We have one and it was great while it worked and while the contractor with the service contract was still in business. BUT he upped and left town in the middle of the night and no one else will service the thing. So now we and dozens of other people in the county have multi-thousand dollar holding tanks.
I can only suggest working with your county and state EPA guys - they should know which systems work where you are and who will work on your system.

 

rebel farmer little brother put in a system using a secnd holding tank after his septic tank with a automatic pump hooked to a sprinkler system. Somewhere in the process the water is chlorinated with pool tablets. So far he has got along fine with it.

 

Pros
Effluent going to the drainfield or irrigation system is much cleaner
Required if you're going to irrigate wastewater
Some states allow less distance to watertable for drainfields
Some states allow less drainfield area

Cons
Much more expensive than a septic tank
Consumes electricity
Must be maintained regularly by a certified contractor (~every 6 months)

 

thanks i didnt know it had to be maintained

 

thanks i didnt know it had to be maintained

Maintenance of Aerobic units 101:
Aerobic units utilize a second "treatment" tank with a removable cover after the standard septic tank. The black water flowing into the treatment tank flows over the bottom tablet in a stack of 3" chlorination tablets (similar to but much softer than swimming pool tablets). As the black water flows over the bottom tablet it dissolves it. Once it becomes small enough it falls through the sieve plate and the whole stack of tablets drops down. Usual configuration is about 6 tablets. The time it takes to dissolve all 6 tablets depends on wastewater produced /inflow into the tank. Once the (now chlorinated) black water is in the tank the aeration begins- Aeration is provided by a glorified air pump located outside the tank but nearby, with the air piped into the tank (think fish aquarium here). It is the introduction of this air that eliminates the black water "septic" smell. The aroma is not unpleasant at all. Air pump requires periodic cleaning of a small open cell foam filter and replacement about once a year. Frequency dependent upon dust in the air and grass clippings blown up against it by the mower. The next component is the "pump" and pop up sprinkler heads. Pump is a standard 1/2hp submersible well pump that pumps the "treated" water to the sprinkler heads. No maintenance unless/until it breaks. Sprinkler heads subject to mower, vehicle and children damage- no maintenance unless/until damaged. Next component- Controller. This is the computer brain of the system. It monitors a set of floats in the treatment tank and when one signals it's time to pump, the controller waits until preset time (during the night) and signals the pump to turn on. Maintenance- reset timer after power failure, subject to total damage during power surges, only replaceable component of the system that is NOT homeowner friendly.
Compare that to a standard septic tank that simply needs periodic pumping and you'll quickly see why they are an "alternative wastewater system" and not a "preferred wastewater system".

 

OkieDave, the ATU systems that I am familiar with, chlorination is the last step in the process, after the aeration step. If one was to chlorinate the blackwater (1) it would take a heck of alot of chlorine compared to chlorinating the relatively clean aerated effluent and (2) chlorinating the blackwater would kill the beneficial microflora that the aeration step is trying to stimulate.

One other need for maintenance is to clean the filters or media that are in the aeration tank. The microflora colonies build up a slime layer on these surfaces. As time goes on, the slime layer becomes thicker and thicker. Without periodic cleaning, this slime layer will eventually plug the system.

 

One more thing to mention on the aerobic tanks is; they make noise. Not extremely loud but ours is about 20ft from our back deck and you can here it humming when you are sitting out there.

Dave

 

CF- so the systems you are familiar with use three tanks (septic,aeration and pump tank)? I've had two of those installed on Recreational Vehicle dump stations where the system loading is infrequent but heavy at times (holiday weekends). The other six I've had installed use the two tank system in campgrounds on shower toilets in areas that would not pass a perk test. Could be a geographic thing perhaps?

Edit: Oops! I stand corrected sir. You are correct. I went back and looked at the records and the two RV systems use FOUR tanks- One is for dosing to ensure that the effluent is aerated for the proper length of time before sending to the chlorination and pumping tank. The other six use the three tank configuration I described above. My error and I stand humbly corrected. Amazing I could forget something like that.......

 

In subfreezing weather, the area around the sprinkler heads builds up with ice. If you have a thick layer of snow, the sprinklers don't work well. In the summer drought, the grass is always greener around the sprinkler heads.

I much prefer a conventional septic system.

 

Dave, the ATU systems that I am most familiar with are models used for single-family homes all the way up to large residential developments. So maybe that's the difference, I don't work with the permitting of campground systems. The brands that I'm most familiar with are made by Orenco, Norweco, Piranha, Aquarobic and Bio-Microbics. In general, these are exactly as you described: septic tank --> ATU --> chlorination --> pump tank --> drainfield. We can't irrigate in Minnesota due to climate. However, some systems go to underground drip irrigation lines.

 

We have an aerobic system. Not by choice. Our ground won't perc.

It does have moving parts that can wear out. Also, if the power goes out, so does your septic. If you're in a rare situation in which you have city water, during a power outage, you'll have back-up. The same thing might happen if you tried to use bucket water to flush tiolets too much during a power outage.

The system does make a small sound. So, think about where you might locate it.

Ours is fairly new. The lateral lines in our old system were beyond recovery. Almost every house in out area uses aerobic.

 

Ours does not have chlorination and was (when it worked) pumped to a conventional drain field. Delta is the company.

 

thanks everyone for their input

 

I always thought aerobic would be great. Then we moved here and it was mandatory. Something is always malfunctioning with it. When it snowed a few days ago the sprinklers froze. When it rains we have to wait a day or two longer to mow the lawn in that area. It's yucky to be caught under the sprinkler when it kicks on. Here it is required to be closer to the house, and it doesn't always smell very good. Even with the chlorine tablets - the first three tanks don't have chlorine, just the last one. And pretty much the only thing our county allows to be grown in that area is native grasses, so I'm not really recycling water, just watering the back lawn.