Commercial Septic Experiences to Share?

I am looking at a Park with a commercial septic installed. 7 homes per tank (concrete), and it’s aerobic in nature (e.g. no leach field), but a slightly custom setup. One of the systems has not been in use for some time as well, but others are operational today…

Aside from the permitting, sizing, and environmental stuff (I am checking these with the city / county) does anyone have practical experience maintaining one this size? How does this compare to a single tank? Differences in pumping frequency, maintenance, problems, etc?

I know very little about aerobic systems except the affluent is supposed to have a hint of chlorine smell. Any “gotchas” to be aware of?

Appreciate all the thoughts from everyone here as always.

An aerobic system has to have either a leach field, or a daylight drain to a stream, lagoon, or something like that. The system has to have a termination point.

More info is needed to even begin to give an answer.

I have a college text book somewhere about an inch thick on design of different private wastewater engineering designs.

You are missing an important piece of info.

If it truly does not have a leach field, and drains to say a stream or pond, I wouldn’t touch it at all, unless you can get it cheap enough to redesign it.

I am NOT a fan of most chlorination systems. Some (older) of the systems I’ve seen I have no idea what the hell the idiot that approved its use was smoking.

Hey @Coach62,

This has something like 12-15 sprinkler heads per system that go off at varying time intervals depending on tank levels and usage - they just water the grass like a regular sprinkler system and are spaced similarly. I thought all aerobics were this way so my mistake.

Not sure if that’s enough or if you need more info. Appreciate it.

Aerobic system simply means air is injected into the tank to encourage the growth of aerobic bacteria instead of anaerobic bacteria.

This system will likely have at least 3 tanks, a pre-treatment tank, the aerobic tank where air is injected, and then a holding tank for treated effluent.

The holding tank will have a pump that sends it to sprinkler heads. So you do have a leach field of sorts, the field where the sprinklers water.

There is obviously some risk here, the effluent is not fit for drinking, so pets, etc. could get sick.

Advantage? the “leach field” is all above ground and visible, no tree roots to enter the drainage tiles, etc.

I think the downside is obvious, but there is upside, unless regulations bite you in the butt. Regular maintenance and monitoring will be CRITICAL.

Also, obviously this type of system isn’t possible where there is a deep freeze risk. I assume it’s a southern state.

Good stuff @Coach62

It seems with this type of setup there is less risk for clogging with wipes and other nasties as you have with leach fields? Would you also venture with the enhanced bacteria activity there should be less accumulation over time, translating to less pumping (assuming tenants aren’t pouring chemicals and grease down the drain)?

I have never heard of someone getting sick from the effluent from one of these, but I guess if your kid is playing in it and having it shot up their nose when the chlorination device isn’t working that would be bad…

I guess it has some different and some similar risks, just need to get a couple experts to look at the system and let me know how they see the management and cost of this thing going. Sounds like it should be comparable to traditional septic as a %.

The wipes should never clog a leach field, they would muck up the tank(s) or pump(s).

There is enhanced bacterial activity, they do function better, BUT - you do HAVE to maintain and monitor them.

What if tank #2 becomes over full and sends sewage to the holding tank, which sends the nasties onto the sprinkler head fields, clogging sprinkler heads, etc.

Do you have a copy of the operating permit? Is it operating within the conditions of the permit? Are they allowed to use the sprinkler to dispose of treated waste water year round? Even if it is raining? … there may be restrictions on when you can operate the sprinkler system. With irrigation disposal being typical in summer and discharge to stream, river in winter (rainy season). How big is the tank to hold the treated waste water prior to irrigation? It should be significant unless it never rains.

Phillip Merrill