Grinder Pump FAQs

The primary method of sanitary sewer disposal within New Castle County is the use of gravity flow sewers. In most instances, wastewater flows by gravity from a home/business’ sewer service line to a public sewer main where it travels to wastewater treatment plants. Not all homes are in this position, and for those homes, it’s necessary to have a grinder pump. A grinder pump is designed to aid homes that are located lower than the nearest sanitary sewer line. Otherwise, the wastewater will back up and contaminate the house. Grinder pumps may also be required for some commercial businesses, regardless of where they’re located relative to the sewer line. This is because these commercial businesses (such as restaurants) produce a larger amount of wastewater with solid waste that must be ground down before entering the sewer line.

What is a grinder pump?

A grinder pump works like a household garbage disposal, but on a larger scale. It grinds up wastewater produced in your home (i.e. toilet use, shower, washing machine, etc.) and pumps it into the public sewer system.

How does it work?

A grinder pump is placed in a tank (or well) that is buried in a convenient outdoor location on a homeowner’s property (grinder pump units also can be purchased for inside installation). The tank provides wastewater holding storage capacity. When water is used in the house, wastewater flows into the tank. When the wastewater in the tank reaches a preset level, the grinder pump automatically turns on, grinds the waste, and pumps it out of the tank via the homeowner’s on-site sewer service line and into the public sewer system. A grinder pump will normally run for one or two minutes and automatically turn off when the tank is emptied. The pump is powered by electricity and is connected to a control panel near your electric meter.

Who is responsible for the grinder pump?

Most grinder pumps are on private property and therefore are the responsibility of the property owner. The same is true for the private sewer service line on the home or business owner’s property. New Castle County’s responsibility for sewer service begins after the property line in the public right-of-way.

How do I protect my grinder pump?

A properly maintained grinder pump should be able to handle wastewater from the kitchen, bathroom, laundry, etc. However, some chemicals and substances can adversely impact a grinder pump and may cause safety hazards. Please check the labels on all chemicals before using/disposing. Additionally, never pour the following items down drains or flush down toilets:

  • Grease, oils, shortening, butter, margarine, food scraps, sauces and dairy products);
  • Explosive or flammable material;
  • Kitty Litter;
  • Aquarium gravel;
  • Strong chemicals or toxic, caustic or poisonous substances;
  • Degreasing solvents;
  • Diapers, feminine products, or cloth of any kind;
  • Baby/Sanitary Wipes;
  • Fuel or lubricating oil, paint thinner or antifreeze;
  • Plastic objects;
  • Seafood Shells.

These items can damage the grinder pump and its controls, causing blockages and backups and may create unsafe conditions in your lines and tank.