Septic tank too dry?

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JohnCT

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I had a company out to pump my septic tank this morning (no problems, just routine), and the guy said the tank was too dry and had my wife turn on all the faucets in the house and flush the toilets repeatedly.

Well, that killed my pump (another guy is here changing the pump right now), but the septic guy said to call them back in six months for another pump-out, and next time they would bring a water truck.

I wasn't here when the septic guy pumping the tank - this is the way my wife relayed the story, but she's got a pretty good memory.

Anyone guess what this was all about? Does it sound like the guy doesn't know what he's doing?

John
 

Jadnashua

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There's normally one inlet and one outlet from the tank. Everything that goes out should go out to the leach field. If the tank leaks, that could be the reason why the tank wasn't full. Normally, the thing is always full, and when you add something, the liquids that have settled for a bit overflow out into the leach field while the incoming solids fall to the bottom. Eventually, if you let it sit too long, there's too many solids, and those get dumped out into the leach field which will eventually cause it to fail and need replacement. In the house I grew up in was built, they used a big steel tank...it eventually rusted, and it was replaced with a concrete one. But, even a concrete one could develop a crack and leak. If the tank is too dry because of leaks, the bacteria can't decompose the solids very well, and it will fill up with them much faster.

So sounds like the tank is leaking. IF there's another reason, I'd be glad to know so I can be more informed for the next time somebody asks.
 

Gsmith22

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OP mentions "pump" though being changed out. A traditional gravity septic system as jadnashua describes wouldn't have a pump. So the OP's system may be a mound type system with a pressurized manifold fed by a pump. in traditional gravity septic systems you have a tank fed by house sewer and outlet from tank that leads to distribution box and bunch of pipes forming leach field. all this runs on gravity so its all downhill. In a mound style pressurized system, you have the same septic tank fed from the house but the outlet of the septic tank feeds a pump tank (all done via gravity). the pump tank slowly fills up with effluent and when level gets high enough, the pump located in the tank comes on and pushes fluid uphill to a pressure manifold in a raised mound. These are supposed to work better than gravity systems because the fluid is only pushed to the field/mound sporadically allowing it to rest and because of the pressure, the entire mound sees the effluent. In a gravity system, the field sees every drop of effluent as soon as something enters the septic tank and typically the leach field pipes closest to the distribution box end up seeing most of the flow overloading the area closest to the distribution box.

But none of that would be related to a septic tank being "too dry" unless they are actually talking about the pump tank. The liquid in the septic tank (in either system) will always be at the same elevation - the invert of the septic tank's outlet pipe. But the fluid level in the pump tank varies between a very low level (just after the pump runs) to a very high level (just before it turns on). I think the OP needs to figure out what system he has/what tank they are talking about. I suppose they could have mistakenly pumped your pump tank if you have a pressure system and thought that was the septic tank? If you just have a traditional gravity system with only a septic tank and you didn't get it pumped in the last month, then it is leaking out of a crack into the ground and not going to your field. I don't think I would wait 6 months to rectify that situation. Fluids can go strange placed below grade and I certianly wouldn't want sewage showing up in my basement.
 

JohnCT

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Sorry guys, let me both apologize and explain. Yesterday was very very hectic and I didn't get the entire story, and what I did get I wasn't clear when telling it here. Everything is taken care of for now, so this morning I was able to question my wife more carefully. So..

I scheduled a septic tank pump out yesterday while I was at work. My wife was home. I would have been there if I expected a problem but this was supposed to be routine. The septic guy showed up about noon and told my wife to run all the faucets, tubs, and flush the toilets because it was "too dry". He told her he normally had a helper with him but he was working alone. The helper he said was to shovel up what was on the bottom. He said more water flowing would help. I don't see how, but then I've never pumped a septic tank. So I don't think the tank was low, I think the guy was a dunce. He said to call them back in 6 months for another pumpout and this time they would bring a water truck.. I think I'll call someone else...

Also, my tank is a 1000 gallon with three hatches. One in the middle that was tight fitting, and two towards the ends that were smaller. The septic guy only removed the middle one. I don't know the significance of that but I'll post a picture of the hatches if anyone wants to see them and comment. I assumed that he would open the end hatches, but again, I'm not a septic tech and don't know. But wait, there's more!!

Now, during the 10 minutes my wife was running the water for the septic guy, the flow slowed and it started putting out sediment. The water stopped completely. My wife called me and I returned home immediately to see about the water. I have a ridiculous reserve of water so I knew that the well wasn't run out. I looked down the well head anyway and the water was around 20' down on a 250' well. Plenty of water.. I found the breaker popped (uh-oh) and the well pressure at 10lbs. I threw the breaker and I could hear something (soft whine?) but it wasn't building pressure, so I shut down the breaker. I pulled the control box off and found the motor start cap hot and leaking. I installed my backup control box, turned on the breaker, and same thing. I checked the voltage to the motor and was getting 238VAC, but about 15 seconds after throwing the breaker I heard a loud buzz from the panel and the breaker tripped.

Cutting to the chase, the pump died during the septic procedure. It was at minimum 15 years old so it was ready to die anyway. I had a local company come out and pull the pump (250') and change it out, so everything for now is back to normal.

Again, sorry for the misinformation and not clarifying that it was my well pump and not a septic pump, and many thanks for the replies.

John
 

LLigetfa

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The very hard draw on the well motivated sediment and the pump ingested it. Your well may not have been fully developed by hard pumping. It either needs to be developed or a dole valve added to limit the GPM. This has happened to me several times and I now limit the GPM output.

A septic tank usually has two chambers with a baffle in between them. Both chambers need to get pumped. I'm guessing the big access in the middle would reach both chambers and the smaller access at each end is to get at the inlet and outlet for inspection/jetting.

I drive a small vac truck that has both water and honey dew tanks for servicing portable washrooms but the larger vac trucks used for septic tanks do not. Normally they are not dispatched with a water tanker. We only dispatch them with a high pressure wash truck for special industrial cleaning or for jetting sewer lines.

It sounds like the driver was too lazy to put in any effort to stir up the sludge and perhaps lacked the skill in how to move the suction hose around so as not to skim off all of the liquid leaving behind "too dry" sludge. I would lodge a complaint with their office, both for the shoddy work and for giving bad advice that resulted in a failed pump.
 

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". He told her he normally had a helper with him but he was working alone. The helper he said was to shovel up what was on the bottom. He said more water flowing would help. I don't see how, but then I've never pumped a septic tank.
I don't think they shovel up what is on the bottom usually. Maybe they use a shovel as a scraper to let the solids mix with water to get sucked out. But asking you to run water is normal.

Cutting to the chase, the pump died during the septic procedure. It was at minimum 15 years old so it was ready to die anyway. I had a local company come out and pull the pump (250') and change it out, so everything for now is back to normal.
A new start cap or control box might have fixed it, but not necessarily.

Going forward, you might want to change out your start cap every 10 years. The start caps have a limited life that is affected by number of starts, years, and temperature.
 

JohnCT

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A new start cap or control box might have fixed it, but not necessarily.
.

I figured it was a long shot, but I have a back up control box, and it took 2 minutes to try. Nothing ventured, nothing gained they say.

John
 

JohnCT

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The very hard draw on the well motivated sediment and the pump ingested it. Your well may not have been fully developed by hard pumping. It either needs to be developed or a dole valve added to limit the GPM. This has happened to me several times and I now limit the GPM output.

.

"Developed"? I don't know that term. But with regards to the well, I have 20gpm minimum, and with a 6" bore and 220 feet of water over the pump, that's like 300 plus gallons reserve. Do you mean that if the pump runs for a longer time, even with plenty of water above the pump, it can still stir up sediment? The guy who replaced the pump told me believed the sediment was introduced from the expansion tank when it got depressurized - quite normal according to him. The tank itself is only a year old, so I don't know what to make of this.

In addition, I was in fear of the pump failing because I discovered my well was cycling every 5 seconds when water was being drawn because of a bad tank about a year ago. I don't know how long it was like that before I replaced the tank, but it was a few weeks minimum and could have been months. After I changed the tank, it ran a year with no trouble so I thought I dodged a bullet.

Also, I put in a lawn many years ago and was running three sprinkles for two weeks in addition to household usage, and never had anything but clear water. The only time I get any kind of sediment is when I have to shut down the system for plumbing repairs, which seems to support the tank being the source of the crud. The pump was changed last night and it was cloudy, and this morning the water is crystal clear.

Due to the history of the well, the age of the pump, and the period of cycling it went through because of the bad tank, I'm inclined to think it just was time for it to go.

Thanks for the info.

John
 

Reach4

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The guy who replaced the pump told me believed the sediment was introduced from the expansion tank when it got depressurized - quite normal according to him.
There can be something to that. It is good to drain your expansion tank, periodically to get rid of accumulated sediment. I should do it at least annually, but I am a few years behind on that.

There should be a spigot near the pressure tank to facilitate this. Maybe watch the first stuff to come out to get a read on how often you should do this.

You should consider some filtering after your tank to stop sand and small rocks that get pumped up. A wye strainer might be good for the pipe to the irrigation. A cartridge filter is good for the house. When plumbing those in, adding a pressure gauge after the filters can be useful to identify a filter getting clogged.
 

JohnCT

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There can be something to that. It is good to drain your expansion tank, periodically to get rid of accumulated sediment. I should do it at least annually, but I am a few years behind on that.

I think I'll add that to my repertoire as well. The well guy said to run the pressure to zero when cleaning the tank; that would release any sediment as opposed to just flushing from the manifold hose bib with the power on and the tank maintaining pressure. I always seemed that when I had to depressurize my system, I always got a crapstorm of sediment. I learned to run a hose from the tank out the slider to clear the water before turning the valve to the main house on.


You should consider some filtering after your tank to stop sand and small rocks that get pumped up. A wye strainer might be good for the pipe to the irrigation. A cartridge filter is good for the house. When plumbing those in, adding a pressure gauge after the filters can be useful to identify a filter getting clogged.

There is a hose bib at the manifold that I use to drain the tank and run the well without sending it through the house plumbing.

I installed a strainer between the output of the tank manifold and the input the calcite acid filter I added two years ago to try to keep the calcite clean. There is no whole house filter, but again, unless I have to shut down and open the plumbing for repairs, my water is crystal clear and has no odor or taste whatsoever. When I had the water tested, it came back virtually perfect except for pH about 6.4 or so (changed seasonally). The calcite tank keeps it at 7.1 now.

John
 

Reach4

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I installed a strainer between the output of the tank manifold and the input the calcite acid filter I added two years ago to try to keep the calcite clean.
Adding a wye strainer on the way to the irrigation should help those nozzles.
When I had the water tested, it came back virtually perfect except for pH about 6.4 or so (changed seasonally). The calcite tank keeps it at 7.1 now.
Nice.
 

LLigetfa

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Unless you have a small upside down or sideways tank or you have a hydro-pneumatic tank, sediment should not be building up in it. A medium to large diaphragm tank has the port on the lowest part of a curved bottom so sediment would exit on every cycle.

I always seemed that when I had to depressurize my system, I always got a crapstorm of sediment. I learned to run a hose from the tank out the slider to clear the water before turning the valve to the main house on.
The way I read that, you are getting sediment on startup which would be with a completely empty pressure tank so the sediment is coming directly from the well, not from the tank. There would not be anything coming from the tank at startup.

Your pump runs on a curve. The higher the pressure, the lower the GPM. The lower the pressure, the higher the GPM. You would have zero pressure at startup so the highest possible GPM flow. It is the high GPM flow at low pressure times that motivates the sediment in the well. Your well was either not developed by pumping it hard, or it has an inexhaustible supply of sediment that gets motivated at high GPM draw.

Opening every faucet in the house will drop the pressure lower than normal use would and increase the GPM the pump draws.
 

Reach4

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Unless you have a small upside down or sideways tank or you have a hydro-pneumatic tank, sediment should not be building up in it. A medium to large diaphragm tank has the port on the lowest part of a curved bottom so sediment would exit on every cycle.
Yet some is there. Not a lot. It may be due to the water still there due to the precharge being a tad lower than the cut-in.
 

JohnCT

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Unless you have a small upside down or sideways tank or you have a hydro-pneumatic tank, sediment should not be building up in it. A medium to large diaphragm tank has the port on the lowest part of a curved bottom so sediment would exit on every cycle.

The way I read that, you are getting sediment on startup which would be with a completely empty pressure tank so the sediment is coming directly from the well, not from the tank. There would not be anything coming from the tank at startup.

I could probably test that by depressurizing the system several times and see if the sediment returns every time. OTOH, would that be a good idea for the pump if the sediment was coming from the well?


It is the high GPM flow at low pressure times that motivates the sediment in the well.

That's something that never occurred to me, but it makes sense

Your well was either not developed by pumping it hard, or it has an inexhaustible supply of sediment that gets motivated at high GPM draw.

I had never heard the term "developed" when used in the context of wells, but I did look it up. Here's what I recall: We moved into the house in late September, but that Labor Day (first week of Sept) my brothers wanted to see the house, so we took a ride up and did a walk through. Out back, there was a hose connected to the bottom of the tank and running into the back yard with the water on. The builders left it running all weekend to clear the well I assumed. The water was clear and it filled an abandoned 10 gallon pail in about a minute, so I knew I wouldn't have a water shortage at least.

Was this "developing" the well?

John
 

Reach4

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I could probably test that by depressurizing the system several times and see if the sediment returns every time. OTOH, would that be a good idea for the pump if the sediment was coming from the well?
I don't expect that would happen. I expect the sediment/rust would be significantly reduced on repeated tries.
he water was clear and it filled an abandoned 10 gallon pail
Probably 5 gallon pail. You are unlikely to get 10 gpm through a regular garden hose. Still, indicates plenty of water, and they were developing the well.
 

LLigetfa

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Still, indicates plenty of water, and they were developing the well.
Sorry, I don't consider a constant 5 or 10 GPM developing. Granted, the pump may have been cycling the whole time so the draw plus the tank filling would not have been a constant 5 or 10 GPM. None the less, the pump would have been up on the curve with the pressure varying only between maybe 40 and 60 PSI. Open up the flow so the pressure drops to 5 or 10 PSI and then see if that motivates sediment. Just beware that too much sediment could overwhelm and lock up the impellers. That happened to me more than once.

If the well cannot be developed to open up the aquifer to a large enough circumference so as to no longer motivate the sediment, then you should put a dole valve on the line to limit the GPM.
 
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