, 1-bedroom, and 2-bedroom apartments. The building is proposed to be serviced from the 406 mm diameter watermain along Donald Street. The domestic demands were calculated using the City of Ottawa s Water Design Guidelines where the residential consumption rate of 350 L/cap/d is used to estimate average day demands (AVDY). Maximum day (MXDY) demands were calculated by multiplying AVDY by a factor of 2.5. Peak hourly (PKHR) demands were calculated by multiplying MXDY by a factor of 2.2. Persons per unit (PPU) for each unit were estimated based on the City of Ottawa s Water Design Guidelines. Table 1 shows the estimated domestic demands of the proposed building. Table 1 - Estimated Domestic Demand Unit Type Number of AVDY MXDY PKHR PPU Units L/d L/s L/d L/s L/d L/s Bachelor , , , Bedroom , , , Bedroom , , , Total 14, , ,

9 The fire flow required was determined following the Fire Underwriter Survey (FUS) method and is provided in the attached spreadsheet. For the FIS calculations, the building is assumed to be wood frame construction. It is understood that the building will not have a sprinkler system. The resulting total required fire flow is 16,000 L/min (267 L/s) for a duration of 3.5 hours. In summary: AVDY = 14,445 L/d (0.167 L/s) MXDY = 36,138 L/d (0.42 L/s) PKHR = 79,503 L/d (0.92 L/s) Fire Flow = 16,000 L/min (267 L/s) The City is requested to provide boundary conditions for the Average Day, Maximum Day, Peak Hour and Fire Flow conditions indicated above. Thank you for your prompt attention to this matter. Please forward the boundary conditions as soon as possible. Tony Mak T.L. Mak Engineering Consultants Ltd Youville Drive, Suite 218 Ottawa, ON K1C 6Z7 Tel: Fax: tlmakecl@bellnet.ca ' 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. 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. Je vous remercie de votre collaboration. '

10 $ Boundary Condition for 324 Donald EVE ST DONALD ST GF EDITH AVE Legend Water Pipe Ownership Private Public

11 From: To: Subject: Date: Attachments: TL Mak John Wu; Donald Street Thursday, November 02, :52:00 AM STANTEC FUS FIREFLOW CALCULATOR Donald.pdf Hi John, The proposed multi-unit residential building located at Donald Street is a 3-storey building with a basement. There is a total of 25 units and are comprised of bachelor, 1-bedroom, and 2-bedroom apartments. The building is proposed to be serviced from the 406 mm diameter watermain along Donald Street. The domestic demands were calculated using the City of Ottawa s Water Design Guidelines where the residential consumption rate of 350 L/cap/d is used to estimate average day demands (AVDY). Maximum day (MXDY) demands were calculated by multiplying AVDY by a factor of 2.5. Peak hourly (PKHR) demands were calculated by multiplying MXDY by a factor of 2.2. Persons per unit (PPU) for each unit were estimated based on the City of Ottawa s Water Design Guidelines. Table 1 shows the estimated domestic demands of the proposed building. Table 1 - Estimated Domestic Demand Unit Type Number of AVDY MXDY PKHR PPU Units L/d L/s L/d L/s L/d L/s Bachelor , , , Bedroom , , , Bedroom , , , Total 14, , , The fire flow required was determined following the Fire Underwriter Survey (FUS) method and is provided in the attached spreadsheet. For the FIS calculations, the building is assumed to be wood frame construction. It is understood that the building will not have a sprinkler system. The resulting total required fire flow is 16,000 L/min (267 L/s) for a duration of 3.5 hours. In summary: AVDY = 14,445 L/d (0.167 L/s) MXDY = 36,138 L/d (0.42 L/s) PKHR = 79,503 L/d (0.92 L/s) Fire Flow = 16,000 L/min (267 L/s) The City is requested to provide boundary conditions for the Average Day, Maximum Day, Peak Hour and Fire Flow conditions indicated above. Thank you for your prompt attention to this matter. Please forward the boundary conditions as soon as possible. Tony Mak T.L. Mak Engineering Consultants Ltd Youville Drive, Suite 218 Ottawa, ON K1C 6Z7 Tel: Fax: tlmakecl@bellnet.ca

12 FUS Fire Flow Calculation Calculations based on: "Water Supply for Public Fire Protection " by Fire Underwriters' Survey, 1999 Stantec Project #: Project Name: Donald Street Fire Flow Calculation #: 1 Date: October 25, 2017 Building Type/Description/Name: Residential Data input by: Alexandre Mineault-Guitard, M a Sc., EIT Notes: Table A: Fire Underwriters Survey Determination of Required Fire Flow - Long Method Step Task Term Options Choose Frame Used for Construction of Coefficient related to Unit type of construction (C) Choose Type of Housing (if TH, Enter Number of Units Per TH Block) Obtain Required Fire Flow without Reductions Apply Factors Affecting Burning Choose Combustibility of Building Contents Choose Reduction Due to Presence of Sprinklers Choose Separation Distance Between Units Obtain Required Fire Flow, Duration & Volume Type of Housing Occupancy content hazard reduction or surcharge Multiplier Associated with Option Framing Material Wood Frame 1.5 Ordinary construction 1 Non-combustible construction 0.8 Fire resistive construction (< 2 hrs) 0.7 Fire resistive construction (> 2 hrs) 0.6 Floor Space Area Single Family 1 Townhouse - indicate # of units 6 Other (Comm, Ind, Apt etc.) 1 Number of Floors/Storeys in the Unit (do not include basement): Non-combustible Limited combustible Combustible 0 Free burning 0.15 Rapid burning 0.25 Choose: Other (Comm, Ind, Apt etc.) Square Feet (ft2) Required Fire Flow (without reductions or increases per FUS) (F = 220 * C * A) Round to nearest 1000L/min Reductions/Increases Due to Factors Affecting Burning Value Used 2.2 # of Storeys 3 3 Storeys Area in 4,464 Enter Ground Floor Average Floor Area (A) based on design with one hour rating for vertical openings Square 3 1,244 Area of One Unit and exterior vertical communications: Meters Unit Wood Frame 1.5 m 1 Units Total Fire Flow (L/min) Sprinkler reduction Adequate Sprinkler conforms to NFPA None 0 N/A 0 None 0 Water Supply Credit Water supply is standard for sprinkler -0.1 Water supply is not and fire dept. hose line standard or N/A Water supply is not standard or N/A 0 0 N/A 0 Sprinkler Supervision Sprinkler system is fully supervised -0.1 Sprinkler not fully Credit Sprinkler not fully supervised or N/A 0 supervised or N/A 0 N/A 0 North Side 30.1 to 45.0m 0 05 Exposure Distance East Side 3.1 to 10.0m 0.2 Between Units South Side 10.1 to 20.0m m 6,120 West Side 3.1 to 10.0m 0.2 Total Required Fire Flow, rounded to nearest 1000 L/min, with max/min limits applied: Total Required Fire Flow (above) in L/s: Required Duration of Fire Flow (hrs) Required Volume of Fire Flow (m 3 ) (m 2 ) 12,000 Limited combustible N/A 10,200 16, ,360 Date: 10/25/2017 Stantec Consulting Ltd.

13 PROPOSED THREE STOREY RESIDENTIAL APARTMENT BUILDING SITE LOTS 187 AND 188 R PLAN DONALD STREET CITY OF OTTAWA APPENDIX B SANITARY SEWER DESIGN SHEET PAGE 1 OF 1

14

15 PROPOSED THREE STOREY RESIDENTIAL APARTMENT BUILDING SITE LOTS 187 AND 188 R PLAN DONALD STREET CITY OF OTTAWA APPENDIX C DEVELOPMENT SERVICING STUDY CHECKLIST SUMMARY

16

17

18

19

20

21