backup sump pump options


After a fair amount of regrading etc., we've manage to get things to the point that, when it rains an inch or so, the sump pit in our basement only has to empty once every 10-15 minutes, rather than every 1-2 minutes like it did when we bought our house.
As much of an improvement as that it, it still means we're screwed if the pump fails on us (which it is has done twice in four years) or if the power is lost for an extended period of time. Until we figure out how to make flooding a virtual impossibility (barring major acts of God), we're reluctant to even finish out our otherwise nicely spacious basement, let alone follow up with extended trips out of town.
Any suggestions on what kind of a backup system to install? I'm aware that there are battery-powered backup pumps, but my impression is they're pretty expensive for any kind of reasonable capacity.
I'm aware that there are simple nozzle devices (eductors) that can use water pressure from a garden hose to suck water out of low-lying areas. I'm wondering if there are adaptations of this idea that could serve as a backup to the sump pump when there's no electricity.
Also, I should mention that there are *two* conventional sump pits/pumps in our basement, but for reasons that are beyond my ken, the drain tiles served by each are unconnected (the ends are separated by about 6'; I know this, because they were installed after the house was built, and you can see where the concrete was chopped up).
Thus, a failed pump on one end of the basement means flooding, even if the pump on the other end *could* have taken up the slack. Again, it's happened to us twice.
Is this just stupid, or is there a good reason (beyond saving the cost of chopping an extra 6' of channel in the basement floor) that I'm just not seeing?
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Grant Petty
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What's the duty cycle on the sump? Can you estimate a total GPH requirement?

I've been looking into this myself, and have come to the conclusion that a properly selected lead acid battery (deep cycle version of standard car battery) _should_ conservatively be able to run a 500GPH marine bilge pump (pulling 1-2A) for about 15-20 hours in total.
If, when you factor in your total GPH requirement, that's within your comfort zone, then this'd work.
[I plan on building my own because the battery will also be used for emergency lighting and an inverter. Yes, that decreases pump time, but, if we're home to need the lighting and the inverter, we can charge the battery off the car if needed. Heck, if necessary, we can run the pump off the alternator-recharged-battery directly.]

There are commercial units that do exactly that - float-valve actuated municipal water pressure eduction sumps.
It'd almost be ideal. Except - we're on a pumped well...



I think it's just stupid.
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wwwZoeller.com and www.basepump.com have city water powered auto backup pumps. Check the GPM rating of your pump to see if these water powered backup pumps will work. 2 pits 2pumps doesnt make sense for drain tile. Can you contact the previous owner. I would dig it up and connect them and keep 2 pits and pumps, one set to go off at a higher level as backup and instal a water powered backup system. If you can afford it get an automatic start generator. Or possibly an auto start gas water pump. The City water powered pumps will work if the ratings match. Battery operated pumps are limited and the ratings GPM go down from day one as batteries age, probably failing in 4 - 7 yrs.
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It seems to me that 2 pumps makes a lot of sense if the water infiltration is at the level the OP claimed. One pump just couldn't be relied upon for that.
Also, connecting the two might not work, as one is probably higher up than the other, and the water will just flow to the lower pump, causing it to work too hard.
On the other hand, in peak times the higher pump could bail some out before it got to the lower pump, I guess.
I've got a similar problem, but only one pump. When the water table rises and it gets going it empties out about once a minute, and water still enters from cracks in the walls and flows across the floor. I'm about to invest in French drains and maybe get a second pump myself.
Home depot has )had) the backup devices that connect to the water line and run the way you described. That wouldn't have worked for me a couple of months ago when the frigid temps caused a local main to break and the winds were high threatening loss of power! Fortunately the power stayed on, but I feel the same way as the OP--I hate to leave home in a heavy rain. Nothing is more upsetting than to come home and find things floating in your basement.

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OP said he will flood if either pump goes out so no it makes  no sense.
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m Ransley wrote:

Actually, either pump *could* handle the load by itself, if they both covered the entire basement drain tile. Unfortunately, the two sections of drain tile are unconnected. Most of our seepage is on one end of the basement, so if the pump on that end fails, the sump pit on that end overflows, even if the other pump is sitting idle with nothing to do.
So ideally, we would connect the two drain tiles so that one pump can serve as a backup for the other (both pits are at the same level, give or take an inch or two). But chopping up concrete to connect the drain tiles would be a big, messy, and probably expensive job, so we probably won't do it any time soon.
And even if we did, it wouldn't address the problem of a power outage, which is what motivated my original post.
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