Old fieldline problems?

[rbh_iii]

Can a old fieldline push water past a bull valve after 3.5 years of no use. The reason why I ask, is when I had a new system installed 3.5 years ago, the old fieldline was pushing water back past the new bull valve into the new lift station tank (lift station was installed because new fieldline was installed up on a hill.)... installer said no problem, old fieldline would stop draining in a few days - week. He was right, I have had no unexplained water entering the lift station tank, until about 3 -4 weeks ago. Now that we have been getting a lot of rain here in GA, for the first time in about 3 years. I have water entering my lift station tank via the pipe from the old tank(old tank holds waste from the house and has the bull valve to the old fieldline and new lift station tank). I disconnected the old fieldline from the bull valve about 3 weeks ago, put a plastic bag over it, put a cap on the bull valve, and just reburied (looking into the old fieldline I could see standing water, about 1 -2 feet from the end of the pipe). Now that I have disconnected to old fieldline, water can now be seen entering the old tank via the exit pipe. (Water appears to be pushing back around the exit pipe and tank wall... sludge is whirlpooling). So my question is... is it normal for an old fieldline to refill with rain/ground water and become a problem?

[Wgoodrich]

Yes the field can flow backwards like a subsurface drain system. If it were me I would find the D box at the head of the old system on top of the hill and disconnect the drain line that used to come from the house. Raise this line end to just below the surface and cap it. Should stop the route the water is flowing back down hill to your tank.

Good Luck


Wg

[rbh_iii]

Thanks... WG, No D box on the old fieldline, old fieldline was directly connected to the outlet pipe of the tank. Old system was just a plain gravity system, with (1) 300 foot gravel fieldline and black pipe with drain holes (1 single fieldline appears to be pretty much standard here in GA). When new fieldline (150 FT EZflow with a D box, still just 1 one line) was installed on the hillside, a lift station was added to the system to pump effluent up to the new field. Installer just disconnected the old fieldline black pipe from the tank outlet, added a bull valve to the outlet pipe, reconnected old fieldline to one side of the bull valve and connected the other side of the bull valve to the new lift station. I have disconnected the old fieldline from the bull valve, put a plastic bag over it and just reburied. Water now appears to be entering around the bull valve/exit pipe of the old tank. I have had the installer back out, he wants to backhoe about 10-20 feet of the old fieldline (abandon it), remove black pipe, remove gravel, get new soil from another location in the yard, fill the 10-20 foot hole with new soil and pack it down. I guess what is bothering me about this, is how the heck a fieldline that has not been used for 3.5 years, could fill with so much water pressure, that it can push past a bull valve when it was connected and now that it is disconnected, can push through a foot of soil to reenter my tank. I hate to have this work done and find out this does not resolve the problem.

[Wgoodrich]

Water not only will push through a foot of soil it can and has pushed through hundreds of feet to create an outlet. I have seen a field tile cut 50' from a house but left open and in the crawl of the house over 20 years the water cut through a path and created three fountains inside the crawls space when heavy rains occurred causing water to shoot 1' in the air against the floor joists of the house in that crawl from soil only as the floor of the crawl and the old field tile cut 50' away.

If your excavator digs a trench no matter how hard he packs it the water will still see an easy path right back to your inlet of your tank.

Cheap fix is to dig up the area by the tank and raise the tile above ground coming from the old septic field and connect a new pipe back to the bull valve running it back to the same location pulling the end also above ground. Plug with a swell plug each line and set a septic tank riser over the two pipes. This should raise the pipes up with the plugs and greatly slow down the flow.

My first reply is your best advice leaving virgin soil between that hill where the old septic field is and the tank. Disturb the soil and no matter how much you pack it the water will see an easier flow directing teh water through that disturbed dirt right back to your tank.

Go on top of the hill and use a probe to find that line and dig it up and plug it and raise it above ground and you will stop that flow of water.

Good Luck

Wg