Water: Uniform National Discharge Standards (UNDS)
Laws & RegulationsLaws & Executive OrdersClean Water ActVessel Water DischargeUniform National Discharge Standards (UNDS)Uniform National Discharge Standards (UNDS) Frequent QuestionsUniform National Discharge Standards (UNDS) Frequent Questions
- What are Uniform National Discharge Standards (UNDS)?
- What is a marine pollution control device (MPCD)?
- How did EPA and the Department of Defense (DOD) evaluate the discharges?
- What have EPA and DOD done to assess armed forces vessels discharges?
- What vessels are covered by UNDS?
- How have EPA and DOD involved the states?
- How does UNDS affect the public, the states, and the armed forces?
What are Uniform National Discharge Standards (UNDS)?
UNDS will set national performance standards that will require the use of marine pollution control devices (MPCDs) to control discharges incidental to the normal operation of armed forces vessels. EPA and Department of Defense (DOD) are given authority, under Section 312 of the Clean Water Act 
, to develop these standards.
EPA and DOD anticipate that the standards will enhance environmental protection of U.S. waters by creating nationally protective standards for previously unregulated discharges from vessels of the armed forces. Other benefits include advancing the development by the U.S. Navy of environmentally sound ships, and stimulating the development of innovative vessel pollution control technologies.
What is a marine pollution control device (MPCD)?
An MPCD is any equipment or management practice designed to treat, retain, or control discharges of a vessel. EPA and DOD must consider seven statutory factors in determining whether it is reasonable and practicable to require the use of an MPCD. The seven statutory factors that must be considered are:
- Nature of the discharge
- Environmental effects of the discharge
- Practicability of using the MPCD
- Effect of an MPCD on the operation of a vessel
- Applicable United States law
- Applicable international standards
- Costs of MPCD installation and use
How did EPA and the Department of Defense (DOD) evaluate the discharges?
| Phase I | Identify and Characterize Discharges |
Joint EPA/DOD Rule |
Final Rule Published on May 10, 1999 |
| Phase II | Establish MPCD Performance Standards |
Joint EPA/DOD Rule |
Batch One Rulemaking Underway |
| Phase III | Develop Implementing Instructions |
DOD Only Rule | Completed One Year After Phase II |
Phase I:
EPA and DOD published Phase I of the Uniform National Discharge Standards rule, on May 10, 1999. The Phase I rule identified all discharges incidental to the normal operation of armed forces vessels, and characterized each discharge to determine if it required control, based on its potential to have an environmental impact. The Phase I rule also established procedures for no-discharge zones.
Phase II:
In Phase II, EPA and DOD, in consultation with the U.S. Coast Guard (USCG), are developing standards for each discharge that was determined to require control in Phase I.
Phase III:
In Phase III, DOD, in consultation with EPA and USCG, will establish regulations governing the design, construction, installation, and use of MPCDs onboard vessels of the armed forces. These regulations will be required to meet the performance standards promulgated in Phase II. The Phase II performance standards do not become effective until Phase III requirements are in place.
What have EPA and DOD done to assess discharges produced by armed forces vessels?
As part of the UNDS process, EPA and DOD evaluated the environmental effects of the discharges, and proposed performance standards for MPCDs to control these discharges. For Phase II, Batch One, EPA and DOD selected and analyzed seven discharges from the 25 discharges identified in Phase I for review and development of controls. Each discharge was evaluated through an environmental effects analysis, a cumulative impact analysis, and a feasibility impact analysis.
Environmental effects analysis:
The environmental effects analysis looks at the extent of environmental impacts of a single discharge from a single vessel in a theoretical harbor, which includes hydrodynamic modeling of discharge plumes. The analysis evaluates many discharge parameters and compares them to previously established acute water quality criteria or other regulatory limits. An environmental effects analysis evaluates the potential for bio-accumulation of chemical constituents of concern, and the presence of human pathogens and potentially invasive species.
Cumulative impact analysis:
Unlike the environmental effects analysis, the cumulative impact analysis evaluates the environmental impacts that result from multiple discharges from multiple vessels. Additionally, the cumulative impact analysis study looks at environmental impacts that include complex toxicological effects, such as impacts to human health, and impacts to water column and benthic communities. San Diego Harbor in California and Norfolk Harbor in Norfolk, Virginia were used for this analysis.
Because UNDS rulemaking will be performed in batches, the cumulative impact analysis considers all discharges of a batch, and the discharges of any prior batches.
Feasibility impact analysis:
A feasibility impact analysis was conducted for MPCDs identified for each of the seven discharges in Batch One. The analysis estimated the practicability and operational impacts, including costs of installing and using an MPCD on armed forces vessels.
What vessels are covered by UNDS?
UNDS is Applicable to:
U.S. Navy
U.S. Army
U.S. Air Force
Military Sealift Command
U.S. Marine Corps
U.S. Coast Guard
UNDS applies to these vessels in all navigable waters of the United States and the Contiguous Zone, (which extends 12 nautical miles seaward of the baseline of the Territorial Sea).
UNDS is Not Applicable to:
Maritime Administration vessels
Time- and voyage-chartered vessels
Vessels while under construction
Memorial/museum vessels
Vessels in drydock
Amphibious vehicles
Army Corps of Engineers vessels
Private vessels
Vessels owned or operated by states, local, or tribal governments
Commercial vessels
How have EPA and DOD involved the states?
The UNDS regulation has substantial direct effects on states.
EPA and DOD will determine performance standards for the discharges in Phase II. The performance standards promulgated in Phase II will pre-empt states from regulating discharges already covered by UNDS once they are implemented as part of Phase III. Additionally, UNDS Phase I identified 14 discharges that would not require an MPCD. Consequently, Executive Order 13132 requires that appropriate state elected officials or their representative national organizations be consulted.
Outreach efforts involving the states, territories, tribes and other federal agencies have been an integral component of the UNDS rulemaking process. Representatives of 26 state environmental offices were briefed on the UNDS Phase II rulemaking. During these meetings, EPA and DOD obtained input from the states, and apprised them of preemption of state regulatory authority.
EPA and DOD have consulted extensively with state environmental agencies. Consistent with the requirements of Executive Order 13132, an invitation to be briefed on the UNDS rulemaking was extended to representatives from the following organizations:
National Governors' Association
National Conference of State Legislatures
Council of State Governments
National League of Cities
U.S. Conference of Mayors
National Association of Counties
International City/County Management Association
National Association of Towns and Townships
County Executives of America
National Conference of Black Mayors
How does UNDS affect the public, the states, and the armed forces?
The public:
UNDS is applicable to all inland navigable waters (for example, the Great Lakes) and all coastal waters out to 12 nautical miles from the coastline.
The states:
Once discharge performance standards are implemented, states are pre-empted from regulating such discharges. States, however, can petition EPA and DOD to review whether or not a discharge should require control by an MPCD. Additionally, the Phase I rule established a process through which states may request the establishment of no-discharge zones (where any release of a specified discharge is prohibited).
The armed forces:
UNDS standards will advance the ability of the armed forces to better design and build environmentally sound ships, to train crews to operate vessels in a manner that is protective of the environment, and to maintain operational flexibility both domestically and internationally. Additionally, UNDS is expected to stimulate the development of innovative vessel pollution control technologies.
