InSinkErator Evolution Septic Assist 3/4 HP Garbage Disposal Review 2019

I recently helped a friend to fit his new garbage disposal. He and his family had just moved to live a little way out of the city, and their new home relies on a septic tank system. The old garbage disposal just could not handle all the food waste produced by his family of two adults and two children. The unit just kept blocking up the septic system.

My friend was excited because he had found a garbage disposal unit that had been designed specifically for septic tanks. It was an InSinkErator Evolution Septic Assist 3/4 HP Household Garbage Disposer.

While some other best home garbage disposal models will work with septic tanks, they can clog up the system if they do not pulverize the food into small enough bits. Not only does the Evolution Septic Assist avoid this by mashing up most kinds of food waste into tiny pieces it also has a secret weapon. InSinkErator calls it Bio-Charge Injection Technology. Attached to the side of the unit, the Bio-Charge automatically injects more than 300 million enzyme-producing microorganisms into the Septic Assist every time it is switched on. The enzymes created by these microorganisms – ‘good’ kinds of bacteria to you and me – break down the starches, proteins, grease, and fats found in food waste.

The Bio-charge in effect gives the septic system a head start or boost with this squirt of concentrated bacteria. Think of it as the turbo on a car engine.

Once the waste goes into the septic tank, this injection and the septic tank’s enzyme producing microorganisms break down the food waste already pulverized by the Septic Assist’s grinders.

The result of all this is your septic tank should never be over-burdened or clogged up with food waste coming from the garbage disposal unit. A bonus is the Bio-Charge system’s odor control. It emits a citrus fragrance along with the good bacteria to mask any nasty smells coming up through the sink plughole.

The Bio-Charge unit is attached to the front base of the Septic Assist. A push button opens it, allowing you to change the cartridge containing the micro-organisms once it has run out. The Septic Assist come with one Bio-Charge cartridge in the box. My friend estimates he will use between three and four cartridges per year.

This kind of organic treatment is considered to be environmentally friendly. It breaks down food waste to such an extent that it can, among other things, be recycled as fertilizer or even converted into renewable energy. Either way, it certainly reduces the amount of waste dumped in landfills.

Best Features of InSinkErator Evolution Septic Assist 3/4

Strong Motor

The InSinkErator Evolution Septic Assist has a ¾ horsepower Dura-Drive Induction Motor. Induction motors – a simple electrical drive unit – are the most commonly used type of motor in home appliances. They are more rugged, easier to maintain and cheaper than other kinds of motors. Induction motors with a decent amount of horsepower tend to be the most robust so they last longer.

At ¾-horse power, the Septic Assist’s motor is big and robust enough to cope with my friend’s family of four, thanks to the two-stage grinding system it drives.

Two-stage grinding

Many of the latest top rated garbage disposals on the market employ multi-stage grinders. Put simply; food waste is pulverized into ever smaller pieces as it passes through each stage.

The Evolution Septic Assist has a two-stage grinding action that uses a Tri-Action Lug system and a GrindShear ring.

The technical details of how these work are not important – unless you aim to do a bit of tinkering with your garbage disposal, which is strongly not recommended if you want to keep your warranty and fingers intact.

It is enough to know the combination of the two liquefies just about any food waste.

This is of particular importance because the waste will go into your septic tank. If the waste is left in too big chunks, they will quickly block up your septic system.

It will also mean the tank will have to be frequently emptied. A septic tank needs food waste to be liquefied as much as possible for it to work efficiently. The Evolution Septic Assist’s two-stages grinding system does this.

The InSinkErator Septic Assist has a 40 oz. Capacity grind chamber, which is big enough to handle reasonably large amounts of food waste. This is combined with a continuous feed operation that allows you to clear away food garbage quickly.

All the Septic Assist’s grinding parts, including the grinding chamber itself, are made from stainless steel that prevents rust and ensures the unit should last a long time.

Hear Almost Nothing

One of the reasons my friend and his family moved out of the center of the city was the noise. They wanted a more peaceful life without the constant drone and whirr of cars and machinery.

They did not want a clunking new garbage disposal unit shattering their peaceful kitchen.

After reading a few garbage disposal reviews, my friend was attracted to the InSinkErator Evolution Septic Assist 3/4 HP Household Garbage Disposer because of its ‘SoundSeal Technology.’ This promises, and delivers according to my pal, a virtually noise-free operation.

The Septic Assist has insulation all around the motor, an anti-vibration sink mount, and an anti-vibration tailpipe. This lagging cuts down on vibrations that cause noise. There is also a sink baffle that reduces the amount of noise coming up through the sink plughole when the unit is in use.

My friend assures me he can talk normally to his wife and children with the unit grinding away.

Easy Installation

InSinkErators score high in garbage disposal ratings because they are easy to install. The Septic Assist is no exception. It features the brand’s stainless steel Quick Lock sink mount. Therefore, despite asking for my help, putting in the new Septic Assist was simply a case of twisting off my friend’s old InSinkErator model and twisting on the new one.

This Quick Lock sink mounting system can just as easily be used to replace other brand garbage disposals.

If you don’t already have a garbage disposal and are putting in a new unit for the first time, it is slightly more complicated but still easy enough for a reasonably DIY-competent person to manage. The unit comes with clear, easy to follow installation instructions.

It is worth noting that the Septic Assist does not come with a power cord, so you will have to buy one separately.

It took my friend and me less than an hour to fit the Septic Assist. I do not think he wanted me to demonstrate how to replace a garbage disposal, but rather to show off his shiny new toy!

We Come to You Warranty

The Evolution Septic Assist’s limited four-year warranty is not as long as many of other brands’ guarantees. Waste King, for example, offer a ten-year warranty on parts and labor and a lifetime guarantee against rust on a similar ¾ horsepower unit.

However, the Septic Assist warranty is at least ”in-home’’. This means free house calls (including parts and labor) if something should go wrong with the unit during the warranty period. It should be just a matter of calling an InSinkErator certified agent to come round and fix the unit. My friend will not have to mess around trying to find a repair center – very handy if you do not live in the city where most of them are.

What is in the Box

When you buy the Evolution Septic Assist garbage disposal, it comes with a Quick Lock sink mount, Sink Baffle, Jam-Buster wrench, anti-vibration tailpipe mount, clamp, and stainless steel stopper, Bio-Charge Injection Technology, and installation instructions.

Pros and Cons of InSinkErator Evolution Essential 3/4 HP


  • Specially designed to work with septic tanks
  • The Bio-Charger is environmentally friendly
  • Easy installation
  • Sound Seal technology makes it quiet


  • The Bio-Charge cartridge can be expensive and must be replaced 3-4 times a year
  • The Bio-Charger is a little bulky, so you need to make sure there is enough room under your sink for the entire unit

Conclusion: Why You Should Buy This Product

Moving out of the city and into a relatively rural area has turned my friend into a bit of a greenie.

Not only does the Septic Assist offer practical, convenient way to dispose of food waste, it is also environmentally friendly. It is an alternative to transporting food waste to landfills. Garbage disposal units help reduce greenhouse gas emissions and at capable wastewater treatment plants, food waste can be recycled to produce renewable energy.

On a practical level, the Septic Assist copes well with his family of four’s food waste. Importantly it does not overtax their home’s septic system. So long as the unit is used correctly, my friend reckons he will not have to worry about the expensive business of emptying the septic tank for a few years to come. Its performance plus the Bio-Charge makes it one of the best garbage disposals and a very worthwhile investment for any home.

Also, despite living in the country, my friend will not have any small furry creatures rummaging around his garbage cans looking for food scraps.

Rating of InSinkErator Evolution Septic Assist 3/4 HP
  • Energy efficiency
  • Price
  • Motor Power
  • Noise Level
  • Features


If you have a septic system, this garbage disposal is definitely worth looking at. My friend and I hope you found this review useful.

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