Integrated Water Quality Monitoring and Assessment Report

Overview
Draft 2026 IR
Approved 2024 IR
Past Reports/Resources
Map of Assessed Waters
Impaired Waters and Recovery Plans (TMDLs)

Alaska's Integrated Report

Every two years, Alaska compiles and analyzes water quality data to determine if waterbodies are meeting Alaska Water Quality Standards. These waterbody assessments help DEC:

Understand water quality in Alaska
Prioritize restoration areas
Protect human health
Identify impairments and areas for restoration
Prioritize grant funding to communities

Collectively this process is called the Integrated Water Quality Monitoring and Assessment Report, or Integrated Report. It satisfies Sections 305(b) and 303(d) of the Clean Water Act. Section 305(b) requires that the quality of all waterbodies be characterized, and Section 303(d) requires states list any waterbodies that do not meet water quality standards (these are known as polluted or impaired waters). The Integrated Report combines this information into a single comprehensive report.

New Integrated Report Website

Draft 2026 Integrated Report

The Alaska Department of Environmental Conservation (DEC) is seeking written comments on the Draft 2026 Integrated Water Quality Monitoring and Assessment Report (Integrated Report). Every two years, DEC reports on the condition of Alaska’s waters, which helps the State prioritize waters for action such as data gathering, watershed protection, and restoration of impaired waters. This report categorizes waterbodies and identifies impaired waters under the Clean Water Act sections 305(b) and 303(d).

The deadline to submit written comments is 11:59 PM Alaska Standard Time on April, 6, 2026. DEC will host an informational meeting on March 18, 2026 from 4 to 6 PM. Join the meeting online by clicking this link at the scheduled time: Integrated Report Informational Meeting Link. You may also attend by calling in to 907-202-7104, access code 138 407 317# (for audio only).

Draft 2026 Integrated Report Map

The Draft 2026 Integrated Report Assessed Waters map shows the cumulative waterbodies assessed during previous Integrated Reports up to and including this draft.

Draft 2026 Integrated Report Documents

Listing Methodologies

Responses to Questions about the Draft 2026 Integrated Report

The following questions were asked of the department during the Draft 2026 Integrated Report public notice period between March 6, 2026, and April 6, 2026. DEC’s response follows each question:

Little Susitna River

The Draft Little Susitna Attainment Summary and Draft 2026 Integrated Report Map, as well as other supporting documents, are available on this website.

1. Can you explain Category 2n again, particularly for the Little Susitna River?

Category 2n applies when water quality excursions occur naturally, not due to human activity. In the Little Susitna, turbidity spikes are tied to storm events and natural watershed conditions, not human uses (e.g., motorboats), which have decreased. The river’s characteristics (steep, naturally eroding, semi-glacial system) contribute to naturally higher turbidity.

2. Their project tributary is upstream of Little Susitna; how should they interpret the waterbody categorization and naming?

Many Alaska water bodies lack sufficient data to be categorized. If a water body is Category 3 or not categorized, that means insufficient information is available. The online map and the Little Susitna summary document can help determine spatial relationships to the project site.

3. How does DEC distinguish between turbidity caused by storm events vs. human impacts? Do you use reports on rainfall or snowmelt?

For assessments, DEC does not directly factor precipitation records into data analysis. Instead, they review water body specific conditions, continuous turbidity monitoring, and seasonal hydrographs and discharge patterns. Analysis is based on continuous turbidity monitoring. Increased turbidity aligning with storm events suggests natural causes. Reference sites (non impacted areas upstream or comparable watersheds) are used to compare natural vs impacted turbidity levels.

4. Does DEC rely on external reports (rainfall, snowmelt, etc.) when assessing causes of turbidity?

DEC looks at any available contextual information to understand anomalies. The assessment begins with Water Quality Portal data, and if exceedances occur, staff investigate potential causes using whatever resources are available. Understanding cause is essential for determining whether restoration or planning actions are needed.

Turbidity assessments require a reference site that reflects natural background conditions. Ideally upstream in the same river; if no upstream site is available then a comparable watershed is used. Continuous monitoring at both impacted and reference sites allows comparison to determine whether exceedances are significant and anthropogenic.

EVOS Beaches

Draft EVOS Beach 4b Demonstration and Draft 2026 Integrated Report Map, as well as other supporting documents, are available on this website. The Exxon Valdez Oil Spill (EVOS) Lingering Oil website includes documents on the Lingering Oil Decision Process, Lingering Oil Technical Approach, and Lingering Oil Literature Review.

1. Why were beaches categorized using model data while others used test pit data? Is this typical?

DEC developed a tiered approach to reviewing data, prioritizing empirical data. Test pit data existed only for certain beaches, usually areas historically known to have lingering oil. These locations were selected based on prior knowledge and the likelihood of continued impairment. Modeled data is used when all other data tiers are lacking; in this analysis, modeled results were consistent with test pit findings.

Historic and current EVOS beach impairments are listed based on modeling data as well.

2. Is the focus on EVOS sites with past data creating a bias?

Historical knowledge influenced where limited resources were allocated. The PWS model used field data (test pit descriptions) from 2001, 2003, and 2007 as model input data. Additionally, the historical oiling predictor variable in the model input parameters is derived from SCAT data from 1989, 1990, and 1991. The output data predict the following:

The probability of encountering subsurface oil in a pit at a given alongshore location.
The probability of encountering subsurface oil categorized as MOR or HOR in a pit at a given alongshore location.
The probability of encountering any subsurface oil in a pit at a given alongshore location at a tidal elevation lower than 1.5 m above mean lower low water.

DEC prioritized empirical data in its review, but due to the lack of availability had to rely on modeled data for many sites. More information is available from the DEC lingering oil webpage, key documents found there include the Decision Process, Technical Approach and Literature Review.

3. I would appreciate receiving all data upon which you based the EVOS analysis, that, in the state's view, constitutes "enough information."

All data used in the Draft IR analysis are available upon request. The below documents were used in this analysis:

Integrated Report Website:

The Draft EVOS Beaches 4b Demonstration available on this website provides a summary of the history and listing decisions of the EVOS Beaches.

The Exxon Valdez Oil Spill (EVOS) Lingering Oil website:

The Lingering Oil Decision Process describes the methods that were used to analyze the available data.
The Lingering Oil Technical Approach describes the approach used to develop the decision process.
The Lingering Oil Literature Review is a comprehensive report about EVOS lingering oil research studies.

4. It appears that of the 16 EVOS shoreline sites, only four have had test pits dug within the past ten years, and none have had any further sampling in the past ten years, and that only modeled data were used to change the category. Is that correct?

Yes, only four sites had test pits dug within the past ten years. The model used historical data during its development, see question #2 above.

Approved 2024 IR

The 2024 Integrated Water Quality Monitoring and Assessment Report, including the 305(b) report on the status of State waters and the 303(d) Impaired Waters List was completed and approved on February 6, 2025. Assessment of water quality data concluded that two streams previously polluted near Fairbanks and Anchorage were found to be clean, two Anchorage streams already polluted for fecal coliform were found to also be polluted with E. Coli, and two polluted waters adjacent to the Red Devil Mine were approved for a cleanup plan. For a more detailed summary of the report, see the 2024 Integrated Report Factsheet.

2024 Integrated Report Factsheet
EPA Letter of Approval
2024 Assessed Waters Map shows waterbodies assessed up to and including the 2024 Integrated Report.
EPA's How's My Waterway is a publicly available mapper that shows the current status of waterbodies in Alaska.
The ATTAINS Expert Query supports querying and downloading Integrated Report assessment results in an excel format.

Historically DEC prepared a paper Integrated Report to satisfy the reporting requirements of the Clean Water Act. There is no longer a paper report, instead water quality assessment information is managed in a system called ATTAINS (Assessment and Total Maximum Daily Load Tracking and Implementation System).

New Integrated Report Website

Past IRs/Resources

Approved Integrated Reports

Final Listing Methodology

Water Quality Data

This map depicts waters assessed up to and including the 2024 Final Integrated Report. There are 5 categories to which a waterbody can be assigned when assessed, based on whether or not water quality standards are being met. Categories 1 and 2 are meeting standards for some or all of their designated uses, category 3 includes waters for which there is not enough information to make a determination, and categories 4 and 5 include waters that are not meeting standards for some designated uses. Waterbodies shown on the map have been evaluated, zoom in to see the assessed portion of an individual waterbody.

View Larger Map

Waters that persistently do not meet Alaska’s Water Quality Standards (18 AAC 70) are placed in Alaska’s 303(d) Category 5 Impaired Waters List through the Integrated Reporting process. When a water is Category 5 listed, it triggers certain requirements in order for that water to move out of Category 5.

A Total Maximum Daily Load (TMDL) establishes the maximum amount of a pollutant allowed in a waterbody and serves as the starting point or planning tool for restoring water quality. A TMDL identifies pollution sources in a waterbody and calculates the amount or 'load' of that specific pollutant that the water can receive and still maintain Water Quality Standards. TMDLs are a necessary first step toward waterbody recovery and are the primary tool per the Clean Water Act for a waterbody to be moved from the Alaska 303(d) Category 5 Impaired Waters List. TMDLs are approved by EPA and once approved, the water-body moves to Category 4a, impaired with a recovery plan in place. TMDL implementation includes taking actions to improve water quality.

TMDLs are not the only tool DEC utilizes for planning water quality improvements in impaired waters. EPA allows alternative plans that identify actions that when implemented are expected to improve water quality in a set amount of time. These types of alternative plans are also approved by EPA and move an impaired water from Category 5 to Category 4b, impaired with an alternative recovery plan in place. DEC developed a 10-year Prioritization Framework as part of the 303(d) program and EPA’s Vision process. The document outlines the approach and considerations DEC uses for restoring and protecting water quality.

TMDL Frequently Asked Questions