There are any number of reasons to add another toilet or full-on bathroom to a home (or wherever). And while it's easy to get wrapped up in designs, colors, finishes and all of the pretty stuff, our best-laid plans are always subject to the cold and sometimes cruel realities of the existing plumbing system...and gravity.
Many homeowners have had their bathroom dreams dashed because of a location that's simply too far from the main drain line to work without a major plumbing overhaul. This happens most often in basements, where the would-be bathroom's drain locations are below grade, or below the level of the main drain line. With no gravitational pull to help move waste out of the home, an alternative means of transport is necessary. Fortunately, there are two possible solutions: the macerating toilet and the sewage ejector pump.
What Is a Macerating Toilet?
When flushed, a normal toilet sends waste through a trap, into a waste line, and onto the main drain line to the sewer or septic tank. Because that drain line is below the level of the toilet, gravity pulls the contents of the waste line into it. It's the same with sinks and tubs. Macerating toilets (aka "upflush toilets"), on the other hand, send waste to a macerating unit located behind the toilet or in the wall. High-powered blades liquefy the waste, which is then pumped out of the unit through normal pipe that's been tied into the main drain line. Macerating toilets are more expensive than standard ones, but connecting a small-diameter pipe to an existing system is much easier and far less expensive than redoing the whole thing.
Pro Tip: Grinder systems - essentially standalone macerating units sans toilet - are great for more demanding situations, or when you don't want a new toilet. The grinder pump sits in a sump pit basin and sends liquefied waste off to the main drain.
Be it a basement-turned-bedroom or a workshop toilet outside the house, macerating units can be installed in a number of situations, provided they're located within range of the main drain. That range is dictated by the power of the pump, and varies between models - usually it's somewhere between 10-15 feet of vertical lift and 100-150 feet of horizontal run. Many units have additional inlets to hook up a sink (kitchen sinks are not recommended), shower, or tub. Macerating toilets are safe to use with septic systems.
Note: Macerating toilets are not recommended as a primary toilet. Though this may be unavoidable in some circumstances, understand that because of the various mechanical parts working together in the unit, failure can come more quickly than with a standard toilet. Using a macerating unit all day every day will significantly shorten pump life. Even if your pump does die, don't worry: replacements are available!
Installation & Use
Installing a macerating toilet is fairly straightforward, and can usually be completed within half a day by a highly experienced DIYer. That being said, even small installation errors can lead to bigger problems down the road - something you definitely do not want to deal with (as it typically involves a slurry of raw sewage). Study the instructions thoroughly, and follow them to the letter. Discharge pipe sizing must be correct, the unit must be properly vented, bends should be sweeping, and right angle turns should be accomplished with two 45° elbows instead of a 90. Keeping an eye on details like these should help you avoid any major issues. And of course be sure that you have an adequate power supply nearby for the macerator unit - most are equipped with a plug for a standard grounded outlet.
Largely maintenance-free (the macerator and pump are usually permanently sealed in an oil-filled enclosure), macerating toilets shouldn't present any significant problems when installed correctly...provided they're used correctly. Recent news stories about "flushable" wipes wreaking havoc on municipal water treatment systems have brought about an increased awareness of what's safe to put down the toilet drain. The same guidelines apply to macerating units, sewage ejector systems, and every other toilet, ever: human waste and toilet paper only - and try not to go overboard on the paper!
Pro Tip: Cleaning products that foam up can trick a macerating unit into running continuously. Manufacturers offer their own specialized cleaners, or you can save money by using plain old vinegar to clean the bowl and limescale inside the unit. When a sink is connected, try to use a soap that doesn't lather too much.
Sewage Ejector Systems
What about those situations where the toilet location is below the main drain, but not a significant distance from it? In those cases, waste doesn't need to be liquefied for easier horizontal transport through a small-diameter pipe - it only needs to go up into the main drain. Instead of paying for a feature you don't need, you can use a sewage ejector pump instead.
Sewage ejector pumps work like most other pumps, but have the advantage of being able to pass solids - usually up to 2 inches in diameter. The pump sits in a sealed sump pit basin, where the toilet and any other fixtures discharge. A float switch usually controls the operation, turning the pump on once the wastewater in the basin reaches a certain level. Some units utilize control panels and alarms (in case of pump failure), which can also be added to many systems.
It's always best to consult with a plumber about the type and size of sewage pump that's right for the situation. Aside from their familiarity with these systems, they should also be knowledgeable about any regulations or special considerations that might apply. Correctly sizing the pump is a somewhat convoluted affair, and involves a few calculations. For heavy-duty situations, a duplex system might even be required.
Whatever your reasons for wanting a bathroom below grade or away from the main drain, you no longer need to compromise or scrap those plans - sewage ejector pumps and macerating toilets show that where there's a will, there's a way. With proper installation and mindful use, these systems can keep a bathroom running for years to come, wherever it might be.