Holding tank dump etiquette + the RV park rules that get you fined

Fresh water tank: holds 30-100 gallons of potable drinking + cooking + bathing water. Refilled at city water hookup OR fresh-water fill station.

Grey water tank: collects shower + sink wastewater. Holds 30-60 gallons typically. Less odorous than black.

Black water tank: collects toilet wastewater + waste. Holds 30-50 gallons typically. Treated with enzyme additive (Happy Camper, Aqua-Kem) to break down solids + control odor.

• Fresh: drinking + cooking + bathing (30-100 gal capacity)
• Grey: shower + sink (30-60 gal capacity)
• Black: toilet (30-50 gal capacity)
• Each tank has separate gauge + separate dump valve

(1) Confirm rig parked level + dump station clear. (2) Connect sewer hose to rig dump valve + secure to dump station inlet. (3) Open BLACK valve first, allow full drain (2-3 minutes). (4) Close black valve, open GREY valve (grey water rinses the hose). (5) Close grey valve, rinse hose + dump station with fresh-water spray if available.

Critical: ALWAYS dump black first, then grey. Grey water rinses the contaminated hose. Reverse order = black-contaminated hose + worse cleanup.

• 1. Park level + dump station clear
• 2. Connect sewer hose, secure both ends
• 3. Open BLACK valve, full drain
• 4. Close black, open GREY valve
• 5. Close grey, rinse hose + dump station

Full-hookup sites have sewer connection at the site. Common mistake: leaving both valves open continuously. Correct procedure: leave both valves CLOSED until tanks reach 75% full, then dump (black first, then grey). Use the same 5-step ritual at the site sewer connection.

Leaving valves open = solids accumulate in black tank (less water to flush through) + flies + odors enter sewer line. Closed-valve dumping is the manufacturer-recommended method.

Most NPS + state-park dump stations: free for in-park-camping guests, $5-15 for non-guests. Private RV parks: $10-25 for non-guests. Truck-stops + travel-plazas (Pilot Flying J, TA): $15-25 per dump.

Free dump stations: Sani-Dump.com + Allstays app maintain US-wide directories. Many BLM areas have free dump stations.

Top violations + typical fine ranges: dumping black water on ground ($500-2,500 + possible state environmental violation), leaving sewer hose connected without dumping (cleanup fee $100-300), failing to clean sewer hose properly ($50-150), dumping at unauthorized location ($100-500 + possible local fine).

Most rental contracts charge $500-1,500 for major dump violations as security-deposit deductions.

The under-shared truth: the single highest-impact pro tip is the 'soak' method. Fill black tank to 50% with water + 1 cup laundry detergent + 1 cup water softener + drive 1 hour with full tank. Drains 90%+ of accumulated film on tank walls. Run quarterly during ownership; once per long rental.

Second under-shared truth: keep a 'dump-only' pair of disposable gloves + a small bucket of bleach-water spray in a sealed bag. Use exclusively for dump-station work. Sanitation discipline prevents the most common gastro-illness risk in RV travel.