The crappiest situation: An overfilled black tank, while stationary, with no way to dump

Heading into our third year of RV living, we have camped without sewer hookups too many times to recall. It's safe to say that when we decided to park at our home-base for the holidays, overfilling our black tank was not one of our worries. Fresh tank freezing like last Christmas? Sure. Getting snowed in like two years ago? Always a risk. But our black tank?!

This comes after a year of making some really great strides in the toilet-realm. We purchased a new Thetford toilet with better water efficiency. We got a bidet that helps us prolong our times between dumps. We've also continued learning about our rig, adapting our routines accordingly in order to better conserve our resources.

In 2021, when we first moved into the RV, everything was so disorganized that we winterized the rig and mostly stayed inside Nicole's parents' house. Last year, when we decided to moochdock at Villa Anderson for the holidays, it was the first time we needed to figure out how we would dump our tanks while stationary, in the off-season, in Massachusetts. We lucked out by finding a pump-out service that works throughout the year, stationed about an hour away. It would cost us, but it was by far the most convenient, lowest-risk option, and since we weren't paying a rate to stay at a campground, the choice was a no-brainer. This year, the plan remained much of the same. Typically, we'd give the guys a few days' notice before we'd need them to come, and then we'd agree on a day, and they'd message us day-of when they were on their way. Super streamlined. We expected to need pump-outs every 2-3 weeks. This was the estimate assuming that we wouldn't want to exclusively forgo toilet paper for the bidet, because freezing water on the nethers sounds a tad unpleasant. But we'd likely opt for the bidet part of the time, thus prolonging black tank space, and we would also be spending some time inside the house, using those facilities instead.

So then how did we find ourselves with an almost-overflowing toilet on day 14, still days away from a pump-out appointment?

To know us is to know our toilet situation. Unfortunately, we've been sitting on something that still hasn't made its way to the blog, and we're not about to blow the lid off the whole thing right now. What we can say though, is that we're in touch with our ATC trailer manufacturer up in Indiana, with plans to head there in the spring to get our black tank looked at. It's a problem that only ATC themselves can fix, and after running through theory after theory with other ATC owners, service techs, and the guys at ATC, we think we have an idea of what might fix it. That fix will hopefully be the conclusion that we need to make a dedicated black tank blog post. Clearly, we were planning on holding off talking about any of this, but our RV had other plans.

Basically, our black tank acts full before it's actually full. Most RVers say that as soon as they start hearing the gurgle gurgle burp burp when they flush, they know it's about time to dump. Well, our gurgle gurgle burp burp starts way earlier, like when our tank is less than half full, so we don't have the audible indicators. Sometimes RVers also have the olfactory indicator...if you know you know. Ours unfortunately also sometimes occurs too early. What does that mean for us? Sometimes we dump sooner than we need to. Sometimes we just hold our breath when we flush.

This time around, things got weird. Around day 8, we started to hear the gurgle gurgle burp burp. Right on time. (No olfactory indicators, thankfully, because the vapors aren't nearly as suspended in the cold weather). But then around day 10, the auditory indicators stopped. Given what we've theorized about our black tank and its issues, we actually considered this a good thing. Perhaps the waste made its way to a vacant part of the tank. We are parked slightly unlevel at our home-base, so it wouldn't be too far-fetched of an idea. Either way, given our toilet usage since our previous pump-out, we expected to get about another week out of our tank, and we planned on seeing if we could get our pump-out at the end of the week just to be on the safe side.

Turns out the silence was just the calm before the storm. We think maybe there was too much in there to even make the gurgle gurgle burp burp. But when it all happened, we thought nothing of the sort. We'd flush the toilet, and the bowl kept filling, filling, filling, and nothing would go down.

We know we're not painting the prettiest picture of RV life right now, but we will give you this tidbit of information to contemplate. If this were a residential toilet, once the flush flushes, that bowl fills and there's very little you can do to stop it. It's an overflow situation waiting to happen. With RV toilets, we control the amount of water we put in, so as soon as we saw that nothing was flushing, we released the pedal. This meant we avoided any actual overflow of the contents inside the toilet.

Our first thought was that maybe we had a clog. Again, we thought there was no way we would have a filled black tank, unless the pets learned how to secretly use the toilet when we weren't around. And given our unfixed black tank issues, a clog could be plausible. And so we began treating the issue like a clog. We used some enzymatic solution to break down the contents. No dice. We attempted to snake the drain pipe, but all that came up was half-disintegrated toilet paper, and this was not the culprit. Anthony even ran to the store to get a plunger, but still, no success. Perhaps we were barking down the wrong hole here.

In a perfect world, something like this would happen when we have the ability to dump our tanks. That alone would give insight into whether the issue is a full tank, a clog, a poo pyramid, or any of the myriad of issues that can happen in RV plumbing. We, however, were stuck. We couldn't drive to a dump station because our toilet bowl was half full of hazardous waste. We didn't have any hygienic way of siphoning stuff out of our toilet and tank. We needed to call our pump-out guys for emergency service, all the while knowing that we might pay for something that might not solve the issue.

Joe and his crew at RV Pump Service really save our butts when we're at our home-base. They were able to come on short-notice and pump us out that afternoon. We kept our fingers crossed that emptying our tank would work, or else we'd be sh*t outa luck.

The pump-out worked, leaving only the obvious conclusion: We had overfilled our black tank in 14 days. The remaining mystery was, how? We calculate our usage very thoroughly, and we know the pets weren't actually partaking in time upon the throne. Water wasn't leaking through our toilet valve; we would notice when it leaks through, leaving the bowl dry. The pump-out guys suggested that maybe one of our roof vent seals was letting in rain. It had rained quite a bit the previous day and overnight, but enough to fill 10 or so gallons of our tank?! Oh, but wait. We're not totally level. So could rainwater have pooled on the roof and then run in? We wouldn't know until we could get on the roof and check the seals.

We needed fresh Flex Seal and ordered it Prime. It was delivered the next day, but too late to get up on the roof before dark. And so, we waited until the following day, only over the course of the night, it snowed. This created a few obstacles. Climbing up on the roof would be cold, wet, and potentially slippery. However, with the forecast predicting warm days by the end of the week, we needed to beat the clock, getting the snow off the roof and resealing the vents before the snow melted and ran into the black tank. This, of course, being that Joe's theory actually held true.

As soon as Anthony got on the roof, he noticed that water was pooling on the roof, but less was pooling around the black tank vent. Considering we were slightly unlevel in that very direction, the most likely conclusion was that the water that was pooling had some place to go...like through a crack near the vent. Anthony did find a few cracks in both seals - around the black tank vent and the gray tank vent. We do check the roof as part of our routine maintenance, but we haven't much since we've been stationary. Our Blitz East had us going through some severe temperature fluctuations, so all the freezing and thawing could have caused some seals to crack since the last time we checked.

With the theory looking more plausible, Anthony got to work resealing. He didn't get far, though. The temperature that day never got above freezing, and the roof was so cold that the seal wouldn't stick. We'd have to wait until the thaw. This would mean that we wouldn't be able to replace the seal until the snow melt, but Anthony did what he could do brush it off the roof.

Once the weather warmed up, we had a short window of time before a rainstorm would follow the warm front.

Anthony got back on the roof and sprayed Flex Seal around the vents, ensuring all the cracks were covered.

Sunday's rain turned out to be a massive storm, dumping several inches of water. If resealing around the vents didn't work, we would know very quickly. It was now one week after our emergency pump-out, and so we listened for the gurgle gurgle burp burp. If the black tank was still filling from rainwater, we would expect the sound soon. But we heard nothing. Taking that as a good sign, we continued with our week, diligently monitoring our black tank usage. The gurgle gurgle burp burp came on day 10, within normal range for how our black tank typically functions. And so, we scheduled our pump-out for the following week and put the crappy situation behind us.

Let this story be a PSA to all our fellow RVers: Check your roof seals often, even around your tank vents. You never know when you might be sitting on a leak when you're sitting on the toilet. We always assumed that if our roof began to leak, the water would be right under our noses. Turns out, it was right under our tushies instead.