A grinder pump is a

wastewater Wastewater is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes. Another definition of wastewater is "Used water from any combination of domestic, industrial ...

conveyance device. Waste from water-using household appliances (

toilets A toilet is a piece of sanitary hardware that collects human urine and feces, and sometimes toilet paper, usually for disposal. Flush toilets use water, while dry or non-flush toilets do not. They can be designed for a sitting position popul ...

, bathtubs,

washing machine A washing machine (laundry machine, clothes washer, washer, or simply wash) is a home appliance used to wash laundry. The term is mostly applied to machines that use water as opposed to dry cleaning (which uses alternative cleaning fluids and ...

s, etc.) flows through the home’s pipes into the grinder pump’s holding tank. Once the

inside the tank reaches a specific level, the pump will turn on, grind the waste into a fine slurry, and pump it to the central sewer system or

septic tank A septic tank is an underground chamber made of concrete, fiberglass, or plastic through which domestic wastewater ( sewage) flows for basic sewage treatment. Settling and anaerobic digestion processes reduce solids and organics, but the treatm ...

. Grinder pumps can be installed in the basement or in the yard. If installed in the yard, the holding tank must be buried deep enough that the pump and sewage pipes are below the

frost line The frost line—also known as frost depth or freezing depth—is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of an area, the heat transfer properties of the s ...

. A grinder pump is different from a sump pump or effluent pump. There are two types of grinder pumps, semi-positive displacement (SPD) and centrifugal.

Components

The grinder pump “station” consists of the pump, a tank, and an alarm panel. A pump for household use is usually 1 hp, 1.5 hp or 2 hp. A cutting mechanism macerates waste and grinds items that are not normally found in sewage, but may get flushed down the toilet. The pump has a level sensor either built into the pump, called “sensing bells,” or attached externally to the pump, typically a

float switch A float switch is a type of level sensor, a device used to detect the level of liquid within a tank. The switch may be used to control a pump, as an indicator, an alarm, or to control other devices. One type of float switch uses a mercury switch ...

. (The level sensing devices vary among grinder pump manufacturers.) If the pump malfunctions and the waste level in the holding tank rises above a certain level, the alarm panel should alert the homeowner that the pump is experiencing problems. The alarm panel should have both a buzzer and an indicator light. The holding tank, likely constructed of

fiberglass Fiberglass (American English) or fibreglass ( Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass clo ...

high-density polyethylene High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, ...

(HDPE) or fiberglass-reinforced polyester (FRP), has an inlet opening and a discharge opening. The pipes from the home are connected to the inlet; the pipe that leads to the sewer main is connected to the discharge. Often, more than one home or restroom (in a park, for example) can be connected to one grinder pump station. In this case, more than one inlet can be installed. It is a good idea to consult the manufacturer or factory representative before purchasing a grinder pump station to ensure that more than one inlet hole can be drilled. The tank has a lid made from heavy-duty plastic or metal that is bolted and/or padlocked shut to prevent entry by unauthorized persons.

Maintenance

Grinder pumps should not require preventive maintenance. However, grinder pumps that use floats to sense the level in the holding tank are prone to grease buildup that may turn the pump on unnecessarily, or not turn on the pump at all, causing the tank to fill up and sewage to possibly back up into the home or yard. To prevent this, grinder pumps that use

es to sense the level in the tank are often hosed down to remove the grease from the floats. Homeowners are not usually limited by what they can or can not pour down their drains because their home has a grinder pump. Feminine hygiene products,

diapers A diaper /ˈdaɪpə(r)/ (American and Canadian English) or a nappy (Australian English, British English, and Hiberno-English) is a type of underwear that allows the wearer to urinate or defecate without using a toilet, by absorbing or conta ...

, kitty litter, paint,

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

(both motor oil and cooking oils), etc. should not be flushed or poured down any drain, whether the home is connected to a

gravity sewer A gravity sewer is a conduit utilizing the energy resulting from a difference in elevation to remove unwanted water. The term ''sewer'' implies removal of sewage or surface runoff rather than water intended for use;''Design and Construction of San ...

system,

, grinder pump or

cesspool A cesspit (or cesspool or soak pit in some contexts) is a term with various meanings: it is used to describe either an underground holding tank (sealed at the bottom) or a soak pit (not sealed at the bottom). It can be used for the temporary co ...

. Disposable wipes that are made by cleaning companies for personal use, cleaning toilets, etc. are causing problems in communities around the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

. Not only do people clog their household

plumbing Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water deliv ...

, they are causing problems with household grinder pumps, lift stations, and

sewage treatment plants Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding en ...

. Some wipe companies say "flush one at a time," some say "not for pump systems," some say "safe for sewers." As recommended by Consumer Reports, wipes should be put into a garbage can instead of the toilet. The National Association of Clean Water Agencies has compiled a list of articles and municipal documents regarding wipes. In large sewage pump stations, clogging problems are often avoided by installing a chopper pump in the tank. A chopper pump is able to handle larger/tougher solids than a residential grinder pump, including hair balls, diapers, sanitary napkins, clothing, etc.

References

Additional Links

Submersible Wastewater Pump Association

Only flush the 3 Ps: pee, poop, and toilet paper!
{{Sewerage Waste treatment technology

Components

Maintenance

See also

References

Additional Links