Frequently Asked Questions
Find answers to frequently asked questions about grinder pumps and low pressure sewer systems.
What is a Pressure Sewer System?
What is a pressure sewer system?
A pressure sewer system uses small-diameter pipes and grinder pumps installed at each home. The sewer lines are buried just below the frost line and follow the countours of the land ("up and down" hills or a constant grade across flat land, for example).
The grinder pump station collects all of the wastewater from the home and grinds it into slurry. The wastewater is then pumped to a wastewater treatment plant or system, a gravity manhole, a larger sewer main or to a septic system.
How do I design a pressure sewer system?
The design process includes the following steps:
1. Collect information: Project layout showing location of connections (scaled); contour information; discharge location
2. Sketch a proposed pipe network layout: Flow should generally always head towards the discharge; no loops
3. Create zones designations where flow changes: More pumps operating simultaneously; and where two branches connect
4. Perform hydraulic calculations. E/One Design Assistant software is available for free in the Design Center
5. Optimize the design as required
E/One offers a no-cost preliminary design service to help users evaluate the feasibility of a pressure sewer for a project. Visit the E/One Design Center for more information.
What type of pipe should be used in a pressure sewer system?
E/One recommends high density polyethylene (HDPE). HDPE is commonly used in water and wastewater applications and has demonstrated to be robust and resilient. E/One recommends type DR11.
Are air valves or vacuum valves required in pressure sewer systems?
E/One recommends that combination air/vacuum valves be utilized.
Air/vacuum valves, air release valves and combination air valves prevent the concentration of air at high points within a system. This is accomplished by exhausting large quantities of air as the system is filled and by releasing pockets of air as they accumulate while the system is in operation and under pressure. Air/vacuum valves and combination air valves also prevent a potentially destructive vacuum from forming.
Air/vacuum valves should be installed at all system high points and significant changes in grade. Combination air valves should be installed at those high points where air pockets can form. Air release valves should be installed at intervals of 2,000 to 2,500 feet on all long horizontal runs that lack a clearly defined high point.
Air release stations are available from E/One. Consult your local distributor for more information.
What is the minimum flow velocity in a pressure sewer system?
E/One recommends the pressure sewer system achieves a minimum periodic velocity of 2 feet per second or 0.6 meters per second.This is generally accepted around the world as the minimum velocity to promote "self-scouring" or self-cleaning of the inside of the pressure sewer pipe network.
Refer to E/One's Low Pressure Sewer System Design Manual for more information.
What is a Grinder Pump?
What is a grinder pump?
A grinder pump is a submersible pump that collects wastewater from a building, grinds up the solids, and pumps it to the sewer system through small-diameter pipes.
When is a grinder pump necessary?
A grinder pump may be needed if your community has a low pressure sewer system, your home is located below grade from the sewer line and you need to pump uphill, or your home is located far away from the sewer line and connecting by a gravity sewer line is not possible.
Grinder pump are also installed to serve the basement of a home when a bathroom, kitchenette, etc is added to a home and the wastewater needs to be pumped vertically.
How does a grinder pump work?
All of the wastewater from the home (from toilets, sinks, dishwasher, washing machine, etc) flows by gravity into the tank. When wastewater reaches a certain level, the pump turns on automatically and pumps the wastewater to the sewer main. As it pumps the wastewater, it draws through a grinding mechanism, turning it into a slurry. The pump will turn off automatically.
Is the grinder pump a replacement for a septic tank or other onsite treatment?
No, the wastewater needs to be pumped to a sewer line or some form of treatment.
How long will the pump run each day?
Typical operation is a total of 10 to 30 minutes per day for single-family residential homes. It is designed to turn on several times throughout the day (20 to 40 times for a single-family home), for 1 to 2 minutes each time. This will vary with water usage — the more water you use, the more often the pump will turn on.
How much electricity does a grinder pump use?
A typical single family home uses approximately 250 gallons of water per day. The E/One will use between 9 and 20 kWh per month (60-240 kWh per year). Check your utility bill for the cost per kilowatt hour in your area. For example, if you pay 11 cents per kilowatt hour: $0.11 KWh x 120 KWh = $13.00 per year cost of electricity to operate the E/One pump.
How long does a grinder pump last?
The life expectancy of an E/One grinder pump is difficult to pinpoint. There are many variables that contribute to the life expectancy of a grinder pump, such as: proper installation, system design, system pressure, run time, and what items go down the drain and into the pump.
E/One grinder pump have been known to last well over 20 years in some cases. The published average mean time between service calls is 10 years.
Grinder Pump Use
What do I need to know about my grinder pump?
All of the wastewater in your home from toilets, showers, dishwashers, sinks, etc. empties into the grinder pump station. When the water in the tank reaches a certain level, the pump will turn on automatically and pump the wastewater to the sewer system. Most of the time, you won't even notice the pump running; it produces about the same level of noise as a washing machine and usually runs for only a few minutes.
Do not dump oil, grease, paint, strong chemicals, sand, kitty litter, etc. down your drain. Feminine products and personal/cleaning wipes should be disposed of in a garbage can. These items should not be flushed into any sewer or septic system. They can damage your pump or build up in the tank and prevent your pump from working properly.
Does my grinder pump need preventive maintenance?
No. The easiest way to keep your grinder pump operating correctly is to take care about what you put down the drain: do not flush harsh chemicals (such as industrial-strength drain cleaners), paint, grease/cooking oil, "flushable" wipes. These items should not go into any sewer system or septic system regardless of having a grinder pump.
What can I flush with a grinder pump?
The only items that should be going down your drains are water, regular toilet paper, and human waste. The following items should not be introduced into the grinder pump station (or any sewer system); they can damage or cause premature problems (parts wearing out) with your pump, or build up in the tank and block your pump from working properly.
Do not dump large amounts of grease, paint, strong chemicals, and avoid putting sand, kitty litter, etc. down your drain.
Feminine products and personal/cleaning wipes (even if they're marked "flushable") should be disposed of in a garbage can, not flushed. "Flushable" only means that the wipes will fit through your home's pipes, not that they will break down in water.
Refer to our Grinder Pump Owners Guide for more information about what not to flush.
Who is responsible for maintaining the grinder pump? Who owns the grinder pump?
Grinder pump ownership and responsibility varies. Contact your local sewer department to find out if your grinder pump is owned and maintained by the municipality or the homeowner.
Why is my grinder pump alarm going off? What does the red light on the grinder pump mean?
The alarm on your grinder pump station will sound when the wastewater in the tank reaches a certain level ("alarm level").
An alarm may occur if a large amount of water goes into the tank and rises above the pump's alarm level, such as emptying a large whirlpool bathtub. After the pump "catches up," the alarm turns off by itself and does not turn on again. We call this a "nuisance alarm." Frequent nuisance alarms during normal water usage (showers, washing machine, etc) may indicate that the pump is having trouble "keeping up" with pumping and needs service.
A nuisance alarm may also occur after a power outage: wastewater may be above the pump’s alarm level and the pump needs a few minutes to pump down the tank to a normal level. If the alarm doesn't turn off, call for service.
An alarm will occur if the pump has stopped working and wastewater in the tank rises above the pump's alarm level. Discontinue water use to avoid causing a backup or overflow. Never silence the alarm and continue using water if your pump is not working; you will cause a backup or overflow and possibly damage the pump.
What should I do if the alarm on my grinder pump goes off or the grinder pump red light stays on?
If the alarm turns off after a few minutes and does not turn on again, the grinder pump should be OK. Check regularly to ensure that the grinder pump is operating and the alarm is not on.
If the alarm turns on and off repeatedly or turns on and stays on, call an authorized service center for service. Discontinue water use to avoid causing a backup or overflow.
Look on your alarm panel for a service sticker with a phone number. If no service sticker is on the panel, call our Service Link (USA) at 1-866-539-9803 to find a service center near you.
How do I know my grinder pump is (or is not) working?
E/One grinder pumps come with an alarm panel. If your grinder pump is working properly, you shouldn't notice it at all — the pump will turn on as needed and pump down the tank; its noise level is similar to that of a washing machine. The pump will turn off after a few minutes.
If your pump stops working, the alarm panel's red light will blink and a buzzer will sound. If the alarm doesn't turn off after a few minutes, call for service. Look on your panel box for our Service Link phone number.
Can I use drain cleaner if I have a grinder pump?
Drain cleaner can be used, but choose carefully: use a household (not industrial strength) drain cleaner and follow the instructions on the bottle. Then, flush enough water to ensure that the pump turns on so the pump isn't sitting in the chemical for any period of time.
Refer to the ingredients or MSDS information for the drain cleaner. Please contact us if you need additional information.
Can I rinse a brush with water based paint down the drain?
Yes, you can rinse paint brushes, but get off as much paint as you can before you start rinsing brushes. This is a good idea for your pipes as much as it is for your grinder pump.
Never disposed of unused paint down the drain -- paint of any kind should never be introduced into a sewer system of any kind per the EPA.
Technical Information & Tech Support
- Video Tutorials
What size grinder pump do I need?
Sizing and selecting an appropriate grinder pump station is important for ensuring long life of the pump. The following are basic guidelines for station sizing. Visit the Design Center or contact E/One if you need further assistance.
E/One manufactures one grinder pump that is available with a number of different tank sizes. Station sizing takes many factors into consideration including:
- Residential or non-residential/commercial application
- Expected total daily flow (not the number of water-using fixtures)
- Regulatory guidelines (local, regional, or national)
The most common application for pressure sewer systems is single-family, residential applications. A grinder pump station is located at each home and is sized to accommodate the home. The most popular residential E/One grinder pump station is the DH071.
Other configurations are available. Contact your local distributor for help choosing what is best for your region and need.
Sizing E/One grinder pump stations for non-residential and commercial applications is more complex. Commercial grinder pump station sizing considers many of the same factors as residential appliations, especially total daily flow. E/One typically uses known/estimated flow from the Table H 201.1 (4) from 2021 UPC Appendix H. This estimates flow based on intended use of the site and the intended occupancy. E/One avoids using fixture counts because, in our experience, flow is typically overestimated and results in an oversized system.
What is the difference between E/One's grinder pump and centrifugal pumps? Why is an SPD pump important in a pressure sewer system?
Constant, predictable pump output is the foundation for proper hydraulic design. It enables the engineer to minimize retention time, pump wear and deep scouring action at effective levels. E/One's semi-positive displacement (SPD) grinder pump was developed for wastewater applications. Pumps & Systems magazine featured an article about SPD pumps for pressure sewer systems that compares SPD and centrifugal pumps.
E/One offers grinder pump stations for residential (simplex stations) and light commercial (duplex through quadplex stations) applications. All grinder pump stations use the 1 hp Extreme Series pump. Visit the Product Catalog for the available tank capacities, tank materials and GPD ratings.
E/One's grinder pump lends itself to complex system designs because of its nearly vertical pump curve and the resulting nearly identical flow rate allows a wide variety of discharge heads. The predictable flows of the SPD pumps provide tolerance of widely varying system pressures.
SPD grinder pumps are crucial to the success operation of a pressure sewer system. The performance characteristics of SPD pumps assist in maintaining a sewer network free from blockages. When deposition of solids occurs, tending to block the pipe, centrifugal pumps will move toward shut off, reducing flow and velocity and increasing the tendency to block the pipe. SPD pumps constantly scour the lines to prevent buildup because flow is maintained although pressure or head increased, effectively scouring the pipe.
Can the on/off/alarm levels be adjusted on the grinder pump?
No. E/One grinder pumps use pressure swtiches, not floats, to control the on, off and alarm operations of the pump. These levels are preset and cannot be changed.
Can I use 208 volts? What if I only have 3 phase power?
E/One pumps are rated for 240V. They require 240V +/- 10% or (216V – 264V) and will not run reliably on 208V.
In situations where the available power supply is 480 wye/277 volts, 60 Hz, 3 phase, a Buck Boost transformer is required to boost power up 32V to 240V.
Buck boost transformers are available from your local distributor.
What size circuit breaker do I need?
For a standard 240V single-phase installation, a dedicated 30A breaker is required, with #10 wire, to the E/One panel. You need to bring L1, L2, N and Gnd. A standard 120V single-phase installation requires a dedicated 40A breaker. A 50A breaker is required for a quadplex (4 pumps) installation.
Refer to the installation instructions for more information.
What size discharge/pipe come out of the grinder pump?
E/One's grinder pump stations have a 1 1/4-inch discharge. Refer to the drawings in the Product Catalog section for more information.
Where can I get your Design Assistant software’s installation instructions?
Visit our Design Center Here
To directly view the pdf, click the button below:
Where can I get a parts list or parts diagram for an E/One pump?
Download Exploded View/Parts Diagrams here.
Replacement parts are available from your local distributor.
Where can I get manuals for E/One grinder pumps?
Installation instructions are available in the Product Catalog section. There are different manuals for each grinder pump station.
Please contact us for a service manual. Also, check out our YouTube channel for video content.
Do I need to ballast or place concrete around the base of the tank?
E/One recommends that all stations are ballasted to prevent flotation. Note that ballast amount varies by the station type and size. Refer to the installation instructions of the specific station for recommended ballast volume.
What if my grinder pump station is too tall or buried too low?
A grinder pump station that is too tall shouldn't be a problem other than aesthetics and possibly being in the way. The station can be shortened, but contact E/One or your local distributor for proper instructions.
A grinder pump station that is too short can allow infiltration into the tank. If this happens, the pump will run much more often than necessary, possibly introduce sand, stones or other debris, and cause problems (or a shorter life) for the pump. In this case, the E/One Extender or another E/One accessway extension is needed. Contact E/One or your local distributor to determine what extension you need.
View some of our Playlists on our Youtube channel
E/One Field Service
Watch walkthroughs, troubleshooting and demonstrations with an E/One Extreme Series grinder pump station.