Beaufort County SC: Adapting Your Water Quality Monitoring Program to Impaired Streams and TMDLs
In 2016, Beaufort County developed a “Monitoring and Assessment Plan for TMDL and Impaired Waters” document and began implementation of monitoring. Much data has been collected in various locations throughout the County in an effort to determine baseline water quality. During a program assessment in 2018, the County determined that a refined focus was needed on TMDL waters, as well as on impaired streams. The County’s refined monitoring goals are to:
- Develop an understanding of baseline water quality in the County’s streams.
- Identify and remove non-stormwater (or illicit) discharges from the stormwater system to protect better the health of streams and rivers within the County.
- Determine if discharges from the County’s SMS4 are or may be contributing to an impairment or TMDL in streams and rivers within the County. As of the date of this revised monitoring plan, there are three TMDLs impacting the County: Beaufort River Dissolved Oxygen TMDL and Okatie and Chechessee Fecal Coliform TMDLs. There are numerous impaired stream segments within the County as well.
- Comply with the County’s SMS4 permit requirements.
- On a project by project basis, develop an understanding of the effectiveness of best management practices installed in the County as they relate to water quality.
The County’s comprehensive monitoring program is divided into 5 categories as follows:
- Category 1. TMDL monitoring. The County’s SMS4 permit requires that the County monitor TMDL watersheds to determine the SMS4’s contribution. This category of points has been established based upon the Beaufort River, Okatie River and Chechessee River TMDL documents.
- Category 2. IDDE screening and monitoring. The County’s SMS4 permit also requires that the County identify priority areas to screen outfalls for illicit discharges. The County’s illicit discharge detection and elimination program includes multiple screening priorities, one of which is focused on known impaired streams. This category includes those impaired streams and places a priority on a desktop analysis and outfall screening in those watersheds to search for potential contributors to those impairments.
- Category 3. Water quality monitoring. The County also monitors water quality in streams that are impaired in an effort to determine causes and begin moving towards improvements. This category of monitoring includes monitoring stations based upon the 303(d) list.
- Category 4. MOA points. The County has entered into Memorandums of Agreement (MOAs) with several other agencies within Beaufort County. These points are monitoring points that fall under these agreements.
- Category 5. Special Project monitoring. Often, the County installs water quality BMPs and monitors those BMPs to show effectiveness. This category of points includes those special projects.
The current monitoring locations include:
55 Monitoring total locations
- 32 Special project monitoring points
- 6 TMDL monitoring points
- 17 Baseline monitoring/MOA points
- 2 defined hot spot locations
The County is working with several partners to complete the monitoring, including the University of SC at Beaufort, Town of Port Royal, Town of Bluffton, and the City of Beaufort .