We've been having some septic headaches and they are really starting to trouble us. We bought our home in 2010. The previous owner had a new drain field installed to "increase capacity". There is a Bull Run brand diverter valve, and I was told to switch between fields every year or so to let the other rest. I never knew which field was which until yesterday...

Upon moving in, the system worked fine for months - then we had extremely heavy rain. For a day or so, the basement toilet wouldn't flush. Rain stopped - toilet worked again. Fast forward exactly one year - another bout of heavy rain. Another day or so without a working basement toilet. This cycle has repeated itself over the last 3 years - the system works fine 363 days a year, then we have this issue.

There is a washout in my patio. I opened it to find waste up inside it. So the main line going to the tank was full. Days later - it was empty.

Since the new, larger field was installed in 2008, I tracked down the guy who did the new field and spoke with him. He seemed very intelligent and well spoken. While he didn't recall my job, he told me that fields can become overly saturated from heavy rain, and temporarily unable to purge off water from the tank. As the ground dries, everything is OK again.

I had the tank emptied less than a year ago. The outlet filter was clean. I told the men about this issue, and they suggested the same thing - sort of a "deal with it" - don't use water heavily during times of heavy rain. Otherwise the tank and everything they could see looked fine. Given the "clean" outlet filter, they didn't believe any solid would have reached the field(s) and clogged it.

Clearly, this is not ideal. However - we can in fact deal with it if it's the only problem. If we lose the basement toilet use a few days a year, no big deal.

But in the past few weeks, we've now had this problem for a few days at a time. Again - very heavy rain. I decided to switch the fields, thinking that although the ground was wet, at least the other field hadn't taken water from inside the home. I finally was able to see the Bull Run valve down in the standpipe, and after cross-referencing a drawing of the entire system, determined that I had been running on the old field. So I switched to the new one.

At the same time, I noticed long, slightly lower depressions in my back yard along where I knew the old field to be. And water was pooling on top. I gambled and smelled it - but it seemed normal. Probably not. Regardless - I was now on my new field at least.

I expected the water to rush out of my system into the new field once I made the switch, instantly solving my problem with the basement toilet. But nothing happened. A day later, and the washout is still full. All I can think is that the new field was already saturated from the rain.

The entire backyard was regraded when the new field was put in. French drains, etc. The area over the old field is lower. But the new field has a really nice slope and higher ground over it and the ground above it doesn't seem too saturated, even with the heavy rain.

The previous owner spent some insane amount of money on the new field.

So it really troubles me - even with the extreme rain, it still seems as if that 2008 new field should be able to handle it. How anyone would go to such large measures to do all that work when there are still issues is beyond me.

That's what has me pondering whether there is some other issue. I suppose there could be something else wrong - perhaps a clog in my main line going to the tank. But it's too coincidental this issue only happens - and now happened again - during heavy rain.

I also spoke to the manufacturer of the Bull Run valve. Excellent fellow. Based on my description, that valve should still be working fine and in fact diverting the water as designed, today - to the newer field.

So if the old field was leeching effluent to the surface - which may be the case - at least I have switched to the new field. I'll let that old one dry out for a few years and consider it a backup.

All the other toilets, etc. upstairs continue to work fine (so far). It was also suggested that the weight of the water in the drain pipes in my walls is enough to "push" water into the tank and effectively squeeze it out the drain fields - since I was on the old field - that may be why water rose to the surface (compounded by heavy rain).

I hope the ground around the newer field will prevent that now.

But at the same time - we haven't had the basement toilet overflow, nor anyting come out the basement shower drain. If my wife does laundry (she won't) - I fear that if the water has nowhere else to go - it will take the path of least resistance and come out in the basement bathroom.

But others have suggested that the drain fields themselves are technically the lowest "drain" in the house. Water wants to escape there, as they are all lower than my home (vs. the basement bathroom).

So to come full circle, now that I'm on my new field - I wonder whether I'll just have to deal with sporadic toilet outages in the basement during heavy rain, and overall - have no fear that I'll have a backup that floods the basement bathroom.

Or - do I have a ticking timebomb and once false move (like a bath or load of wash) could tip the balance and send septic waste into my basement bathroom.

Scary part to me is that we've done major improvements to our home. We have young kids - we want to stay forever. But there is no place to put another septic field, nor the money to do it. And how could that possibly be needed when a new one was just installed 4 years ago.

I you agree with anything I've said, or have any advise - I'd greatly appreciate it!!!!