Grease Trap and Drain FAQ’s
Grease Trap FAQ's
Nothing. The terms "interceptor" and "trap" are completely interchangeable.
A grease trap is a passive plumbing control device designed to reduce the amount of fats, oils and greases (FOG) and food solids that enter the sanitary sewer collection system or on-site waste treatment system. In the case of a sewer system, local regulating authorities set by-law limits to the amounts of FOG and solids concentration that is permitted in the discharge wastewater. In the case of on-site treatment (or septic) systems, excessive FOG and solids will cause serious operational problems that can lead to system failure.
A grease trap is a tank specially designed to reduce the velocity of wastewater and allow the separation of the wastewater into three basic fractions - floatables (fats, oils & greases), solids and water - and allow the discharge of only the water fraction. This separation occurs because some wastes (such as fats, oils and greases) are lighter than water and others (such as food particles) are heavier. The lighter material floats to the top of the grease trap and is retained or intercepted. The heavy material sinks and is retained or intercepted, and the 'clean' water layer in the middle is allowed to pass out of the trap to the sewer.
Unfortunately, grease trap manufactures are NOT required to design traps to meet sewer-use bylaws, and only a very few do. As a result, most grease traps are seriously undersized and incapable of removing adequate amounts of FOG waste from wastewater.
A flow restrictor is a device designed to constrict the drainage pipe size between a plumbing fixture and the grease trap that services it, and thus, reduce the drainage flow so that a smaller grease trap can be used. Flow restrictors cause sinks, and the fixtures they service, to discharge very slowly (by as much as 10 times slower) and are extremely susceptible to causing drain blockages. Flow restrictors are required wherever small "box-type" grease traps are used. Removing a flow restrictor will severely reduce the grease trap’s efficiency. We strongly recommend you avoid grease traps that require a flow restrictor, but if your trap has a flow restrictor, do not remove it.
A grease trap only needs to be cleaned (emptied) when enough waste has accumulated to degrade its ability to effectively continue to separate waste. At this point the grease trap is bypassing waste to the sewer. The amount of waste a particular grease trap can retain is based on its waste retention capacity and its efficiency. Our technical service and sales staff determine optimal service intervals based on each individual site's waste accumulation rates and the size/efficiency of the grease trap. In addition, some municipal jurisdictions have mandated minimum service requirements.
The waste captured in the grease trap is organic. The grease trap is designed to capture and retain waste. Organic waste decomposes (rots) over time. As it decomposes, it creates odorous gasses. To minimize grease trap odours you can:
- reduce the amount of waste discharged down the drain - always use sink strainers, etc.
- make sure the grease trap lid is properly sealed and secured, and all required maintenance and repairs are completed
- make sure that fixtures connected to a grease trap have P-traps which are properly primed and full of water
- have your grease trap serviced regularly, before organic waste begins to decompose
A grease trap is always full of water. It takes very little grease to float and cover the surface of the water, giving the appearance that the trap is full. A grease trap only needs to be cleaned (emptied) when sufficient amounts of waste have accumulated to reduce the trap’s ability to separate waste.
No. Unfortunately, all grease traps allow some amounts of grease and solids to discharge into the drainage system. In addition, there are many factors that contribute to drain blockages, including drain piping deficiencies, discharging waste down the drain, having drains that are not connected to a grease trap, and other variables. However, regular scheduled grease trap maintenance performed on an adequate frequency cycle, combined with a properly sized and installed grease trap, is the best protection you can provide.
A grease trap will back up or flood only if there is a problem with the lid fastening system, and one of the following occurs:
- The drainage system downstream is blocked or partially blocked, causing the drain exiting the trap to flow slower than the drain entering the trap
- The outlet port of the grease trap is blocked or partially blocked, restricting the flow of waste out of the trap
- The grease trap is full of waste, which causes the outlet and drain to become blocked
Waste accumulates continuously, and the grease trap reaches capacity on a regular basis. Regular scheduled service gives you the peace of mind that you never have to worry about waste discharging to the sewer and causing you to be:
- In violation of sewer-use bylaws
- Susceptible to costly drain blockages, and the potential disruption/damages caused thereby
- Liable for damages and clean-up costs, if discharged waste (grease, etc.) causes a blockage downstream, off property. These costs are usually very high as municipal sewers are quite large and when a blockage occurs, can detrimentally affect many users. Considerable amounts of FOG can build up over long periods of time, even from the smallest generator
- Susceptible to expensive (and sometimes irreparable) damage to your septic bed
Blockages occur two ways:
- Instantaneous; resulting from an event such as vandalism or an inappropriate item being discharged into the drainage system
- Build-up over time; resulting from constant build-up of undesirable material in the drainage system eventually causing a blockage
The following is a list of things you and your staff can do to help minimize the chance or frequency of blockages:
- Always use basket strainers or screens on every drain
- Do not dispose of grease down the drain
- Do not use enzymes, bacteria, detergents, hot water, or other additives to push FOG through the trap further down your drains
- Avoid using a garbage disposer. If you must, run with lots of water and keep the blades sharp
- Avoid powdered soaps that can leave a waxy residue
- Ensure that grease traps are properly sized, installed and maintained
- Perform a periodic preventative drain flushing
Drain "snaking" is performed by inserting a steel cable (or rod) that has an auger type cutting tool attached at the front, into the clogged pipe and "working" the blockage free, or "punching" through the blockage. A Snake can be manually operated or motorized and is typically used on pipes up to 6" in diameter. This temporary action can be used to help minimize disruptions during an emergency until full preventative measures can be arranged.
Flushing is performed using pressurized water that is pumped through a hose to a specially designed directional nozzle. Typically, flushing equipment is self-contained on the service truck. Flushing can be performed on drains and sewers from 1 ½ inches to about 3 6 inches in diameter, and can effectively reach up to 250 feet, from the drain lines directly connected to the trap out to the plumbing stack or main line. Flushing is particularly affective in cleaning or removing build-up from drainage piping and is the preferred method for preventative maintenance.
The best way is to have us perform a detailed visual and Camera Inspection of the system. Our specially trained technicians will provide you with a written assessment that will include a recommendation, and a detailed quotation for any one-time and periodic maintenance requirements.