Dumping grey and black
The clock on this site is water in, grey and black out. Fresh water runs you dry; grey and black fill you up. Every other note here is about the running-dry side — this is the one about the filling-up side. Where tank waste is allowed to go, where it never goes, and how to empty without fouling a spot or catching a fine. It's not glamorous, and almost nobody plans it until the grey tank's already burping up the shower drain. So plan it into the town run instead — here's the honest version.
Your tanks are half the clock too
Fresh water is only half the story. The other half is where it goes after you've used it: grey (your sink and shower) and black (the toilet). They fill up while you sit, and for a lot of tank rigs the grey tank is one of the first things to send you to town — sometimes before the fresh tank's even low. Which one fills first depends on your rig, your habits, and your tank sizes, and the stay limit or your food can beat both. The camp card's day count is a sample estimate, not a promise. But the honest takeaway is simple: don't plan a stay on fresh water alone. A full grey tank ends a trip just as hard as an empty fresh one.
The iron rule — a dump station, nowhere else
Out here the rule is simple and it doesn't bend: tank waste goes in a real dump station, and nowhere else. Not on the ground, not down a vault toilet, not into a storm drain, and not "just the grey, it's only dishwater." Grey water isn't only dishwater — it carries soap, grease, and food bits that draw animals, foul a site, and leave a stink the next person inherits. Black is a health matter on top of that, and dumping either one on public land is a good way to earn a fine and wreck a spot for everyone behind you. This is the field rule for a fixed grey or black tank on the road and on public land: it empties at a dump station, full stop. A cassette or composting toilet is a different animal — those go by local rules, covered at the bottom.
Where to actually find a dump
A dump station is any spot that runs a real RV sewer connection — not a facility type you can guess at from the sign out front. The usual ones: campground and park dump stations, some highway rest areas, some truck stops, and municipal or wastewater sites that advertise an RV dump. Don't assume a solid-waste transfer station or a random gas station will take a tank load — most won't, and rolling up with a sewer hose to a place that refuses it just means a longer drive with a full tank. Cost runs from free in a lot of places to a fee at staffed stops — think a rough handful of dollars up to twenty-plus; treat any number as a range, not a quote. Apps and crowd lists will point you at dumps, but the same rule holds as every pin on this site: a listing is a claim, not a guarantee. It can be closed, guest-only, seasonal, fee-only now, grey-water-only, or gone. Confirm it before you count on it — and we don't route you a loop, so the dump is one more stop you fold into the town run yourself.
How to do it without a mess
Gloves on, a dedicated sewer hose you never mix up with your fresh-water gear, and a clean connection. Black first, then grey — the grey water rinses your black out of the hose on the way through, so you finish clean instead of the other way around. Don't leave the black valve open when you're parked at a full-hookup site: the liquid drains off and the solids stack up into what RVers politely call a poop pyramid, and now you've got a plugged tank and a bad afternoon. Keep it closed, let it fill, and dump it all at once with plenty of water behind it. Rinse the connection, stow the hose in its own bay, and leave the pad cleaner than you found it — the next rig is watching. No fixed tank? A portable tote wheels a load to the dump so you don't have to break camp, and a cassette toilet lifts out to empty at a proper receptacle.
The rinse spigot is not drinking water
Most dump stations have a spigot right there for rinsing the sewer hose. That water is not drinking water. Treat it as non-potable, full stop — it's meant for flushing a filthy hose, and it sits inches from raw waste. Never fill your fresh tank there, and never let your sewer hose and your fresh-fill hose touch or get swapped. If a station has a separate potable-water fill, look for one that's clearly marked and set apart from the dump; that's the only place to even try a fresh fill. This is the same rule the whole site runs on — never assume water is safe because it comes out of a tap. Keep your fresh-fill hose in its own bay, keep it off the ground, and when in doubt, treat what you collect.
Keep the tank happy — and know your toilet
A black tank works best with enough water to float the solids — flush with more water than feels necessary, especially on the first fill after a dump, because a starved tank is how you build that pyramid. A tank treatment or enzyme packet keeps things breaking down and cuts the smell on a hot week; it's cheap insurance. Keep the black valve closed until you're ready to empty. And know your setup, because not every toilet is a fixed black tank: a cassette toilet empties at a toilet-emptying point or a dump station, never on the ground or down a vault. A composting toilet keeps liquids and solids apart, and both still need real disposal — solids bagged to the trash where that's allowed, liquids to a toilet or dump. All of it goes by local rules, and every county and land manager writes its own — we can't cover every jurisdiction, so check the rules where you actually are.
Here's the honest split one more time: the map can show you a dump was listed nearby — in a straight line, as an OpenStreetMap claim — but it can't promise the place is open, that it takes black, or how far it really drives. Grey and black are half your clock. Plan the dump into the town run, confirm the stop before you lean on it, keep the fresh and dirty hoses forever apart, and leave every pad cleaner than you found it. That's the whole job.