How to Dump RV Black and Gray Tanks, Step by Step

Dumping your tanks is a five-minute job once you've done it a few times. The steps below follow the guidance cities and state agencies give RV owners. When you need a station, the RV dump & water layer shows 3,138 RV dump stations across the US.

Know your tanks

Most RVs have a black tank for toilet waste and a gray tank for sink and shower water. Both are wastewater. Oregon's Department of Environmental Quality treats graywater as sewage under state rules, so it can't be drained onto the ground, and San Diego's RV fact sheet describes both black and gray water as needing a dump station.

Gear to bring

• Disposable gloves, and safety glasses if you have them.
• A sewer hose with secure fittings at both ends.
• A spill kit or absorbent and a trash bag.
• A separate hose or tank flushing device for rinsing. Never use your drinking water hose.

Step by step at the dump station

1. Pull up so your tank outlet is on the side of the drain, and set the brake.
2. Put on gloves. Connect the sewer hose to the RV outlet first, then put the other end firmly into the dump inlet. San Diego's guidance is to secure both hose ends before opening a valve.
3. Open the black tank valve first and let it drain fully. Stay with the hose.
4. Close the black valve, then open the gray tank valve. The soapy gray water helps rinse the hose. The City of Springfield, Oregon gives the same order.
5. If the station allows it, flush the black tank with a tank flushing device, not your potable water hose.
6. Close all valves. Disconnect the RV end first, then rinse the hose into the inlet so all rinse water goes into the dump.
7. Rinse the pad with the station's non-potable hose, cap your outlet, and store the sewer hose away from your fresh water hose.

What never to do

• Never drain black or gray water onto the ground, a lawn or a street, or into a storm drain. Storm drains often lead straight to creeks without treatment.
• Never dump into a pit toilet or vault toilet, which Springfield, Oregon's fact sheet specifically warns against.
• Don't use bleach or formaldehyde treatments in the waste system. Springfield suggests enzyme or bacteria-based products instead.
• Don't fill your fresh tank from the rinse hose.

It's the law in many places

Florida makes it unlawful to empty RV liquid waste except into an approved sewerage system. San Diego's municipal code bans discharging anything but stormwater into the storm drain system, with administrative penalties of up to $10,000 per day. In Oregon, hauling RV wastewater in a portable tank to a dump station requires a pumper license, according to DEQ. If you can't get to a station, Oregon DEQ lists hiring a licensed pumper as an approved option.

Common questions

Should I dump the black or gray tank first?

Black first, then gray. The gray water rinses the sewer hose. San Diego and Springfield, Oregon both give that order.

When should I dump the black tank?

Springfield, Oregon suggests keeping the black valve closed and dumping when the tank is more than half full so it drains properly.

Can I dump gray water on the ground?

No, in many states. Oregon DEQ treats graywater as sewage that must be disposed of properly. Use a dump station.

Can I use a dump station's hose to rinse my tank?

Use it for the pad and hose rinse only, and never for your fresh water tank. It's non-potable.

Find a dump station

Open the RV dump & water layer, search your ZIP or city, and pick the closest orange pin. Each listing shows any listed fee and access notes. See also free vs paid dump stations.

Sources: City of San Diego Think Blue RV dumping fact sheet; City of Springfield, OR RV & boat waste fact sheet; Oregon DEQ RV wastewater fact sheet; Florida Statutes 513.08; City of Oakland RV wastewater disposal tips. Checked October 20, 2026. Fees, hours and rules change, so confirm with the site before you go.