Dumping your gray water, or emptying your gray tank, is generally only permitted on BLM managed lands, but may still be illegal by state law. Despite that, it’s very common for boondockers to dump their gray water on the ground on BLM lands.

Can I Dump my Gray Water on the Ground?
Of the six different federal land management agencies, only the BLM does not prohibit dumping of gray water on the ground. Technically, they use the term “wash water” when describing what kinds of waste is excepted from dumping. Below are subsections for each of the land management agencies and their regulations…
Bureau of Land Management
The BLM is the only federal land management agency that does not specifically prohibit dumping gray water on the ground. This is based on a BLM rule codified under CFR Title 43, § 8365.1-1 Sanitation, which states…
“On all public lands, no person shall, unless otherwise authorized:
(3) Drain sewage or petroleum products or dump refuse or waste other than wash water from any trailer or other vehicle except in places or receptacles provided for that purpose;“
The regulation does not specifically define, “wash water”, but it is understood to mean any water that was used for washing purposes (i.e. hands, dishes, showering, clothes, brushing teeth, etc.), which meets the definition of gray water, or water from a gray tank. Generally, as long as your gray tank contains water that was used for washing, it’s legal to dump it on the ground.
Note: Some boondockers have stated that this only applies to gray water from a shower or sink that was captured in a tub or bucket, but water that was allowed to drain into the gray tank is not. However, the actual Code of Federal Regulation (above) does not make this distinction.
Also note: The above rule applies only to “public lands” which is a term the BLM uses to describe all lands they manage except for developed areas (campgrounds, visitor centers, OHV areas, et al.)
U.S. Forest Service
The U.S. Forest Service has rules codifed under CFR Title 36, § 261.11 Sanitation which states…
The following are prohibited:
(b) Possessing or leaving refuse, debris, or litter in an exposed or unsanitary condition.
(c) Placing in or near a stream, lake, or other water any substance which does or may pollute a stream, lake, or other water.
(d) Failing to dispose of all garbage, including any paper, can, bottle, sewage, waste water or material, or rubbish either by removal from the site or area, or by depositing it into receptacles or at places provided for such purposes.
The last rule (d) is what specifically prohibits dumping of gray water on the ground. We have, however, heard from boondockers that claim they were given permission by forest rangers to dump their gray water on the ground. Because laws and rules are only as effective as the officials who enforce them, the matter is a case-by-case basis.
National Park Service
The National Park Service has rules codified under CFR Title 36, § 2.14 Sanitation and refuse, which states…
(a) The following are prohibited:
(1) Disposing of refuse in other than refuse receptacles.
(4) Draining refuse from a trailer or other vehicle, except in facilities provided for such purpose.
(6) Polluting or contaminating park area waters or water courses.
(8) In developed areas, the disposal of human body waste, except at designated locations or in fixtures provided for that purpose.
(9) In nondeveloped areas, the disposal of human body waste within 100 feet of a water source, high water mark of a body of water, or a campsite, or within sight of a trail, except as otherwise designated.
The National Park Service specifically defines “refuse” as…
Refuse means trash, garbage, rubbish, waste papers, bottles or cans, debris, litter, oil, solvents, liquid waste, or other discarded materials.
Bureau of Reclamation
The Bureau of Reclamation has rules codified under CFR Title 43, § 423.34 Sanitation, which states…
(a) You must not bring or improperly dispose of refuse on Reclamation facilities, lands, and waterbodies. Both the owner and the person bringing or disposing refuse may be issued a citation for violating this provision.
The Bureau defines, “refuse” as…
Refuse means any human or pet waste, litter, trash, garbage, rubbish, debris, contaminant, pollutant, waste liquid, or other discarded materials.
Because the Bureau of Reclamation is focused on bodies of water (lakes and rivers), it’s understandable that dumping waste water of any kind on the ground is not permitted.
Army Corps of Engineers
The Army Corps of Engineers has rules codified under CFR Title 36, § 327.9 Sanitation which states…
(a) Garbage, trash, rubbish, litter, gray water, or any other waste material or waste liquid generated on the project and incidental to authorized recreational activities shall be either removed from the project or deposited in receptacles provided for that purpose. The improper disposal of such wastes, human and animal waste included, on the project is prohibited.
(c) The spilling, pumping, discharge or disposal of contaminants, pollutants or other wastes, including, but not limited to, human or animal waste, petroleum, industrial and commercial products and by-products, on project lands or into project waters is prohibited.
Because the Army Corps of Engineers is largely focused on constructions projects around water ways, it’s understandable why dumping gray water on the ground is not allowed.
U.S. Fish & Wildlife Service
The USFWS administers all National Wildlife Refuges in the United States. They have rules codified under CFR Title 50, § 27.94 Disposal of waste, which states…
(a) The littering, disposing, or dumping in any manner of garbage, refuse sewage, sludge, earth, rocks, or other debris on any national wildlife refuge except at points or locations designated by the refuge manager, or the draining or dumping of oil, acids, pesticide wastes, poisons, or any other types of chemical wastes in, or otherwise polluting any waters, water holes, streams or other areas within any national wildlife refuge is prohibited.
While the above rule does not actually describe waste water or wash water, they do use the term “refuse sewage” which many would argue includes gray water. It also uses the term “chemical wastes” which could include soaps, detergents, or other cleaning agents you may wash into your gray tank.
State Public Lands (Parks, Forests, Beaches, etc.)
State laws and regulations vary from state to state, and vary from one park, forest, or beach to the next.
- Even if you are camped on BLM or USFS land, your waste water may flow or drain into underground aquifers leading to sources of drinking water (lakes, rivers, steams, reservoirs). Most states have laws and regulations under the scope of public safety or environmental quality that make it a crime to pollute these sources. Hence, even if it’s perfectly legal to dump gray water on BLM land, state officials may still cite (and arrest) you for violating state laws.
- Many local water districts own land located well away from homes, businesses, and often times these properties border BLM and USFS lands. In Southern California, for example, the Metropolitan Water District owns millions of acres of land, many of which is located next to BLM and USFS areas. Be careful when dumping gray water that water district employees are not nearby, or else may bring charges against you for polluting their water sources.
- Many states are now permitting the use of gray water to irrigate lawns and gardens, but it’s only permitted when gray water is used primarily for this purpose, and not as a secondary benefit from dumping RV tanks.
Idaho
- Department of Parks & Recreation…
IDAHO ADMINISTRATIVE CODE, IDAPA 26.01.20…
200. CAMPING.
06. Liquid Waste Disposal. All gray water and sewage wastes shall be held in self-contained units or collected in water-tight receptacles in compliance with state adopted standards and dumped in sanitary facilities provided for the disposal of such wastes.
- Department of Fish and Game…
IDAHO ADMINISTRATIVE CODE IDAPA 13.01.03…
100. PUBLIC USE RESTRICTIONS.
01. Activities Prohibited Without Director Authorization. Unless specifically authorized by the Commission or under lease, permit, contract, or agreement issued by the Director, Regional Supervisor, or other authorized agent, the following activities are PROHIBITED:
l. To discard dead fish, birds, animals, or parts or remains thereof, waste water, metallic cans, bottles, plastic or paper cartons, shotgun shell casings, yard and agricultural wastes, garbage, machines, appliances, or other litter on or in any lands or waters.
- Department of Lands (State Endowment Lands)…
The Department has not yet adopted general regulations with respect to the dumping of waste water, including black water. However, the Department has carved out 10 different “supervisory areas” of the State for the purpose of managing endowment lands, and each area is authorized to establish its own policies with respect to waste water, gray water, black water, sewage, and refuse.
Keywords: gray water dumping, grey water dumping, rules for dumping gray water, rules for dumping grey water
It’s only illegal if you agree with the laws otherwise it’s not illegal.
February 24, 2022 at 1:40 pmWhat’s the point of seperating black and grey if it’s not to dump the grey more easily?
The detergents are bad for the soil life as food remains are bad for the wildlife. Dumping any kind of tank on the ground, anywhere is an obvious no for us.
April 27, 2022 at 10:49 amTed, they separate it so you can dump the black first then rinse it out with grey.
May 21, 2022 at 5:52 pmScott G Graham, you can do either if they’re seperate. There’s also black tank flush. Seriously, who is going to make a special trip to a dumping station creating unecessary road noise, wear and tear, pollution, fuel consumption, just to dump wash water into a hole in the ground when they could avoid all that and stay longer by dumping it onto the ground instead? This topic is just ANOTHER mountain out of a mol;ehill and all this talk of “is it legal?” is just more nonsense. I just passed a law making it illegal for you to wear white socks; are you going to obey the law? You could tell me I have no authority to be making laws to which I would reply “ditto”.
October 15, 2022 at 9:05 am