Septic System - Infiltrator System

[greenmojo]

I guess gophers could dig and access the tunnels and use the chambers but they would get urine and feces dripping on them so I doubt they would enjoy the chambers.

The chambers are 3 feet wide and 4 feet long per chamber.

I guess the bigger septic tank is a safer option in case of an overload.

If I am remembering correctly when I was reading our new design, it required that the tanks were large enough to handle a certain time period of failure so it could be pumped, etc. I suppose enough time to allow us to continue to use the system while a pump truck is scheduled to empty it.

~Moses

 

[Pettrix]

The price difference is $800 between the 2,000 GAL vs 2,500 GAL tank.

6 feet tall x 9 feet wide x 18 feet long = 2,500 GAL
7 feet tall x 8 feet wide x 14 feet long = 2,000 GAL

 

[greenmojo]

The price difference is $800 between the 2,000 GAL vs 2,500 GAL tank.

6 feet tall x 9 feet wide x 18 feet long = 2,500 GAL
7 feet tall x 8 feet wide x 14 feet long = 2,000 GAL

18' long... geesh. Big tank.

 

[TomSeller]

The price difference is $800 between the 2,000 GAL vs 2,500 GAL tank.

6 feet tall x 9 feet wide x 18 feet long = 2,500 GAL
7 feet tall x 8 feet wide x 14 feet long = 2,000 GAL

The 2000 gallon is taller than the 2500?

 

[Pettrix]

The 2000 gallon is taller than the 2500?

Yep, the 2,500 GAL tank gets the capacity with an extra 1 foot wide and 4 feet longer.

 

[Billrog]

I don't know what the over load discussion is about if the tank gets that full of crap the field would be compromised. Pressure systems with a pump-out tank require a 3 day grace period. A septic tank is sized a 3 day retention period for the solids to bread down & a 2,000 2 comp tank would certainly do that. A larger tank is a good thing but 2,500 gal. is getting to a commercial size. An under sized tank can cause grief when multiple loads of laundry are done in 1 day by stirring things up & allowing sludge to enter the field. With a 2 comp. tank this is taken care of with the second comp. Use the $800 to pay for pumping over the next 15 years.

 

[greenmojo]

I don't know what the over load discussion is about if the tank gets that full of crap the field would be compromised. Pressure systems with a pump-out tank require a 3 day grace period. A septic tank is sized a 3 day retention period for the solids to bread down & a 2,000 2 comp tank would certainly do that. A larger tank is a good thing but 2,500 gal. is getting to a commercial size. An under sized tank can cause grief when multiple loads of laundry are done in 1 day by stirring things up & allowing sludge to enter the field. With a 2 comp. tank this is taken care of with the second comp. Use the $800 to pay for pumping over the next 15 years.

Our tank was sized larger by our engineer in the event the pressurized system failed, that you'd have extra storage capacity and be able to have time to call for a pump truck, rather than when the failure alarm goes off, everyone has to 'hold it'.

~Moses

 

[Billrog]

Moses that would not be for the septic tank.Pressure systems with a pump-out tank require a 3 day grace period. I would agree a few extra days in that case would be of benefit. Pump chambers are generally 500 gal. I've installed 1,000 just for that reason in rural areas where getting a pump repaired during holidays may be difficult.

 

[greenmojo]

Moses that would not be for the septic tank.Pressure systems with a pump-out tank require a 3 day grace period. I would agree a few extra days in that case would be of benefit.

I know we live rural, but telling the whole family to go use the yard... ;-)

 

[Pettrix]

18' long... geesh. Big tank.

Is that a bad thing?

 

[Pettrix]

Use the $800 to pay for pumping over the next 15 years.

So your vote is to go with the 2,000 GAL tank and not the 2,500 GAL?

 

[TomSeller]

Is the $800 difference total, delivered, excavated and set?

 

[Pettrix]

Is the $800 difference total, delivered, excavated and set?

Yes that is the total difference

 

[TomSeller]

Yes that is the total difference

Then 2500 is the way I would go if it were me.

 

[Pettrix]

Then 2500 is the way I would go if it were me.

I agree. The $800 is nothing compared to having the extra safety margin. For me, it was more the fact that the tank is so big that I was a little worried about the size of it but I will put down 6" of compacted base material.

Nobody ever says, geez I wish I put in a smaller tank. It's always the opposite, when the tank gets overloaded on special occasions (party, family visit, etc), that's when people wish they had a larger tank.

 

[TemporaryKubotaOwnerMark]

Should I go with a Distribution Box or the installer offered an alternative that doesn't use a D-Box but just feeds directly into the leach fields first line?
I am leaning towards a D-Box since it distributes the waste evenly among all 4 leach field lines, instead of just feeding 1 field and then overflowing into the 2nd field.

D-box. No question. Distribute the load evenly. Give the soil a better chance to keep up with the load, rather than wait for one to get overloaded, then overflow.

When I replaced mine a couple of years ago, I added a 4" PVC pipe up to the surface, topped with a clean-out. Now I can inspect, add chemicals, or whatever, as needed.

The other question is in regards to the backfill over the infiltrator chambers. It can be native soil (which is rocky and silty). I am considering putting down washed 3/4" gravel over the chambers which will help prevent silt from getting into the chambers.

No it won't. It will just slow it down, a bit. Only a bit. I'm currently putting in a French drain which connects to a recently installed French drain on my neighbor's property. It was put in by a ... not very good contractor who didn't use any filter cloth under the gravel, just some Cheapo weed barrier on top. That "drain" has been in place all of two, maybe three months, and when we opened it up to make the connection, we found the gravel is already well-infiltrated with silt.

And it's been pretty dry here until the last few days!

I will also put down landscape fabric/geotextile OVER the chamber tops prior to backfilling to also help with preventing silt from getting into the chambers.

That might help, but I'm not sure even that is needed. If you are going to do it, though, get the good stuff. 3.5 to 4 oz, not the weed barrier junk you get at the home store.

 

[Pettrix]

D-box. No question. Distribute the load evenly. Give the soil a better chance to keep up with the load, rather than wait for one to get overloaded, then overflow.

That might help, but I'm not sure even that is needed. If you are going to do it, though, get the good stuff. 3.5 to 4 oz, not the weed barrier junk you get at the home store.

I am going with the Mutual Industries WF200 Polyethylene Woven Geotextile Fabric. It looks like heavy duty fabric.

 

[justinramani]

FWIW - I think you are probably stressing out way more than necessary. Chances are that the septic guys are pretty familiar with what system will work in your area given the soils that are present. They are probably more qualified in your area than anyone you are likely to find on here. Lay down the extra $800, get the larger tank, and move on. In a year from now, when your system is functioning as designed, it will seem like an insignificant aspect of your overall project.

 

[Pettrix]

FWIW - I think you are probably stressing out way more than necessary. Chances are that the septic guys are pretty familiar with what system will work in your area given the soils that are present. They are probably more qualified in your area than anyone you are likely to find on here. Lay down the extra $800, get the larger tank, and move on. In a year from now, when your system is functioning as designed, it will seem like an insignificant aspect of your overall project.

Point taken.

I am a "belt & suspender" type of guy when it comes to this stuff. I tend to "over-engineer" things so as to prevent future problems. I've seen and dealt with too many shoddy jobs in my time and when it comes to my house, I always research and design it so that I don't have to deal with problems later on. I've learned that it's better to pay a little more now than later on to go back and fix something which will cost triple the costs.

 

[TomSeller]

Point taken.

I am a "belt & suspender" type of guy when it comes to this stuff. I tend to "over-engineer" things so as to prevent future problems. I've seen and dealt with too many shoddy jobs in my time and when it comes to my house, I always research and design it so that I don't have to deal with problems later on. I've learned that it's better to pay a little more now than later on to go back and fix something which will cost triple the costs.

Same here for anything critical like that. Little things I tend to roll the dice on, but not something like a septic tank. Gotta do it right.