Rainwater that lands on bare soil can dislodge soil particles and transport them into streams and rivers. There, the increase in suspended sediment blocks sunlight from reaching aquatic plants, fills in the habitat of insects and fish, and deposits pollutants like phosphorus that attach to soil. Sediment also has negative economic impacts, including causing stress to fisheries and creating the need to dredge navigable waters.
Putting erosion and sediment control practices in place during construction activities protects water resources. These practices prevent rainwater from carrying soil particles as water flows off of a construction site. Practices generally work by filtering sediment or allowing sediment to settle out of the runoff. By retaining the soil on the site, sediment and nutrients are prevented from polluting streams and the Chesapeake Bay.
Starting in the early 1930s, the State of Maryland began establishing legislation to protect waters from various pollutants. In 1961, Maryland’s Attorney General determined sediment to be a pollutant of concern. This decision was based on a 1957 State statute and authorized sediment control regulations to be developed. The State’s General Assembly passed the Sediment Control Law in 1970 that mandated a statewide erosion and sediment control program. Maryland’s program was established to protect the Chesapeake Bay. The federal National Pollutant Discharge Elimination System (NPDES) permit program further created an incentive for the development of State and local programs. In the 1980s and 90s, the Chesapeake Bay Agreements, the U.S. Environmental Protection Agency’s (EPA) 319 Nonpoint Source Program, and the NPDES municipal stormwater program have added to the legal framework that supports and guides erosion and sediment control.
The basic requirements of the State program remain in place today. Construction activities that disturb at least 5,000 square feet or 100 cubic yards of earth must follow a plan approved by a local Soil Conservation District (SCD). Local jurisdictions must adopt a grading ordinance. Criminal penalties may be assessed for sediment pollution. Other program elements have been added, such as requiring sediment control plan approval prior to issuing grading and building permits (1973) and requiring training and certification of "responsible personnel" (1980). In 1984, enforcement authority was shifted from local to State control and criteria were established for local jurisdictions to be delegated the authority to operate an enforcement program with the State’s oversight. Starting in 1991, construction activity is required to be covered under a NPDES stormwater discharge permit; and in the following year the State began enforcing sediment control for agricultural land management.
Maryland’s current erosion and sediment control laws and regulations outline specific requirements for local jurisdictions that have been delegated inspection and enforcement authority. These include establishing a local ordinance, criteria for plan review and approval, minimum procedures for inspection and enforcement, and types of construction that may be exempted. The law also specifies procedures for delegating enforcement authority, as well as requirements for training and certification programs. To learn more about erosion and sediment control programs in Maryland, click here.
At all construction sites disturbing the minimum area or volume, the developer must operate an approved plan that includes a selection of controls. Erosion controls prevent the displacement of soil by reducing concentrated flow across the site. Examples include temporary stabilization mats and check dams. Sediment controls help soil particles to settle out from site runoff, thereby preventing it from leaving the construction area. Examples are sediment traps and filter logs. Criteria for the proper design, installation, and maintenance of all approved practices are found in the State of Maryland’s 2011 Standards and Specifications for Soil Erosion and Sediment Control (2011 Standards). The 2011 Standards describes many other ways sediment pollution may be controlled, such as fencing off areas that will not be developed, cleaning mud off vehicles before they leave the job site, and growing grass on areas where work has been completed.
Clean, productive, and navigable waterways are critical to the communities, economies, and ecosystems they support. Effective erosion and sediment control policies are a cornerstone of Maryland’s mission to protect and grow economic and recreational opportunities. Maryland continually works to improve water quality through implementing strong regulations and updating them as we continue to grow our understanding of the natural world.