Cacapon River Watershed TMDL
WVDEP Water Quality Standards and Assessment Section (WQSAS)
The WVDEP WQSAS presents this StoryMap to guide the public through the TMDL Development Process towards creating the Draft 2025 Cacapon TMDL which will address impairments in select streams in the Cacapon River Watershed.
Currently, monitoring is complete and data evaluation is taking place. Data suggests that impairments exist in several streams within this watershed. Causes of impairment are under investigation to guide how this will be represented in a model.
*See the Cacapon Watershed Map for geospatial representation of the impaired streams and sampling locations.*
The StoryMap provides basic information about TMDLs, as well as links to resources that provide access to regulations requiring TMDLs, as well as previous TMDLs and associated documents.
Return to this Storymap for further updates and a draft TMDL.
What is a TMDL?
A TMDL or “Total Maximum Daily Load” is how much of a pollutant a stream or lake can receive and still meet water quality standards. The WVDEP WQSAS develops TMDLs as a plan of action to clean up waters (i.e., streams and lakes) that are not meeting water quality standards.
The plan identifies pollution sources and develops a strategy to reduce or eliminate loads.
Why are TMDLs Needed?
Public awareness and a desire to control water pollution led to passage of the federal Clean Water Act of 1972 . The Clean Water Act established the basis for the regulation of discharging pollutants. Pollution control programs greatly reduce the amount of pollutants discharged into streams and navigable waters.
The West Virginia Water Pollution Control Act sets the goal of maintaining “reasonable standards of purity and quality of the water of the state” in order to protect the use of the water. One of many important tasks assigned to the WVDEP is establishing (with legislative approval) these standards of protection, called Water Quality Standards.
The West Virginia Water Quality Standards designate specific uses for waters of the state. Designated uses include drinking water supply, propagation of fish and other aquatic life, water contact recreation, agricultural use, wildlife use, and industrial water supply. Our Water Quality Standards also list “conditions not allowable” (CNA) in West Virginia waters that interfere with the designated use. Some examples of conditions not allowable are taste and odor, algae blooms, and condition which adversely alter aquatic ecosystems.
For each water listed as impaired by a pollutant, the Clean Water Act requires that a TMDL be developed. Full implementation of the TMDL would provide reasonable assurance that the stream or lake will meet Water Quality Standards to restore the designated use.
Impairments map
In a sense, the Water Quality Standards serve as a “measuring stick” to assess the quality of our state’s waters. Section 303(d) of the Clean Water Act and regulations developed by the U.S. Environmental Protection Agency (EPA), require states to identify all waters that do not meet water quality standards even after pollution controls required by law are in place. Streams or lakes not meeting the appropriate water quality standards are considered to be impaired. Every two years, WVDEP is to publish a report that contains a list of all streams and lakes in the state that do not meet Water Quality Standards, known as the 303(d) list. You can view West Virginia’s 2016 EPA-approved list here .
Currently, the 2018-2022 303(d) list has a DRAFT status. This map shows the DRAFT 2018-2022 303(d) impaired streams for each pollutant. (Click the expand icon in the top right corner to view the full map. To view the legend, click the icon in the bottom left of the map.)
Data Collection
Pre-TMDL Site Selection
When selecting Pre-TMDL sites, WVDEP WQSAS identifies monitoring stations that will characterize water quality in streams.
Sampling stations are identified for 303(d) listed streams as well as those for which WVDEP WQSAS lacks data throughout the watershed. Stations are also placed on streams with minimal human disturbance to better understand the background water quality conditions of an area. These stations are sampled monthly by WVDEP WQSAS for one year.
Monitoring
The WVDEP WQSAS process for developing TMDLs begins with intensive “pre-TMDL” monitoring to collect information about the streams that are impaired in a watershed.
Pre-TMDL Monitoring occurs between July and June each year; the timing varies depending upon weather and work loads.
In 2021, WVDEP field staff began pre-TMDL monitoring in the Cacapon River Watershed. Monitoring stations established throughout the watershed were visited 10-12 times between June 2021 and June 2022.
QA/QC
Quality Assurance/Quality Control
WQSAS staff enter agency field monitoring data collected both in-house and submitted from 3rd party providers. Data includes water quality, habitat ratings/notes, & aquatic life records to be used in the assessment and evaluation process of TMDL development.
Prior to final assessments, data is verified through Quality Assurance/Quality Control to identify and correct (where possible) errors or outliers in data. This is performed at various stages and involves thorough communication with analytical laboratories as well as field staff to validate data in question.
Corrections are noted, tracked, and communicated to appropriate parties at all stages of the TMDL process. Training and communication on proper data collection/reporting methods is offered by WQSAS staff to interested 3rd party data providers.
Assessment
Data assessment determines impairment in streams that will be the subject of the TMDL project.
The monthly data collected during sampling is used to assess water quality of the streams within the current TMDL watershed.
Pollutant Source Investigation
Pollutant Source Investigations documents sources that cause or contribute to impairment in streams.
Think of a TMDL as a “Pollution Budget.” If a TMDL is being calculated for a stream, we already know that the stream is impaired because it is receiving too much of a given pollutant. The question then becomes, what sources of the pollutant load have to be reduced – and by how much.
WVDEP WQSAS gathers available information for the sources of pollution in the watershed.
Typical sources include National Pollutant Discharge Elimination System (NPDES) permits, abandoned mine lands/discharges, mining permits, logging, pipelines, oil and gas well drilling, roads, agriculture/pasture, and residential/urban areas.
WVDEP is currently working with landowners and third party organizations to potentially develop an Advance Restoration Plan as an alternative approach to TMDL development to address the biological condition in certain portions of the Cacapon Watershed.
This strategy is consistent with a United States Environmental Protection Agency (EPA) goal that States may use alternative adaptive management approaches to traditional TMDL development where such approaches are better suited to achieve water quality goals.
WVDEP accepted public comments for monitoring location, pollutant source information, stream condition, 3rd party data, and other related information.
TMDL Development
Modeling
Model building and TMDL Development represent pollutant sources and a range of flow regimes to predict loads at baseline and allocated scenarios.
Once the pollutant source data are complete and the computer model is calibrated, the model predicts instream concentrations of the modeled pollutants (e.g., total iron, and fecal coliform bacteria).
Reductions can then be made in the computer model to predict how much reduction is needed for a stream to attain water quality standards. The percent reduction of the load from different sources of pollution depends upon an allocation approach established by the WVDEP WQSAS working with point and non-point stakeholder communities.
Allocation Strategy
The allocation strategy in West Virginia TMDLs takes a “top-down” approach using a computer model to predict loads from a watershed over different seasons and flow regimes for a six-year time period. This graph is an example of a model output for iron. Working from the headwaters or "top" of a watershed, the model tests if load reductions will result in attainment of water quality standards in these headwater subwatersheds, then presents a “cumulative load” progressively moving down toward the mouth of the stream. Once the model demonstrates that streams meet specific water quality standards, the percent reductions and final TMDL allocations for each pollutant source result in the final TMDL product.
The TMDLs are described in a TMDL public report and support documentation. After sharing the public report and addressing comments, WVDEP WQSAS sends TMDLs to the USEPA for approval before implementing the TMDLs.
Use the scroll bar to compare Baseline to Allocation Scenario for Iron.
*Note: The scales for iron concentrations on the y-axis are different between baseline and allocated scenarios.*
Baseline Scenario - Iron (0-25 mg/L), left | Allocation Scenario - Iron (0-2.5 mg/L), right
Cacapon River Watershed Map
This map displays the Cacapon River Watershed broken into smaller “subwatersheds” for the TMDL development effort. The map also displays streams that are modeled for fecal coliform and hydrology.
To view the legend, select the icon in the lower left corner of the map.
Use the + and - in the lower right corner to zoom in and out of the map.
Use the extent icon in the top right of the map to see the map's full view.
Within each layer are shapefiles representing the geographical features of the watershed. The layers and the shapefiles contained therein are described below. WVDEP WQSAS decisions on select outlets, permits, or other features that are to be deleted or modeled will be updated as the TMDL project progresses.
The Draft Cacapon TMDL Sampling Locations layer contains the WVDEP WQSAS sampling locations within the Cacapon Watershed.
The Draft Cacapon Streams layer contains the TMDL modeled streams located within the Cacapon Watershed.
The Draft Cacapon Subwatersheds layer contains Cacapon subwatershed boundaries located within the HUC 8 Cacapon Watershed.
The Cacapon Watershed layer contains the geospatial boundary of the HUC 8 Cacapon Watershed.
*Contents of the Draft layers are subject to change and will be updated as the TMDL project progresses.*
The streams included in this TMDL project are essential to effectively address impairments in the Cacapon River Watershed.
Public Comments
WVDEP will prepare a Draft TMDL for the Cacapon River Watershed that will be available for public review.
Presenting our Draft TMDLs publicly, provides the public an opportunity to review Draft TMDL documents and submit comments to WVDEP WQSAS at depwqsas@wv.gov.
Comment period lasts for approximately 30 days.
The Draft TMDL is expected to be released by 8/1/2025.
TMDL Documents
Use the link above to access specific resources related to previous and current WVDEP WQSAS TMDLs.
ArcGIS Shapefiles and Layer Description are available upon request.
If you want to contribute specific information to the TMDL development, please reach out to:
depwqsas@wv.gov
