PART 8 — SEWAGE SYSTEMSUpdated for the 2024 Ontario Building Code

8.2.1.3.Sewage System Design Flows

(1) For residential occupancies, the total daily design sanitary sewage flow shall be at least the value determined in accordance with Table 8.2.1.3.-A. (See Note A-8.2.1.3.(1) and (2)) (2) For all other occupancies, the total daily design sanitary sewage flow shall be at least the value determined in accordance with Table 8.2.1.3.-B. (See Note A-8.2.1.3.(1) and (2)) (3) Where a building contains more than one establishment, the total daily design sanitary sewage flow shall be the sum of the total daily design sanitary sewage flow for each establishment. (4) Where an occupancy is not listed in Table 8.2.1.3.-B, the highest of metered flow data from at least 3 similar establishments shall be acceptable for determining the total daily design sanitary sewage flow. Table 8.2.1.3.-A Residential Occupancy Forming Part of Sentence 8.2.1.3.(1) Residential Occupancy Volume, litres Apartments, Condominiums, Other Multi-family Dwellings - per person(1) 275 Boarding Houses (a) Per person, (i) with meals and laundry facilities, or, 200 (ii) without meal or laundry facilities, and 150 (b) Per non-resident staff per 8 hour shift 40 Boarding School - per person 300 Dwellings (a) 1 bedroom dwelling 750 (b) 2 bedroom dwelling 1 100 (c) 3 bedroom dwelling 1 600 (d) 4 bedroom dwelling 2 000 (e) 5 bedroom dwelling 2 500 (f) Additional flow for(2) (i) each bedroom over 5, 500 (ii) (A) each 10 m2 (or part of it) over 200 m2 up to 400 m2 (3) , 100 (B) each 10 m2 (or part of it) over 400 m2 up to 600 m2 (3) , and 75 (C) each 10 m2 (or part of it) over 600 m2 (3) , or 50 (iii) each fixture unit over 20 fixture units 50 Hotels and Motels (excluding bars and restaurants) (a) Regular, per room 250 (b) Resort hotel, cottage, per person 500 (c) Self service laundry, add per machine 2 500 Work Camp/Construction Camp, semi-permanent per worker 250 Notes to Table 8.2.1.3.-A: (1) The occupant load shall be calculated using Subsection 3.1.17. (2) Where multiple calculations of sanitary sewage volume is permitted, the calculation resulting in the highest flow shall be used in determining the design daily sanitary sewage flow. (3) Total finished area, excluding the area of the finished basement. Table 8.2.1.3.-B Other Occupancies Forming Part of Sentence 8.2.1.3.(2) Establishments(1) Volume, litres Airports, Bus Terminals, Train Stations, Dock/Port Facilities (Food Services excluded) (a) Per passenger, and 20 (b) Per employee per 8 hour shift 40 Assembly Hall - per seat (a) No food service, or 8 (b) Food service provided 36 Barber Shop/Beauty Salon - per service chair 650 Bowling Alleys (Food Service not included) - per lane 400 Churches and Similar Places of Worship - per seat (a) No kitchen facilities, or 8 (b) Kitchen facilities provided 36 Country Club (excluding Food Service) (a) Per resident, 375 (b) Per employee per 8 hour shift, and 50 (c) Per member or patron 40 Day Care Facility per person (staff and children) 75 Dentist Office (a) Per wet service chair, and 275 (b) Per dry service chair 190 Doctors Office (a) Per practitioner, and 275 (b) Per employee per 8 hour shift 75 Factory (excluding process or cleaning waters) - per employee per 8 hour shift (a) No showers, or 75 (b) Including showers 125 Flea Markets(2) (open not more than 3 days per week) (a) Per non-food service vendor space, 60 (b) Per food service establishment / 9.25 m2 of floor space, and 190 (c) Per limited food service outlet 95 Food Service Operations (a) Restaurant (not 24 hour), per seat 125 (b) Restaurant (24 hour), per seat 200 (c) Restaurant on controlled-access highway, per seat 400 (d) Paper service restaurant, per seat 60 (e) Donut shop, per seat 400 (f) Bar and cocktail lounge, per seat 125 (g) Drive-in restaurant per parking space 60 (h) Take-out restaurant (no seating area) (i) per 9.25 m2 of floor area, and 190 (ii) per employee per 8 hour shift 75 Table 8.2.1.3.-B (Cont’d) Other Occupancies Forming Part of Sentence 8.2.1.3.(2) Establishments(1) Volume, litres (i) Cafeteria - per meal 12 (j) Food outlet (i) excluding delicatessen, bakery and meat department, per 9.25 m2 of floor space, 40 (ii) per 9.25 m2 of delicatessen floor space, 190 (iii) per 9.25 m2 of bakery floor space, 190 (iv) per 9.25 m2 of meat department floor space, and 380 (v) per water closet 950 Hospitals - per bed (a) Including laundry facilities, or 750 (b) Excluding laundry facilities 550 Long-Term Care Homes, etc. - per bed 450 Office Building(3) (a) Per employee per 8 hour shift, or 75 (b) Per each 9.3 m2 of floor space 75 Public Parks (a) With toilets only per person, or 20 (b) With bathhouse, showers, and toilets per person 50 Recreational Vehicle or Campground Park (a) Per site without water or sewer hook-up, or 275 (b) Per site with water and sewer hook-up 425 Schools - per student (a) Day school, 30 (b) With showers, 30 (c) With cafeteria, and 30 (d) Per non-teaching employee per 8 hour shift 50 Service Stations (no vehicle washing)(3) (a) Per water closet, and 950 (i) per fuel outlet(4), or 560 (ii) per vehicle served 20 Shopping Centre (excluding food and laundry) - per 1.0 m2 of floor space 5 Stadiums, Race Tracks, Ball Parks - per seat 20 Stores(3) (a) Per 1.0 m2 of floor area, or 5 (b) Per water closet 1 230 Swimming and Bathing Facilities (Public) - per person 40 Theatres (a) Indoor, auditoriums per seat, 20 (b) Outdoor, drive-ins per space, or 40 (c) Movie theatres per seat 15 Table 8.2.1.3.-B (Cont’d) Other Occupancies Forming Part of Sentence 8.2.1.3.(2) Establishments(1) Volume, litres Veterinary Clinics (a) Per practitioner, 275 (b) Per employee per 8 hour shift, and 75 (c) Per stall, kennel or cage if floor drain connected 75 Warehouse (a) Per water closet, and 950 (b) Per loading bay 150 Notes to Table 8.2.1.3.-B: (1) The occupant load shall be calculated using Subsection 3.1.17. (2) Flea markets open more than 3 days per week shall be assessed using the volumes stated under the heading “Stores”. (3) Where multiple calculations of sanitary sewage volume is permitted, the calculation resulting in the highest flow shall be used in determining the design daily sanitary sewage flow. (4) The number of fuel outlets is considered the maximum number of fuel nozzles that could be in use at the same time

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Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.