Aerobic vs. Anaerobic Septic Systems

[MossRoad]

I think a lot of it also depends on your soil type, slope, water table, propenstiy to flood, etc... for instance, our property sits on slopes up to 60 feet above the water table. The only flood that will effect it would be tipped off by the neighbor building an arc!

There are many housing developments in our county that are built on clay soil and high water tables. The poor choice of location, greedy housing developers packing them in like sardines, and innefective local health departments has led to a new set of rules for septic systems that takes effect in 90 days. It was a long time coming, but affects folks like myself in a negative way. I will not be allowed to install my own system, even if it meets all the health department requirements. Only licensed installers will be allowed to do them.

 

[MossRoad]

The air pumped into the second tank enhances the bacteria and allows them to more completely digest the solids suspended in the water. The light chlorine treatment on the way out makes the water safe for above ground use. Basically a minature sewage treatment plant. Hence the need for regular inspections as a malfunction would result in untreated water being sprayed above ground.

Who adds/checks the chlorine and how is it done?

 

[Bird]

The line from the second (aeration) tank to the third (water) tank has a section that angles downward, then there's a vertical pipe coming up above ground from that. It has a cap or plug that is screwed on and can be unscrewed and removed by hand. I believe those were 4" pvc pipes. Then there's a short piece (2' or less) of 3" thin walled pvc with slots cut in the bottom end and a cap cemented on. You can just drop the chlorine tablets into that 3" pipe and in fact, stack quite a few of them if you wish. Water running very slowly across the bottom tablet will eventually dissolve it and let the next ones down. I think some people stack them in there and forget it until the next quarterly inspection. Personally, I checked mine, washed that inner pipe or tube, and put just a couple of 3" tablets in it on the first of each month.

 

[jinman]

I had my aerobic system installed in 2001 at a cost of $6500 including the county fee and the engineering report. Here is a picture on the day it was installed before the backfill. It was two years after this picture that I built my house. In the meantime, the septic system was more expensive than that little building I lived in.

My system has been trouble free except for a timer that was supposed to turn the aerater motor on for 30 min and off for 30 min. When it went out, I just wired it to run all the time and it has worked fine ever since. It the motor goes out, I can buy another one for $500 to $600. So far, the bearings sound fine and the motor just runs and runs.

 

[Bird]

When my system was installed, it was completed on 6/30/97. But after the initial 2 year warranty period during which the installer (from Palestine) did the quarterly inspections, I contracted with a company that was closer to do the inspections. They were also the ones who I'd had install my parent's septic system. The system had both audible and visual alarm in the event of a malfunction and it went off twice during the first month with no problem found. I simply reset it. But then after three and a half years, the air pump (which ran continuously) went bad (my brother's had gone bad just a few months before mine) and the guys I had doing the maintenance then said the installer used a cheap, non-repairable, disposable air pump and they replaced it with one that was rebuildable. The new one cost me $433 on 1/31/01.

 

[shaley]

Wow. Not only are you guys using an aerobic system but spray irrigation as well. Not much spray allowed on the coastal plains of VA but maybe in the Piedmont.

 

[Unclebuck257]

When I got my aerobic system installed the basic price was $5500.00, however because of rock since I live in the Barnett Shale, mine wound up costing me $6300.00. Since installation, I've replaced the air pump motor at a cost of $600.00. I generally put chlorine in the third (last) tank myself, once a month.

They have systems set up now where instead of chlorine, you can use plain chlorox bleach, by adding a gallon of chlorox and the system disterses the chlorox itself automatically. Also, I've been told that for $2000.00, they can make alterations to my original system to qualify it for not having to have those 4Xs a year inspections. I don't know the particulars though since I didn't have that alteration done to mine yet.

 

[Bird]

Wow. Not only are you guys using an aerobic system but spray irrigation as well. Not much spray allowed on the coastal plains of VA but maybe in the Piedmont.

Steve, I'm sure regulations vary all over the place, but the first time I ever heard of the aerobic systems was when one of my brothers told me that was the only thing they were allowed to use when they built houses on an island in a big lake in Alaska because the effluent ran into the lake and the lake water was also the drinking water for the town.

I was told that the water from my system could even be used to water a vegetable garden as long as it ran on the ground, but that it would be illegal to "spray" it on vegetables you were going to eat. Of course, all I wanted to do was water some grass anyway. But when I went from the house to the barn every morning to take care of my rabbits, I walked by about 10-15 feet from one of the sprinkler heads. Sure enough one morning, it came on just as I was walking by and I got a full broadside; soaked me good, but at least it just appeared to be clean water with no odor.

 

[Mickey_Fx]

Thanks for all the info on the aerobic systems. Guess a lot depend upon locale. Have never heard of septic systems like this in this area.

My system is the old traditional anaerobic system and has server me well for going onto 4 decades. Been pumped 3 times in that period.

 

[Tom_H]

We have a foot or 2 of clay topsoil on top of durapan (hardpan that's silica cemented, rock hard, and water impermeable) that's 4-16' thick. The clay won't perc. Below the hardpan there's sand. Instead of leach fields, we have 3' dia holes augered to 33' deeper than the bottom of the hardpan. This is filled with cobble, and capped with a concrete plug. The effluent is sent into these dry wells and dissipates from there. Code requires the # of dry wells to equal or exceed the # of bedrooms in a house.

Water wells go down to about 300', with layers of rock between this sand layer and the aquifer.

Winter rains turn the clay topsoil into muck, but the rain doesn't get into the dry wells because of the concrete plug at the top.