Water Quality Assessment Report - Integrated Report

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Notice of Public Solicitation of Water Quality Data for the 2026 Integrated Report of Surface Water Quality in Maryland.

The Maryland Department of the Environment (MDE) is currently requesting data for the 2026 Integrated Report (IR) of Surface Water Quality in Maryland. As part of the federal Clean Water Act, MDE submits a biennial Integrated Report to the Environmental Protection Agency (EPA) that provides information on both impaired and non-impaired waters within the State of Maryland. In order to provide the most comprehensive report, the Department relies on water quality data from a variety of sources including Federal and State agencies, local government agencies, researchers, students, and watershed organizations.

If your organization collected water quality data in Maryland within the past five-year period (January 1, 2019- December 31, 2023), please consider submitting your data. MDE is particularly interested in water quality data that are comparable to state water quality standards and criteria (e.g., dissolved oxygen, pH, turbidity, various toxics, benthic macroinvertebrate and fish community data). Other water quality data, including conductivity, nutrient species, chlorophyll, habitat conditions, and field observations may also be used to assess ambient water quality.

To submit data, please complete this 2026 Integrated Report Submittal Form and follow the appropriate data pathway. For additional information on the types of data accepted and how to submit data, please visit MDE's Data Solicitation webpage.

Because the IR is a regulatory document, some data received may not be suitable for water quality assessments. However, the Department will track all data received and data submitters can contact MDE to inquire how their data were used and why. Please contact Becky Monahan at Becky.Monahan@maryland.gov with any questions.

What is the Integrated Report of Surface Water Quality [303(d) List and 305(b) Report]?

The Integrated Report (IR) combines two water quality reports required under sections 305(b) and 303(d) of the federal Clean Water Act. Section 305(b) requires states, territories and authorized tribes to perform annual water quality assessments to determine the status of jurisdictional waters. Section 303(d) requires states, territories and authorized tribes to identify waters assessed as not meeting water quality standards (see Code of Maryland Regulations 26.08.02). Waters that do not meet standards may require a Total Maximum Daily Load to determine the maximum amount of an impairing substance or pollutant that a particular water body can assimilate and still meet water quality criteria. Historically, the 303(d) List and the 305(b) report were submitted to the Environmental Protection Agency (EPA) as separate documents but more recent guidance has called for combining these two reports into a single biennial publication. Maryland’s 2008 IR represents the first edition of a fully combined 305(b) and 303(d) report.

In accordance with recent US Environmental Protection Agency guidance, Maryland’s current List of Impaired Surface Waters [303(d) List] is contained in an Integrated Report that describes five different categories of water quality, including: Category 1 - waters attaining all standards; Category 2 - waters attaining some standards; Category 3 - waters with insufficient information to determine if water quality standards are attained; Category 4 – impaired or threatened waters that do not need or have already completed a TMDL; Category 5 [the historical 303(d) List] - impaired waters for which a TMDL is required.

Why compile an Integrated Report?

The CWA requires States, territories, and authorized tribes to: 1) develop water quality standards for all jurisdictional surface waters; 2) monitor these waters; and 3) identify and list those waters not meeting water quality standards. A water quality standard is the combination of a designated use for a particular body of water and the water quality criteria designed to protect that use. Designated uses include activities such as fishing, swimming, drinking water supply, and oyster propagation and harvest. Each use has associated water quality criteria, both numeric and narrative. Besides being required by EPA, the IR serves many other purposes relating to water quality planning for a number of state, county, and local agencies. By providing an update on the status of water bodies, the IR helps to prioritize which watersheds should be addressed by restoration and which watersheds are in need of protection.

How Does Maryland Determine if a Water Body is Impaired?

Maryland has developed Assessment Methodologies (AMs) to document the decision-making process by which water body impairment determinations are made. The AMs document the minimum data requirements, analytical/statistical methods, and other standard operating procedures used to determine if water quality standards are attained. When updates to the AMs are necessary as a result of improved scientific/statistical methods or new water quality criteria, the revised methodologies are made available for public review and comment in the biennial Integrated Report Process/Update.

How does Maryland’s Integrated Report relate to TMDLs?

All impairing substances or pollutants identified in Category 5 of Maryland's Integrated 303(d) List must generally be addressed by either a water quality analysis (WQA) or a TMDL. A WQA is completed when new water quality monitoring data suggest that a waterbody is meeting water quality standards (i.e., belongs on Category 2 of the Integrated List). TMDLs are completed when a waterbody continues to violate water quality standards. A TMDL establishes the amount of pollution, plus a margin of safety, that a waterbody can assimilate and still attain water quality standards. Local jurisdictions or responsible parties determine specifically where pollutant loading reductions will be made. In some cases, listings can be removed with an explanation, which may include application of inappropriate water quality criteria, improper delineation of impairment and/or additional data [under the Good Cause Provision (40CFR130.7)]. These listing changes may not require a WQA or TMDL. Maryland is also pursuing alternative approaches to TMDLs that result in more rapid implementation measures to address waterbody impairments.

How can the public get involved?

There are many opportunities for public involvement in the Integrated Report process. Data solicitations are conducted prior to each two-year listing cycle where volunteer and community groups, academia, local/State/federal governments and non-profits can submit water quality data for use in assessments. Draft Assessment Methodologies used to guide impairment determinations are placed on the web and in libraries for public comment. A public meeting is held during the open comment period for the Integrated Report and draft reports are posted on the web. Also, the State will attend/hold special meetings and develop briefing for interested groups on a case by case basis.

Contact Information

For more information, please contact Becky Monahan at 410-537-3947 or Becky.Monahan@maryland.gov.

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