Septic tank, what is normal?

[Dobber30052]

AHA! I found the On-Lot Sewage System Owners Manual document, and it's <A target="_blank" HREF=http://www.chesco.org/health/pdf/owners%20manual.pdf>HERE!</A>
I haven't read it yet, but it is printing as I type...

Dob

 

[gmason]

Ok, I've just completed my training to be a Subsurface wastewater operator. Basically, the nut and bolts of conventional gravity fed and low pressure (LPP) systems inspections. Here in NC the LPP residental systems need inspected and the laterals cleaned every 6 months.

Very good class, we got to see up close systems above ground that NCSU has built to simulate below ground systems.

I'll post more a little later.

gary

 

[gmason]

One of things we learned in the class was there's very little evidence to support using anything to help with the anerobic action in the septic tank including rid-ex type products.

Your pump should be pumped when the bottom sludge level reaches 25-33% of the depth of your tank. Of course allowing grease and certain other chemicals into your system could greatly degrade the process of breaking down the solids.
One of the real new ideas is , if you can, alowing your system(drain field) to rest for 9 months, this will help break-up the biomat layer that is formed under your lateral lines.

There's a valve called a "bull run" that is basicaly a Y that you can switch to route effluent to one field for a year then switch to the other for a year.

I can scan chapters out of our book if anyone would like a few pages.

gary

 

[tugokc]

I can't believe not a single person has posted a picture of their septic tank in this thread. Can we at least get a picture of the cb antenna that started this off?

 

[MDNY]

I will be glad to post the pics of our septic when it is installed in the next few weeks. They are waiting for the siding crew to finish and theny they will get to work. So I should have pics shortly.

 

[gmason]

I just preformed my first inspection/servicing of our LPP septic system. Everything was fine and the system checked out in order.

One of of the tools that I made is a way to tell what your head presure is set at. When your LPP system was designed, there should be a calculation as to what the head pressure should be set to on the lateral turn ups. In most cases it's around 2ft, based on the pump used and the size of your field.
I put together a 5ft piece of clear plastic 1 1/4"tubing, it's actually the plastic sleve that goes over floresent lights, but it fits perfectly into a 1 1/4" sch 40 pvc. I put a small piece of a mesh potatoe sack over the tube before sliding it into the pvc coupling to keep the bright orange fishing bobber from backflushing down into the line. It was such a snug fit, no pvc cement was needed. Depending on what kind of pvc cap/plug on your turnups, you may have to add another coupling to the end to mate to your system.


Before screwing on the tube, take a ruler/measuring tape and measure down to the elbow at the bottom of your turnup. Take that number and subtract it from the total head preasure number you got from your system specs and then measure up the tube to get where the float should stop for the correct head preasure. There should be a 3" gate or ball valve for each set of laterals for the drain field. This is where you can go and set the valve opening to get the bobber to the correct height(ie. 2ft of head).

The other tool I bought is called a Sludge Judge This is for measuring the about of solids in the bottom of the tank as well as giving you a look at a cross section of the contents of the tank. That way you KNOW when to have your tank pumped and not have to guess.

gary

 

[BigDave]

I read the manual, it was pretty informative. Thanks /w3tcompact/icons/grin.gif

I bought a garbage disposal made for septic systems. It contains something called "Biocharge" and supplies some with each use. I've been in the house for 1.5 yrs so far, I'll let you all know in another 1.5yrs if the disposal was a good idea or not.

 

[upgw]

I've been in my (new) home for a year now, and the LPP SandMound system was just inspected. I chatted with the crew for a while, it was interesting. He reiterated that washing machine output is the primary cause of failure, because:
1) The huge discharge of water stirs the tank(s)
2) Large amount of synthetic fiber is insoluble and ends up in the drain field (due to #1).

He didn't mention any filtering devices like the one you mention, but it looks interesting.

Older sand mounds systems failed quickly (5 to 8 years). New ones are much better (20+ years) because:
1) They are HUGE compared to old ones (mine is 100X10)
2) Two stage settling tank, catches more, ahem, solids
3) Rudimentary filter between second settling tank and the pump tank
4) Pump tank has large space at the bottom to catch any solids that get through (space below pump inlet)

He warned us against putting any 'feminine products' or wipes down, but primarily because they make cleaning the tank more difficult, not really because they hurt the drain field. The paper in these things degrades slowly, and can combine with grease in the 'scum' on the top of the tank and they have to chop it up with a shovel and get it out during cleaning. It slows them down.

I think these will continue to go down the pipe at our house.

We are required to pump every two years (by the County I think).

Anybody actually install that filtering device mentioned?

- Patrick W.

 

[dummy]

Did you or the builder install a wire mesh over the area for moles? Never considered it before, but one of our mounds got infested and almost collapsed it. Noticed some leaching and found the moles had tunneled all the way into the gravel layer, not good. Just finished repairing the mound and covered it with galvanized rat wire.

 

[RJohnson]

I haven't built my house yet but I do plan on using a washing machine filter. This site <A target="_blank" HREF=http://www.septicprotector.com/productinfo.htm>http://www.septicprotector.com/productinfo.htm</A> contains information about the product I plan on using. There is too much data pointing to leach field failures due to solid particles getting into the leach field and clogging it up to ignore. I also plan on adding an efluent filter in the tank.

Randy

 

[gmason]

Patrick, do you know if you are using your sand mound system to reduce the size of you drain field by a certain %. Here that say you can get a xx% reduction in your drain field because the sand filters remove a great deal of Nitrogen from the effluent. One the sand filter systems here collects the water at the bottom of the sand and returns it to the pump tank with a 80% reduction in N.

But sand filters need to be "rolled over" every 10-15 years to re-aerate the sand.

Also, has far as "solids" getting into the LPP system, some suspended solids will get into the drain field. But these help to create what is called the Biomat layer that forms where the native soil layer meets the bottom of the rock layer. There are good things the biomat does and bad things.

Good- it helps to filter some of the finer suspended particles in the effluent and evenly distributes it along the entire drain field.

Bad- If the biomat get too clogged it can cause the system to fail /w3tcompact/icons/sad.gif One way to prevent this is to "rest" the drain field for 8 months to allow the biomat to break down(justification for having 2 drain fields) Of course anything that gets into the biomat that NEVER breaks down is bad.

We were told that about the only thing that floats in the septic tank is the grease layer, that within a few hours most everything sinks to the bottom. As far as stirring-up the solids on the bottom of the tank with washing machine water, I can't see where water the enters the septic tank from the top and the tank being 5-6' deep(for a 1000g+ tank) is going to do much stirring of the water 5' below the surface.

The real hazards to a system are the I/I...inflow and infiltration. Inflow being where water gets into your septic tank from downspouts, stormdrains etc and infiltration where you have ground water leaking into your tank(more common than you'd think) both causing your system to handle much more gpd(gallons per day) than it's designed for.

A well installed well maintained underground wastewater disposal system should last many many trouble free years. It's when the system is misused/abused or neglected that troubles begin and usually at big $$$.

If a system is designed for 1500gpd and 2500gpd is going through it then it's going to fail eventually. Most soils are very capable of treating/purifying effluent to a certain point then if they get overloaded they will fail.

Sorry for rambling....
gary

 

[n6ckv]

In Santa Clara County (CA) they are requiring dual leach fields, we switch ours once a year. A good book is "The Septic System Owner's Manual", it can be found on the www.shelterpub.com web site.


carl

 

[upgw]

Gary, Not exactly sure what you mean, I think the Sand Mound IS the drain field, so to speak. Or at a minimum sits on top of it. Effluent seeps down through the sand and into virgin soil (never run over by equipment). No actual return through any kind of filter. It's so huge because the soil is heavy red clay and the water table is very high (I have a natural spring 100 yards away). The law requires that there be room on the lot for a replacement mound should/when the original one fails.

I don't know how big the settling tanks are, the pump tank is 500 gallons. The settling tank was huge.

The area over the main tank has settled about 8 inches, and rain pools there. I need to get that fixed so the rain water doesn't inflitrate the system, but then, it's not actually raining much (for now).

I think he said there 100 yards of special (blue/gray colored) sand in it,and that costs quite a bit of $$$$.

- Patrick

 

[gmason]

Patrick, sure, you've got a common system for a site that has little or no percable soil. States are coming up that more and more creative ways to handle waste water on marginal lands. The recirculating sand mound is just one of them. I'll see if I can scan that page out of my book and post it here over the weekend.

They are trying out the above ground spray systems.... in a couple of new developments near us. Land is going for 40-50k/ac and is solid clay after the first 6". But, as far as the state regulations are today, these systems don't have to have a operator, AND, do not have any regular inspections. Go figure....

gary

 

[upgw]

I poured a 5 gallon bucket of water into a post hole I was hand-digging to soften it up a little. 12 hours later, the hole was still full of water... so I guess it's pretty bad. Two houses down (lower elevation a little) the guy has a "Pete Box Filter" system... they put a giant square fiberglass box filled with Pete (Moss??) in.. I think you replace the whole box in 10 years. It's really small next to the sand mound systems. Sounds expensive to maintain long term. The septic maintenance guys didn't know how to service it.

- Patrick

 

[LazyJ_Arabians]

After pumping your septic tank and before the next big rain event, make sure you have discharged enough waste to keep the tank from floating out of the ground. Painful memory for me!

 

[Ozarker]

I have one of the systems that aerates the waste with an air compressor and turns black water into gray water suitable for drip irrigation for all but food crops. It has been maintenance free, except sludge pump out, for 15 years until this week. The compressor quit and I have a new one on order for $400.

 

[Hank]

<font color=blue>I have one of the systems that aerates the waste with an air compressor and turns black water into gray water suitable for drip irrigation for all but food crops.</font color=blue>

Do you have any links or references for this type of system? I am interested in learning more about it.

 

[Ozarker]

http://www.agwt.org/SepticSystems.htm#HOW DO AERATION SYSTEMS WORK?


http://www.uchd.net/departments/environmental/aeration.htm

 

[Earnsfan]

That is a very funny reply
Mike