Septic Reduction Chamber

[Jim Morrison]

I inspected a 5 bedroom home today built in 1998. It has a 1500 gallon septic tank which drains downhill into a 3-400 gallon concrete 'reduction chamber', which then drains into a reasonably sized leaching field.

Educate me. What is a reduction chamber? Never heard of 'em.

[AHI in AR]

I've never heard of one either. But then, septic tanks aren't common in my market area. Based on your description, I'd suspect that the "reduction chamber" is a way to further filter out some of the more solid materials before the effluent reaches the field lines.

I'm sure someone who actually knows the answer will chime in. I'd like to know.

[David Meiland]

Are either of those tanks the two-chamber variety?

[Jim Morrison]

I didn't see inside the septic tank, but the 'reduction chamber' seemed to have a solid bottom. Also, I should have said in my initial post that I ran a hot shower for 15 minutes and never saw any water flow into or out of the reduction chamber.

Odd.

[Ben H]

So the 'reduction chamber' was buried in line with the septic tank? Got a pic?

[Jim Morrison]

Yes, it was buried in line, but I didn't take any pics.

[kurt]

Was it an Infiltrator system?

[John Kogel]

Jim, you might find an answer here. I'd keep looking, but there's hockey.

http://www.heavyequipmentforums.com/sho ... stem/page2

They may be confusing reduction in total length, by using the new pipe systems. It sounds like it is simply the second chamber of a typical system, separated because of the slope.

If the lids are off and the tanks have been pumped, you will need fill the first tank before you'll see any water in the second tank. That's 1500 gallons thru a shower head, eh? []

[Tom Raymond]

If the second tank is empty and Boston is anywhere near as wet as WNY this time of year, that tank will float up out of the ground and create a break in the system. Once placed, the tanks should never be more than 1/2 empty.

I have no idea what a reduction chamber is, but in my neck of the woods 1500 gallons is a 3 bedroom rig. Perhaps you have multiple tanks that are in parallel rather than in line with a shared leaching field.

[Chad Fabry]

Jimmy, you're not talking about a distribution box are you?

[Jim Morrison]

No, it's not a D box. It's something different altogether. I think it's meant to be another place for solids to settle out before going to the leaching field, but I don't understand why, when I ran water for 10 minutes, nothing drained into the tank. I'm going to call the company that's been servicing it and ask them for more info.

Jimmy

[Tom Raymond]

Plans? Here they would be on file with the County Health dept.

[allseason]

If the second tank is empty and Boston is anywhere near as wet as WNY this time of year, that tank will float up out of the ground and create a break in the system. Once placed, the tanks should never be more than 1/2 empty.

I have no idea what a reduction chamber is, but in my neck of the woods 1500 gallons is a 3 bedroom rig. Perhaps you have multiple tanks that are in parallel rather than in line with a shared leaching field.

I agree. It could float like a boat on the water if the water table rises and exerts enough pressure on the tank when it's empty. All depends on the soil profile and where how high the water table gets at its highest point. Ask for the plans if your inspecting it yourself. If a septic company is doing the inspection they shoule review the plans at the municipality, if they exist.

[Kyle Kubs]

I've never heard of a "reduction tank" either, but what someone call stuff in their neighborhood can be totally different just 50 miles away. On rare occasions, when someone wants to build a Cadillac system, they will put in a second treatment tank, around here typically called a settling tank. It just provides that much more opportunity for the solids to settle out and not make it into the field.

You say the pipe runs downhill to this tank... is it a steep pitch? Maybe this tank was there to "reduce" the velocity of the effluent before it hit the d-box or drain field?

Nothing coming into it after 15 minutes is not normal. Unless the primary tank was pumped or otherwise not at normal operating level.

No pump of any kind involved anywhere?

[Jim Morrison]

It is a steep pitch, an extraordinarily steep one. The primary tank hadn't been pumped in 6 months and the house has been lived in since then. I have a call into the septic company and will post whatever I learn here.

Thanks all,

Jimmy

[ghentjr]

Jim: Not sure this is correct, but if the drop from the main tank to the fields is sharp the second tank acts both as a flow moderator as well as allowing additional sediment to drop out before going into the fields. A very sharp drop directly into the fields could cause some erosion especially when they have large amounts of drainage like a jacuzzi tub.

[allseason]

But where is the outlet in these other tanks, how are they empty with no pumps, considering the fact that the system had water introduced. Important to know, is the house vacant or occupied? The interior of the first tank has to be looked into. Maybe it's leaking, could be broken pipes, number of things. Might want to bring in a camera to go into the system too.

[Jim Morrison]

It turns out the the reduction chamber (a solid concrete tank) is intended to reduce velocity and not flow on this unusually steep pitch. I still don't understand why there was no flow in the pipe (the top of the 'T' had no cover) while I was running water in the house, but I know enough to know that something wasn't right. A septic specialist is on their way to ferret it all out, but I very much appreciate all of your input.

Cheers,

Jimmy