Glossary

Section 303(d) of the Clean Water Act (CWA) requires states to develop a list of waters not meeting water quality standards or that have impaired uses. Listed waters must be prioritized, and a management strategy or total maximum daily load (TMDL) must subsequently be developed for all listed waters.

A geologic stratum containing groundwater that can be withdrawn and used for human purposes.

Any area draining to a point of interest. Basins of interest in Baltimore include the Inner Harbor (also known as the Northwest Branch) and the Middle Branch.

Activities or structural improvements that help reduce the quantity and improve the quality of stormwater runoff. BMPs include treatment requirements, operating procedures, and practices to control site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage.

A water quality practice that utilizes landscaping and soils to treat stormwater by collecting it in shallow depressions and then filtering it through a planting soil media.

A specified amount of storm rainfall, with its areal and temporal distribution, used to estimate a design discharge. Typically, the design storms are based on a return period (refer to definition below) of 2-years, 10-years, 25-years, or 100-years.

Effluent reuse is a process where treated wastewater is recycled for useful purposes and is not discharged to a natural waterway. The treated water may be used in industry, for golf courses or to water plants.

Removal of soil particles by wind and water. Often the eroded debris (silt or sediment) becomes a pollutant via stormwater runoff. Erosion occurs naturally but can be intensified by human activities such as farming, development, road-building, and timber harvesting.

Underground water usually found in aquifers. Groundwater usually originates from infiltration. Wells tap the groundwater for water supply uses.

The circuit of water movement from the atmosphere to the earth and return to the atmosphere through various stages or processes such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transpiration.

Any discharge to a municipal separate storm sewer that is not composed entirely of stormwater and is not authorized by an NPDES permit, with some exceptions (e.g., discharges due to firefighting activities)

Water is essential to human life and to the health of the environment. As a valuable natural resource, it comprises marine, estuarine, freshwater (river and lakes) and groundwater environments, across coastal and inland areas. Water has two dimensions that are closely linked - quantity and quality. Water quality is commonly defined by its physical, chemical, biological and aesthetic (appearance and smell) characteristics. A healthy environment is one in which the water quality supports a rich and varied community of organisms and protects public health. Water quality in a body of water influences the way in which communities use the water for activities such as drinking, swimming or commercial purposes. More specifically, the water may be used by the community for:

1. supplying drinking water
2. recreation (swimming, boating)
3. irrigating crops and watering stock
4. industrial processes
5. navigation and shipping
6. production of edible fish, shellfish and crustaceans
7. protection of aquatic ecosystems
8. wildlife habitats
9. scientific study and education

Artificial structures, such as pavements, that are covered by impenetrable materials such as asphalt, concrete, brick and stone. Soils compacted by urban development are also highly impervious.

The portion of rainfall or surface runoff that moves downward into the subsurface rock and soil.

Litter is any solid waste object (disposable item or resource) that can be held or carried in a person's hand that is left behind or placed in an inappropriate location. Any such material or item disposed of in an inappropriate manner is to be regarded as litter - the end outcome of an environmentally undesirable disposal action.

A sustainable landscaping approach that can be used to replicate or restore natural watershed functions and/or address targeted watershed goals and objectives. One of LID's primary goals is to reduce runoff volume by infiltrating rainfall water to groundwater, evaporating rainwater back to the atmosphere after a storm and finding beneficial uses for water rather than exporting it as a waste product down storm drains.

The Maryland Department of the Environment, like similar State agencies across the county, issues to local jurisdictions including Baltimore, Municipal Separate Storm Sewer System (MS4) permits to regulate how much pollution a jurisdiction is allowed to send into the local streams and harbor. Included in the Permit, which is issued every 5 years, are requirements to invest in improving the current stormwater infrastructure so our streams and Harbor become cleaner, rather than more polluted. The City of Baltimore has recently received its MS4 draft permit that would cover until 2016.

National Pollutant Discharge Elimination System, the two-phased surface water quality program authorized by Congress as part of the 1987 Clean Water Act. This federally mandated system is used for regulating point source and nonpoint stormwater discharge. The second phase of the program requires local governments to implement the following six minimum measures:

1. Public Education and Outreach
2. Public Participation/ Involvement
3. Illicit Discharge Detection and Elimination
4. Construction Site Runoff Control
5. Post-Construction Runoff Control
6. Pollution Prevention/Good Housekeeping

Pollutants coming from multiple undefined places. Unlike point source pollution, non point source pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, depositing them into lakes, rivers, wetlands, coastal waters and ground waters.

The point where wastewater or stormwater drainage discharges from a sewer pipe, ditch or other conveyance to a receiving body of water like a stream or the Harbor.

The characteristic of soil that allows water or air to move through it. Usually described in inches/hours or inches/day.

Pollutants from a single, identifiable, localized source such as a factory, refinery or place of business.

The total quantity of pollutants in stormwater runoff. Total Daily Maximum Loading (TMDL) is the limiting of pollutant loading into a body of water, such as a lake or river.

A rain barrel collects water from your rooftop that travels through your gutter or downspout to your lawn and patio, or piped directly to the street or alley. This water flushes pollution that has settled on your roof into the storm drain system. This runoff also picks up other contaminants like fertilizer, oil, gas, litter, and animal waste as it runs off your lawn, driveway or sidewalk.  Stormwater entering the storm drain system is piped directly and untreated to your local stream. Using the rainwater collected in your rain barrel to water your lawn and garden actually helps filter the pollution naturally. Using a rain barrel also helps to reduce the volume of stormwater runoff thereby reducing stream bank erosion.

A process that halts the downstream progress of stormwater runoff. This is often accomplished by digging ponds into otherwise flat land so that the water can be contained until it filters into the ground over a period of time. Often called a detention pond.

Of, or pertaining to, rivers/streams and their banks.

Vegetated areas next to water resources that protect water resources from nonpoint source pollution and provide bank stabilization and aquatic and wildlife habitat.

Also known as stormwater, Runoff is rainwater or snow melt that flows over impervious surfaces or soil that is compressed or fully saturated. Runoff flows over the land, carrying with it litter, oil, harmful fertilizer and other pollutants into our neighborhood streams and into the Harbor.

A system of underground pipes that carries sanitary waste from our toilets and drains to a wastewater treatment plant. In Baltimore our sanitary sewer system is not connected to the storm drain system, however, the sewer lines are very old and often cracked or broken. This allows sewage to leak into our streams and storm drains. Some houses and businesses have connected their toilets and drains to the storm drain system, instead of the sanitary sewer system. These connections are illegal, but most home and business owners do not even know they exist.

Soil, dirt, and sand washed off during a rainfall into our neighborhood streams and Harbor. Sediment can destroy fish-nesting areas, clog animal habitats, and cloud water so that sunlight does not reach aquatic plants. This is why you often see black plastic wrapping around construction sites – these wrappings are intended to catch sediment during a heavy rainfall and keep it from flowing off the construction site and into the storm drain system.

Persistently sewage-contaminated stormwater outfalls that are significant contributors to in-stream surface water pollution.

Identifies strategies to bring a small watershed into compliance with water quality criteria. Strategies go beyond traditional government capital projects and include projects in partnership with local watershed associations, citizen awareness campaigns and volunteer activities. The development of a SWAP has been completed for the Lower Jones Falls watershed and will help to guide restoration projects in the surrounding neighborhoods.

This is the opening we often see at curb lines, especially at corners. Sometimes they are labeled with “Chesapeake Bay Drainage”. These openings collect stormwater, which is often contaminated with pollutants. Storm drains connect to pipes that discharge directly to our neighborhood streams and the Harbor without receiving any treatment. What enters the storm drain exits to our waterways.

The system built to collect and transport runoff to prevent flooding. This system consists of storm drains, drainage ditches, pipes and culverts. Anything that flows into the storm drainage system flows directly into local creeks and waterways. (Storm water runoff is not treated.) Storm drainage systems are completely separate from those that carry domestic and commercial wastewater (sanitary sewer system).

Stormwater is water from rain or melting snow that does not soak into the ground. In a forest, meadow, or other natural landscape, stormwater soaks into the ground and naturally filters through the soil. When forests and meadows are developed, they are replaced with neighborhoods, shopping centers, and other areas that introduce impervious surfaces such as rooftops, roads, parking lots, and even laws. Impervious surfaces prevent rain or melting snow from soaking into the ground and create excess stormwater runoff and stormwater pollution.

Functions associated with planning, designing, constructing, maintaining, financing and regulating the facilities (both constructed and natural) that collect, store, control and/or convey stormwater.

When stormwater runs off impervious surfaces it picks up and carries with it anything on the ground. Whether it’s a street, parking lot, roof top, or compressed soil, pollutants such as oil, cups, bottles, fertilizer, pet waste and cigarette butts are transported by stormwater runoff into the nearest storm drain system and deposited into our rivers, streams, and the Harbor.

The entire assemblage of stormwater facilities located within a watershed.

A dedicated and reliable source of revenue based on user fees, rather than taxes, to help solve stormwater management problems. This steady revenue source ensures that funds will be available to support a local stormwater management program.

Water that remains on the surface of the ground, including rivers, lakes, reservoirs, streams, wetlands, impoundments, seas, estuaries, etc.

A low lying or depressed, at least seasonally, wet stretch of land. Often lined with grass (grassy swale) and used as a conveyance for stormwater.

A Total Maximum Daily Load is a regulation that states what amount of a single pollutant a waterbody can handle before it impairs uses such as swimming, finshing, and recreation. TMDLs are typically set for pollutants such as nutrients, sediment, bacteria, and trash. For regional waterbodies, like the Chesapeake Bay, TMDLs are issued by the Environmental Protection Agency (EPA). For local waterbodies, like the Baltimore Harbor, TMDLs are issued by the State and approved by the EPA. MS4 permits must address the pollution reductions mandated by the TMDLs.

Stormwater from urban areas, which tends to contain heavy concentrations of pollutants from vehicles and industry.

Water is essential to human life and to the health of the environment. As a valuable natural resource, it comprises marine, estuarine, freshwater (river and lakes) and groundwater environments, across coastal and inland areas. Water has two dimensions that are closely linked - quantity and quality. Water quality is commonly defined by its physical, chemical, biological and aesthetic (appearance and smell) characteristics. A healthy environment is one in which the water quality supports a rich and varied community of organisms and protects public health. Water quality in a body of water influences the way in which communities use the water for activities such as drinking, swimming or commercial purposes. More specifically, the water may be used by the community for:

1. supplying drinking water
2. recreation (swimming, boating)
3. irrigating crops and watering stock
4. industrial processes
5. navigation and shipping
6. production of edible fish, shellfish and crustaceans
7. protection of aquatic ecosystems
8. wildlife habitats
9. scientific study and education

A geographical area that all drains to the same waterway, usually a confluence of streams or rivers (also known as drainage area, catchment or river basin).

These plans are required as part of the Clean Water Act and consider such things as ecological restoration and sustainability while allowing for greater transparency and accountability for improved performance. Each of the seven Bay watershed jurisdictions will create a WIP that documents how the jurisdiction will partner with federal and local governments to achieve and maintain water quality standards. These plans will assist jurisdictions to become very specific in laying out ways they will improve the water pollution in their communities.

Water entering storm drains during rainstorms.

Land with a wet, spongy soil, where the water table is at or above the land surface for at least part of the year. Wetlands are characterized by a prevalence of vegetation that is adapted for life in saturated soil conditions. Examples include swamps, bogs, marshes, and estuaries.