OK, time to bring in the pro water treatment guys.
Gary hit it way back in post #2. I'm pretty sure that what's happening is that the neutralizer is backwashing every 4 days, on schedule, and the septic tank can handle it, as long as there's nothing else going on. However, once in a while the softener decides to regenerate, and it happens to be a "neutralizer night". It looks like they set the softener to regenerate at, say, 2AM, and the neutralizer later -- at 4AM, maybe. (Setting the times apart by a couple hours ensures that only one valve is drawing water at a time. They're conscious of trying to draw too much water from the well to satisfy the high flow rates required during backwash, but didn't take into account the cumulative effect on the septic tank.) On these nights, the softener pretty-much fills up the septic tank, then the neutralizer kicks in and overwelms the tank and it backs up. You can solve the immediate problem by ensuring the two regenerations occur on separate nights. I don't know enough about the controllers to advise you on this. Ideally there's a way for them to talk to each other so that the neutralizer knows that the softener has claimed this night, and to wait another night to do its thing (or vice-versa), but I've never heard of such a communication link being available. My 2501 is purely mechanical, but fancier computer-controlled valves exist, and there might be a way to coordinate their backwash cycles.
Find out, if you can, the exact models of the 2510 and 5600 controllers, and whether the 2510 is mechaical or demand-driven. I suspect you've got a 5600SXT (with an LCD screen, computer-controlled), and the 2510 is mechanical (7 or 12-day "skipper wheel", no computer). I can imagine a simple controller that would signal the 5600 that it's OK or not-OK to regenerate, but there may be a built-in way to do that. But I are an EE, not a Fleck controller expert; the experts here can tell you if it's easy to do.
You may have a larger problem - the septic system. Your septic guy can tell you how much headroom -- the amount of empty space -- exists at the top of the tank, and should know how well the drainfield accepts the tank's outflow. If the drainfield is inadequate, the tank will fill up rapidly and drain slowly. But as I said earlier, the septic system is designed to handle "normal" residential loads. Whether an inrush of over 100 gallons in 3 or 4 hours is "normal" or not, I don't know. But the septic guy can easily test your existing system to see what its limits are, and since it seems to handle the everyday household load, you're probably OK for the time being. Just don't get any ideas about adding a giant whirlpool tub.
Both of the systems are mechanical. No lcds or computers.
The softener kickoff happens so infrequently (I bet once a month, and it happens based on how much water has been used), that I don't think it's the issue, since I've already had flooding twice this week. Plus, the softener does its thing later than the neutralizer. I 100% guarantee both systems did not go off this last week when the system flooded twice.
I do feel, though, that your general assessment appears correct: the system can't handle the load at times. The question is why now? Has a small enough blockage occurred somewhere recently, and that's why I have an issue only when the neutralizer goes? I see no evidence whatsoever of any issues of backup during daily water use.
It seems what I have to do is have a plumber come in first and make sure the drain pipe in the house is clear and adequately sized. My guess is I'm going to get a pass on that considering it's a straight, clear shot out the back of the house.
Assuming that checks out, septic people are the next call. They can hopefully give me some insight as to whether the system has some sort of problem that only rears its ugly head when the neutralizer does the backwash (and why for 11 months I've had no problems, and only recently there's been an issue).
The thing that's frustrating, of course, is that I expect every 4 days to clean up a flood, and my concern is perhaps the flooding will get worse as time goes on, so I have to stay on this problem so it gets fixed ASAP (and historically I've had trouble getting people to respond promptly and keep their appointment).
Boy, you sure do know how to bust my balloons. One more theory and I'm done... While that truck was cracking your plastic septic tank, it was also possibly damaging the distribution box and drainfield components. Your septic guy can explain and really determine what the problems, if any, are. The plumber might run a camera through the line right up to the septic tank and eliminate any problems (or find some) up to the tank. Then it's up to Mr Septic Person. How old is the house and drainfield? What is your soil like? Drainfields do have a life limit, and they do fail. January isn't the best time to be digging up drainfields, but it may come to that. Good luck; let us know what the outcome is.
Normally a softener should be programmed to regenerate after a filter; filter first. In this case the filter probably should run later in the night due to baths/showers/laundry possibly being done in the evening or closer to midnight but...
A softener usually takes an hour and a half or less to finish although a 5600 mechanical metered timer doesn't get back to Service on the dial for like 3 hours.
Since you say snow melts in the yard above the septic tank, I suspect the inlet sewer line or the outlet may be freezing, or ice is forming on the top of the water in the tank, when the temp gets down low enough for long enough. That is the only thing that is not consistent and could cause the infrequent backups or...
There is something wrong (possibly a blockage) in the septic system inlet pipe or the drain field pipe, or in the tank or the drain field itself and that is preventing large volumes of water from exiting the tank.
If it were mine I would go to the septic guy first and when the temps are low if possible. Otherwise they will have to dig up on each end of the septic tank to see that the lines are not broken etc.. But... another choice would be a plumber that does drain line cleaning to check/clean the inlet pipe. That would help the septic system guy if they knew there was no blockage in the inlet pipe and... he wouldn't be needed if cleaning found a blockage. Sewer line cleaning is where you get a camera inspection too but, my guess is that not all those guys will have a camera.
You have a 2.0' AN filter and I would suspect a larger than 4 gpm DLFC. The softener is a 1.0' and should have a 1.2-1.5 gpm DLFC.
The softener will regenerate based on gallons used using a mechanical meter. The filter has a day timer that is set to how many days between backwashes and at random the two will do their thing on the same night. The softener starts a regeneration at 2AM and unless you lie and set the time of day wrong, you can't change the time of the start. On some 2510 timers you can change the time of the filter starting its backwash, otherwise you lie as to the time of day. Backwashed or regenerated filters rarely have metered control valves.
Thanks all for the comments to you both. Gary, the way you describe the backwashes fits what I am seeing perfectly. I have the time of day set properly, and yes, the few times I've caught the softener regenerating, it's probably starting at 2 am.
Mikey: the house was built in 1987, so I assume that's when the original septic tank (now gone) and drainfield (still there) was put in.
I think I'm going to test the freezing theory. It's supposed to get above freezing tomorrow night, and go up to the 50s on Wednesday. The neutralizer would normally run on Tuesday night, but I'm going to unplug it so it happens Wednesday night instead. Not a perfect test, but I really do want to see if I can get a backwash cycle to complete without any flooding.
I didn't know a plumber would check the inlet pipe to the septic tank. I'm not sure the guy I normally use does that sort of work. I can definitely call and ask.
I'm also going to contact my general contractor tomorrow, who was going to talk to some people as well, and see what he found out. It seems pretty clear I have to start with a plumber or septic expert, it's just a question of which first, in the (probably futile) attempt to not spend more money than I need to.
A small update, although not that much to add. The system ran tonight and still overflowed. My estimation is about 3-5 gallons spilled. For the heck of it, a few minutes after the system stopped regenerating, I flushed toilets and ran water, and saw and heard no problems whatsoever.
Since it was above 50 degrees today, and was above freezing yesterday, that pretty much rules out an issue with something frozen in the pipes or septic system.
Curiously enough, in the last minute or so of the regeneration, it seemed to settle and more or less stop overflowing. Since I haven't seen this happen before, and I can't imagine the water flow is lessened at the end of the cycle, I really wonder if this is an indication that there's something about the way it's connected into my drain lines that's causing an issue. Seems unlikely (because if this was the case, why doesn't the problem with flooding occur instantly?), but the fact that it started to stop overflowing as the cycle ended is very odd.
Exactly how and where does the drain line tie in to the waste system?
Here's a photo. I apologize in advance if it's a bit big. The backwash line is the transparent tube entering the top of the pipe. It's overflowing out of the hole right underneath it. As you can see it goes down, does an elbow loop, then heads left into the main drainage system, which continues straight for about 50 feet, when it then exits the house.
Have you taken the trap apart to see if there's any obstruction in there?
Not yet...I'd probably mess it up! :) The installer is coming next week to check the system, whether the flow is set properly, etc. I can also have him check the trap. I'm also waiting for my contractor to get back to me about the possibility of checking the rest of the line/septic for blockages.
Something to consider, the air gap may have difficulty handling the flow rate of the Calcite system. Make sure it is rated for the high flow rate of the calcite system. The proper flow rate for the backwash of the 12" calcite tank should be around 8-10 GPM.
Also, the fast rinse can be reduced considerably. I would set it to no more than 5 minutes. You mentioned it was currently at 12 minutes. You can also extend the time between the 2 cycles if your septic is having problems. Extending the time between cycles is not te correct solution, a properly operating septic system should be able to handle the volume, but... Let us know what you find.
The guys who installed the system came out and extended the wait time between the backwash and rinse from 5 minutes to one hour. This helps a bit, and once (out of three times) it didn't overflow at all, but it's not perfect.
Since I'm still entertaining the idea that their may be a blockage, I went down to the local health department to get the records on my septic system. While there I spoke to one of their inspectors, and he told me it was, in fact, illegal for them to have hooked up the system to my existing septic.
Armed with that information, I called back the installers, and they said while they have protection in place so contaminants cannot flow back into the house, they also normally tell people about installing a separate small leeching field/drywell (and claims they have lost business when people find out about the extra cost). I explained they they most certainly did not tell me about this, because if it had been explained to me that this was in fact an illegal hookup, no matter what protection they can put in place to prevent health hazards, I certainly would've gone with a legal option. I also pointed out it was not mentioned in my proposal/contract, and had copies to prove it. I also pointed out that when I started complaining about a flooding issue, that would've been the time for them to say, "Well, we told you there could be issues hooking it up to your existing drainage line."
Upshot: they admitted to not doing this properly, they're going to come out again to try to tweak the cycles a bit more for the short term, and then install a separate drainage area for it in April, once the snow softens (we had over 30" due to the blizzard, and it's now as hard as a rock).
I'm curious as to why it's illegal. I thought the venting looked a little shaky, but are they saying it's simply illegal to drain the backwash into the septic tank, period? This was discussed here: http://www.terrylove.com/forums/show...ystem-bad-idea, and now that I read that, I see one poster said it IS in fact illegal to dump softener backwash into septic systems in CT.
Yeah, it's illegal to dump it into the septic tank, period. It sounds like it's a concern about contamination coming back into the house. The installer told me they have preventative measures in place for that, BUT, I wouldn't have gone ahead with this solution, no matter what workarounds they have, unless it was 100% legal to do so.
You may have one of those cleanable filters in the outlet of the septic tank that needs to be cleaned. Or you have a failing or undersized septic system IMO.
So now you are going to go with a in ground drain which for the AN filter is not bad but it is for a softener due to the salt water contaminating your well IF the drain is inside the well recovery area in your yard. The AN filter drain water could flush contaminates in the soil into the well recovery area or the well itself also.
Residential septic saystems are sized based on the number of bedrooms and 2 people each to each bedroom. Most houses never have that many people living in the house at the same time so no septic system that is sized properly and not damaged by broken baffles or a sludge build up or from dumping grease, oils or cleansers or products that kill bacteria etc. should not have a problem accepting a water filter or softener discharge.
Your air gap is EPA approved and trapped as required by codes. If this was mine, I'd be grateful of learning about a problem with my septic system and fixing it ASAP before it quits working all together. And I'd be leave the filter drain as it is instead of running a risk of contaminating my well; but that's just me, I don't suffer government foolishness very well.