Maryland Department of the Environment (for pda/handhelds)

Water Quality Standards

What are water quality standards?

The purpose of water quality standards is to protect, maintain and improve the quality of Maryland surface waters. The following are three components of water quality standards:

• Designated Uses;
• Water quality criteria to protect the designated uses; and
• Antidegradation policy.

 Designated Uses

The State of Maryland has defined the following Uses:

• Use I: Water Contact Recreation, and Protection of Nontidal Warmwater Aquatic Life
• Use I-P: Water Contact Recreation, Protection of Aquatic Life, and Public Water Supply
• Use II: Support of Estuarine and Marine Aquatic Life and Shellfish Harvesting
  - Shellfish Harvesting Subcategory
  - Seasonal Migratory Fish Spawning and Nursery Subcategory (Chesapeake Bay only)
  - Seasonal Shallow-Water Submerged Aquatic Vegetation Subcategory (Chesapeake Bay only)
  - Open-Water Fish and Shellfish Subcategory (Chesapeake Bay only)
  - Seasonal Deep-Water Fish and Shellfish Subcategory (Chesapeake Bay only)
  - Seasonal Deep-Channel Refuge Use (Chesapeake Bay only)
• Use II-P: Tidal Fresh Water Estuary – includes applicable Use II and Public Water Supply
• Use III: Nontidal Cold Water
• Use III-P: Nontidal Cold Water and Public Water Supply
• Use IV: Recreational Trout Waters
• Use IV-P: Recreational Trout Waters and Public Water Supply

Each major stream segment in Maryland is assigned a use. The Use is a goal for water quality and may or may not be served now, but should be attainable.

Factsheet: Frequently Asked Questions about Chesapeake Bay Water Quality Standards

For more detailed description of these Uses check COMAR 26.08.02.02 - Go to COMAR Online at 
http://www.dsd.state.md.us/comar/comarhtml/26/26.08.02.02.htm

 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 - Go to COMAR Online at http://www.dsd.state.md.us/comar/subtitle_chapters/26_Chapters.aspx Click on Subtitle 08, then on Chapter 2 - Water Quality (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.
• MDE is proposing draft regulations.

Triennial Review of Water Quality Standards Available for Public Comment

On April 24, 2009 in the Maryland Register, MDE published a notice announcing the public comment period for the revision of Maryland's water quality standards.  A public hearing will be held on June 3, 2009 from 2:00PM to 5:00PM at the Department's offices in Baltimore.  MDE will accept comments on the revision through June 17, 2009.  A subsequent promulgation of new water quality standards will follow this review period.  For more information, please click here.

Public Notice of Intent to Develop a Process and Approach for Use Attainability Analyses

On Wednesday, March 19, 2008, MDE held a public meeting to solicit initial input on the Use Attainability Analysis (UAA) process. At that meeting, MDE answered questions to clarify the issues and begin to develop the approach.  MDE is currently forming a workgroup to explore options for this using this valuable Clean Water Act tool.  MDE anticipates convening this workgroup by the end of 2008, with an approach drafted and made available for public comment by spring 2009.   When this approach is applied and a decision is made that a specific water quality standard cannot be attained, revision of the water quality standard and development of new criteria will go through the formal, public, promulgation process.

 Relevant Presentations

Water Quality Standards in the Chesapeake Bay and Tributaries: Background & Implementation (pdf: 677 KB)

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