Integrated Report of Surface Water Quality [303(d) List] Assessment Methodologies

 

Announcements​​​

Notice of The Public Comment Period for the 2024 Integrated Report Assessment and Listing Methodologies.  

The Maryland Department of the Environment (MDE) is announcing the availability of final draft assessment and listing methodologies for the 2024 Integrated Report of Surface Water Quality for public review and comment.  For the 2024 reporting cycle, changes were made to three assessment methodologies. The Listing Methodology for Identifying Waters Impaired by Bacteria in Maryland’s Integrated Report, The Fish Tissue Assessment Methodology section which is part of the Methodology for Determining Impaired Waters by Chemical Contaminants for Maryland’s Integrated Report of Surface Water Quality, and the Temperature Assessment Methodology for Use III (-P) Streams in Maryland were all updated.  Please refer to the list below for more details on the updates and links to the methodologies. 

Starting in 2002, Maryland developed and solicited public review of the assessment methodologies used to document the state's assessment of its WQS and which establish objective and statistically based approaches for determining water body impairment.  These methodologies are designed to provide consistency and transparency in Integrated Reporting so that the public and other interested stakeholders understand how assessment decisions are made and can independently verify listing decisions.  The assessment methodologies are living documents that can be revised as new statistical approaches, technologies, or other improved methods are identified.  


The public is invited to review and comment on any of these methodologies.  Comments should be submitted in writing to Becky Monahan at becky.monahan@maryland.gov by Friday, November 10, 2023.  The Department plans to have a draft Integrated Report ready for public comment in January 2024.


2024 Assessment Methodology Updates 

The Listing Methodology for Identifying Waters Impaired by Bacteria in Maryland’s Integrated Report  
Both sections of this methodology, The Interpretation of Fecal Coliform Data for Assessing Use II Shellfish Harvesting Areas, and The Interpretation of Bacteria Data for Water Contact Recreation Use, were updated to be more consistent with the criteria and determine which Maryland waters require restoration.  Changes include larger sample sizes and assessment decisions over a longer term to identify chronic bacteria issues.  There are also updates regarding the use of best professional judgement in reviewing data that doesn’t meet the minimum data requirements and in identifying chronic impairments from individual exceedances.  

The Fish Tissue Assessment Methodology section which is part of the Methodology for Determining Impaired Waters by Chemical Contaminants for Maryland’s Integrated Report of Surface Water Quality  
The Fish Tissue section of this methodology was updated with concentration thresholds for Perfluorooctane sulfonic acid (PFOS).

The Temperature Assessment Methodology for Use III(-P) Streams in Maryland  
The Temperature Assessment Methodology was updated to include information on the minimum sample size for impairment determinations, decisions for multiple monitoring locations on a single segment, and additional details on delisting a stream segment. 

There were no other substantive changes in any other assessment methodology for the 2024 IR cycle.  



Provided below are links to Maryland’s Assessment Methodologies (AMs) used in water body impairment determinations for the Integrated Report (IR) of Surface Water Quality. The AMs provide a consistent logical framework for ​reviewing​ water quality data. The public is invited to comment on any of the assessment methodologies during the public comment period for assessment methodologies that occurs during each IR cycle.  

All files below are in portable document format (PDF).

Bacteria Assessment Methodology​​ updated! (165KB)

Biological Assessment Methodology for Non-tidal Wadeable Streams (940KB)

Delisting Methodology for Biological Assessments (388​​​KB)

Biological Data Quality Guidelines (221KB)

Chesapeake Bay Benthic Biological Assessment Methodology (522KB)

Chesapeake Bay Assessment Methodologies (1793KB)

Assessment Methodology for Dissolved Oxygen and Chlorophyll a Criteria in Maryland’s Seasonally Stratified Water-Supply Reservoirs (88KB)

pH Assessment Methodology (77KB)

Sediment Assessment Methodology (29KB)

Temperature Assessment Methodology for Use Class III(-P) Waters ​ updated!  (288KB)​​​

Toxics Assessment Methodologyupdated! ​(456KB)

 
Please direct any questions or comments to Becky Monahan at becky.monahan@maryland.gov.​

Human Trafficking GET HELP

National Human Trafficking Hotline - 24/7 Confidential

1-888-373-7888 233733 More Information on human trafficking in Maryland

Customer Service Promise

The State of Maryland pledges to provide constituents, businesses, customers, and stakeholders with friendly and courteous, timely and responsive, accurate and consistent, accessible and convenient, and truthful and transparent services.

Take Our Survey

Help Stop Fraud in State Government

The Maryland General Assembly’s Office of Legislative Audits operates a toll-free fraud hotline to receive allegations of fraud and/or abuse of State government resources. Information reported to the hotline in the past has helped to eliminate certain fraudulent activities and protect State resources.

More Information