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BCC Ruling No. 99-24-680

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

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

AND IN THE MATTER OF an application by Mrs. Virginia Hinckley, cottage owner, 83 Lincoln Street, Melrose, Massachusetts, for the resolution of a dispute with Mr. Michael J. Gravel, Chief Building Official, , Peterborough County-City Health Unit, Ontario to determine whether the two proposed 5,000 litre holding tanks to serve a 110 m2 cottage containing 6 bedrooms situated on a 1,538 m2 island provide sufficiency of compliance with Article and Sentence of the Ontario Building Code at Island 15A, Stoney Lake, Township of Burleigh, Peterborough County, Ontario.


Mrs. Virginia Hinckley
Melrose, Massachusetts


Mr. Michael Gravel
Chief Building Official
Peterborough County-City Health Unit


Mr. Roy Philippe (Chair)
Mr. Doug Robinson
Mr. Bryan Whitehead


Toronto, Ontario


April 15, 1999


April 15, 1999


Mr. Richard Hinckley
Husband of Owner
Melrose, Massachusetts
Agent for the Applicant

Mr. Michael Gravelr
Peterborough County-City H. U.
The Respondent


  1. The Applicant

Mrs. Virginia Hinckley, cottage owner, Melrose, Massachusetts, has received a building permit under the Building Code Act, 1992 to install a Class 5 (holding tank) sewage system at her seasonal residence at Island 15A, Stoney Lake, Township of Burleigh, Peterborough County, Ontario.

  1. Description of Construction

The Applicants are proposing to install a new Class 5 sewage system at her 19th century single, detached, one and a half storey, Group C- seasonal residential dwelling located on Stoney Lake. The building is described as having six small bedrooms, 4.5 fixture units and a total finished floor area of 190 m2. The calculated daily design sewage flow rate is 3,000 litres per day. The Applicants are not contemplating any renovations to the existing structure.

The construction in dispute involves the Applicants' proposal to revise the current building permit allowing the installation of a 21,000 litre holding tank and instead installing two fibreglass 5,000 litre holding tanks to serve the grey water from the subject dwelling by means of gravity disposal. The cottage is equipped with a pressurized water system and the 10,000 litre holding tank system is proposed as a replacement for the current Class 2 leaching pit used for grey water disposal. (The two toilets in the cottage are electric incinerator models and will not be connected to the proposed holding tanks.) The Applicants are also proposing to install the two holding tanks mostly below grade 5 m to the north of the cottage. They have begun discussions with a local sewage hauler to enter into a holding tank service agreement.

The site is a 1,538 m2 island with a very gentle downward slope to the north and is covered with grass and some trees. The soil is described as sandy loam and has a variable depth from zero to 1.5 m in a few areas. Approximately thirty per cent of the island is exposed rock. The cottage is situation on the southern portion of the island, with the shoreline being 1.5 m to the south of the building and 16.8 m to the north. The percolation time of the native soil is 12 minutes per centimetre.

The subject dwelling is served by surface supply water pumped from the lake.

  1. Dispute

The issue at dispute between the Applicants and Respondent is whether the proposed holding tanks, with a total capacity of 10,000 litres, provides sufficiency of compliance with Sentence of the Ontario Building Code. This provision requires that residential buildings served by holding tanks must have a seven day holding capacity based on the daily design sewage flow rate. When applying this provision to the subject building which has a daily design sewage flow calculated at 3,000 L/d times seven days in accordance with sentence means that a 21,000 litre holding tank is required.

  1. Provisions of the Ontario Building Code

Article Acceptable Installation

(1) A Class 5 sewage system may be installed in the following circumstances:

(a) where the proposed use of the sewage system is for a temporary operation, excluding seasonal recreational use, not exceeding 12 months in duration,

(b) to permit the extension of an existing single-family dwelling provided that

(i) the extension will not increase the wastewater load, and

(ii) the building is already served by a Class 5 sewage system,

(c) to remedy an unsafe sewage system where the remediation of the unsafe condition by the installation of a Class 4 sewage system is impracticable,

(d) to upgrade a sewage system on an existing lot or parcel of land, where upgrading through the use of a Class 4 sewage system is not possible due to lot size or clearance limitations, or

(e) as an interim measure for a lot or parcel of land until municipal sewers are available, provided that the municipality undertakes to ensure the continued operation of an approved hauled sewage system until the municipal sewers are available.

(2) Where a Class 5 sewage system is installed, a written agreement for the disposal of sanitary sewage from the sewage system shall be entered into with a hauled sewage system operator.

Sentence Sizing of Holding Tanks

(1) All holding tanks used in residential dwellings shall have a minimum 7 day holding capacity based on the total daily design sanitary sewage flow.

  1. Applicant's Position

The Applicants submitted that the proposed 10,000 litre tank provides sufficiency of compliance with Sentence of the OBC. As they argued, the size of the proposed tank is more than adequate to serve the cottage and its current use. In describing the use of the cottage they indicated that it is not heated nor insulated and is therefore only occupied between late June and early September. They calculate that the cottage is only in use for 270 man days per year and that while it has six bedrooms they are never all in use, except for approximately six weekends during the summer.

The Applicants also argued based on a monitoring of usage that their cottage does not produce anywhere near the estimated 3,000 L/d of sewage flow. As they noted, they are continuing to use their electric incinerator toilets which means they would not contribute any sanitary waste to the holding tanks. Despite having a pressurized water system , the amount of grey water is also limited because of their current practices of using water such as taking "navy showers", etc. The Applicants estimated, in fact, that their actual water usage is 4,200 litre per month.

Moreover, both the barge and truck belonging to the local sewage hauler are not large enough to pump out the required 21,000 litre tank, the Applicants noted. This would likely require two pump outs per year. As they noted, for this cost they could also get the smaller tanks pumped out twice a year, if in fact they were to reach capacity at all.

Regarding the issue of the placement of the holding tanks, they argued that the larger tank would cause certain problems. The size of the tank, for example would mean that it would either very difficult or very costly to install it below grade at all. Having the tank installed basically on grade would create other problems, such as requiring mechanical pumping of effluent to reach the top of the tank. As well, since the island is situated in the Trent-Severn waterway, for water control purposes the waterway operators sometimes increase the water level to levels higher than nature would create and this high water may cause exposure problems for an unprotected holding tank not submerged below grade. They also added that the larger tank would dominate the limited landscape of the island.

Due to the fact that the island is too small and has very little ground cover, installing a Class 4 system is impossible, the Applicants argued. For this reason they approached the Health Unit with a proposal to install a holding tank suitable to their needs. However, because of the number of bedrooms in their cottage they are required under OBC Table to provide an excessively large holding tank, they argued. This Table, they noted, does not provide any allowances for seasonal dwellings. It is not their intent to avoid compliance with the regulations but they are looking for a practical application of the rules that takes into consideration their difficulties.

  1. Respondent's Position

The Respondent submitted that the Code requires that the holding tank for a six bedroom cottage is 21,000 litres based on a daily design sewage flow rate of 3,000 L/d. Although he sympathized with the Applicants' position, the Code, he noted was quite clear on the requirements for the subject holding tank. While he respected the Applicants' arguments regarding limited water usage, he indicated that he could not accept this as an alternative to the larger tank. The Respondent expressed concern that future users or owners of the cottage may have larger occupant loads at the cottage because of the number of bedrooms. For these reasons, he argued that the 21,000 litre holding tank was necessary.

Lastly, the Respondent indicated that he felt he had no authority to accept the Applicants' proposal.

  1. Commission Ruling

It is the decision of the Building Code Commission that the proposed two 5,000 litre holding tanks to serve a cottage containing 6 bedrooms situated on a 1,538 m2 island provides sufficiency of compliance with Article of the Building Code provided; a) it serves as a grey water system or, b) the holding capacity is increased to three tanks and 15,000 litres to serve the complete sewage system.

  1. Reasons

i) The toilets are presently electric and do not contribute to the sewage flow.

ii) Evidence presented indicate that monitored sewage flow is significantly below the daily design flow calculated in Table

iii) The cottage is a seasonal occupancy and that only four bedrooms are functionally useable.

iv) The Code presently requires monitoring of levels and contracts for pumping.

Dated at Toronto this 15th day in the month of April in the year 1999 for application number 1999-14

Mr. Roy Philippe, Chair

Mr. Doug Robinson

Mr. Bryan Whitehead