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BCC Ruling No. 99-54-710

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BUILDING CODE COMMISSION DECISION ON B.C.C. #99-54-710

IN THE MATTER OF Subsection 24 (1) of the Building Code Act, 1992.

AND IN THE MATTER OF Sentence 8.4.2.2.(1) of Regulation 403, as amended by O. Reg. 22/98, 102/98, 122/98, 152/99 and 278/99 (the "Ontario Building Code").

AND IN THE MATTER OF an application by Ms. Lillian Hall & Mr. Larry Hall, property owners, Ajax, Ontario, for the resolution of a dispute with Mr. Michael Strachan, Public Health Inspector, Regional Municipality of Durham, Ontario to determine whether the proposed Class 1 and 2 sewage systems to serve a residential dwelling equipped with certain water conservation devices but with an estimated daily sanitary sewage flow of 2,700 litres per day provides sufficiency of compliance with Sentence 8.4.2.2.(1) of the Ontario Building Code at 24 Chalk Lake Road, Scugog, Ontario.

APPLICANT

Ms. Lillian Hall & Mr. Larry Hall
Property Owners
Ajax, Ontario

RESPONDENT

Mr. Michael Strachan
Public Health Inspector
Regional Municipality of Durham

PANEL

Mr. Bryan Whitehead (Chair-Designate)
Mr. Bill Fellner
Mr. Doug Robinson

PLACE

Toronto, Ontario

DATE OF HEARING

August 19, 1999

DATE OF RULING

August 19, 1999

APPEARANCES

Mr. Martin Liefhebber, Architect
Martin Liefhebber Architects Ltd.
Toronto, Ontario
Agent for the Applicant

Mr. Michael Strachan
Public Health Inspector
Regional Municipality of Durham

The Respondent

RULING

  1. The Applicant

Ms. Lillian Hall and Mr. Larry Hall, property owners, have applied for a building permit under the Building Code Act, 1992 to install Class 1 and 2 sewage systems at their proposed year-round dwelling at 24 Chalk Road, Scugog, Ontario.

  1. Description of Construction

The Applicants are proposing to install a new Class 1 and 2 sewage systems to serve a single detached Group C - residential dwelling. The proposed dwelling will contain two bedrooms, and will have a total finished area of 181.2 m2.

The proposed Class 1 system will consist of two composting toilets. The greywater generated by the 13.5 fixture units is to be disposed of in the proposed Class 2 leaching pit. The building is to be equipped with a pressurized water system.

The construction in dispute involves the calculated total daily design flow. The proposed building has an estimated daily design sewage flow of 2,700 litres per day, based on 13.5 fixture units at an assumed 200 L/day per unit with a pressurized water system. The Applicants, however, are proposing to install water conservation devices on as many of the fixture units as possible. The showers and faucets, for example, will be fitted with low flow heads. According to the Applicants' calculations this will reduce the daily sewage flow to roughly 450 L/day.

The Applicants had previously received a building permit for the construction of a Class 4 sewage system equipped with an Ecoflo tertiary treatment unit. This proposal was not pursued by the Applicants since installing this entire system, including the 15 by 7 m mantle, was considered to be destructive to the natural conditions of the site.

The lot is described as sloping (1:10) to the lake, mostly covered with mature trees (the lower third of the property is wetland) and measures approximately 67.8 by 35 m, for a total approximate area of 0.3 ha. The depth to the high groundwater table is roughly 1.1 m. The native soil has a percolation rate ranging between 15 to 30 minutes per centimetre. The site is located in the Oak Ridges Moraine and thus the soil is described as a mixture of sand and silt with bedrock found 80 m or more below the surface.

The water supply to the site will be by a drilled well.

  1. Dispute

The issue at dispute between the Applicant and Respondent is whether the proposed Class 1 and 2 sewage systems to serve the subject permanent residential dwelling with an estimated daily design flow of 2,700 litres per day but which is equipped with certain water conservation devices provides sufficiency of compliance with Sentence 8.4.2.2.(1) of the Ontario Building Code. This Sentence requires that a greywater system, used in conjunction with a pressurized water system, that discharges into a Class 2 leaching pit be limited to a maximum capacity of 1,000 litres per day. The calculated flow far exceeds this amount. The Applicants have tried to achieve this limit by fitting many of their fixture units with water conservation devices.

  1. Provisions of the Ontario Building Code

Sentence 8.4.2.2.(1) Maximum Sewage Flow

(1) A Class 2 sewage system shall not be constructed where the daily design greywater flow to the system exceeds 1,000 L/day.

  1. Applicant's Position

The Applicants submitted that the proposed water conservation measures reduce their actual daily design flow to less than the calculated flow of 2,700 L/day. They indicated that they have proposed numerous devices to ration their water use. Besides low flow faucets and composting toilets they are also proposing to install a Miele dishwasher and a tumbler-type washing machine. The combined effect of all these devices would, they argued, reduce the daily flow to less than 450 L/day.

The Applicants described each fixture unit and indicated the potential water savings they would achieve. For example, since the composting toilets would not be connected to the proposed sewage system this would yield 100% savings. They explained that they derived these figures based on various sources, including the Light Grey Option report by CMHC which provided a break-down of water use per fixture units in a house. The Applicants also indicated that based on the OBC flow rates and estimated duration of use would mean that extremely high water consumption would have to occur (e.g. 55 loads of the dishwasher) to achieve anywhere near the volumes specified in the Code.

The Applicants argued that their derived figure of 450 L/day is a conservative estimate. They indicated that number was based on four people occupying the house when only two will use the residence on an on-going basis.

Lastly, they expressed a willingness to have their proposed system monitored.

  1. Respondent's Position

The Respondent submitted that the calculated daily flow for the proposed dwelling with 13.5 fixture units is 2,700 L/day. Sentence 8.4.2.2.(1) of the Code, they noted, only allows 1,000 L/day for a leaching pit combined with a pressurized water system. As a result, they noted that the proposal did not conform to the requirements of the Code.

The Respondent also indicated that monitoring would be difficult due to lack of resources and a clear mandate.

  1. Commission Ruling

It is the decision of the Building Code Commission that the Class 2 sewage system proposed to service a permanent residential dwelling fails to provide sufficiency of compliance with Sentence 8.4.2.2.(1) of the Ontario Building Code.

  1. Reasons

The total fixture units which would drain to the Class 2 leaching pit would be 13.5. Based on 8.4.1.2.(2) the calculated flow for design purposes would be 2,700 litres per day, which exceeds the 1,000 litres per day permitted under Sentence 8.4.2.2.(1).

Dated at Toronto this 19th day in the month of August in the year 1999 for application number 1999-45

Mr. Bryan Whitehead, Chair-Designate

Mr. Bill Fellner

Mr. Doug Robinson