Septic Tank Garbage Disposal

It looks like a garbage disposal actually helps a septic tank. I will also buy some Rid-X today.

although this article gives me encouragement in choosing to buy a garbage disposal it states that a garbage disposal is good for a septic tank, but doesn't tell me why.

Cliff,
That is because you didn't read *all* of the other columns here on the website about the same topic. I often write more than one column about an issue.

I am in the process of buying a home in the Pensecola aera of Florida and the contractor told me that I can not have a garbage disposal because I am going to have a sepic tank. Is this a building code or does he just not to put one in. Thank you Elvis 1326

Elvis,
Something tells me your builder is messing with you. You can see in my column why disposers do not cause a problem. But as crazy as it sounds, there may be some strange aspect of your local plumbing code that prohibits disposers on septic systems. To get to the bottom of this, you need to talk directly with your building inspector and your plumbing inspector.

I need to replace an existing disposer that has failed. I have a septic system and have not had any problems in the past (I pump my tank every 3-4 years). Is a "Septic Assist" disposer (one that adds a Bio-charge solution) worth a look?

I was told that there was a new kind of garbage disposal that actually has a canister (or the like) that contains bacteria that releases everytime you use your garbage disposal therby alllowing the homeowener to extend the life of a sand mound almost twofold. Can you comment or let me know what you think and where I might find such a disposal.

Thanks

Your comments about garbage disposals are inaccurate and misleading. Small Flows states exactly the opposite of your comments.

Garbage disposals discharge untreated solids into the tank, reducing the effective capacity of the tank. Most of these solids are in suspension and are discharged into the drain field untreated.

You are doing a disservice to your readership with your inaccurate and misleading information.

I'm confused now - is it or isn't it ok to install a garbage disposal with a septic system? We were told we "couldn't have one", but no one really explained why - I thought it would prevent larger particles from accidentally getting down the drain & would be good, but the whole bacteria question is very confusing to the average person. Thanks!

I own a Septic Insinkerator with the Biocharge attachment and it has worked quite well. When I had my septic tank pumped, the service guy said that the tank looked like new. I know the Septic version works. What I would like to know is if a standard Insinkerator would work with a Biocharge additive added on occasion?

I have lived in Tampa for 30 years and have had a septic tank and a disposal. I have not experienced any difficulty with using a disposal with a septic tank. I do try to use them correctly. I have found that many people do not understand how to do either. (And it is so simple.) Always fill the sink up with water when using the disposal then turn it on and the contents are sucked down like a whirlpool and liquified in the process.

Add Rid-x to your system by flushing it down the toliet once every other month. Drain the septic tank at least every 5 years depending on the number of users. If you have many users drain it more frequently. Don't flush things like dental floss down the toilet or other solids that do not easily degrade.

That makes alot of sense, Mike. Your advice is appreciated (even if my comment was written 4 mos. ago!) I'm finding it harder to adjust to no disposal than to no dishwasher. Thanks, and Happy 2009.

As a septic system inspector (both permitting and inspecting the installation of septic systems) I agree with Rick. A garbage disposal should not be placed on a septic system.

Some reasons are as follows:
1) The use of a garbage disposal increases the flow into the system. Your septic system may not be sized for this extra flow.
2) The type of solids that a garbage disposal would add to the system are not always the type to break down in the tank like the other solids that the system is designed to treat.
3) Most importantly, a garbage disposal will cause the solids that pass through it to enter the system suspended in the liquid, and is not likely to fall out in the septic tank before it reaches the drainfield.

If only the tank is inspected, the damage a garbage disposal does may not be apparant. Most negative affects of a garbage disposal are going to be seen in the drainfield (i.e., clogging of pores as mentioned in the article).

If you do have a garbage disposal on a septic system, you can do a few things to minimize the negative impact.
1) Pump the tank on a regular basis (3-4 years).
2) Install a commercially rated filter in the tank (one with 1/32" filtration).
3) Take care to only put biodegradable items in the garbage disposal.

The following link has good information on the usage of garbage disposals with septic systems: http://www.nesc.wvu.edu/pdf/ww/septic/pl_fall04.pdf

The US EPA says otherwise - that disposals are a problem for septic systems:

http://www.epa.gov/ORD/NRMRL/pubs/625r00008/fs2.pdf

Does your advice apply to above ground septic tanks? I am planning a move to an area where above ground systems are required. Thanks.

I have an insinkerator with a biocharge additive. Is it ok to put coffee grinds into the disposal?

If it was fine to put any old garage disposal on a septic system why would they make one just for that application. The food waste cannot be broken down properly and will kill all the "bacteria" that is a very important part of the system working for a long time.

are ther any foods that you should not put down a garbage disposal if you have a septic systemP

The problem is the organics from the food you put down your garbage disposal could be composted, and if it is in the tank it does not break down and clogs your feild. I hope this clears it up.

I used to work for the National Small Flows Clearinghouse, the U.S. EPA recognized small authority on on-site, decentralized and wastewater treatment systems for less than 1 MGD. I worked in their technical department for 5 years.

While a garbage disposal isn't exactly going to kill your septic system, if you plan on using one, you should "up size" the septic tank for increased solids capacity by at least 20% ( I would consider 50%). Unless you are using an aerobic treatment unit (ATU) all the action in your septic tank is anaerobic in nature. Anaerobic decomposition is slower than aerobic. Indeed, there are well documented studies of carrots existing in landfills for 20+ years with little degradation, due to the anaerobic decomposition process.

In short, if you're planning to use a garbage grinder use a bigger than calculated septic tank (1500 gallon versus 1000 gallons for example, and consider using an effluent filter. Such a filter is very useful at preventing solids from entering the drainfield, and that is the number one killer of systems.

Adding additional solids to the tank is never beneficial, and having worked with Ask the Builder in the past, I am quite perplexed as to why they seem to elude that it is a positive. Excess solids, especially vegetable peelings, can easily exit a tank with no effluent filter, which means they can only build up in your drainfield.

Additives, such as some brand names mentioned in earlier posts, have been studied scientifically in at least one study, and they're basically snake oil. You don't need them, short of accidentally dumping a gallon of bleach down your drain. If you want to do something more beneficial for your system, have it pumped out regularly (1-3 years).

I am planning to purchase about 3 acres of land near St. Louis. It's in a somewhat rural area where the St. Louis Sewer District has not extended their municipal sewer system. Consequently, this land must rely on a septic tank / field system. In my previous homes in the city, I've used a regular Insinkerator garbage disposal for years, but this has been on the regular city sewer system. I've been told that I cannot use a garbage disposal with a septic system -- and that septic systems are primarily for human waste. Is this true? Then I read that Insinkerator has a special disposal for use with septic systems. Is this true? I'D SURELY LIKE TO KNOW WHETHER I SHOULD -- OR SHOULD NOT -- HAVE A GARBAGE DISPOSAL IN MY NEW HOME WHICH I PLAN TO BUILD IN AN AREA RELYING ON A SEPTIC SYSTEM. Thank you! Dave near St. Louis

In 35 yrs. in the building trades, I have never heard of a garbage disposal screwing up a septic tank. Lack of servicing is the biggest problem with septics as are water heaters. If you don't take care of the unit, how is it going to service you? Don't let a contractor spin your wheels on the " It will ruin your septic" theory. If he states this, he is not a respectable contractor. They are known as the " The Quick Buck Builder"!

Is it really that difficult to throw away your waste food , or even recycle it by putting it in a compost pile? why spend more money for nothing

From the National Environmental Services Center (PIPELINE – Fall 2004; Vol.15, No. 4 pg 5)

Garbage disposals can increase
the amount of solids in the tank
up to 50 percent and should not
be used. Eliminating a garbage
disposal can greatly reduce the
amount of grease and solids that
enter the drainfield.
Because a garbage disposal
grinds kitchen scraps into small
pieces, once they reach the septic
tank, they are suspended in the
water. Some of these materials
are broken down by bacterial
action, but most of the grindings
must be pumped out of the tank.
As a result, use of a garbage
disposal will significantly increase
the amount of sludge and scum
in your septic tank.

@Atomic Punk. I considered the Septic Insinkerator, but it's actually nearly worthless and doesn't work how people think it does. The idea is that it is supposed to inject the food with biocharge to break it down. However, it doesn't have enough time to attack the food. In fact all it does is wash the biocharge down the drain. So it does almost NOTHING to the food as it goes down.

The only thing that could be of benefit is that if you needed the enzymes in your septic, it would slowly get there. That's nice, but you can also buy the same enzymes cheaper and just pour them down your drain and it would do the same thing. That is, if it's needed. And that depends on the size of the tank, and how much people use it, plus what goes to the tank. But as stated, most experts agree you don't need the enzyme. Perhaps if someone with a small tank w/ tons of abuse, then maybe..

But I've lived with a septic at this house for 24 years now and we use a 1 stage garbage disposal. We never had any problems. However, it's not like we dump huge quantities of food down it. Just a few left over scraps of vegetables etc. But we use it about average etc.. That said, we need a new garbage disposal.

So I'm purchasing an Insinkerator. However, I'm not going to get the one with BioCharge. Simply because it limits which model I can choose, and then I have to buy their brand of biocharge (if I used that). But I don't even add enzymes! Instead I'm likely buying the Insinkerator Evolution Essential. I may also get their 3 stage Evolution Excel with the 1HP motor for $299 because I like that it chops food more finely than the model you mentioned. That helps it break down better.

But again, the biocharge just washes down the drain and won't affect anything for a long time. Sure that can be good for SOME people, but not all, however you can buy any enzime for septic. The only other advantage of the biocharge version is it would automatically add it for you. But again, that's only if you needed it. And I haven't needed it for 24 years even though I run a garbage disposal. So the problem becomes that many people THINK they need it. I'm just writing this to hopefully help people out. Just consider whether you really need enzymes before adding them. If your septic guy says you have problems, then that's the point to reconsider. Again, my 24 years here is proof that it's not absolutely a requirement.

Also, had I used BioCharge in an InSinkErator for the last 24 years, my total payments in refills would be about. $1400. That's right. For me, that would mean $1400 down the drain. Their cartridge must be replaced 3-4 times a year and is about $15 to $20