Question:

I’m interested in cleaning drainfields and flow-testing with water or air. Thoughts?

 

Answers:

I have been cleaning drainfields since around 1990. I first tried using a jetter at 30 gpm at 2,000 psi (not a good idea). I found out that 6-10 gpm at 3,500-4,000 psi works the best. With this you can blast into a biomat, cut out roots and flush solids back into the tank.

If the field is trapped by a biomat or sludge, once you establish a flow, treat the field with bacteria. If roots are the problem, buy a good jetter head (one that cuts with water, not blades). Roots usually cause a problem at the start of the drainfield or branch of fields blocking flow to the rest of the field or branches.

I have had great success and the last few years almost a perfect track record. If you start cleaning drainfields, you need to check the field first. Saturated ground will not take water, period. Bad installs will fail. Some systems can’t be cleaned (open dome, dog house type). I have not had good luck with ground-tire systems or foam-peanut systems.

The good, old-fashion rock and pipe systems that worked for years and just stopped working can be fixed 99 percent of the time.

Another point about drainfields: Back in the 1980s, plumbers in my area — including me — had separate drainfields installed for washing machines. If you try to clean one of these and a lint trap tank was not installed, you are wasting your time and your customer’s money.

Between all the lint, soap, sand, and oil, the field cannot be cleaned (by me). The rock bed will be packed and clogged so tight that I will only make a big mess in the yard. Sink drainfields with grease traps can be cleaned. I have cleaned 40- to 50-year-old fields full of grease with good results, but not overnight.

***

Phosphates also will plug the wash-only lines. I even tried to Terralift a couple of them with no luck.

 

***

I have had good luck jetting sludge-filled drainfields. I pull everything back to the D-box and pump it out with the truck.

 

How do I avoid driveway damage?

Question:

I have a single-axle truck with a 2,200-gallon tank. I was pumping out a customer when, about half-loaded, I noticed my rear tires sinking into his driveway. I know some pavers lay the material thin. I had a tri-axle dump truck start cracking the blacktop as it moved and we had to unload it on the main road. But I have heard that a tandem pump truck does less damage to driveways than a single-axle due to weight distribution between the two axles. Would the weight of the tandem truck damage the driveway anyway?

 

Answer:

It depends on the driveway. All of our trucks have tandem axles, and while we don’t have too many problems, it always is a possibility. We recently cracked a 6-inch concrete driveway on one of the edges where the dirt underneath washed away a little and the wire mesh was rusted. Before we drive on a driveway, we always get the customer to sign a form agreeing to let us drive on their driveway and that we are not responsible for any damage.