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
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).