How are assessments conducted?
The Department of Health does not have any legislation outlining how subdivision assessments are to be conducted. This is up to the individual and/or company and includes any requirements that the local Planning Commission may impose such as requiring larger lots for density control.
However, if a conventional onsite sewage disposal is intended to be installed on a newly subdivided lot, then the lot must be subdivided such that a conventional system can be installed and meet all regulatory requirements (including setback distances, lot size and lot configuration) as outlined in the Onsite-Sewage Disposal System Regulation and Technical Guidelines for On-site Sewage Disposal Systems.
Onsite sewage disposal systems are designed and sized based on the estimated daily sewage flow while also considering the soil conditions and percolation rates as often determined by a test pit assessment. Laboratory soil analyses can also be used.
Minimum Requirements for New Lots (including remnants) requiring conventional onsite sewage disposal systems.
Minimum Lot Size – All lots created must be at least sized in accordance with Appendix B of the Technical Guidelines. Land area before the buffer (e.g. between 0-30 metres of a watercourse) may be included in the Lot Size calculation
Minimum Width and Depth – All lots created must include the minimum width in accordance with Appendix B of the Technical Guidelines. All lots created should also include a minimum depth of 38m.
Setback Distances - The septic tank and disposal field may be permitted at any location on a lot provided that all regulatory setbacks are respected. Please see Table 1 of the Technical Guidelines.
Estimated Daily Sewage Flow – Please refer to Appendix D of the Technical Guidelines. It is important to note that there is an increased minimum lot size and width for an estimated sewage flow above 1365 L/Day. As noted in Appendix D, 1365L/Day is considered the flow for a 3 bedroom home. A 4 bedroom home requires increased lot size and width as the estimated sewage flow is increased to 1705 L/Day.
When assessing a lot, special consideration should be given to slope, setbacks (i.e. wetlands, right-of-ways, watercourses, etc), environmental regulatory requirements (wetlands, watercourse, protected wellfields, etc.), whether the area is subject to flooding, proximity to industry, landfills, etc. to ensure an onsite disposal system can be installed on the property. Particular attention should be given when evaluating “oddly” shaped lots.