So awhile ago I was in a trailer park for a month. I was camping there for work. I hooked up to the water supply. The water didn't have a funky rotten egg smell, which means sulfur, but it was yellowish and stained the toilet yellow. Other than sulfur, any ideas on what would cause this? It was a trailer park, so I don't know if it was a well or city water. I would suspect a well if I had to guess. I'll be flushing out the lines in my trailer. I'm not really worried, but more curious on what it may be. I don't have a sample of the water since I'm not there anymore. Any ideas?

Iron will do that.

Moosetrot

Iron or rust

Yep, I'd guess they had iron pipes for the water supply lines.

Odd, brown or red usually is iron. Yellow is usually not.

Must have been tinkle then.

Moosetrot

We, often, had yellow water after the fire dept in our small town in Nebraska filled tankers causing a rush through the water mains. Was nasty. Could have been the tannins from the lake water that supplied the city, also...

As a kid growing up, we had a well that was 90 feet deep,
The water was 28% hard , it was iron in the water.
Get a glass and let it sit for an hour, and it had red rust like coating in the bottom.

It is iron.
I never noticed the smell untill I installed cartridge filters infront of the on demand water heater and the wash machine.
Now we get the smell in the water lines because the organics are captured.

Change or pull the filter and the smell is gone.

Looking for a better system, buT The one i like back flushes 100 gallons every night to clean the media.
I will probably build a clay pond and replace evacuation with the system unless i can find a better

I used to get water from the city well in Pilot Point Alaska that was crystal clear when you first pumped it, after a day or so it would be nearly as green a Gator Aide. If you let it sit for a couple of weeks it was clear again, but there would be a later of rust on the bottom of the water barrel.

My conclusion is that there is dissolved iron and some sulfur in the water (doesn't taste or smell like sulfur though). Then after exposure to air/oxygen the iron/sulfur form iron sulfate, resulting in the green color. I understand that chemistry. What I don't understand is how it then changes to a precipitate of iron oxide (rust) and back to clear.

Another well just a couple hundred yards away, where I now get my water, is always clear. Both taste fine however.

Theres yellow rust, brown, red, black. Yellow rust is Iron Oxide-hyrdoxide instead of the normal red rust thats iron oxide.