Great info Jim, thank ya. If I am reading between the lines correctly, the designer is the one who would dictate the trees for the design and condition of soil. I will be sure to keep an eye on the pump tank and inspection tubes to see if the levels rise any until I can get everything cleaned up and replanted. Then I'll install a line of tress down the middle to help if needed. This was installed in 03, and I have been wondering about how the system is handeling the family growth/water usage. No alarms to date or any other system issues except having to replace a the aerator a few years back.
Joe, the uses for the poles are unlimited :smiley_clap:
Actually, nowadays, yes. But prior to '07, no. Back then the was no requirement for any engineered designs. The system choices were all cookie cutter designs. 135' long for 3 bedrooms, 170' long for 4 bedrooms, etc, regardless of the soil and site characteristics. That's why the ETA mounds had so many problems... Some were simply undersized from day one and doomed for failure.
If the mound can't handle the water usage, what you'll notice is a wet/soggy area at the ground surface somewhere along the perimeter of the mound. The way they were constructed is the installer would dig a trench 18" deep and 36-48" wide into the ground. Then a clay berm was built up around the edge of the trench, 18" high. This creates a long trough, almost like a bath tub. The discharge pipe from the pump tank is laid in the bottom of the trench and covered in gravel. Then the whole thing is covered over with topsoil and pine or spruce or arborvitae are planted in an offset manner, directly over top of the "bathtub" area of the mound. The clay berm is meant to hold the water in the trough, allowing the trees to make the most use of it. What happens is, when trees are gone or they simply don't suck up enough water, or you use too much water, the water level in the mound rises higher than the clay berm and spills over, creating a wet spot in the topsoil.
If you have a 4" vent pipe installed somewhere on top of the mound, you can look down in there too see where the level of the water is at... Since that vent pipe should extend down to the bottom of the gravel trench.