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Department of Stormwater
The Department of Stormwater's mission is to monitor, protect, restore, and enhance Frederick County’s waterways.
We work to improve our community’s quality of life, defend from climate-driven flooding, and contribute to the health of the Chesapeake Bay ecosystem. The Department of Stormwater ensures regulatory compliance through cost-effective decisions that provide the greatest community and environmental benefit. Please use the links on this page to learn more about our work and our public programs.
Our work is structured by requirements of the National Clean Water Act and administratively enforced by the State of Maryland under the National Pollutant Discharge Elimination System (NPDES) permit program. The State of Maryland issues two permit types to Frederick County to ensure it is abiding by the Clean Water Act: the Municipal Separate Storm Sewer System (MS4) permit and a General Permit for Discharges from Stormwater Associated with Industrial Activities permit (20-SW). The MS4 permit requires the County to perform permit and program administration, stream and forest restoration, and environmental enforcement to protect our waterways.
We submit an annual report to the State of Maryland that details our MS4 Permit-related work. You can review the latest submission here.
The Frederick County Department of Stormwater's work is structured by compliance with a Municipal Separate Storm Sewer System permit issued by the State of Maryland, also known as the “MS4.” That permit is required by a larger federal Clean Water Act program, the National Pollutant Discharge and Elimination System (NPDES). Our current MS4 Permit requires Frederick County to complete the restoration of 1,027 impervious equivalent acres and address pollutant load reductions for the Chesapeake Bay and local Total Maximum Daily Loads (TMDLs).
What does that mean? This means there are regulated, legally-required activities we take that help us be good stewards of the environment, conserve valuable natural resources, improve the health of our waterways, and protect our community's infrastructure. Those activities must be measured and reported to the State to meet our mandated goals.
To accomplish these goals, DEE must identify stormwater projects that receive the required impervious equivalent acre credits (see the Glossary of Terms on this page for more info) in accordance with the Maryland Department of Environment’s (MDE) Accounting for Stormwater Management guidance document. On a large scale, this is accomplished through Watershed Assessments that identify multiple areas where there is a need for stormwater management. Then our staff completes more focused assessments through Feasibility Studies.
Stormwater Management Terminology
- Best Management Practices (BMP):
Actions that treat or reduce pollutants in stormwater and/or reduce the volume of stormwater runoff.
- Bioinfiltration:
Using plants and other biological materials to enhance infiltration of water into the soil to preventrunoff.
- Bioretention:
The process of collecting stormwater in a treatment area consisting of soil and plant materials to facilitate infiltration and remove sediment and contaminants through physical, biological, and/or chemical processes.
- Buffer:
A vegetated area between a waterbody and developed land, such as farm fields or housing developments. Buffers are designed to provide soil stability, slow the flow of stormwater runoff, and imprpve water quality by filtering pollutants.
- Equivalent acres:
The MS4 Permit requires us to take specific actions to make up for acreage in Frederick County that has had trees removed, impervious surfaces installed, or otherwise negatively impacted stormwater management. These actions might not occur on the same land where the environment was changed, so the Permit specifies a total amount of acreage that must be improved, restored, or replaced to improve the flow of stormwater.
- Illegal discharge:
The unauthorized release of any material (that can enter local waterways and/or the County stormwater system. This can be direct, such as a pipe directing material into a storm drain, or indirect, such as a chemical spill or leaking septic tank.
- Impervious surface:
A hard surface, such as paved road or parking area, that doesn’t allow water to seep into the ground. Instead, the water runs off the impervious surface, often picking up many types of pollution in the process, and then flows into a storm drain or a nearby body of water.
- Non-point source pollution: Pollution that does not come from a single, identifiable source. Includes materials that wash from roofs, streets, yards, driveways, sidewalks and other land areas. This is the largest contributor of stormwater pollution.
- Outfall:
A flow of water from one drainage system into a larger system, or into a body of water like a creek, river or lake.
- Point source pollution: Pollution from a single identifiable source such as a factory or a construction site.
- Runoff: Precipitation that the ground does not absorb and flows over surfaces and land. Runoff contributes to waterway pollution and soil erosion. Excessive runoff creates flooding.
- Storm drain system:
A network of underground pipes and open channels designed to control the flow of water and provide flood control. Typically, stormwater systems discharge directly to creeks and rivers, not through sewer and filtration systems.
- Stormwater:
Precipitation that does not penetrate the ground, instead runs off and enters the storm drain system, flowing into local waterways.
- Stormwater pollution:
Water from rain, irrigation, or other activities (such as washing cars) that picks up pollutants from streets, parking lots, driveways, and yards and carries them through the storm drain system and straight to local creeks and rivers. Common pollutants include pet waste, cigarette butts, trash, automotive fluids, used oil, paint, landscape debris, fertilizers and pesticides.
- Total Maximum Daily Load (TMDL): A calculation of the maximum amount of a pollutant that a waterbody can accept and still meet the state's water quality standards to ensure public health and healthy ecosystems. The federal Clean Water Act requires all states to identify waterbodies that do not meet state standards and develop TMDLs for them.
- Watershed:
A defined area of land that funnels water towards a waterway, such as a stream or river, which eventually flows to an outflow point such as a bay, and on to the ocean.