normal sludge in tank?

[rfryed0214]

Hi everyone new to the forum. I have a question. I Have a two 1000 tank system (required by my site), after 8 years I opened the tanks and found that the first tank had no sludge and the second only had about 4-6". This seems low to me. Granted we have a single bathroom house with only two people, but still... I designed and built the drain field, but someone else installed the tanks. I assume that a pre-manufactured concrete tank has the necessary internal Tee's, but then again this was ten years ago and I was so busy I didn't inspect the interior of them. Anyone that has more experience with some insight would be great.

 

[kappitts]

Your first tank from the house is a trash tank and the second tank is primary effluent. Chances are the tank with top solids (scum layer) is the first tank, and the tank that appears empty is the effluent tank. Both tanks will have a good amount of bottom solids (sludge layer) as well. If you were to measure your tanks for total solids (scum and sludge) with a sludge gudge, you would find a higher number of total solids. If you take the total number of inches of solids and divide that by the total inches of used capacity you get the percentage of solids. When dealing with primary effluent to the drainfield, pumping should occur at 35%.

 

[rfryed0214]

The first tank has the scum layer and no sludge. The second has no scum and 4-6 inches of sludge and the effluent is pretty clear (relatively speaking). We do practice water conservation and do not have a garbage disposal. Further research gave a general pump schedule for our system and occupant size at 12.5 years. I just thought it was remarkable how little sludge there is and want to make sure my drain field is not being over taxed.

 

[kappitts]

If you have access to the discharge you can carefully take a sample and have it analyzed for total suspended solids (TSS). The test should be around $20. You can dig up a portion and visually inspect the drainfield as we.