Environment & Inspections

Algoma Public Health

Class 5 - Holding Tank

  • Facebook
  • Email


If you would like to learn more please call the Environmental Health team at 705-759-5286.


Where an on-site sewage system cannot be installed on a property due to poor soil conditions or lack of area, holding tanks may be installed:

  1. Where the purposed use of the sewage system is for temporary operation, excluding seasonal use,
  2. To remedy an unsafe sewage system where the installation of a Class 4 sewage system is impracticable,
  3. To upgrade a sewage system for an existing building where upgrading through the use of a Class 4 sewage system is not possible due to lot size, site slope or clearance limitations,
  4. As an interim measure until municipal services are available.


Overall, the use of holding tanks is the last option when no other services are available or practical. All sewage that is generated from a household is plumbed to the tank(s), and then hauled off site to an approval disposal facility. Every year, millions of gallons of sewage is hauled from surrounding areas, and disposed at municipal treatment facilities, or approved sewage disposal sites. While holding tanks may be initially cheaper to install than a traditional sewage system, the pumping and hauling costs over the long term become more expensive to the property owner.


Please note the chart below for clearance distance for holding tank (Class 5) installations when preparing your site plan.


  Minimum Horizontal Distance in Metres From:  

A well with a water tight casing to a depth of at least 6 metres (Drilled Well)

Any other Well Any of: a lake, river, pond, stream, reservoir, or a spring not used as a sources of potable water A property line




15 15 15 3


*Please check with the municipality governing the location you are installing the system in to see if there are increased clearance distances in place - if so, the greater distance must be followed.


A Class 5 sewage system requires a written agreement for the disposal of sanitary sewage be entered into with hauled sewage system operator. All Class 5 systems shall be equipped with an audible and visual alarm to warn that the sewage system is nearing capacity. All holding tanks require a minimum 7-day holding capacity. Calculate your Daily Design Sewage Flow (Q) using the provided sheet, and multiply this value by 7 to determine the minimum volume of the holding tank.


Please note that these forms are not intended to be a comprehensive interpretation of the OBC design standards, but simply an aid for common installations. If you have any further questions about design or construction it is recommended you contact a licensed Designer or Installer.


Date of Creation: June 1, 2015

Last Modified: Oct 20, 2015