How and where you dispose of your toilet cassette and your grey water has legal, environmental and practical sides. Here's what you actually need to know to do it right anywhere in Australia.
What's the Difference?
- Black water — toilet waste, sanitary additives. Goes from your cassette toilet into a dump point.
- Grey water — sink, shower and washing machine water. Different rules apply.
Mars caravans typically have a removable toilet cassette (Dometic) and a grey water tank or open grey water outlet — depending on your model and options.
Black Water — Where to Dump
Designated Dump Points
- Caravan parks — most have a dump point on site. Often available to non-guests for a small fee.
- Local councils — many regional councils provide free public dump points. Some are at recreation reserves or town entries.
- Roadhouses — increasingly common on major touring routes.
- RV-friendly towns — towns that have officially welcomed RV travellers usually have public dump points.
Finding Them
- WikiCamps — comprehensive crowdsourced database; the most-used tool by Australian travellers
- Camps Australia Wide — bookable resource that's been around forever
- CMCA (Campervan and Motorhome Club of Australia) — runs the National Dump Point Database
- Google Maps — search "dump point" + town name
- State touring apps — many state tourism authorities now list dump points
How to Use a Dump Point
Covered in detail in our Cassette Toilet Quickie. Quick recap:
- Roll cassette to the dump point
- Stand upright, rotate spout up, remove cap
- Point spout DOWN into the dump point opening
- Press vent button only once spout is down (avoids splash)
- Rinse thoroughly with the dump point's flush hose
- Re-add sanitary additive, refit cap
- Leave the area clean — rinse any splashes
Dump Point Etiquette (Don't Be That Person)
- One person at a time — don't queue behind someone in their face
- Leave it cleaner than you found it
- Don't dump grey water at a black water-only dump point unless permitted
- Don't park your van across the access while you do other things
- Keep kids away from the dump point area
- Wash your hands — there are taps nearby for a reason
Grey Water — The Murkier Subject
It Varies by Location
Grey water laws vary by state, by council, and by site. There's no single national rule.
General Principles
- In caravan parks — almost always required to be plumbed or contained. Most parks have grey water drains at the site.
- In national parks — generally must be contained. Open grey water release is usually prohibited.
- In free camps and remote areas — varies. Some are tolerant of "spread on grass" approaches if the area allows; others require all grey water leaves with you.
- In urban areas — must be discharged to designated dump points.
What Causes Restrictions
Three concerns:
- Soaps, detergents and chemicals in grey water harm soil, plants and waterways
- Food scraps and grease from sink water attract wildlife and pests
- Volume concentration — many vans in one spot creates a real environmental load even if each individual release is small
The Right Approach
- Use grey-water-safe soaps wherever you camp — biodegradable, low-phosphate, septic-safe
- Capture grey water in your tank by default — don't open the outlet unless you've checked the site rules
- Empty at dump points when you're somewhere with capacity
- If permitted to release on the ground — spread widely, away from waterways, in vegetation that can absorb it. Don't pool it.
- Filter solids at the sink — drain strainer in every sink, food scraps to a sealed bin, not down the drain
Grey Water Dump Points
Some dump points are specifically marked for grey water (separate from black). Use these where available. Caravan parks typically have site-level grey water drainage.
National Parks — Stricter Rules
- Generally: leave no trace
- Both black and grey water typically must leave with you
- Some parks have dump points at entry/exit; many don't
- Plan your dump schedule around park visits — empty before you go in
Free Camps — Read the Signs
- Each free camp typically has signage stating what's allowed
- "Self-contained" requirements are common — you must have black water containment
- Repeated breaches by travellers result in free camps being closed. Don't be the one who ruins a good site.
Carrying Capacity vs Dump Frequency
Black Water (Cassette)
Typical Mars Dometic cassette is 19L. Empty triggers at ~80%. In real use:
- 2 adults, normal use: empty every 2–3 days
- Family of 4: every 1–2 days
Grey Water
Grey water tanks (where fitted on Mars vans) typically hold 60–100L. Daily usage:
- 2 adults, no showers in van: 10–20L/day
- 2 adults with showers: 40–60L/day
- Family with showers: 60–100L/day
Reality check: many vans need to empty grey water more often than black, especially with full van showering. Plan accordingly.
- WikiCamps — best single tool for dump points, camps, drinking water and reviews
- National Dump Point Database (CMCA) — official and accurate
- Toilets Map (the official Continence Foundation app) — for the human side of the equation
The Law in Plain Terms
Dumping waste at non-designated locations is illegal across Australia. Penalties vary but can be significant — and they apply to both black and grey water in many jurisdictions. The legal risk is real; the environmental damage is worse.
Common Mistakes
- "Just emptying" the cassette into a public toilet — not legal, blocks the system
- Tipping grey water down a stormwater drain — pollutes waterways, illegal in most states
- Burying waste — doesn't work, animals dig it up, surface water contaminates
- "Just driving until you find one" with a full tank — overflow inside the van is a much bigger problem than backtracking 30km
The Easy Habit
Plan your dumps around your route, not the other way around. When you're booking the next stop, check what's nearby for emptying. If you're a couple of days from a dump point, modify your water use accordingly. It becomes second nature within a few trips.
Related: Cassette Toilet — Full Owner Guide · Cassette Toilet Quickie