What are Designated Uses?

A designated use is a goal for water quality. Typically, the goal is the description of an appropriate intended use by humans and/or aquatic life for a water body.  Designated uses for a particular waterbody may include recreation, shellfishing, water supply and/or aquatic life habitat. The goals established may or may not be met currently, but must be attainable. Each stream segment, lake, bay, etc. in Maryland is assigned a designated use or multiple designated uses.

For more detailed information on Maryland’s designated uses including maps of streams and their associated designated uses, please click here.

 Water Quality Criteria

• Numeric criteria set the minimum water quality to meet the designated uses.
• Maryland has numerous numeric criteria for protection of aquatic life and human health (e.g., 5 mg/l for dissolved oxygen; 82 mcg/l for Pb (acute, freshwater))
• Criteria are published for toxics, dissolved oxygen, turbidity, bacteria, and temperature.
• Where specific numeric criteria are not available (e.g., oil, grease, odor, nuisance), narrative criteria apply.

Numerical Criteria for Toxic Substances in Surface Waters: COMAR 26.08.02.03-2 - Go to COMAR Online at
http://www.dsd.state.md.us/comar/comarhtml/26/26.08.02.03-2.htm

Water Quality Criteria Specific to Designated Uses: COMAR 26.08.02.03-3 - Go to COMAR Online at
http://www.dsd.state.md.us/comar/comarhtml/26/26.08.02.03-3.htm

 Antidegradation

• Maryland’s antidegradation policy assures that water quality continues to support designated uses.
• EPA regulations provide for three tiers of protection:
  • Tier 1 specifies the minimum standard that must be met—support of balanced indigenous populations and support of contact recreation—this is often referred to as "fishable-swimmable."
  • Tier 2 protects water that is better than the minimum specified for that designated use. For your county's Tier 2 waters, click here. 
  • Maryland is developing the third Tier of protection (Tier 3) called an Outstanding National Resource Water or ONRW.  

COMAR 26.08.02.04-1 - Go to COMAR Online at
http://www.dsd.state.md.us/comar/comarhtml/26/26.08.02.04-1.htm

For additional information, please click here.

Current Water Quality Standards

For the text of Maryland Water Quality Standards please check COMAR 26.08.02. 

Changes to the Water Quality Standards

Changes to the Water Quality Standards are implemented through regulatory changes which are subject to the normal promulgation process.

• Every three years, the CWA requires that States review their water quality standards.
• Active public involvement is a clear priority.

Factsheets:  Frequently Asked Questions about Chesapeake Bay Water Quality Standards

                     Frequently Asked Questions about EPA's Recreational Water Quality Criteria - 2012 

Contact:

For more information, please contact John Backus at jbackus@mde.state.md.us  or at (410) 537-3965.

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