Division B
Part 8 - Sewage Systems
Section 8.1. General Copy linkAdd bookmark
8.1.1. Scope Copy linkAdd bookmark
8.1.1.1. Scope Copy linkAdd bookmark
(1)The scope of this Part shall be as described in Subsection 1.3.3. of Division A.
8.1.1.2. Definitions Copy linkAdd bookmark
(1)Except as provided in Sentence (2), words that appear in italics are defined in Article 1.4.1.2. of Division A and in the Building Code Act, 1992.
(2)In this Part,
- Soil means in-situ, naturally occurring, unconsolidated mineral or organic material, at the earth's surface that is at least 100 mm thick and capable of supporting plant growth, and includes material compacted or cemented by soil forming processes, but does not include displaced materials such as gravel dumps, mine spoils, or like deposits.
8.1.2. Application Copy linkAdd bookmark
8.1.2.1. Classification of Systems Copy linkAdd bookmark
(1)All sewage systems shall be classed as one of the following:
(a)Class 1 — a chemical toilet, an incinerating toilet, a recirculating toilet, a self-contained portable toilet and all forms of privy including a portable privy, an earth pit privy, a pail privy, a privy vault and a composting toilet system,
(b)Class 2 — a greywater system,
(c)Class 3 — a cesspool,
(d)Class 4 — a leaching bed system, or
(e)Class 5 — a system that requires or uses a holding tank for the retention of hauled sewage at the site where it is produced prior to its collection by a hauled sewage system.
8.1.2.2. Operation and Maintenance Copy linkAdd bookmark
(1)Operation and maintenance of sewage systems shall comply with Section 8.9.
8.1.3. Limitations Copy linkAdd bookmark
8.1.3.1. Discharge Copy linkAdd bookmark
(1)Except as provided in Sentences (2) to (6), the sewage system shall be designed and constructed to receive only sanitary sewage of domestic origin. (See Note A-8.1.3.1.(1))
(2)Where laundry waste is not more than 20% of the total daily design sanitary sewage flow, it may discharge to a sewage system.
(3)Where industrial process waste water is treated to the contaminant levels found in domestic sanitary sewage, it may discharge to a leaching bed provided the treatment unit and sewage system are designed in accordance with good engineering practice. (See Note A-8.1.3.1.(3))
(4)Where kitchen waste water from a restaurant has passed through an operating grease interceptor, it may discharge to a leaching bed provided the sewage system has been designed in accordance with good engineering practice.
(5)Waste water from a kitchen equipped with a garbage grinder may be directed to the sewage system provided the system has been designed to accept such waste water.
(6)Water softener and iron filter discharge may be directed to the sewage system provided the system has been designed to accept such discharges.
(7)Storm sewage shall not be discharged into a sewage system.
(8)The interceptor required in Sentence (4) shall,
(a)have a minimum flow rate as required by Sentence 7.4.4.3.(8) using a 60 second drain down time, and
(b)conform to,
(i)CSA B481.1, “Testing and rating of grease interceptors using lard,” or
(ii)CSA B481.2, “Testing and rating of grease interceptors using oil.”
Section 8.2. Design Standards Copy linkAdd bookmark
8.2.1. General Requirements Copy linkAdd bookmark
8.2.1.1. Scope Copy linkAdd bookmark
(1)This Subsection applies to the design of sewage systems.
8.2.1.2. Site Evaluation Copy linkAdd bookmark
(1)A site evaluation shall be conducted on every site where a new or replacement sewage system is to be installed. (See Note A-8.2.1.2.(1))
(2)The percolation time shall be determined by,
(a)conducting percolation tests, or
(b)classifying the soil according to one of the following methods,
(i)the Unified Soil Classification System as described in MMAH Supplementary Standard SB-6, “Percolation Time and Soil Descriptions,” or
(ii)the Soil Texture Classification as described in Chapter 3 of USDA, “Soil Survey Manual.”
(See Note A-8.2.1.2.(2))
(3)Where the percolation time is determined by a percolation test, there shall be a minimum of 3 locations selected, suitably spaced to accurately evaluate the leaching bed area, with the highest percolation time of the tests being used.
(See Note A-8.2.1.2.(3))
8.2.1.3. Sewage System Design Flows Copy linkAdd bookmark
(1)For residential occupancies, the total daily design sanitary sewage flow shall be at least the value in Column 2 as determined from 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 in Column 2 as determined from 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.
| 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:
| 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 |
| (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 |
| 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:
8.2.1.4. Clearances (See Note A-8.2.1.4.) Copy linkAdd bookmark
(1)Unless it can be shown to be unnecessary, where the percolation time is 10 minutes or greater, the location of all components within a sewage system shall be in conformance with the clearances listed in Article 8.2.1.5. or 8.2.1.6.
(2)Unless it can be shown to be unnecessary, where the percolation time is less than 10 minutes, the clearances listed in Articles 8.2.1.5. and 8.2.1.6. for wells, lakes, ponds, reservoirs, rivers, springs or streams shall be increased to compensate for the lower percolation time.
(3)No building shall be constructed closer to any part of a sewage system than the clearances listed in Article 8.2.1.5. or 8.2.1.6.
(4)If more than one sewage system is located on a lot or parcel of land, there shall be no overlap of any part of the systems.
8.2.1.5. Clearance Distances for Class 1, 2 and 3 Sewage Systems Copy linkAdd bookmark
(1)Except as provided in Sentences 8.2.1.4.(1) and (2), no Class 1, 2 or 3 sewage system shall have a horizontal distance of less than that permitted by Table 8.2.1.5.
| Sewage System | Minimum horizontal distance in metres from a well with watertight casing to a depth of at least 6 m | Minimum horizontal distance in metres from a spring used as a source of potable water or well other than a well with a watertight casing to a depth of at least 6 m | Minimum horizontal distance in metres from a lake, river, pond, stream, reservoir, or a spring not used as a source of potable water | Minimum horizontal distance in metres from a property line |
|---|---|---|---|---|
| Earth Pit Privy | 15 | 30 | 15 | 3 |
| Privy Vault Pail Privy | 10 | 15 | 10 | 3 |
| Greywater System | 10 | 15 | 15 | 3 |
| Cesspool | 30 | 60 | 15 | 3 |
8.2.1.6. Clearances for a Class 4 or 5 Sewage System Copy linkAdd bookmark
(1)Except as provided in Sentences 8.2.1.4.(1) and (2), a treatment unit shall not be located closer than the minimum horizontal distances set out in Table 8.2.1.6.-A.
| Object | Minimum Clearance, m |
|---|---|
| Structure | 1.5 |
| Well | 15 |
| Lake | 15 |
| Pond | 15 |
| Reservoir | 15 |
| River | 15 |
| Spring | 15 |
| Stream | 15 |
| Property Line | 3 |
(2)Except as provided in Sentences 8.2.1.4.(1) and (2), the centreline of a distribution pipe or leaching chamber shall not be located closer than the minimum horizontal distances set out in Table 8.2.1.6.-B and these distances shall be increased when required by Sentence 8.7.4.2.(11).
(3)Except as provided in Sentences 8.2.1.4.(1) and (2), a holding tank shall not be located closer than the minimum horizontal distances set out in Table 8.2.1.6.-C.
| Object | Minimum Clearance, m |
|---|---|
| Structure | 5 |
| Well with a watertight casing to a depth of at least 6 m | 15 |
| Any other well | 30 |
| Lake | 15 |
| Pond | 15 |
| Reservoir | 15 |
| River | 15 |
| Spring not used as a source of potable water | 15 |
| Stream | 15 |
| Property Line | 3 |
| Object | Minimum Clearance, m |
|---|---|
| Structure | 1.5 |
| Well with a watertight casing to a depth of at least 6 m | 15 |
| Any other well | 15 |
| Spring | 15 |
| Property Line | 3 |
8.2.2. Treatment and Holding Tanks Copy linkAdd bookmark
8.2.2.1. Application Copy linkAdd bookmark
(1)This Subsection applies to any tank used in a sewage system for collecting, treating, holding or storing sanitary sewage.
8.2.2.2. Tanks Copy linkAdd bookmark
(1)A tank that is used as a treatment unit in a Class 4 sewage system or a holding tank in a Class 5 sewage system shall conform to the requirements of CSA B66, “Design, material, and manufacturing requirements for prefabricated septic tanks and sewage holding tanks.”
(2)Material standards, access and construction methods and practices for a tank used for other Classes of sewage systems shall conform to the requirements of CSA B66, “Design, material, and manufacturing requirements for prefabricated septic tanks and sewage holding tanks.”
(3)Sentence (2) does not apply to a tank that is an integral part of a prefabricated Class 1 sewage system.
(4)Access openings shall be located to facilitate the pumping of all compartments and the servicing of the inlet and outlet of each compartment not accessible by removal of the tank top or part of it.
(5)A tank shall not be covered by soil or leaching bed fill having a depth greater than the maximum depth of burial that the tank is designed to withstand.
(6)A tank shall be securely anchored when located in an area subject to flooding or where ground water levels may cause hydrostatic pressures.
8.2.2.3. Septic Tanks Copy linkAdd bookmark
(1)The minimum working capacity of a septic tank shall be the greater of 3 600 L and,
(a)in residential occupancies, twice the daily design sanitary sewage flow, or
(b)in non-residential occupancies, three times the daily design sanitary sewage flow.
(2)Every septic tank shall be constructed in such a manner that any sanitary sewage flowing through the tank will pass through at least 2 compartments.
(3)The working capacity of the compartments required in Sentence (2) shall be sized such that,
(a)the first compartment is at least 1.3 times the daily design sanitary sewage flow but in no case less than 2 400 L, and
(b)each subsequent compartment shall be at least 50% of the first compartment.
(4)Where multiple tanks are to be used to meet the requirements of Sentences (2) and (3), the tanks shall be connected in series such that,
(a)the first tank in the series shall have at least a capacity as calculated in Clause (3)(a), however at no time shall a tank having a working capacity of less than 3 600 L be used,
(b)all additional tanks after the first tank, excluding pump or dosing tanks shall have at least a working capacity equal to the volume required by Clause (3)(b),
(c)the pipe between the outlet of one tank and the inlet of the next tank in the series shall have a minimum slope of 2 percent,
(d)there shall be no partitions in the tank except where a partition is required to maintain the structural integrity of the tank, in which case openings within the partition shall be provided to allow the free movement of sanitary sewage throughout the tank, and
(e)all piping between tanks shall be continuous and shall be connected to the tank through the use of flexible watertight seals that will permit differential movement between the tanks.
(5)Partitions separating the septic tank into compartments shall extend at least 150 mm above the liquid level at the outlet, and there shall be one or more openings through or above the partition.
(6)The openings required between compartments referred to in Sentence (2) shall have a total cross-sectional area of at least three times the area of the inlet pipe and be located between the top and a level 150 mm above the liquid level at the outlet to provide for the free flow of air between compartments.
(7)Sanitary sewage shall pass from one compartment to another of the septic tank as follows:
(a)by means of a device similar to that described in CSA B66, “Design, Material, and Manufacturing Requirements for Prefabricated Septic Tanks and Sewage Holding Tanks” for outlet devices, or
(b)through two or more openings through the partition located in a horizontal line, and evenly spaced across the width of the partition, centred at approximately 40% of the liquid depth below the surface of the liquid, and having a total area of between three and five times that of the cross-sectional area of the inlet pipe.
(8)A septic tank shall be of such design and construction as will permit the collection and holding of sanitary sewage in it to a depth of not less than 1 000 mm, except that a depth of not less than 900 mm is permitted where the excavation is in rock, or to avoid rupture or displacement of the tank due to ground water pressure.
(9)Except as provided in Sentences (10) and (11), every septic tank shall be installed in such a manner that the access openings are located not more than 300 mm below the ground surface.
(10)Where the top of the septic tank is located more than 300 mm below the ground surface, it shall be equipped with risers that extend from the access opening of the septic tank to within 300 mm of the ground surface.
(11)Where risers are used they shall conform to the requirements of CSA B66, “Design, material, and manufacturing requirements for prefabricated septic tanks and sewage holding tanks,” and shall have adequate access openings to allow for regular maintenance of the septic tank.
8.2.2.4. Holding Tanks Copy linkAdd bookmark
(1)All holding tanks shall be of such design and construction as will allow the complete removal of solid matter that can be expected to settle in the holding tank through an apparatus or device suitable for allowing the contents of the holding tank to be removed from the holding tank.
(2)A holding tank shall have a working capacity of not less than 9 000 L.
(3)Where two or more tanks are used to meet the requirement of Sentence (2), they shall be deemed to be one holding tank provided they are connected in such a manner as will allow the sanitary sewage contained in them to flow between the tanks.
(4)The working capacity of the tanks described in Sentence (3) shall not include any portion of any tank that cannot be completely drained due to the manner in which the connections are made.
Section 8.3. Class 1 Sewage Systems Copy linkAdd bookmark
8.3.1. General Requirements Copy linkAdd bookmark
8.3.1.1. Scope Copy linkAdd bookmark
(1)This Section applies to the construction of a Class 1 sewage system.
8.3.1.2. Application Copy linkAdd bookmark
(1)Except as provided in Sentence (2), a Class 1 sewage system shall be designed to receive only human body waste for disposal.
(2)Where the sewage system is specifically designed for the biological decomposition of non-waterborne biodegradable kitchen wastes or requires the addition of small quantities of plant matter to improve the decomposition of human body waste, it may receive such wastes in addition to human body waste.
(3)Where the sewage system is designed with a drain for the removal of excess liquid, then the sewage system shall drain to a Class 3, 4, or 5 sewage system.
8.3.2. Superstructure Requirements Copy linkAdd bookmark
8.3.2.1. Construction Requirements Copy linkAdd bookmark
(1)A privy as described in Subsections 8.3.3. to 8.3.5. shall be enclosed with a superstructure that,
(a)is constructed of strong durable weatherproof materials,
(b)has a solid floor supported by a sill constructed of treated timber, masonry or other material of at least equal strength and durability,
(c)is easily sanitized,
(d)unless it is equipped solely as a urinal, is equipped with one or more seats each having a cover and being supported by an enclosed bench or riser that is lined with an impervious material on all interior vertical surfaces,
(e)is equipped with a self-closing door,
(f)has one or more openings for purposes of ventilation, all of which are screened,
(g)has a ventilation duct that is screened at the top end and that extends from the underside of the bench or riser to a point above the roof of the superstructure, and
(h)shall not have any openings for the reception of human body waste, other than urinals and those constructed in accordance with Clause (1)(d).
8.3.3. Earth Pit Privy Copy linkAdd bookmark
8.3.3.1. Construction Requirements Copy linkAdd bookmark
(1)An earth pit privy shall be constructed in the following manner:
(a)the bottom of the pit shall be at least 900 mm above the high ground water table,
(b)the sides of the pit shall be reinforced so as to prevent their collapse,
(c)the pit shall be surrounded on all sides and on its bottom by not less than 600 mm of soil or leaching bed fill, and
(d)the soil or leaching bed fill around the base of the sides of the superstructure of the earth pit privy shall be raised or mounded to a height of at least 150 mm above ground level.
8.3.4. Privy Vaults and Pail Privy Copy linkAdd bookmark
8.3.4.1. Construction Requirements Copy linkAdd bookmark
(1)A privy vault or a pail privy shall be constructed in the following manner:
(a)the container or structure that is to be used for the holding or storage of sanitary sewage shall be watertight and made of a material that can be easily cleaned,
(b)the soil or leaching bed fill around the base of the sides of the superstructure shall be raised or mounded to a height of at least 150 mm above ground level, and
(c)the surface of the ground in the area of the privy vault or pail privy shall be so graded that surface drainage will be diverted away from the privy.
8.3.5. Portable Privy Copy linkAdd bookmark
8.3.5.1. Construction Requirements Copy linkAdd bookmark
(1)A portable privy shall be constructed in the following manner:
(a)the portable privy shall have a watertight receptacle that shall be suitable for the holding and storage of any sanitary sewage deposited in it,
(b)the receptacle for the holding and storage of sewage shall be designed and constructed in such a manner as to allow it to be easily emptied and cleaned, and
(c)the portable privy shall be constructed of such material and in such a manner that it can withstand the stresses to which it will be subjected during its transportation to and from sites where it is to be used and during loading and unloading from vehicles used for the transportation of the portable privy to and from sites where it is to be used.
Section 8.4. Class 2 Sewage Systems Copy linkAdd bookmark
8.4.1. General Requirements Copy linkAdd bookmark
8.4.1.1. Scope Copy linkAdd bookmark
(1)This Section applies to the construction of a Class 2 sewage system.
8.4.1.2. Application (See Note A-8.4.1.2.) Copy linkAdd bookmark
(1)A Class 2 sewage system shall be designed only for the treatment and disposal of greywater.
(2)The total daily design flow for a Class 2 sewage system shall be calculated based on the fixtures discharging to the system as follows:
(a)200 L per fixture unit where there is a supply of pressurized water, and
(b)125 L per fixture unit where there is no supply of pressurized water.
8.4.2. Design and Construction Requirements Copy linkAdd bookmark
8.4.2.1. Construction Requirements Copy linkAdd bookmark
(1)The bottom of the pit shall be at least 900 mm above the high ground water table.
(2)The pit shall be constructed in such a manner as to prevent the collapse of its sidewalls.
(3)Any material used to support or form the sidewalls of the pit shall be an open jointed material of a type that will permit leaching from the pit.
(4)The pit shall be provided with a tight, strong cover that shall remain over the pit except when it is necessary to remove it for purposes of adding greywater to or removing greywater from the pit or for purposes of maintenance of the pit.
(5)The earth around the perimeter of the pit shall be raised or mounded to a height of at least 150 mm above ground level.
(6)The surface of the ground in the area of the pit shall be so graded that surface drainage in the area will be diverted away from the pit.
(7)The pit shall be surrounded on all sides and on its bottom by at least 600 mm of soil having a percolation time of less than 50 minutes.
8.4.2.2. Maximum Sewage Flow Copy linkAdd bookmark
(1)A Class 2 sewage system shall not be constructed where the daily design greywater flow to the system exceeds 1 000 L/day.
8.4.2.3. Sizing Copy linkAdd bookmark
(1)A Class 2 sewage system shall be designed and constructed so that the loading rate to the side walls shall be not more than the value calculated using the formula, LR = 400 / T where, LR = loading rate of the sidewalls in litres per day/m2, and T = percolation time.
Section 8.5. Class 3 Sewage Systems Copy linkAdd bookmark
8.5.1. General Requirements Copy linkAdd bookmark
8.5.1.1. Scope Copy linkAdd bookmark
(1)This Section applies to the construction of a Class 3 sewage system.
8.5.1.2. Application Copy linkAdd bookmark
(1)A Class 3 sewage system shall not be constructed where the daily design sanitary sewage flow to the system exceeds 1 000 L/day.
(2)A Class 3 sewage system shall be designed to receive only the contents of a Class 1 sewage system or effluent from a Class 1 sewage system for disposal.
8.5.2. Design and Construction Requirements Copy linkAdd bookmark
8.5.2.1. Construction Requirements Copy linkAdd bookmark
(1)The bottom of the cesspool shall be at least 900 mm above the high ground water table.
(2)The cesspool shall be constructed in such a manner as to prevent the collapse of its sidewalls.
(3)Any material used to support or form the sidewalls of the cesspool shall be an open jointed material of a type that will permit leaching from the cesspool.
(4)The cesspool shall be provided with a tight strong cover that shall remain over the cesspool except when it is necessary to remove it for the purposes of adding sanitary sewage to or removing sanitary sewage from the cesspool or for purposes of maintenance of the cesspool.
(5)Where the cesspool extends to the ground surface, the cover required in Sentence (4) shall be lockable.
(6)The soil or leaching bed fill around the perimeter of the cesspool shall be raised or mounded to a height of at least 150 mm above ground level.
(7)The surface of the ground in the area of the cesspool shall be graded such that surface drainage in the area will be diverted away from the cesspool.
(8)The cesspool shall be surrounded on all sides and on its bottom by at least 600 mm of soil or leaching bed fill, except the top where the cesspool extends to the surface of the ground.
Section 8.6. Class 4 Sewage Systems Copy linkAdd bookmark
8.6.1. General Requirements Copy linkAdd bookmark
8.6.1.1. Scope Copy linkAdd bookmark
(1)This Section applies to the construction of a Class 4 sewage system.
8.6.1.2. General Requirements Copy linkAdd bookmark
(1)The treatment unit shall be connected to a leaching bed constructed in accordance with the requirements of Section 8.7.
8.6.1.3. Pumps and Siphons Copy linkAdd bookmark
(1)Where the total length of distribution pipe or leaching chamber required is 150 m or more, the sewage system shall have at least one pump or a siphon contained in a dosing tank that may be a separate compartment within the tank structure, for distribution of the effluent.
(2)Where the total length of leaching chamber is 150 m or more, a distribution pipe shall be installed at the centreline of the leaching chamber and extend the total length of leaching chamber to allow for dosing of the effluent.
(3)Alternating siphons shall not be installed in a sewage system.
(4)Where 2 or more pumps are employed within a dosing tank, the pumps shall be designed such that the pumps alternate dosing, and dosing shall continue in the event that one pump fails.
(5)Where a pump or siphon is required, the pump or siphon shall be designed to discharge a dose of at least 75% of the internal volume of the distribution pipe within a time period not exceeding fifteen minutes.
(6)Where a pump or siphon is required, the pump or siphon shall be equipped with a device that shall produce an audible and visual alarm signal that indicates a high water level in the pump or siphon chamber.
8.6.2. Treatment Units Copy linkAdd bookmark
8.6.2.1. Septic Tank Systems Copy linkAdd bookmark
(1)An effluent filter shall be installed in the outlet flow path of every septic tank that discharges effluent to a leaching bed.
(2)The septic tank effluent filter required by Sentence (1) shall,
(a)conform to the requirements of NSF/ANSI 46, “Evaluation of Components and Devices Used in Wastewater Treatment Systems,”
(b)be sized to filter particles of 1.6 mm,
(c)have a minimum area of 550 cm2, and
(d)be installed in accordance with the manufacturer’s recommendations.
(3)A secured access opening to allow for regular maintenance of the effluent filter shall be provided at the ground surface.
8.6.2.2. Other Treatment Units (See Note A-8.6.2.2.) Copy linkAdd bookmark
(1)Except as provided in Sentence (2), a treatment unit, other than a septic tank, shall be designed such that the effluent does not exceed, for the level of the treatment unit set out in Column 1 of Table 8.6.2.2., the maximum concentrations set out opposite it in Columns 2 and 3 of Table 8.6.2.2.
| Classification of Treatment Unit(1) | Suspended Solids(2) | CBOD5(2) |
|---|---|---|
| Level II | 30 | 25 |
| Level III | 15 | 15 |
| Level IV | 10 | 10 |
Notes to Table 8.6.2.2.:
(2)A treatment unit that is used in conjunction with a leaching bed constructed as a shallow buried trench, Type A dispersal bed or Type B dispersal bed shall be designed such that the effluent does not exceed the maximum concentrations set out opposite a Level IV treatment unit in Columns 2 and 3 of Table 8.6.2.2.
(3)All treatment units referred to in Sentences (1) and (2) that contain mechanical components shall be equipped with an audible and visual warning alarm so located to warn the occupants of the building served or the operator of the treatment unit of a malfunction in the operation of the treatment unit.
(4)All treatment units referred to in Sentences (1) and (2) shall permit the sampling of the effluent.
(5)A treatment unit is deemed to comply with Sentences (1) and (2) if it has been certified to CAN/BNQ 3680-600, “Onsite Residential Wastewater Treatment Technologies” using a temperature condition listed under option a) or b) of Clause 8.2.2. of that standard. (See Note A-8.6.2.2.(5))
(6)Every operator of a treatment unit shall obtain, from the manufacturer or distributor of the treatment unit, literature that describes the unit in detail and provides complete instructions regarding the operation, servicing, and maintenance requirements of the unit and its related components necessary to ensure the continued proper operation in accordance with the original design and specifications.
Section 8.7. Leaching Beds Copy linkAdd bookmark
8.7.1. General Requirements Copy linkAdd bookmark
8.7.1.1. Scope Copy linkAdd bookmark
(1)This Section applies to the construction of leaching beds.
8.7.1.2. Limitation on Installation Copy linkAdd bookmark
(1)The design and installation of a shallow buried trench, Type A dispersal bed or Type B dispersal bed shall be carried out by a person competent in this field of work.
8.7.2. Design and Construction Requirements Copy linkAdd bookmark
8.7.2.1. General Requirements Copy linkAdd bookmark
(1)A leaching bed shall not be located,
(a)in an area that has an average slope that exceeds one unit vertically to four units horizontally,
(b)in soil or leaching bed fill having a percolation time of,
(i)less than one minute, or greater than 125 minutes if constructed as a shallow buried trench, or
(ii)less than one minute, or greater than 50 minutes for all other leaching beds, or
(c)in or on an area that is subject to flooding that may be expected to cause damage to the leaching bed or impair the operation of the leaching bed.
(2)A leaching bed shall not be covered with any material having a hydraulic conductivity less than 0.01 m/day.
(3)The surface of the leaching bed shall be shaped to shed water and together with the side slopes of any raised portion, shall be protected against erosion in such a manner as to not inhibit the evaporation and transpiration of waters from the soil or leaching bed fill, and to not cause plugging of the distribution pipe.
(4)No part of a leaching bed shall be sloped steeper than 1 unit vertically to 4 units horizontally.
(5)A leaching bed shall be designed to be protected from compaction or any stress or pressure that may result in,
(a)the impairment or destruction of any pipe in the leaching bed, or
(b)the smearing of the soil or leaching bed fill.
8.7.2.2. Distribution Pipes within Leaching Beds Copy linkAdd bookmark
(1)Sentence (2) applies to the design and construction of a leaching bed with distribution pipes used within the leaching bed.
(2)The header line and distribution pipes within a leaching bed shall be designed and constructed so that they can be detected by,
(a)magnetic means,
(b)means of a 14 gauge TW solid copper light coloured plastic coated tracer wire, or
(c)other means of subsurface detection.
8.7.2.3. Leaching Chambers within Leaching Beds Copy linkAdd bookmark
(1)Leaching chambers are permitted for use in conjunction with an absorption trench, shallow buried trench, filter bed or Type A dispersal bed.
(2)Leaching chambers shall comply with the dimension requirements for either a Type I or Type II leaching chamber listed in Table 8.7.2.3.
(3)Leaching chambers shall conform to the requirements of IAPMO PS 63, “Plastic Leaching Chambers”.
(4) The header line and leaching chambers within a leaching bed shall be designed and constructed so that they can be detected by,
(a)magnetic means,
(b)means of a 14 gauge TW solid copper light coloured plastic coated tracer wire,
(c)means of a 12 gauge copper clad steel light coloured plastic coated tracer wire, or
(d)other means of subsurface detection.
| Type of Leaching Chamber | Width, mm | Height, mm |
|---|---|---|
| Type I | 380 to 410 | 280 to 305 |
| Type II | 555 to 575 | 300 to 320 |
8.7.3. Absorption Trench Construction Copy linkAdd bookmark
8.7.3.1. Length of Distribution Pipe Copy linkAdd bookmark
(1)The total length of distribution pipe shall,
(a)not be less than 30 m when constructed as a shallow buried trench, or
(b)not be less than 40 m for any other absorption trench.
(2)Except as provided in Sentences (1), (3), and (4) every leaching bed constructed by means of absorption trenches shall have a total length of distribution pipe not less than the value determined by the formula, L = QT / 200 where, L = total length of distribution pipe in metres, Q = the total daily design sanitary sewage flow in litres, and T = the design percolation time.
(3)Except as provided in Sentence (1), where a leaching bed receives effluent from a Level II, Level III or Level IV treatment unit as described in Table 8.6.2.2., the leaching bed may have a total length of distribution pipe not less than the value determined by the formula, L = QT / 300 where, L = total length of distribution pipe in metres, Q = the total daily design sanitary sewage flow in litres, and T = the design percolation time.
(4)Except as provided in Sentence (1), where the leaching bed is constructed as a shallow buried trench, the total length of the distribution pipe shall not be less than the value determined by Table 8.7.3.1. where, Q = the total daily design sanitary sewage flow in litres, and T = the design percolation time.
| Percolation Time, (T) of Soil, min | Length of Distribution Pipe, m |
|---|---|
| 1 < T ≤ 20 | Q/75 |
| 20 < T ≤ 50 | Q/50 |
| 50 < T < 125 | Q/30 |
8.7.3.2. Length of Leaching Chamber Copy linkAdd bookmark
(1)The total length of leaching chamber shall,
(a)not be less than 30 m when constructed as a shallow buried trench, or
(b)not be less than 40 m for any other absorption trench.
(2)Except as provided in Sentences (1) and (3), the total length of leaching chamber shall not be less than the value determined by the formula, L = QT/200, for a Type I leaching chamber, or L = QT/300, for a Type II leaching chamber, where, L = total length of leaching chamber in metres, Q = the total daily design sanitary sewage flow in litres, and T = the design percolation time.
(3)When a treatment unit described in Article 8.6.2.2. is used in conjunction with a leaching chamber, the total length of leaching chamber shall not be less than the value determined by the formula, L = QT/300 where, L = total length of leaching chamber in metres, Q = the total daily design sanitary sewage flow in litres, and T = the design percolation time.
(4)Except as provided in Sentence (1), where the leaching bed is constructed as a shallow buried trench, the total length of leaching chamber shall not be less than the value determined by Table 8.7.3.2. where, Q = the total daily design sanitary sewage flow in litres, and T = the design percolation time.
| Percolation Time, (T) of Soil, min | Length of Leaching Chamber, m |
|---|---|
| 1 < T ≤ 20 | Q/75 |
| 20 < T ≤ 50 | Q/50 |
| 50 < T < 125 | Q/30 |
8.7.3.3. Absorption Trenches Copy linkAdd bookmark
(1)Except as provided in Sentence (2), absorption trenches shall be,
(a)approximately the same length and not more than 30 m in length,
(b)not less than 500 mm and not more than 1 000 mm in width,
(c)not less than 600 mm and not more than 900 mm in depth,
(d)centred not less than,
(i)1 600 mm apart where used in conjunction with,
(A)a distribution pipe,
(B)a Type I leaching chamber, or
(C)a Type II leaching chamber constructed in leaching bed fill, or
(ii)2 400 mm apart where used in conjunction with a Type II leaching chamber, other than a Type II leaching chamber constructed in leaching bed fill,
(e)located so that the bottom of the absorption trench is not less than 900 mm above the high ground water table, rock or soil with a percolation time of more than 50 minutes, and
(f)backfilled, after the installation of the distribution pipe or leaching chamber with leaching bed fill, so as to ensure that after the leaching bed fill settles, the surface of the leaching bed will not form any depressions.
(2)Absorption trenches constructed as a shallow buried trench shall be,
(a)approximately the same length and not more than 30 m in length,
(b)not less than 300 mm and not more than 600 mm in width,
(c)not less than 300 mm and not more than 600 mm in depth,
(d)centred not less than 2 000 mm apart,
(e)not less than 900 mm at all points on the bottom of the absorption trench above the high ground water table or rock, and
(f)backfilled, after the installation of the distribution pipe with leaching bed fill, so as to ensure that after the leaching bed fill settles, the surface of the leaching bed will not form any depressions.
8.7.3.4. Distribution Pipe Copy linkAdd bookmark
(1)Except for a shallow buried trench, the distribution pipe used in the construction of a leaching bed shall be,
(a)not less than 3 in. trade size for gravity flow systems,
(b)installed with a uniform downward slope from the inlet with a drop of not less than 30 mm and not more than 50 mm for each 10 m of distribution pipe for gravity flow systems, and
(c)installed within a layer of stone conforming to Sentence (5).
(2)Prior to backfilling, the stone layer required by Clause (1)(c) shall be protected in such a manner so as to prevent soil or leaching bed fill from entering the stone by completely covering it with,
(a)untreated building paper, or
(b)a permeable geo-textile fabric.
(3)Every pressurized distribution pipe shall be self-draining so as to prevent freezing of its contents.
(4)Every pressurized distribution pipe shall,
(a)be not less than 1 in. trade size, and
(b)have orifices of at least 3 mm in diameter, spaced equally along the length of the pipe to provide even distribution of the effluent.
(5)The stone layer required by Clause (1)(c) shall,
(a)be comprised of washed septic stone, free of fine material, with gradation conforming to Table 8.7.3.4.,
(b)be not less than 500 mm in width,
(c)extend not less than 150 mm below the distribution pipe, and
(d)extend not less than 50 mm above the distribution pipe.
(6)This Article does not apply to a distribution pipe within a leaching chamber.
| Particle Size | Percent Passing |
|---|---|
| 53 mm | 100 |
| 19 mm | 0 - 5 |
| 75 µm | 0 - 1 |
8.7.3.5. Leaching Chamber Copy linkAdd bookmark
(1)Prior to backfilling, the leaching chamber shall be,
(a)installed level over the length of the absorption trench,
(b)securely connected together, section to section,
(c)free of structural damage, uncut and used full length,
(d)equipped with end caps installed on both ends,
(e)equipped with an integrated splash plate at the inlet end of each line of leaching chamber, to prevent soil scouring, and
(f)protected in such a manner so as to prevent soil or leaching bed fill from entering the leaching chamber.
(2)Except for a shallow buried trench, the distribution pipe within a leaching chamber shall be not less than 3 in. trade size for dosed systems.
(3)Every pressurized distribution pipe within a leaching chamber shall,
(a)extend over the entire length of the leaching chamber,
(b)be not less than 1½ in. trade size,
(c)have orifices of at least 6 mm in diameter, spaced equally along the length of the pipe to provide even distribution of the effluent,
(d)be supported,
(e)be self-draining so as to prevent freezing of its contents, and
(f)have cleanouts installed at the downstream end of each line of leaching chamber to allow for servicing of the system.