Sump pump for drainage system -need help
I need help figuring out sump pumps – any advice or links appreciated. My client’s lot slopes to the back yard and away from the street. So in order to actually get the water off her property and not dump it on the neighbor, I have to install a sump pump to take the water flow off the roof to the street. I calculate the maximum flow at 16 gpm.
My questions: are there better brands? Any to avoid? How shall I size the sump and the sump pump? How shall I deal with debris flowing into the sump from the gutters? I saw something about not using a GFI outlet…, can you get extra long cords so I can install one electrical outlet instead of two for the pumps? Is it even remotely possible to dig a dry well and NOT have to use a pump? Our soil is clay. We only get about 20 inches of rain a year (bay area, ca) so I’m not too concerned about burning the pump out, but it’s worth considering of course.
Any other tips, suggestions or advice appreciated.
Replies
Here's a little bump, since nobody answered...
thanks Kate,So I'm a bit closer to my answer, the Zoeller rep emailed me back and recommended the 'Sump and Sewage Pump Manufacturer's Association' website (but of course!) The link is here: http://www.sspma.org/pubs/index.htmlThis all starting to seem a bit absurd to me, my client WAS just dragging a drain pipe to the downspout and routing the water to the fence line. All this effort and engineering for what might not actually be that much of a problem in the first place, arggh!My latest thought is to glue the drain pipes and take it all the way to the street and run the pipes up the side of the house a foot or so so it creates enough head to push the water out at street level. I think that should work fine but I'll need to cut out some concrete to get there. We don't get freezes here often and what with global warming perhaps not at all now so I think the standing water in the pipes should be ok (I hope!) Since I also need to install a french drain on one side I can then take that out the back way and since it's a much smaller amount of water just set up a small leach field in the back corner of her lot. Thought I'd post my email so that the next guy can find it a bit faster...Here's our exchange:ME:I'm a landscaper and I need help figuring out sump pumps - any advice or links appreciated. My client's lot has a gentle slope to the back yard and away from the street. So in order to actually get the water off her property and not dump it on the neighbor, I have to install a sump pump to take the water flow off the roof to the street. I calculate the maximum flow at 16 gpm and the lift is only 1-2 feet. We only get about 20 inches of rain a year (bay area, ca) and the roof is 1200 ft^2 so I'm not too concerned about burning the pump out, but it's worth considering of course. I went through your sizing tool but it came up with no results when I plugged in my numbers. ZOELLER REP:The majority of our smaller fraction horsepower pumps require a minimum of 5' of head in order to create enough back pressure for the pump. This may be accomplished by choosing a basin with a deeper bottom for pump mounting. With a minimum vertical and horizontal head capacity and the flow that you've mentioned, we will more than likely end up looking at one of our 53 series pumps. Because of the opportunity for debris to enter the pit, I would also recommend looking at a standard sewage ejector pump which would have a 2" solid capacity. In this case, I would look at our model 264 series. (I've attached a link to both of these pumps.)
http://www.zoeller.com/zcopump/zcopdfdocs/FM0493.pdf
http://www.zoeller.com/zcopump/zcopdfdocs/FM1495.pdf ME:
My questions: How shall I size both the sump and the sump pump? What about debris flowing into the sump from the gutters? I read something about not using a GFI outlet for sump pumps and another comment saying it was ok if the GFI was dedicated. I'll have 2 pumps plugged in and possibly running at the same time. Can I get extra long cords so I can install one electrical outlet instead of two for the pumps? (I'll need one on each side of a 30' wide house). ZR:
We would recommend that each pump be on it's on dedicated circuit whether or not it is placed on a GFCI. If the pumps do have the chance to come on at the same time, there is a small chance of the pumps tripping the circuit breaker and this would allow neither pump to operate. Either pump is available with an extended cord lengths. Using a single pump on a dedicated line is suggested regardless of whether or not the outlet is a GFCI type.ME:
Any other tips, suggestions or advice appreciated, NDS (who make drain fittings) has a nice booklet on drainage engineering but nothing on sump sizing or sump pumps so I've been looking for a good resource on this - if you know of a book or a technical pamphlet I'd appreciate a link or a name. And of course, if you want to suggest one of your pumps that would be appropriate I'd appreciate that. ZR:
If you visit the SSPMA's website, they have some great pamphlets that would help to size most small dewatering/effluent/sewage systems. After a few practice sizings, our sizing software will take some of the hard work out of the calculations. If a pump is not requested, it typically means that there are some criteria that is excluding certain pumps. If you have any questions about the sizing, feel free to contact either myself or any one of our other qualified technicians in our Technical Department.
Thanks - Good Luck - looks like a pretty informative site.
sigh, just realize my hydraulic head solution isn't going to cut it - once leaves get in, they'll never flush. Oh well - just got to explain it to the client I guess.So kate, it looks like you and are the only two people on this board interested in the fascinating and exciting topic of drainage - who would have thought? Maybe we need to start a booster society - we could have secret handshakes and wear funny hats. You might find this useful: NDS has some good info as well, their pubs can be found here:
http://www.ndspro.com/technical_info/index.aspx
Hello,
We live in the SF Bay area and we have clay soils also and we had a similar problem to you. In our case our yard and all the surrounding yards sloped towards our house. Around here there is top soil for the first couple of feet then straight solid clay like you used to make bowls out of in grade school. What was happening was, the water was percolating down thru the soil and hitting that clay layer and running horizontal to the interface. I had a good sized underground stream running under my house.
To fix this I used 2" ABS drain fittings connected up to the round downspouts. I ran both sides forward to the front of the house. On one side I have a raised planter bed that was perfect for hiding the drain pipe. The pipe exits just above sidewalk level and drains across my driveway and into the gutter. I should of just broke up the sidewalk and put in a pipe but that might of caught the citys attention. So that took care of my roof runoff.
Now the underground stream from all my neighbors runoff had to be taken care of. I built a giant drywell/moat across my backyard and between my house and the neighbors. Sides and bottom of drywell lined with landscape fabric, perf drainage tube covered with filter sock with surface level cleanouts and filled with clean 3/4" gravel. When I redid the foundation in the back of the house the external french drains were connected to the sump pit. The drywell drains to a deep sump pit. The sump pump is connected to the ABS fittings on one side of the house (thru a check valve). This drywell stops the flow of water under my house completely. If I had to do it over the only thing that I would change would be the shape of the sump pit. I should of gone with short and fat instead of tall and skinny. A tall and skinny pit fills with water faster than a short and fat pit which means my sump pump turns on more often than I like.
Almost forgot, I bought the 'best' sump pump from Home Despot the 3/4 hp 110V model and it pumps a fierce amount of water.
Hmm, hope that was sorta helpful.
Daniel Neuman
Oakland CA
Crazy Home Owner
Edited 10/25/2005 2:32 pm by madmadscientist
thanks daniel, the cycling you've mentioned is possibly a problem as it can lead to early pump failure. Other threads on this board speak highly of Zoeller brand pumps if it comes to a new pump.What's the check valve checking in your system? Is it to keep the house gutter drains from backflowing into your dry pit?
What's the check valve checking in your system? Is it to keep the house gutter drains from backflowing into your dry pit?
Since the sump pump is like ~8' down (I did mention it was a big moat) I put a check valve right on its output so that the water that's in the tube running up from the pump to the gutter drainage system does not flow back down into the pit and cause excessive cycling. It would also prevent the gutters from backflowing into the system but this should not happen unless something is blocking the system down the line. I have all the pipeing done like regular plumbing and that water should not be flowing uphill I hope.
I don't actually have any trees nearby to clog my gutters but if there were leaves in the system I think that when the pump kicks on it would have no problem pushing them out the end. Even with my home despot 3/4hp pump the water flow and pressure is pretty impressive. We used to have the drain line come up thru one of those downspout gargoyles. The water would shoot out of its mouth and most of the way across the sidewalk.
I also have not noticed any foul odor coming from my drain pipes even though I know that there must be water trapped in there. Maybe because there is no p-trap the line just dries out in the summer when the pump is not cycling?
Daniel Neuman
Oakland CA
Crazy Home Owner
I think that you are using the wrong term.
What you want is not a sump pump, they are for clean water.
It might be a trash pump or a drainage pump or some other term.
Look at Zoeller web page and see how they classify pumps.
A while back (I think with in the last year, but it might have been a little longer) someone posted some pictures of an system that they have at there house to drain a below ground area in front of a walk out basement.
They had a dual pump with automatic cycling controlls.
I think that it was Zoeller. Use the advanced search and try looking for Zoeller.
Maybe also patio drainage.
thanks for the tip, the Zoeller rep said as much when I called.