Septic Tank Pump Question

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Skifastbadly

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Hi,

This is my first post in this forum.

About 5 1/2 years ago I bought a house in the greater Seattle area which has a septic system. It's the first house I've ever had that wasn't connected to a sewer, so lots of stuff to learn, even if it is a *ahem* crappy topic.

The second winter I was here, it rained. I mean it RAINED, a lot even for the Seattle area. And my tank alarm went off, indicating that it was full. The tank I refer to is the 'grey water' tank, not the primary. Because of the lot layout, the drain field is uphill from the tanks, meaning instead of a gravity feed, the water is pumped to the field.

When I looked into this, I found that the pump was controlled by a float...which makes sense. The float senses when it needs to be pumped, and turns on.

However, here's the weird thing. In addition to the float, the pump also has a timer on it. Which can override the pump. In other words, whether the tank is full or not, the pump was set only to run a few minutes an hour, which was the primary cause (that and ground water getting in) to the alarm.

So, I don't understand why a timer would be required on a pump which already has a float to sense when it needs to be turned on. Is there some issue of the pump burning out in very wet conditions? Is this perhaps to prevent overpumping into the drain field? Does this make any sense?

Thanks in advance.
 
I have the same septic setup, except I don't have a timer. But I think the timer might have to do with avoiding an overdose of your septic field (leech field). Especially in an uphill field, you would probably have backflow if the pump was allowed to run too long; which would only force the pump to run longer.
I do have an alarm but I've never had my pump tank overflow. So I don't know what the best solution for that would be.
 
Just in case you haven't heard this advice before: be sure to have your tanks pumped about every 3-4 years. There is a certain amount of solids that don't dissolve and they will accumulate at the bottom of your septic tank...and possibly also the pump tank. You definitely do not want the solids to enter your leech field.
 
I think Slownsteady is right on the mark. There would be another reason the timer might be in there and that would be if the float sticks or malfunctions. When they set it up they may have waited for the tank to fill and then watch how long it took to empty the tank and then set the timer to something a little longer than that. If your float didn’t give the signal to shut off the pump the timer would and at the same time turn on the alarm. I have a grinder pump lift station and have something similar but I have two floats. The main one runs the pump and the second one is set higher and lower I believe and controls the alarm and also the shut off switch.

It could also be to prevent over dosing the field also in regards to rain. You shouldn’t be getting ground water into your tank though.
 
It could also be to prevent over dosing the field also in regards to rain. You shouldn’t be getting ground water into your tank though.

Real good point that I hadn't caught. Might be worth your while to get in a septic inspector to check it out.

Unless it really is a gray water tank and not part of your septic system....Hmmmm.
 
I have a guy coming out this Friday morning to pump it. It's been about four years and we're empty nesters so I went a bit longer than the three recommended between pumping. I discussed ground water getting into the system he didn't seem to concerned. The way it rains around here I get the impression that's not unusual. But better to be prepared, hence my question here. Interesting point about overwhelming the leech field. Might explain the timer. Nobody at the local HW store had any idea why there'd be a timer on that pump.


Thanks for the feedback, I'm glad I'm not the only one who finds this configuration confusing.
 
I don't like the idea of a timer. I don't think the pump want to run dry too much.

If I understand how the system works, the timer AND the float must both be 'on' for the pump to run. In other words, if the timer is on but the float ain't floating, it shouldn't run.

That's a big IF, though.
 
If I understand how the system works, the timer AND the float must both be 'on' for the pump to run. In other words, if the timer is on but the float ain't floating, it shouldn't run.

That's a big IF, though.

You would think one would be a back up for the other.
 
if your tank is getting water back from your field thru the discharge. your ck valve is bad

there is a check valve on the pipe coming off of the pump. it is their to prevent water from coming back into the tank when the pump turns off

if it was not their. the pump would lift the water up and out. turn off, and the water would run right back down where it just came from

fill the pit up, the pump would come back on, pump the water out. turn off
over and over again. we call it jacking off. crude, but hey! we play with turds ;)

unless. the float is being over ridden by a timer.
then, it would pump dry, turn off, fill back up. and wait till the timer told it to do it all over again

if you have a second float, that float is called high water alarm
it SHOULD sound an alarm AND kick the pump on, overriding a timer
IF. it was wired correctly in the control panel
 
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Frodo, that's a very clear explanation and it makes a lot of sense to me.

Some more detail....a couple of years ago, on a very rainy Sunday night (when having a guy come out costs doubletime) my system filled up completely. So I call a company and they come out and pump the tank(s). Now I'm not an expert here, but there are three tanks....two primary (where the waste from the house goes and are actually two compartments in a single enclosure, I believe) and a third, which is where the gray water goes from the primary and is from there pumped to the leech field. When the covers were removed from the primary compartments to pump them out, we could tell water was dripping into them....it's rare but it happens. It's hard to imagine how those could be fully waterproof as they seem to be poured concrete and I assume cracks develop. But since you seem very knowledgeable, the key question I guess is "if water is leaking into the primary tanks during heavy rain, do they need to be replaced?"

Thanks
 
test the tank, using http://www.bing.com/images/search?q=plumbing+test+plugs+balloon&id=9B0BB0C17D5E5CC3EB36FCF1C4AADD2AB7B492CA&FORM=IQFRBA
plug the tank, fill with water. see if it leaks or not. how much? how bad?

little seeping leak i would not worry over, big old gusher, i would

if a tank is set correctly. on a bed of at lesat 12" of sand. level. it should last a long time with out leaking
if some jack leg, dug a hole, dropped the tank in, with out leveling the bottom. the tank can settle
twist, crack, and need to be replaced

not saying this is your problem.

before going any further. have the ck valve replaced.

if primary tank gravity drains into secondary , and ck valve is bad in secondary, secondary can fill up,
and the liquid can run back to the primary from the secondary. via the drain line
 
@frodo; suppose you have a 1000 gal tank. you would fill that with water, perhaps after it was just pumped? Doesn't sound very do-able to me. And when you're done testing, all that will just be dosing your field without ever giving it a rest. is there an air pressure test?

@skifast: what kind of shape are the lids in? Do they fit snugly after inspection? Are there chips along the edges? And what about the topography of your property: do you get stormwater runoff through your yard?
 
Well the guy who's going to pump the tanks and inspect the system will be here at 8 tomorrow morning. I started this thread because I mentioned the weird (to me) wiring of the pump and he couldn't think of any reason for a float AND a timer. The small leakage into the tank is something I'll ask him about, but as this is the Seattle area where it's wet half the year I imagine he'll be familiar with the situation and let me know if I need to seal the tank which sounds as expensive as hell.

@slownsteady: The development I live in is 25 years old and built on old forest land. It is not flat, and it gets plenty wet. I do not have storm water running across the yard during rains, but I do have a constant (in the winter months) seeping of water out of the ground right at the street level, which then flows to the storm drain....unless it's below freezing, in which case it gives the kids something to slide around on.
 
I asked because one of my neighbors lives at the bottom end of a local road. He had to install a curtain drain in front of his leech field in order to stop storm water from flushing his leech field. Not the same in your case 'cuz his tanks weren't filling with water, but you never know what knowledge will connect in a forum like this.

But I am curious why your tanks fill with water. Please let us know what you find out.
 
But I am curious why your tanks fill with water. Please let us know what you find out.

Well firstly, they haven't filled up for a couple of years. Which I suspect is because I reset the timer so it basically is always on and the pump is governed by the float. And, it's been a few years since it's been that wet. However, I will be glad to post the results of the inspection tomorrow for the benefit of the forum.

Thanks all for your interest in this topic. I can see I've found a good forum.
 
slowansteady, not only are you required to fill a 1000 gallon tank with water. but if you do not leave the water in it when you get done
there is a very high chance it will be sitting on top of the hole the next morning.

an empty tank will float to the top.

scan0001.jpg
 
It sounds like your system is more modern than a leach field system and sounds more like a sand mound system. In these new systems they have the septic tank to break down solid waste and then the dosing tank. In a mound system there are very few holes and small holes and it requires a head pressure to inject the water into the mound. They don't want the water to trickle in it is to take a full dose when pump runs. They also don't want a check valve as the back wash is part of the design to flush and keep from freezing the shallow pipes. You can get extender rings to bring lids up higher if you need to for ground water and they get mortared in place. Will be interested in what the report says.


Sent from my iPhone using Home Repair
 
Good point Bud, some one should know what there is before making much in changes. Someone has the the approved set of plans for the system, maybe the permit dept. like here it would be a regainal health something or other.
 

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