Under the Clean Water Act, cities and industries are required to obtain a permit to treat and discharge wastes.

These permits ensure that sewage treatment systems are effective and that both the U.S. Environmental Protection Agency (EPA) and that the public know how much pollution is actually being discharged.

Yet cruise ships are not required to have discharge permits. They can dump sewage into the oceans without monitoring or reporting what they release. As a result, neither the government nor the public know how much pollution is released and there are no means for citizen enforcement.

Cruise ships are allowed to release treated sewage wherever they sail except the state waters of California. They are also permitted to release untreated gray water — wastewater from dishwashers, baths, showers, laundries, sinks and wash basins — anywhere they sail except in Alaskan and Californian state waters.

Once outside of three miles from the U.S. coastline, cruise ships can also lawfully release untreated sewage, or black water, anywhere, except in the Alexander Archipelago in Alaska, where treated sewage and gray water may be discharged only while cruise ships are under way, traveling at least six knots.

Cruise ships are required to have onboard waste treatment systems, known as marine sanitation devices (MSDs), but the industry is not required to monitor or report MSD discharges to either the government or the public. A study in Alaska showed that sewage from large cruise vessels “treated” by MSDs failed to meet federal standards for treated sewage in 69 out of 70 samples. Cruise ships also are not required to monitor the quality of the waters into which they routinely dump their waste.