Lagoon Septic Systems in British Columbia have been traditionally used to provide dispersal on large (4 acres or larger) sites with heavy clay soils.
These types of waste water treatment systems rely on evaporation, (and some infiltration into the soil) of the effluent to achieve safe dispersal of the effluent.
These systems can have septic tanks present to facilitate pretreatment and maintenance of the system, and having one can extend the life of the cell almost indefinitely.
Though the regulations refer to them as “zero discharge”and they are not cesspools(sometimes referred to as rock pits), many lagoon septic systems can in fact be discharging.
The cause of the discharge is sometimes due to the manner in which the cell was installed. If the organic soils in the berm areas are not properly removed at the time of installation, the effluent in the cell can migrate through the organic soil and escape the cell.
Another very common cause of effluent escaping the cell is lack of maintenance. The lagoon cell will have an “Operation and Maintenance Plan” if it was constructed after the end of May, 2005. This plan requires that the vegetation be controlled within the cell. Leaving plant growth in the cell unchecked can result in animals entering the cells to feed on the plants.
While deer and moose can do damage to the fence around the cell, a far more serious and potentially costly problem can result when rodents enter the cell.
Close examination of lagoon cells with an overabundance of vegetation often reveal the presence of muskrats and even beaver. While a muskrat is a relatively small creature, the problems they can create can be surprisingly large.
Muskrats, like beaver, live in dens. The abundant vegetation in an un-maintained lagoon cell offers a perfect place for muskrats to set up housekeeping and start a family. The adult muskrat will start by digging a den into the soft clay banks of the lagoon. The vegetation surrounding the cell is harvested and brought into the den by the adults as food for themselves and their young.
While it can be interesting to observe this beaver like activity, the long-term effects on the lagoon cell can be devastating.
The first signs of a rodent problem can be the browsed off vegetation, and small trails inside the fenced off area. If the muskrats have been present for some time you might notice sunken areas in the lagoon berms. This is caused when the tunnels and dens they have created eventually collapse. This is often followed by the appearance of 7.5-10 cm holes in the berms, some of which can lead to the outside area of the berms. These 3″-4″ holes can cause the liquid level in the cell to drop rapidly as the un-contained effluent escapes, and this can create a potentially serious health, safety, and environmental issue.
The work required to restructure the berms of an affected lagoon cell can be both costly and disruptive. The best way to avoid this problem is to ensure that the required maintenance is done to protect the lagoon cell. If you are unsure how to do this, you should contact an ROWP and have the cell looked at, along with a review of the operation and maintenance plan.
Onsite Installations Inc. provides these reviews free of charge, so please call or email if you would like to ensure that your lagoon wastewater treatment system is operating as designed.