Gravelless products

[jmenchhofer]

I would like to hear from those who have used chambers or bundled polystyrene products in leaching trench systems.  Have you had any problems?  What kinds of soils have you used them on?  Do you give/get a sizing reduction for gravelless trenches as opposed to stone and pipe trenches?  If you have had some real world experiences with these products, please share them.   

[Stuart Meade]

J,

Chambers (especially infiltrator brand) have been used in Indiana for over 10 years.  Some excavators like to use them while others don't. Whether or not an excavator uses them seems to depend on the type of equipment that he has.  Smaller outfits with smaller trucks seem to prefer  chambers.

Indiana allowed a reduction of about 20%.  This reduction was conditional, though.  The site had to have a full sized set aside area for a repair.  Some counties allowed the reduction but don't anymore.  Shoot, some counties have never even allowed chambers (or at least one that I can think of).  I feel that Southern Michigan counties were at one point very "Pro - Chamber".  I now see that attitude was waned.
I've heard complaints of the chambers settling, especially in sandy soil.  Chamber manufactures say that the settling occurred because the chambers where not installed correctly. 

I think that chambers are very good, especially in tight installations (like repairs).  Are they better than stone trenches?  I think the verdict is still out and probably will be for some time to come.

When I design a system, I specify which ever technology the excavator or homeowner prefers.

[Toxic Avenger]

Chambers systems work best when individual trench lengths are less than 50 feet.  Even the manufacturer's recommend not extending chamber trenches beyond certain distances.  The longer you run a row of chambers, the less effective the system becomes.  For example, I have seen systems with chambers, where the trench bottom was completely level, as required, but the length of the trenches was well beyond 50 feet in length and even though the system had been in the ground for 3 years, the ends of the trenches were completely dry and effluent had never even reached the end.  The point is, chambers do not spread out effluent as uniformily throughout the entire septic field as stone and pipe systems do.  Now I am referring solely to gravity-feed here.  I have seen pressure distribution systems with the pipes installed inside chambers, hanging from the inside by ties, but the holes must be pointed upward, and these systems work very well. 

[LM Excavating]

I quit using chambers several years ago due to problems we saw with ours and others installations.
I'll make one quick point here on chambers, If I were to install a gravel bed would I be allowed to cover it with PLASTIC vs. cloth or straw???

We use EZflow and I guess Infiltrator likes it too or they wouldn't have bought the company last year. I don't have any complaints on EZflow as of yet but we keep a close eye out.

As for gravel dispersing effluent better,,, well maybe but not assured by any means. lowest hole will see the bulk of flow in gravity and lowest holes will in flood dose. Yes even with pipe dead level there will ALWAYS be a lowest hole.

If effluent isn't getting to the end of a lateral in my counties I would be skipping around like a little girl but the truth is most all systems we see have a pretty wet bottom all the way. In my mind that tells me we are pushing sizing limits on a lot of our soils but I guess the goal is "just enough"

And YES we installed inspection ports on each end of every chamber lateral we ever buried, that helped me in my decision to stop using them.

I'm sold enough on EZflow that we are building a special trailer to haul it right now, I also bought a 53' semi trailer to store it as well. It is quite bulky to work with.

[Toxic Avenger]

ISDH Rule 410 states, "Barrier materials used to cover aggregate in an absorption system must be a six (6) inch layer of straw, or else a geotextile fabric with an effective opening size no smaller than 0.20 mm and no larger than 0.85 mm.  Building paper shall not be used as a barrier material."

So, ISDH would have to first approve the use of the "plastic" before a county could allow it.  And even if the State were to allow it one day, each individual county can chose to still NOT allow it if they choose.  The counties can be MORE stringent than ISDH, but they cannot be LESS stringent. 

Right now, plastic would not be allowed in my county, and I have heard or seen nothing in writing from ISDH saying it is allowed at all.

[LM Excavating]

OK after reading that again I butchered it,, what I meant was WHAT IF I WERE TO INSTALL,,,,

So anyway point is,,,,,,

Unless your chambers are made differently than any chamber I have ever seen ISDH DID APPROVE covering a trench with plastic(Chambers are plastic with no pores in the top)

So,,,,,,, take a gravel bed and cover it with black plastic and you now have a chamber system,,,,,,, that is why we don't use chambers anymore.

[Toxic Avenger]

We don't allow chambers to be covered by ANYTHING, only stone/pipe or rubber chips & pipe get covered with fabric.  ISDH does not even require chambers be covered with anything.

[LM Excavating]

You are missing the point here,,,,,

A Chamber system "IS" one big plastic cover over the trench,,,,, (chambers are made of plastic,,,, solid plastic,,, no pores,,,, only sidewall slots)

No moisture moves "UP" through the soil,,,,,

You have the exact same results using chambers as you would by covering a gravel trench with black plastic sheet.

If you look into a chamber system BEFORE it is in service you will see moisture on TOP of the INSIDE of the chambers,,,, now where do you think that cam from??

It is a natural process for water to move UP through the soil just as it is a natural process to move down, 2 individual processes working together.

When you cover a trench with plastic you just eliminated one of those processes.

It is also a positive to get Oxygen to the lateral,,,,, try putting a plastic bag over your head and then tell me how well oxygen moves through plastic.

[jmenchhofer]

LM,

I've never worked with chambers, but I have seen them a couple of times.  Wouldn't the sidewall slots facilitate oxygen and water movemement from above?  It's been a while since I've taken a close look at a chamber, so I couldn't begin to tell you what percentage of the surface area is actually open slots (I'm sure it's small), but it should make SOME difference, shouldn't it?

[Stuart Meade]

I just returned form the IOWPA conference where I saw Infiltrator's new low profile chamber.
http://www.infiltratorsystems.com/productline/quick4plus.asp
This chamber is, as the name implies, lower than the quick 4 and has "Feet" in the middle of the chamber that extend to the trench bottom.  These "feet" are there for structural reasons but may also help to stabilize the chamber in the soils.  Some excavators have complained that the chambers sometimes settle in sandy soils.  I don't know if this is a problem or not.  If this is a problem, these "feet" should help to solve it.

J.,  I think LM is most concerned with the fact that the chamber cannot breath through the "roof".  Gravel systems get a lot of grass roots extending down into the trench.  Conventional wisdom is that these roots not only help to remove water through evapotranspirationn, but they also introduce oxygen into the trench (which is good).  The chambers have some slots on the sides but do not have a "breathable top" as gravel trenches do.

[LM Excavating]

Stuart,

YEP That's it!!

Even if you cover a gravel trench with black plastic you still have 3-4 times more sidewall contact than a chamber,, maybe 5-6 times more.

I have seen them settle in Alford soils but these were the original sidewinder, I have never installed any of the new lesser models.

Stuart, I just glanced over that ISDH Chamber sheet a couple weeks back but something in there I think may exclude that low-pro chamber here in Indiana.


jmenchhofer,

You are better off not having experience with chambers.


The whole chamber argument of more "storage" is bull anyway, what are we doing storing or dispersing? In those wet times of the year head pressure is what makes things disperse, not volume. 100 feet of old chmbaers only stored about 1200 gallons anyway if I remember correctly.

[Stuart Meade]

When I asked ISDH if these new low profile units are approved in Indiana, they referred me to an Infiltrator approval letter from 2006.  This letter included the Quick 4 but not the low profile one.  So, I assume this means they are not approved in Indiana YET (at least not by ISDH).

[LM Excavating]

Hey Stuart,

If you read this http://www.in.gov/isdh/files/Standard_Chamber_SAF_Final_Revision_2__09-12-22.pdf  PAGE 2 B-1 I think they would be approved.

If you look on ISDH website there is a page of submitted technology and all corresponding actions after that although it is quite behind at times.

[Toxic Avenger]

I think chambers work best in a middle-grade loading rate soil (for example, 0.5 in Indiana).  Not too sandy and not too clayey.  They do tend to sink and settle more in sandy soils (0.75) than in finer soils.  The worst part of chambers is unequal distribution compared to stone/pipe systems.  The effluent is draining directly onto bare soil without having gone through any other medium beforehand, and this is unlike any other tecnology that I am aware of.  Chambers have their benefits, for example sites that are practically impossible to get stone into the area due to slope and/or space.  I know NO ONE that is willing to take a wheel barrow at a time of gravel from the front yard to the backyard.  Do you?  If so, then I hope they don't charge by the hour.    

(EDIT:  When I say "chambers work best in a middle-grade loading rate soil" I'm not saying that chambers are the BEST type of system to install in those cases, I'm saying that chambers work at THEIR best in those soils.  Just wanted to clarify that statement). 

[LM Excavating]

even distribution still doesn't happen in any gravity feed system,

If you have ever wtched the flow of effluent into and out of a d-box you would understand that.
The flow is so slow it will end up falling out of the lowest spot it finds.
First It is completely impossible to get all the drain holes on the same elevation so the lowest hole will get the flow.
Even if they could all be equal the flow would not be enough to make it to the end of the lateral.
I seriously doubt any flows makes it much past the first 10' of pipe.

Take 10' feet of pipe glue a 90 (facing up) on one end and a cap on the other, set it level and slowly pour water in the 90 and you'll see what I am talking about.
Keep in mind you will be looking at a flow of about 1 quart per minute.