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List of State Officials - Martin O'Malley, Governor; Anthony Brown, Lt. Governor; Shari T. Wilson, MDE Secretary 

Volume IV, Number 5

 June 2010

eMDE is a quarterly publication of the Maryland Department of the Environment. It covers articles on current environmental issues and events in the state. 

Protecting Maryland’s High-Quality Waters

By Angel Valdez, Science Services Administration

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Tier II Map 

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If you walk along a stream with clean water, lush plants, mossy rocks, and an abundant fish stock, you would probably want someone to keep it that way.

That’s where MDE’s program to protect high-quality waterways known as “Tier II” comes into play.

States are required by the federal Clean Water Act to develop policies, guidance, and implementation procedures to protect and maintain existing high quality waters and prevent them from degrading to the minimum allowable water quality. Tier II waters have chemical or biological characteristics that are significantly better than the minimum water quality requirements. All Tier II designations in Maryland are based on having healthy biological communities of fish and aquatic insects. 

Maryland has long had an antidegradation policy, and implementation procedures were developed in 2004. The implementation procedures:

  • explain how Tier II waters are identified
  • identify when the policy applies
  • outline the basic antidegradation review process
  • explain what must be done if some degradation of a Tier II water is necessary for social and economic reasons

Proposed development projects that could potentially impact high-quality waters may, depending on the specific circumstances, be required to satisfy tougher environmental standards in order to obtain state permits or other approvals (for example water and sewer plan amendments). There are currently 235 identified Tier II stream segments, with at least one in every county in Maryland except Baltimore City. The map to the left represents the current extent of Tier II waters and catchments.

MDE’s responsibility to protect high-quality waters includes confirming existing Tier II streams, and identifying any new Tier II streams, every three years. New stream designations are subsequently proposed by MDE for adoption in State regulation, a process well underway for the current cycle. In addition, the agency works internally to ensure that MDE’s relevant permit and approval programs are aware of and, where required, impose special Tier II water quality protections.

MDE also develops implementation guidance for the regulated community and conducts outreach to local government as well as other stakeholders including outreach most recently in 2007 and 2009. Finally, MDE must periodically update Tier II guidance as necessary to reflect changes at the federal level. For instance, new federal guidance regarding anti-degradation is expected from EPA in 2011. Federal guidance, in addition to the results of Maryland’s Tier II monitoring efforts or other relevant scientific developments, is an important consideration in each state update cycle.

Click here for information regarding the general Antidegradation Policy and the most current list of identified Tier II streams including links to county specific maps.
 
Click here for general information about Water Quality Standards.

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Editorial Board
Maryland Department of the Environment
1800 Washington Boulevard, Baltimore, MD 21230
http://mde.maryland.gov/
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