No-Discharge Zones

No vessel sewage dumping here!

The U.S. Clean Water Act No-Discharge Zone program establishes ocean and freshwater aquatic areas where ships and boats are not allowed to discharge vessel sewage of any kind. The purpose of creating these zones is to protect human health, sensitive habitats, and aquatic organisms, birds and other animals utilizing the water from adverse impacts of vessel sewage. Within NDZ boundaries, vessel operators are required to  store sewage onboard their ships for disposal at onshore pump-out facilities or outside the zone’s boundaries. Most no-discharge zones are a result of States applying to the U.S. EPA to designate specific water bodies as such.

Finally! California gets its ship sewage discharge ban. Read about California’s application for a No-Discharge Zone.

What is vessel sewage?

  • Vessel sewage is untreated or inadequately treated human wastes discharged from ships.
  • If vessel sewage is not treated properly, it can contain high concentrations of fecal matter, bacteria, viruses, pathogens, nutrients, and pharmaceuticals, all of which can be harmful to human health and aquatic life.

Why is controlling vessel sewage important?

Human Health: When beaches are closed, it is often due to sewage contamination. Swimming and wading in waters with inadequately treated sewage increases the likelihood of contracting diseases, such as infectious hepatitis, diarrhea, bacillary dysentery, skin rashes, typhoid, and cholera.

Food Safety: Sewage contamination can contaminate shellfish beds. Since oysters and clams are filter feeders, bacteria and viruses that contaminate shellfish can be passed on to consumers who often eat these foods raw.

Environmental Protection: Sewage contains large concentrations of nitrogen which is a source of food for algae. Excess algal growth can starve an aquatic ecosystem of oxygen thereby stressing fish, and in extreme cases causing fish kills. Excess algal growth can also smother and kill coral reefs and lead to a loss of biodiversity.