Possible water contamination issue

[Gary325]

Background:
2017 Reflection 367BHS
Water connection: City Water
Nautilus set up per the instructions:
White: right
Blue: down
Black: right
Red: up
Green: up

The concern is the "brown" water seen after a Black tank, then Gray Tank, then the other gray tank flush.
This occurs after a weekend camp (at our seasonal site). Getting ready to leave, I execute the "Tank Flush" process. All tanks are shut off and filled during our weekend stay (Friday to Sunday). After the Sunday flush, we fill the toilet/black tank with about 2 gallons and drop a deodorizer packet into toilet for the week (we are away). It is at this time that the "brown" water is seen in the toilet.
I think about this and cannot think of where the brown water comes into the fresh water supply. Is the toilet water supply separated from the rest of the trailer water system? Is there a check valve that could be damaged? Is there something not connected as it should be behind the panel?
This situation has prevented us from using the "city" water supply for any consumption. Washing dishes, showers, toilet, etc... are all OK. Drinking: NO.
Any help/Tips would be approciated.

[J&J___]

Background:
2017 Reflection 367BHS
Water connection: City Water
Nautilus set up per the instructions:
White: right
Blue: down
Black: right
Red: up
Green: up

The concern is the "brown" water seen after a Black tank, then Gray Tank, then the other gray tank flush.
This occurs after a weekend camp (at our seasonal site). Getting ready to leave, I execute the "Tank Flush" process. All tanks are shut off and filled during our weekend stay (Friday to Sunday). After the Sunday flush, we fill the toilet/black tank with about 2 gallons and drop a deodorizer packet into toilet for the week (we are away). It is at this time that the "brown" water is seen in the toilet.
I think about this and cannot think of where the brown water comes into the fresh water supply. Is the toilet water supply separated from the rest of the trailer water system? Is there a check valve that could be damaged? Is there something not connected as it should be behind the panel?
This situation has prevented us from using the "city" water supply for any consumption. Washing dishes, showers, toilet, etc... are all OK. Drinking: NO.
Any help/Tips would be approciated.

Brown water is most likely from you city water source. You said you stay at your seasonal site and you only see brown water after you end of weekend flush. So you always see the brown water at the same site after flushing the tanks. You will need a white five gallon bucket. When you see the brown water in the toilet go to your water source, disconnect the trailer and with a white bucket draw a bucket of water. Is it brown? Water systems will collect sediment and running a bunch of water for tank flushing might stir it up.

[boyscout]

The concern is the "brown" water seen after a Black tank, then Gray Tank, then the other gray tank flush. This occurs after a weekend camp (at our seasonal site). Getting ready to leave, I execute the "Tank Flush" process. All tanks are shut off and filled during our weekend stay (Friday to Sunday). After the Sunday flush, we fill the toilet/black tank with about 2 gallons and drop a deodorizer packet into toilet for the week (we are away). It is at this time that the "brown" water is seen in the toilet. I think about this and cannot think of where the brown water comes into the fresh water supply. Is the toilet water supply separated from the rest of the trailer water system? Is there a check valve that could be damaged? Is there something not connected as it should be behind the panel? This situation has prevented us from using the "city" water supply for any consumption. Washing dishes, showers, toilet, etc... are all OK. Drinking: NO. Any help/Tips would be approciated.

Wow, that's a really good mystery, thanks! I don't think I'm gonna solve it for you, but the following will answer some of your questions.

By "brown water" you do mean sewage, right? Not iron-contaminated, for example?

Is the trailer yours from new? Any chance that someone has modified something the wrong way? The following is based on factory build.

Your Nautilus settings are correct for using City Water. Toilet water supply is NOT separate from the supply for the other water fixtures in the trailer.

The black tank flush system is completely standalone, separate from all other plumbing. Water rises from the inlet on the Nautilus panel, up through tubing to a vacuum breaker valve that's probably located behind your shower wall, and then down into a spray fitting in the black tank. No other connections. There should not be any way for raw sewage to get from that system into your system plumbing to make your water "brown".

Do you leave a hose connected to the black tank flush? Is it connected in any way to your fresh water supply (through a 'T' connection, for example)? The water supply to the black flush inlet should be disconnected *immediately* after water pressure is removed. I have a ball valve on the end of the hose; I turn off the supply at that valve and immediately remove the hose, whereupon fresh water comes back out the inlet until the front half of the system has drained itself. (The other half of the system - again fresh water - drains into the black tank.) If you leave a hose connected, and it's connected in any way to your fresh water supply, then there is a chance that something could be siphoned from one to the other but the chance of it being "brown" rather than just having possible traces of bacteria is miniscule. Nevertheless, even though it's not likely your problem, NEVER leave a hose connected to the black flush.

There should not be any connection between sewage and other plumbing anywhere. A mix-up in plumbing behind the Nautilus shouldn't explain your problem because there shouldn't be any sewage in plumbing back there.

Even if you mean "rusty" when you say "brown", I cannot conceive of a place where iron-contamination could gather, after you've used the trailer for days, only to show itself after you've removed your fresh supply and re-attached it (if you even do that).

A very good mystery. Hope someone smarter / more imaginative comes along with a solution.

Good luck.

[Gary325]

Good test! I'll do that exactly as you state. I may even disconnect and check water source after the dump.
Of special note: I do not do a Tank Flush (connecting a water line to the Tank Flush inlet) during any of this activity. I mistakingly used "Tank Flush" to mean dumping Black, then Gray, then the other Gray!
For future terminology, I'll use "Tank Dump" to mean dumping Black, then Gray, then the other Gray. "Tank Flush" will mean connecting a hose to the Tank Inlet and spraying the inside of the black tank.

[boyscout]

Brown water is most likely from you city water source. You said you stay at your seasonal site and you only see brown water after you end of weekend flush. So you always see the brown water at the same site after flushing the tanks. You will need a white five gallon bucket. When you see the brown water in the toilet go to your water source, disconnect the trailer and with a white bucket draw a bucket of water. Is it brown? Water systems will collect sediment and running a bunch of water for tank flushing might stir it up.

If it's the city water supply, why does @Gary325 only see the problem at the END of a weekend of using the trailer?

[Gary325]

Wow, that's a really good mystery, thanks! I don't think I'm gonna solve it for you, but the following will answer some of your questions.

By "brown water" you do mean sewage, right? Not iron-contaminated, for example?

I believe that it is sewage, not very concentrated, but it does "fade" to clear as more water is run.

Is the trailer yours from new? Any chance that someone has modified something the wrong way? The following is based on factory build.

It is not new to me. The previous owner (for only 1.5 years) was very meticulus in maintenance.

Your Nautilus settings are correct for using City Water. Toilet water supply is NOT separate from the supply for the other water fixtures in the trailer.

The black tank flush system is completely standalone, separate from all other plumbing. Water rises from the inlet on the Nautilus panel, up through tubing to a vacuum breaker valve that's probably located behind your shower wall, and then down into a spray fitting in the black tank. No other connections. There should not be any way for raw sewage to get from that system into your system plumbing to make your water "brown".

Do you leave a hose connected to the black tank flush?

NO

Is it connected in any way to your fresh water supply (through a 'T' connection, for example)? The water supply to the black flush inlet should be disconnected *immediately* after water pressure is removed. I have a ball valve on the end of the hose; I turn off the supply at that valve and immediately remove the hose, whereupon fresh water comes back out the inlet until the front half of the system has drained itself. (The other half of the system - again fresh water - drains into the black tank.) If you leave a hose connected, and it's connected in any way to your fresh water supply, then there is a chance that something could be siphoned from one to the other but the chance of it being "brown" rather than just having possible traces of bacteria is miniscule. Nevertheless, even though it's not likely your problem, NEVER leave a hose connected to the black flush.

Don't plan on it and never have. I also use a separate hose for that function.

There should not be any connection between sewage and other plumbing anywhere. A mix-up in plumbing behind the Nautilus shouldn't explain your problem because there shouldn't be any sewage in plumbing back there.

Even if you mean "rusty" when you say "brown", I cannot conceive of a place where iron-contamination could gather, after you've used the trailer for days, only to show itself after you've removed your fresh supply and re-attached it (if you even do that).

A very good mystery. Hope someone smarter / more imaginative comes along with a solution.

Good luck.

I mistakingly used "Tank Flush" to mean dumping Black, then Gray, then the other Gray!
For future terminology, I'll use "Tank Dump" to mean dumping Black, then Gray, then the other Gray. "Tank Flush" will mean connecting a hose to the Tank Inlet and spraying the inside of the black tank.

[J&J___]

If it's the city water supply, why does @Gary325 only see the problem at the END of a weekend of using the trailer?

From this statement.
“The concern is the "brown" water seen after a Black tank, then Gray Tank, then the other gray tank flush.” I read this as dump the tanks then run water in them to flush them out. Running a bunch of water through a contaminated water system can disturb sediments making the water brown. The way these trailers are designed there is no way to get brown water from the waste tanks into the house water system. Now if you have a real nasty fresh water tank and use the on board pump to pump from that tank then that would be a possibility. I have been to many parks with discolored water. Whenever I hook up the water at a new site I always run the water for at least a few seconds or longer. Many times I will see a shot of brown come out. If you are on city water systems they tend to be a whole lot better than well systems. My bet is that Gary235 is getting the brown water from the city/well water supply.

[Gary325]

So it was another great weekend at camp.
I tried the Tank dump process a little differently.
The original method:

1. Pull Black tank and allow to dump the tank
2. Without closing the black tank, pull the kitchen gray tank to dump that tank and push the rest of the black tank contents along with the kitchen contents.
3. Close the Black tank
4. Without closing the kitchen gray tank, pull the bathroom gray tank to dump that tank and push the rest of the gray tank contents along with the bathroom contents.
5. Close the kitchen gray tank.
6. Close the bathroom gray tank.

The modified process:

1. Pull Black tank and allow to dump the tank
2. Close the Black tank
3. Pull the kitchen gray tank to dump that tank and push the rest of the black tank contents along with the kitchen contents.
4. Close the kitchen gray tank.
5. Pull the bathroom gray tank to dump that tank and push the rest of the gray tank contents along with the bathroom contents.
6. Close the bathroom gray tank.

Then we added water, via the toilet flush pedal, to the black tank. No brown water!!
Of course this was a single instance, but we will use the method the rest of the summer to see if that "corrects" our brown water issue.

[boyscout]

So it was another great weekend at camp... No brown water!!

Gary, thanks for the update, but there is nothing in your original first process that would cause "brown" water to enter your fresh water system, and nothing in your changed process that would "prevent" it either. In fact your original process is closer to what I and many others do ALL the time except that you don't mention using the black flush system.

Your original dumping process was not the problem and your modified process didn't "fix" it, sorry.

This has something to do with rust in the water supply where you noticed the issue. @J&J___'s theory is that you're somehow disturbing the water system while dumping - maybe you ARE using black tank flush? If that's it, it was a rare thing that probably won't recur.