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2024 Pennsylvania Integrated Water Quality Report
Clean Water Act Section 303(d) List and 305(b) Report
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Introduction
This report, prepared by the Pennsylvanian Department of Environmental Protection (DEP), is the sixteenth in a series of reports for the Federal Clean Water Act (CWA) Section 303(d) listing of impaired waters requiring total maximum daily loads (TMDLs), and Section 305(b) reporting of the overall condition of Pennsylvania’s aquatic resources. It is compiled and submitted to the United States Environmental Protection Agency (EPA) once every two years. Unlike the 305(b) report, EPA must approve or disapprove the 303(d) list.
The following narrative contains the data used to satisfy the requirements of CWA Sections 303(d) and 305(b). This report covers the current status of Pennsylvania's waters and summarizes various programs in place to protect and improve water quality.
This report format is interactive and offers the ability to convey tremendous amounts of information in a way that is flexible and easy to understand. Please scroll down to view the Integrated Report or use the top menu to jump to a specific topic. If you encounter problems while viewing the content, please try opening the website using another web browser. Changing the browser zoom level may also provide a better user experience. DEP hopes this digital format significantly increases the transparency and public understanding of the programs currently in place to protect Pennsylvania's waters. To facilitate the use of this report, DEP has also created a demonstration video that provides useful instructions and covers some advanced features of this report.
DEP provided notice in the Pennsylvania Bulletin of a 45-day public comment period for this Integrated Report that was open from October 28, 2023 through December 11, 2023. After the public comment period, DEP compiled, considered, and responded to the comments provided. The comment-response document is available by clicking on the link below.
Disclaimer: The information contained in this report is based on the data contained in DEP information systems at the time of publication. Most information pertains to the biennial reporting period (October 1, 2021 to June 30, 2023); however, some information may cover longer periods of record. Some datasets may be incomplete due to DEP's jurisdictional restrictions.
Protected Water Uses and Categories
As part of the obligation to protect Pennsylvania's waters, DEP conducts assessments of protected water uses (e.g., Potable Water Supply, Fishing). For more information on Pennsylvania's protected water uses, see 25 Pa. Code § 93.3 .
Assessment determinations fall into three general statuses: supporting, impaired, or unassessed. For example, a body of water is considered "impaired" if it fails to meet one or more water quality standards. The categories below follow these general statuses but add more qualifiers. Category 5 and Category 5r (previously called Category 5alt) are the “list” of impaired waters (i.e., 303(d) list) that require the development of a TMDL. In the process of developing this list, a full status of all Pennsylvania waters is created to satisfy CWA Section 305(b) reporting requirements. It is the integration of these requirements (i.e., CWA Section 303(d) requirements and CWA Section 305(b) requirements) that establishes the structure and function of DEP’s Integrated Report. A fully interactive mapping application with advanced search capabilities is also available with DEP’s 2024 Integrated Report Viewer . DEP has also created a demonstration video that covers all of the advanced features of this tool. It is important to note that DEP uses the United States Geological Survey’s National Hydrography Dataset (provided at the 1:24,000 scale) to represent data geospatially throughout this Integrated Report and in the Integrated Report Viewer.
Category 1: Waters supporting all uses.
Category 2: Waters where some but not all uses are supported. The assessment status of the remaining uses may be unknown because data are insufficient to assess the water, or it may be impaired.
Category 3: Waters for which there are insufficient or no data to determine if any uses are supported.
Category 4a: Waters impaired for one or more uses, not needing a TMDL because a TMDL has been completed.
Category 4b: Waters impaired for one or more uses, not needing a TMDL because uses are expected to be supported within a reasonable timeframe.
Category 4c: Waters impaired for one or more uses, not needing a TMDL because the impairment is not caused by a pollutant.
Category 5: Waters impaired for one or more uses by a pollutant that requires the development of a TMDL.
Category 5r: Waters impaired for one or more uses by a pollutant that are selected for advance restoration implementation. A TMDL is still required if the advance restoration is not successful.
2022 to 2024 Changes
The data that make up this Integrated Report consists of over 300,000 assessment records ; however, much of this information has been reviewed and approved by EPA during previous Integrated Reports. To make reviewing new information easier, DEP produces lists of changes that were made from the previous Integrated Report (2022).
Changes in assessments over the past two years have mostly consisted of confirming previously supporting assessments as well as assessing uses that were not previously assessed. The high number of assessments that were confirmed as supporting suggests that many surface waters are maintaining their water quality. DEP has also put significant effort into assessing portions of the West Branch Susquehanna River and Susquehanna River for the 2024 Integrated Report; approximately 195 miles were reassessed for Aquatic Life Use and 353 miles were assessed for Aquatic Life Use for the first time. For more details on these new assessments, click the buttons below to view changes in tabular format, or explore the dashboard for an interactive experience.
ArcGIS Dashboards
2024 Cause Removal Report
DEP provides additional information for assessment changes called "cause removals", which include: removal of one or more causes from other impairment categories (i.e., 4a, 4b, and 4c); full restoration of water quality standards; or even corrections to previous assessment determinations or delineations. These cause removals also include "delistings", which are any removal of a cause of impairment from Category 5 and Category 5r (i.e., the 303(d) list). EPA must review and approved delistings, but DEP exceeds EPA's delisting reporting requirements by providing a report on all cause removals. Click the button below to see DEP's cause removal report for 2024.
Section 303(d)
The List - Categories 5 and 5r
Section 303(d) mandates the creation of a list of impaired waters that require the development of a TMDL (Categories 5 and 5r). Once a TMDL is approved by EPA, the related causes will be placed in Category 4a until water quality standards are restored.
Category 5r - known as advance restorations - is a list of waters where implementation of restoration activities will begin immediately without the development of a TMDL. DEP first incorporated Category 5r (then-known as Category 5alt) in the 2016 Integrated Report. Waters are selected to be in the 5r category because they have implementation plans and active public engagement. The goal of 5r listings is to restore water quality standards before TMDLs are written, which brings possible advantages to the regulated community and to people who reside or recreate in 5r watersheds. Category 5r still requires that a TMDL be completed unless water quality standards are achieved through advance restoration activities within a reasonable time.
Use the Integrated Report Viewer to view the status of waters in Category 5 and Category 5r. It is important to note that Categories 5 and 5r make up a large portion of Pennsylvania's impaired waters, but these categories do not include all impairments. Impaired waters also include Categories 4a, 4b, and 4c.
Section 305(b)
Groundwater Status
Groundwater monitoring efforts in Pennsylvania are displayed in the Status of Statewide and Legacy Groundwater Quality Monitoring Programs . The Legacy Ambient and Fixed Station Network Groundwater Quality Monitoring Program began in 1985 to characterize general background and assess changes in groundwater quality within 478 groundwater basins identified in the state. Because of resource constraints, monitoring efforts have been limited since the late 1990s and only ~12% of the state has been monitored. Under a joint funding agreement with DEP in 2005, the United States Geological Survey (USGS) compiled electronically available groundwater quality data to help point out data gaps and guide future monitoring efforts. Over 24,000 wells from 14 different agencies/programs were included in the project. For more information and to access the full report, please visit the USGS reports webpage .
A project was initiated in 2014 to sample select stations throughout the state on a regular basis. This effort is referred to as the “Expanded” (or “Statewide”) Fixed Station Groundwater Quality Monitoring Network to distinguish it from the original “Legacy” effort. From this information, DEP has begun to better understand the status of groundwater quality in Pennsylvania. A report by USGS titled “ Characterization of Ambient Groundwater Quality with a Statewide Fixed Station Monitoring Network in PA, 2015-2019 ” detailing project findings, was published in January 2022. Use the map to see the status of select water quality parameters in Pennsylvania’s groundwater from the new, expanded/statewide network.
DEP previously identified and prioritized sources of groundwater contamination based upon regional office input for earlier versions of the report. The information was reviewed and updated in the Sources of Groundwater Contamination and Prioritization Document .
Rising to the Challenge
Measuring Progress
Participate and Stay Informed
eComment
DEP will provide notice in the Pennsylvania Bulletin of a 45-day public comment period for this Integrated Report that was open from October 28, 2023 through December 11, 2023. DEP encourages the public to provide constructive comments during this period. To submit comments and see comments from other individuals, please use DEP's eComment tool . The links to view and comment on the Integrated Report will be made available in the “Open Comment Periods” section at the top of the eComment website during the public comment period. Written comments may also be mailed to the Department of Environmental Protection, Policy Office, Rachel Carson State Office Building, P.O. Box 2063, Harrisburg, PA 17105. DEP suggests that comments be organized using the main headings above (e.g., INTRODUCTION, SECTION 303(d)), or by scrolling down and using the subsection headings (e.g., PENNSYLVANIA WATER RESOURCES, LISTING DATA, TRENDS). Persons in need of accommodations as provided for in the Americans With Disabilities Act of 1990 should contact DEP’s Water Quality Division at 717-787-9637 or the Pennsylvania Hamilton Relay Service at 800-654-5984 (TTD users) or (800) 654-5988 (voice users) to discuss how DEP may accommodate their needs.
Comment and Response Document
After the public comment period, DEP compiled, considered, and responded to the comments provided. The comment-response document is available by clicking on the link below.
How's My Waterway?
How's My Waterway is EPA's newest data tool for everything related to water quality. It was designed to provide the public with water quality information that state, federal, tribal, and local agencies provided to EPA. Water quality information is displayed based on three scales (community, state, and national) to improve the user's experience and understanding. Explore the How's My Waterway factsheet and demonstration video for more information before diving in.
eNotice
DEP developed an electronic notification system – eNotice – that the public can use to stay up-to-date by receiving free notifications about a range of actions DEP takes in various program areas and geographies.
DEP Newsletter
DEP publishes a newsletter that features information about hot topics, recent actions, regulatory updates, webinars, and upcoming events.
Contact Us
For questions or assistance please contact the Water Quality Division at 717-787-9637 or send an email to RA-epwater@pa.gov .