Treatment Plants & Tanks
A commercial system is defined by flows from a facility greater than 1,250 gallons per day. As flows increase, so does the need for a larger tank size and treatment plant. Pumps also need to be larger, control panels more complex, and mechanical components installed deeper.
How a Commercial Septic System Works
A typical commercial septic system with treated effluent uses a minimum of three tanks:
1. The first tank is a flow equalization tank that separates the sludge and scum from the water (effluent). This can be a two or three chambered tank that is connected to a treatment plant and controlled by a pump and control panel.
2. The second tank is the treatment plant. We use mostly MBBR (moving bed biofilm reactor) treatment plants that are engineered to meet the flow requirements of the specific project. These units can treat more than 25 cubic meters per day. A treatment plant changes the quality of the contaminated effluent by 80% once it has passed through them. Having a higher quality of effluent is extremely important to prevent the septic field form being organically overloaded (meaning when organics in the effluent overtake and coat the soil, reducing its absorption rate by blocking the ability for water to move through it). It’s important that effluent testing be done on these plants regularly to ensure the quality of the effluent meets manufacturer and design standards.
3. From the treatment plant, the now-treated effluent flows by gravity into the third tank – a dose tank. This tank is designed to hold all flows that are produced by the facility and time the flow’s release into the field. The configuration of pumps and valves will vary depending on the type and size of septic field required. Through a control panel, we manipulate when the pump’s on and off cycles will be activated. This is a huge benefit and protection for the septic field, as it’s then receiving a consistent amount of effluent at set times every day. The dose tank must be sized to handle different levels of flows, including peak flows. Learn more about septic fields here.