Holding Tanks

A holding tank is an alternative method to treat domestic wastewater and differs from the typical septic system which consists of a septic tank and leaching bed. They are usually a last resort for permanent residences and more common among seasonal cottages. A holding tank consists of only a watertight vessel designed to store untreated household wastewater. Holding tanks are typically constructed of polyethylene, concrete, or fiberglass. Residents may have to install a holding tank, as opposed to a full septic system, due to limiting soil conditions, or proximity to water, neighbours etc. The main difference between a holding tank and a septic tank is a holding tank does not allow any of its content to leach away into the ground, whereas a septic tank releases partially treated wastewater to run through a leaching field for a second stage of treatment. When the wastewater enters the holding tank from the house, it stays there until a hauler pumps it out.

Since effluent does not drain into the soil, contents must be pumped out more frequently and hauled away. Depending on the size of the tank along with water usage, holding tanks may have to be pumped anywhere from every two weeks to every eight weeks. It’s important to get your holding tank pumped out as failure to do so will lead to wastewater backing up in the house. However, many newer holding tanks equipped with alarms which let the homeowner know that the tank needs to be pumped out.

Many residents have a written agreement with the sewage hauler which states the hauler will pump out the holding tank at reasonable intervals to avoid overfilling of the tank. Therefore, it is crucial that the holding tank be located and installed to accommodate regular removal of sewage. It is the responsibility of the homeowner to maintain their holding tank, if the tank gets damaged, untreated effluent could enter the surrounding soil and potentially reach the groundwater. Water conservation in the house is encouraged to decrease volume of wastewater entering the holding tank.