Burning Man RV · pump-outs & water

Poo Math

How many gray/black pump-outs & fresh-water refills does your rig need — and when? Name your crew (women & men use water differently), pick your RV, split by Build / Event / Strike.

💩 Poo fact: An average adult passes roughly 1 pound of poop a day — multiply that by a full rig and you see why black tanks fill up.

🔥 Event window & phases

The Event window is always planned. Nights before gates are Build, nights after close are Strike — switch those on only if your crew is there for them. Camp service usually runs during Event only.

🎇 Key nights / burns

DateLabel⭐ Key
⭐ Key → shown bold on the chart with a tank-status check so you can service before the big night.

🚐 Trailer / RV

Valves = gray + black tanks · all drain to 1 sewer hookup → 2 valves / 1 hookup

👥 Who’s in the rig

2 people · 1♀ / 1♂ · peak 2 aboard
Each person has their own arrive/depart dates, so solo stretches & overlaps are handled automatically. Gender sets a default shower length (below); Use × nudges one person up/down (heavier user ≈1.3, lighter ≈0.8).

💧 Water use

Showers (the big gender difference)

Playa-conservative defaults (short navy showers). Bump these up if folks shower fully every day → watch the pumpouts climb.

Sink → gray (per person · night, gal)

Toilet → black (per person · night)

Black = 6×#1 + 1×#2 per person/day (EPA: ~5 flushes/day, ~6:1 #1:#2). Gravity-toilet volumes — cassette/electric is far less (~0.07 gal/flush), macerating more (~0.85).
Drinking & cooking water is assumed bottled/jugged (brought separately) — not drawn from the fresh tank, so it doesn’t count toward water refills. Porta-potty offload (default none — set it to your own habit) cuts black-tank fill & saves flush water. The exact share is anecdotal, not measured.
📏 Reality check: at peak occupancy (2 aboard) your gray tank fills about every 2.8 days. Tune the shower/sink numbers until that matches what you’ve actually seen.

Service triggers

🚱 Gray water can’t be dumped on the playa (Leave No Trace) — it’s tank-limited. During build/strike you’re likely self-servicing, so watch those phase counts.
📚 Data behind these numbers
Defaults scale metered residential data down to playa conservation (no gray dumping → every gallon in is waste you pump out):
· Burning Man Survival Guide — 1.5 gal/person/day (all uses)
· Burning Man — Gray Water — zero dumping on the playa
· Residential End Uses of Water (REU2016) — shower 2.1 gpm × 7.8 min baseline
· Harris Poll — Shower Habits — women 16.8 vs men 15.4 min (~1.4 min gap)
· RV Geeks — RV toilet flush — #1 ~0.15 gal, #2 ~0.75–1 gal (gravity)
· EPA WaterSense — faucet 1.5–2.2 gpm; ~5 flushes/day & ~0.2 gal/hand-wash basis
· Boondocker's Bible — conservation per-activity split

📊 What you need — totals

3
Pumpouts
over the whole stay
3
Water refills
over the whole stay
30A
Shore power
hookup
2 / 1
Valves / hookup
gray+black
Aug 30 – Sep 6 · 8 nights 16 person-nights Limiting tank: gray

🔨🔥🧹 Split by phase

PhaseDatesNightsPpl-ntsPumpoutsRefills
EventAug 30–Sep 781633

🎲 Pump-out risk · Monte Carlo

Most likely 3 pump-outs · range 2–4 · plan for 3 to cover 90% of scenarios. “Service by” keeps you ahead of the tank in 85% of cases.
Pump-outLikely dateService byChance
#1Sep 1Sep 1100%
#2Sep 5Sep 4100%
#3Sep 6Sep 681%
Pump-out count across 1000 random scenarios (each varies daily showers & dishes):
19%
2
80%
3
1%
4
“Service by” = dump early enough to stay ahead of the gray tank in your chosen % of scenarios.
🌧️ Weather closure risk (Typical): ~18% chance a no-driving spell (rain/mud) overflows the gray tank before trucks return · worst-case fill 134%. Dump the gray tank to empty before any rain in the forecast — a 2023-style 2–3 day lockdown would overflow it.
🌧️ Playa weather history & closure sources
Rain falls in the event window roughly 1 in 3 years (usually ≤0.25 in); driving was meaningfully impacted in 5 of the last 14 events (2014, 2015, 2023, 2024, 2025) — but only 2023 was a true multi-day lockdown (~0.5–0.8 in over ~24 h, ~2.5–3 days no driving). September averages just ~0.2–0.3 in. Track it yourself:
· xmACIS2 / RCC-ACIS — official NOAA station data (Gerlach COOP USC00263090 through 2018; Reno KRNO USW00023185)
· gerlachweather.com — nearest year-round station to Black Rock City
· BRC Airport (88NV) weather — on-playa tower station, webcam & brcweather.com forecast
· BLM — ~0.25 in makes the playa undrivable (halts truck service)
· CNN — 2023 driving ban lifted Mon Sep 4 (~2.5–3 days)

📈 Tank levels over the trip

Fresh Gray Black Pumpout Refill Build Event Strike ⭐ Key

🗓️ Service & event timeline

Aug 30 Event Gates open fresh 30 · gray 12 · black 3
Sep 1 Event Water refill #1 tank → 45 gal
Sep 1 Event Pumpout #1 gray 35 · black 10 · gray full
Sep 3 Event Water refill #2 tank → 45 gal
Sep 4 Event Pumpout #2 gray 35 · black 10 · gray full
Sep 5 Event Water refill #3 tank → 45 gal
Sep 5 Event ⭐ 🔥 Man Burn fresh 30 · gray 12 · black 3
Sep 6 Event Pumpout #3 (pre-departure) gray 24 · black 7
Sep 6 Event 🛕 Temple Burn fresh 15 · gray 24 · black 7
Sep 7 Strike Exodus —

🧾 Summary

Mid travel trailer (24–28 ft) · 2 people (1♀ / 1♂) · on playa Aug 30 – Sep 6 (8 nights)

  • Pump-outs 3 total (3 during event week) — 35 gal gray + 35 gal black
  • Water refills 3 total (3 during event week) — 45 gal fresh, 75 gal/voucher
  • Hookups 2 dump valves / 1 sewer · 30 amp shore power
  • Limiting tank gray fills first
  • Pump-out dates Sep 1, Sep 4, Sep 6
  • Refill dates Sep 1, Sep 3, Sep 5

🚐 Burning Man RV water & pump-out FAQ

How much water do you need per person per day at Burning Man?

Plan for roughly 6–8 gallons per person per day in an RV, and showers dominate. At Poo Math’s defaults — a 1.6 gallon-per-minute shower for about 3 minutes — one person uses 5–6 gallons of greywater from washing alone, before drinking water, dishes, and toilet flushes.

How often do you need to pump out RV tanks at Burning Man?

Usually every 2–4 days, set by whichever tank fills first — typically the gray tank, because showers dominate. A 35-gallon gray tank shared by 2–3 people fills in about 2–3 days. Poo Math triggers a service at 95% full and schedules pump-out trucks across build, event, and strike.

Can you dump RV greywater or blackwater on the playa?

No. Burning Man’s Leave No Trace rules prohibit draining any greywater or blackwater onto the playa. You must keep it in your tanks and have it removed by a licensed pump-out truck, or haul it out yourself. Dumping on the ground is a serious violation.

How big are RV black and gray water tanks?

Most rentals hold about 25–45 gallons each for gray and black. A mid-size travel trailer is around 35 gallons gray and 35 gallons black; compact campers can be 15–20. Poo Math includes presets for common Cruise America, El Monte, Airstream, and trailer models.

How much fresh water should you bring for an RV at Burning Man?

Your fresh tank rarely lasts the week, so plan refills. Fresh use roughly equals gray plus black output — about 6–8 gallons per person per day. A 45-gallon fresh tank serving two people lasts only about 3 days, so Poo Math schedules water deliveries before you run dry.