accessing a septic tank

[dan614(Guest)]

I bought a place with a 1000 gal tank and four 50 foot lines. Guy who had it put in used his camper on the place and only had a 3 or 5 inch pipe that came off the top (which he put his trailer hose into) for access. It is a "gravity" design. I need to access it to build some sort of bathroom as first priority this spring. What should I look for if I hire it out. Can I do a Y to a temporary shed with a sink and toilet and have the other part of the Y go to where I think I will eventually have the bathroom on my cabin. Can you tell me about pipe size, depth and traps in the ground? I paid extra because this place had the septic, I want to use it.  

[JRR]

We could "guess" along with you.  But if you really want to know, and you should ... grab a shovel and start digging.  

It shouldn't be that difficult to uncover the trench and line going to the septic tank unless its been there for many, many years ... or if the septic contractor backfilled with large stones.

[Daddymem]

Or if it too deep (twitch in my back reminds me of some of them...)

[glenn-k]

Once you find it, Dan, 1/4 inch per foot slope per foot up on the pipe coming from the tank back to your building -working backward since the tank is already there-

3 or 4" ABS - no traps except on sinks showers, other fixtures -total  vents should equal pipe size area as an old rule of thumb I remember.  You could easily setup a restroom in a small building.  

[dan614]

Yes,  I was thinking of a small building for just the bathroom as I will not really have enough greenbacks and/or time for the full fledged of what I want this season. The lot is 100 by 410 with 100 on the inlet to an Adirondack lake. No slpoe/flat with dock right there. Very private with a 20 by 12 one room cabin and a 10 by 16 shed. Think I will make the shed a bunk house, the cabin a kitchen lving area and build off that. I may do 8x8 for a bath with slight storage or room for a water heater. Water is from the lake in non frozen season. I did think you needed a trap from the septic.

[dan614]

Will there be a knock out in the tank? How does gravity fed work. What would NYS code be for depth of the tank?  Would I put a line into the top or the side?

[Amanda_931]

Gravity fed is good.

Everything else costs extra.  Maybe lots extra.

Oh, yes.  And if you're really smart, after you've located everything, put a piece of metal close to the inlet of the tank so that when time comes to pump it out, you could find it by means of a metal detector.

As opposed to having the guy with the pump truck run around the yard with a stick and a shovel trying to find it for half an hour or so.  (or so, once at my house).

[glenn-k]

If they already had a trailer dump line you just hook into the same place- dig down to the bottom of the line - gravity fed is just that -hence to 1/4 inch per foot slope toward the tank - this assures the proper amount of water staying behind the solids and pushing and floating them along to the tank.  

In 48 feet the line would have to be 12" higher than the bottom of the pipe at the tank inlet. (1/4" x 48' = 12")

Usually there is a minimum of 12"dirt over the tank but if the tank is far from the house it could be deeper - usually at least 18" to the bottom of the inlet pipe.

[dan614]

So the tank itself could be pretty shallow and since it is new is most likely plastic so............I don't want to drive over it do I ? How deep would the lines off the tank be?

[glenn-k]

Either plastic or concrete are rated to drive over - I have heard of a plastic collapsing under a big truck in soft ground -haven't seen it- The lines should be about 12 " below the top --inlet is about 2" higher than outlet.  Tank depth can vary from about 12" to 3' of so most being shallower.

[Amanda_931]

Around here there's a concrete company, but not someone who distributes plastic tanks--probably have to be sent from a factory, like in Ohio.  I've got a concrete tank that's five years old.

[Daddymem]

Plastic tanks still cost much more than concrete tanks do.  They are used for special applications mostly; where watertight is required, they are easier to keep watertight than concrete.  And no, just because it is concrete does not mean it is made for traffic.  You may be able to drive over it without collapsing, but to be truly safe to drive over it the tank should be "H-20" rated and that is usually tied to a minimum depth of cover.

[dan614]

When plans are submitted to the building department do they have to go to the detail of stating what type of tank etc? The certificate of completion tells the size of the tank and lines but I wonder if he has a whole set of plans as it was done only a few years ago.

By the way, when I went to close I found there was no final inspection certificate issued by the sanitation officer. I called when I put myf irst offer in on the place and he said "well I have a permit for them to put in a septic so I guess it is OK". The seller opened his mouth 6 weeks later and I found the final certificate was never issued. Some paper work SNAFU. Well you know these days an incorrectly installed system near waterfront would cost thousands to fix. I told them $10,000 in escrow $10,000 off the price or hold on the closing. The realtor finally got moving and found the PE who inspected prior to backfill and got him to write a letter that all was kosher and the realtor went ond found the sanitation inspector in his tree stand and got him to issue the final permit. If I had closed without this no one would jumping for me and I would be wondering what was wrong with the system that they never got this certificate. Don't trust what they tell you. I just happened to put in the sales contract, seller to provide all copies of final permits for the septic system.

[Daddymem]

If there are no records, the PE who did the inspections or the contractor could probably tell you what tank is  in there and what the specifications are.  Usually contractors go to the same place or places over and over so at the least they may point you to whom may have manufactured the tank.  This is one of them "when in Rome things," I can only speculate based on my experience as a septic system designer here in MA.

[harry51]

Getting all the paperwork in order BEFORE close of escrow was very wise! That's just the kind of thing that can later bite you in the butt so hard you can't stop the bleeding.

[glenn-k]

Thats true-- it's not over until the paperwork is finished.

Hey Daddymem, thanks for correcting me about driving on the  tanks-- If I had assumed it was OK and drove something big over the septic tank - I may have found myself in deep doodoo. :-/

[Daddymem]

No problem, I'd love to tell you I just knew this without the experience of actually being around when a truck went through one but....

[glenn-k]

So -is that engineering by trial and error --- I sometimes do that-- .

My boss at the phone company - about 1973 put up a great big roof  -probably about 30' x 100' - with no permit.  No engineer but he knew his stuff pretty well.  Steel frames that he designed - I welded with telephone poles lagged to the top and pan decking over that.  City came down on him for no permit- agreed to let us tie a truck to it and raise it off the ground with a chain hoist for testing.  We did -- the truck came up -roof stayed there - city ok'd it.  The old do it first- deal with it later theory in action - he had a lot of pull with the city though.

I guess the wind over the last 30 years has been doing the uplift testing- the post were anchored pretty good though.  I got my first welding cert on that one.