Materials to Use

Septic Tank and Holding Tanks

  • Must conform to the requirements of Canada Standards Association Standard B66 and must be marked to indicate conformance with CSA B66
  • Prefabricated tanks must be installed according to manufacturer’s specifications. Ex. a tank must be installed not deeper than the depth specified by the manufacturer
  • The tank must not be installed in an area where vehicles can drive over the top of the tank


  • Article specifies that distribution pipes for leaching beds must be not less than 3-inch trade size for gravity flow systems and 1-inch trade size for pressurized systems. The pipe most commonly used for gravity flow systems is either a 3-inch or 4-inch trade size PVC pipe, perforated at the 4,6, and 8 o’clock positions
  • The pipe should have an indicator strip in the 12 o’clock position to permit the alignment of all pipes and ensure perforations and positioned correctly
  • Pipes and fittings for pressurized systems must be strong enough to withstand pressure
  • Fittings are potential sources of failure, it is advisable to use as few as possible

Fill Materials

  • Septic stone must be washed and free of fine material
  • Fines should be less than 1% of total mass of the product
  • Stone layer should be covered with geo-textile to ensure pore spaces are not plugged
  • For a raised leaching bed, fill material should be uniformly graded, fine-to-medium sand with T-time ranging between 5 and 15 min/cm.
  • Uniformly graded soil is ideal because it does not compact over time whereas well graded soil will
  • Fill material with a T-time greater than 20 min/cm is not recommended for raised leaching beds and mantles, and can be difficult to install.