25 CFR 247.18 - What are the sanitation prohibitions?
(a) You cannot deposit in any toilet, toilet vault, or plumbing fixture anything that could damage or interfere with the operation or maintenance of the fixture.
(b) You must dispose of all garbage, including any paper, cans, bottle, sewage, waste water or material, either by removal from the site, or by depositing it into receptacles or at places provided for such purposes.
(c) You may not bring refuse, debris, or toxic or hazardous materials to the sites for disposal.
(d) All toxic or hazardous materials must be properly removed from the sites. You may not dispose of such materials in a sewer line, tank, drain, storm drain, or on the ground.
(e) You must not place in or near the river or other water any substance that pollutes or may pollute the water.
(f) If dumping stations are not available, you must transport sewage off site.