ShinDiors
New Member
House we bought a year ago had this strange setup. In order to accommodate the addition of a 2-car garage and the sunroom above at the rear of original house, they carved the driveway into the original backyard, and now the driveway is downward, with the end of it enclosed by the retianing walls. The only route that the run off water from the driveway, and from neighboring lot, backyard is a grated channel with a 4inch pipe buried under garage floor connected to a sump pit at the corner of the garage. Currently I have a liberty LE50 sewage pump in the pit, which goes 8400 gph at 5ft, but the discharge tube that connects to it is half inch smaller than the pump's 2 inch port. That tubing is partially buried into the cinder block wall then goes underneth/around the house to the street side drain. Pump is hooked up to the backup generator, so the power failure was not too much of a concern. Here is the problem:
The grated channel + the sewage pump inside garage sometimes could not cope with the speed of water accumulation from crazy heavy rain plus the water seeping through the retaining wall (from neighboring yard, and my back yard), I'm discussing with neighbor to have a french drain behind the retaining wall on their side to divert part of the water.
Water cannot get pumped out quick enough when it rains heavy for long period of time, then accumulated, went into the garage and worse case into the house.
A few plumbers/landscapers have thrown the idea of adding 2nd pump. Idea was to put the pit at the corner of where gutter is at, and pump the water straight up and flow with that gutter water, but some concerns were brought up that the dirty ground water may clog the gutter's drain pipe. Now the idea became using separate pipes to go around that retaining wall (sitting on top of the wall, or sitting at the drive way) and then go to street. Pretty long distance to the street (drive way is at least 4-5 car length, plus the width of it). However, no one seems to think about the possibility of the external pump got busted/frozen during DC's winter.
Combined with the 2nd pump idea was to adjust the grated channel's position, length and depth, so that the channel will go past the garage doorposts (so the run off water would be go into the channel instead of hitting on the garage door post, got it rotten), also make the external pit the lowest spot, that the external pump taking the most burden, only overflown water drained into the original 4inch pipe into the sump pit inside garage.
I got a quote of $5k labor to finish #3 and #4, but unsure about two things
1. What type of pump I need? Looks like trash pump is the way to go instead of the sewage pump I have in the inside. Any recommendation of the pump model? Liberty, Zoeller do not have trash pump, it looks like. Maybe this ? https://smile.amazon.com/dp/B000PDU9...5&ref=aa_scomp (it works with a tethered float too)
2. How to avoid the potential frozen for the external pump or should I put it inside the garage (just across the door from the current thinking spot)
Any other ideas, alternatives? VA is a non-disclosure state, so seller did not have to disclose anything, plus the neighboring house was a tear down new built finished right about the time we bought the house. It could well be the case that this setup worked fine when neighboring house was a 50s rambler, but got worse with a 6000 sqft mcmasion.
