Harwich Water Department & Wastewater

Grinder Pumps

Grinder Pump Release Form  |  Grinder Pump Policy  |  E-1 Grinder Pump Owner's Guide

Grinder Pumps 101

What is a Grinder Pump?

A grinder pump is a small wastewater pumping system that helps move sewage from your home to the Town’s sewer system when gravity flow is not possible.

Unlike a conventional gravity sewer connection, a grinder pump uses electricity to pump wastewater from a holding basin on your property through a pressurized sewer line.

Grinder pumps are designed to handle wastewater from your home—but they are not designed to handle everything that can be flushed or poured down a drain.

How Does It Work?

The grinder pump system typically includes:

• A pump basin located on your property
• A grinder pump that grinds wastewater into a slurry
• A control panel that operates the pump
• An alarm that alerts you if the wastewater level in the basin becomes too high
• A discharge pipe that carries wastewater to the Town sewer system

Under normal conditions, wastewater flows from your home into the basin. When the wastewater reaches a predetermined level, the pump automatically starts and sends the wastewater into the sewer system.

What Goes Down the Drain Matters

Your grinder pump is designed for normal household wastewater. Items that do not belong in the sewer can damage the pump, clog the system, or result in costly repairs.

Never flush or pour the following into your sewer system:

• Wipes—even those labeled "flushable"
• Paper towels
• Feminine hygiene products
• Diapers
• Cotton swabs
• Dental floss
• Grease, fats, and cooking oils
• Cat litter
• Coffee grounds
• Sand, dirt, or gravel
• Paint, solvents, or chemicals
• Prescription or other medications
• Automotive fluids
• Other objects that do not readily break down in wastewater

What About "Flushable" Wipes?

Don't flush them.

Even products labeled "flushable" can cause problems in sewer systems and grinder pumps. These materials generally do not break down as quickly as toilet paper and can become tangled around pump components.

The only things that should normally be flushed are human waste and toilet paper.

Grease Is a Problem, Too

Cooking grease and oils should never be poured down a drain.

As grease cools, it can harden and build up inside your plumbing and sewer system. Over time, this can contribute to blockages and pump problems.

Allow cooking grease to cool and dispose of it in the trash according to local disposal guidelines.

What If the Grinder Pump Alarm Sounds?

If your grinder pump alarm activates, don't panic.

The alarm generally means the wastewater level in the basin has reached a high level. In many cases, the pump may still operate and clear the basin.

If the alarm sounds:

1. Stop or significantly reduce water use in your home.
2. Avoid flushing toilets, running the dishwasher, washing clothes, or taking showers until the issue is resolved.
3. Check the grinder pump electrical service and make sure the pump has not been inadvertently shut off.
4. If the alarm continues or the pump does not operate, contact the appropriate service provider or the Harwich Water & Wastewater Department as directed by the Town.

Important: Do not open the grinder pump basin or attempt to repair the pump yourself. Wastewater systems can contain hazardous materials, and electrical components can present a serious safety hazard.

Power Outages

Grinder pumps require electricity to operate. During a power outage, the pump cannot operate normally.

If you lose power, limit water use until power is restored. Once power returns, the pump should normally resume operation automatically.

If the alarm remains on after power has been restored, contact the appropriate service provider or the Town as directed.

Taking Care of Your Grinder Pump

A few simple habits can help protect your grinder pump and avoid unnecessary problems:

• Flush only toilet paper and human waste.
• Keep grease and cooking oil out of your drains.
• Never pour chemicals, paint, or solvents into the sewer.
• Do not dispose of wipes in the toilet.
• Be mindful of water use during power outages.
• Know where your grinder pump alarm and electrical disconnect are located.
• Keep the pump basin and surrounding area accessible.

Remember: Your Grinder Pump Is a Pump—Not a Garbage Disposal

The grinder pump is an important part of your home's wastewater system. Treating it properly can help prevent blockages, pump failures, backups, and unnecessary service calls.

When in doubt, throw it out—don't flush it.

Quick Reference

Questions?

For questions regarding grinder pump operation, maintenance, or wastewater service, please contact the Harwich Water & Wastewater Department.