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BCC Ruling No. 99-43-699

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

AND IN THE MATTER OF Article 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 Mr. Andre Beaudet, homeowner, Carp, Ontario, for the resolution of a dispute with Mr. R.W.J. Moore, Chief Building Official, Township of West Carleton, Ontario to determine whether the deck, as constructed, with less than 1.5 m setback from the septic tank provides sufficiency of compliance with Article and whether the proposed screened porch situated on the subject deck provides sufficiency of compliance with the same Article of the Ontario Building Code at 128 Greystone Drive, Carp, Ontario.


Mr. Andre Beaudet
Carp, Ontario


Mr. R.W.J. Moore
Chief Building Official
Township of West Carleton


Mr. Bryan Whitehead (Chair-Designate)
Mr. Bill Fellner
Mr. Frank Wright


Toronto, Ontario


June 24, 1999


June 24, 1999


Mr. Andre Beaudet
Carp, Ontario
The Applicant

Mr. R.W.J. Moore
Chief Building Official
Township of West Carleton
The Respondent


  1. The Applicant

Mr. Andre Beaudet, homeowner, has received an order to comply under the Building Code Act (BCA), 1992 to provide the required minimum clearance distance between a deck attached to the rear of his residence and the septic tank and he has also applied for a building permit under the BCA to enclose the subject deck with a screened porch at 128 Greystone Drive, Carp, Ontario.

  1. Description of Construction

The Applicant's Group C - residential dwelling is currently served by a raised Class 4 sewage system. The building is described as a two storey, single detached structure containing 3 bedrooms, 23.5 fixture units and has a total finished floor area of 234.6 m2. The calculated total daily design flow is 2,200. Both the building and the sewage system were built in 1991.

The existing sewage system consists of a 4,500 L septic tank which feeds, by gravity disposal, a leaching bed composed of six runs of 8 m each (spaced 0.75 m apart on centre) for a total of 48 m of distribution pipe. The partially raised disposal bed and surrounding mantle has a total hydraulic footprint of 127.8 m2 and was constructed with 25 mm crushed stone as the filter media set in and covered with sand fill. The sewage system appears to be functioning well.

The site is a 0.8 hectare "country lot". The soil profile is sand to a depth of 0.9 m and the high water table is located at least 0.9 m below grade. The site is served by a well water system.

The construction in dispute involves an "L-shaped" deck (6.7 m by 3.66 m) connected to the rear of the dwelling. The deck does not provide a minimum of 1.5 m clearance distance to the septic tank servicing the property. The actual distance between the edge of the deck and the septic tank is 0.45 m. (The deck was apparently built sometime after the house and septic system were constructed. There is disagreement between the parties as to whether the deck had been constructed at the time of the final inspection and when the final inspection occurred - either early 1992 or March 93.) The rectangular septic tank measures approximately 2.9 m by 1.65 m, with the width of the tank running parallel to the deck.

In the fall of 1998, the Applicant submitted a building permit application to enclose the deck with an unconditioned screened porch. This proposal is also in dispute. As part of the proposed work the existing deck foundation piers would be replaced with 6 x 6 pressure treated posts to support the weight of the enclosure. It was during an inspection for the proposed work that the clearance distance deficiency was discovered. The application for the porch enclosure was subsequently denied and an Order to Comply was issued regarding the noncompliance with the spatial separation.

  1. Dispute

The issue at dispute between the Applicant and Respondent is whether the deck, as constructed, with less than 1.5 m clearance distance from the existing septic tank, provides sufficiency of compliance with Sentence of the Ontario Building Code. This provision requires a minimum horizontal clearance distance of 1.5 m between a structure and a treatment unit, such as a septic tank. The Applicant's existing deck, which he is proposing to enclose, is currently situated only 0.45 m from the septic tank.

  1. Provisions of the Ontario Building Code

Article Clearances for a Class 4 or 5 Sewage System

(1) Except as provided in Sentences and (2), a treatment unit shall not be located closer than the minimum horizontal distances as set out in Table

(2) Except as provided in Sentences and (2), a distribution pipe shall not be located closer than the minimum horizontal distances set out in Table and these distances shall be increased when required by Sentence

(3) No building shall be constructed closer to any part of a sewage system than the clearances listed in Articles or

  1. Applicant's Position

The Applicant submitted that the deck as it is currently constructed does not interfere with the operation nor effectiveness of the septic system. He noted that since the development of the property eight years ago, the septic tank has needed servicing only once. Consequently, he argued that the existing configuration meets the intent of Sentence of the OBC regarding clearance distances.

The Applicant noted that when these sewage system were regulated by the Ministry of Environment under the Environmental Protection Act the Ministry circulated a directive dated June 14, 1999 stating that a person should not construct nor renovate a building in relation to a sewage system if it is "likely to affect the operation or effectiveness of the sewage system." He further noted that the letter goes on to indicate that "(c)learly,... a deck, provided that it does not cover the sewage system, will not affect the sewage system." Since the current setback requirements found in the OBC are the same as those under the Environmental Protection Act, he argued that the intent behind the provisions is similar. Therefore, because his deck does not cover the septic tank the Applicant indicated, in his view, that the existing setback of 0.45 m meets the intent of Sentence

The Applicant also argued that despite the proximity of the deck, the tank is still accessible. He argued that there is enough space on his two acre property that the tank could easily be removed and/or serviced without any interference with the deck or the leaching bed. He indicated that he had consulted an area sewage system contractor who assured him that removing the tank would not be a problem.

Lastly, the Applicant stated that he inherited this problem in February of 1992 when they purchased their house. He indicated that the house and deck have not been altered in any way since then.

  1. Respondent's Position

The Respondent submitted that with only a 0.45 m separation, the subject deck does not meet the stipulated distance found in Sentence The actual clearance distance is less than one third of the required setback, he noted. A deck, the Respondent argued, should appropriately be viewed as a structure under Part 8 of the Code. The foundation for a deck raises similar construction issues as other, larger structures. Moreover, the same replacement and maintenance concerns would be present. He indicated that a quick sampling of other jurisdictions in North America found that 1.5 m seemed to be the minimum clearance to a treatment unit.

Further, the Respondent argued that because structure is not defined in the OBC there is no direction to specifically exclude decks from this setback requirement. He also noted that there are no exemptions that would be applicable to this situation since it should not be considered a renovation under Part 11, nor do the soil conditions warrant it.

As the Respondent noted, the deck was built without a building permit. Had a permit been applied for, it would have been refused. This would have true even under the previous regulations in the Environmental Protection Act. As well, without benefit of design review and inspection, he indicated that he had concerns about the structural adequacy of the existing deck.

Finally, the Respondent indicated that he had serious doubts about whether replacement of the current septic tank would be possible without significant disruption to the deck foundation. In his view, a 1.5 m excavation pit around the perimeter of tank would be necessary. Lastly, he expressed concern about the proposed new foundation piers and the possibility that they may undermine the soil under the tank and the leader pipe from the house.

  1. Commission Ruling

It is the decision of the Building Code Commission that the separation between the existing septic tank and the existing deck provides sufficiency of compliance with Table

With respect to the proposal to construct a screened porch on top of the existing deck and to modify the existing support piers, it is the decision of the Building Code Commission that the separation between the modified structure and the existing septic system provides sufficiency of compliance with Table as long as the design of the support piers is confirmed by a consulting engineer and the engineer certifies that the construction did not negatively affect the performance of the septic tank.

  1. Reasons

i) The deck and tank have been in co-existence from some six plus years and the presence of the deck has not apparently impacted on the performance of the septic tank.

ii) The septic tank is adequately separated from the foundation of the existing dwelling.

iii) The existing deck and proposed structure will not negatively impact on the maintenance of the tank.

iv) There is sufficient area and accessibility to replace the septic tank 1.5 metres beyond the structure.

v) The engineering certification ensures that the performance of the tank will not be negatively impacted by the construction.

Dated at Toronto this 24th day in the month of June in the year 1999 for application number 1999-36

Mr. Bryan Whitehead, Chair-Designate

Mr. Bill Fellner

Mr. Frank Wright