Office of Communications

Maryland's No Discharge Zones

Added Protection for Sensitive Waters

Maryland has taken an extra step towards protecting sensitive waterways by working with the Environmental Protection Agency to designate No Discharge Zones (NDZs) in two areas: Herring Bay and the Northern Coastal Bays. A No Discharge Zone is an area of water where the discharge of all boat sewage is prohibited. This includes raw sewage, which is prohibited anywhere within the three-mile limit, as well as sewage treated by an approved marine sanitation device (MSD). An NDZ does not restrict the discharge of gray water.

Herring Bay and the Northern Coastal Bays were chosen as Maryland’s first NDZs for several reasons:
  • high concentration of boats
  • resources sensitive to boat sewage
  • water contact activities
  • local support for added protection


Proper handling of boat sewage is an important part of restoring Maryland waterways. Adequate facilities are required to help boaters act responsibly. Maryland has one of the country’s most successful pumpout programs. Over 300 marinas are equipped with one or more units designed to handle waste from holding tanks and portable toilets. Copies of Maryland’s Pumpout Guide are available at area marinas or from the Department of Natural Resources.


When navigating within an NDZ:
  • Secure Type I and Type II MSDs (treat and release systems). Acceptable methods to secure these systems include locking the door to the head or disabling the seacock.
  • Use the available pumpout facilities located at nearby marinas to empty Type III systems (holding tanks) and portable toilets.
  • Report NDZ violations and inoperable pumpouts to state authorities.


Cooperation by boaters is the key to successful implementation of No Discharge Zones. Please respect restrictions in these areas and encourage other boaters to do so. Violators will be subject to fines up to $1,000.


Maryland Department of the Environment
410-537-3510 (weekdays)
866-MDE-GOTO (evenings and weekends)


Maryland Department of Natural Resources
410-260-8772 (weekdays)

These maps are for illustrative purposes only. The precise locations are detailed in the Code of Maryland Regulations.Here is the "Maryland's No Discharge Zones" .pdf file.

Chesapeake Bay Hotline

Call 1-877-224-7229

to report any of the following

  • Boating accident or reckless activity
  • Fish kill or algal bloom
  • Floating debris that poses a hazard to navigation
  • Illegal fishing activity
  • Public sewer leak or overflow
  • Oil or hazardous material spill
  • Critical area or wetlands violation
  • Suspicious or unusual activity