Mascouche: septic tank with phosphate removal system now mandatory

Mascouche: septic tank with phosphate removal system now mandatory

Are my septic tank and drainfield compliant?


It is now a requirement for many residences in Mascouche to install septic tanks with a phosphate removal system. The goal is to avoid discharging wastewater with phosphate into certain watercourses that already have a much too high level.

The water pond in Grand-Coteau Park in Mascouche is now considered a lake, called Lac Henri. All residences discharging wastewater into this lake must have a septic system that minimizes the phosphate level as much as possible. This mainly affects residences in Mascouche Heights.


What is a phosphate removal system? Two possible options for homeowners:

1. Opt for a sealed leach field

If your septic tank does not have a phosphate removal system, it is possible to install a leach field with a layered membrane to reduce the phosphate level. A membrane, composed of a Premier Tech Disinfection Filter (FDI), is used, and aeration pipes are installed over several layers of sand and stones, which act as a filter.

This type of leach field is often the most cost-effective solution but is only possible on large plots of land.

2. Choose a septic tank with phosphate reduction

Often used on plots of land that do not have space for a leach field, the septic tank itself can reduce the phosphate level through an electronic mechanism with aluminum plates. For example, the Premier Tech DPEC septic tank can reduce the amount of phosphate discharged into the environment to concentrations below 1 mg/L while minimizing the size of the leach field as much as possible.

This solution is more expensive but is often necessary for smaller plots of land.



Do I absolutely need to change my septic tank?

Although this new regulation is in effect, it is not mandatory to change your septic installations today. When your septic tank or drainfield no longer functions properly, you will need to review your installations, and depending on your residence’s location, you may need to install a new septic tank and drainfield with a phosphate removal system.

Want more information? Vallex Excavation has completed several sanitary installations in the municipality of Mascouche. Contact us for the installation of your septic tank and drainfield.


Vallex is constantly developing its expertise and is looking for new employees that wants to work in a dynamic team and a family atmosphere. Excavation is a job directly related to heavy machinery and in our domain, “heavy machinery” means passion. If you are one of those passionate, apply online now!