D.C. Mun. Regs. tit. 21, r. 21-599
When used in this chapter, the following terms and phrases shall have the meanings ascribed:
Advanced Design (AD) - Detailed design for an area of a project described explicitly in a:
Affordable Housing - a single-family or two- family house that is built to be offered for rent or for sale for residential occupancy below market value and is made available to, and affordable to, a household whose income is equal to, or less than, eighty percent (80%) of the Area Median Income calculation provided by the United States Department of Housing and Urban Development.
Anacostia Waterfront Development Zone (AWDZ) - the following areas of the District of Columbia, as delineated on a map in the Department's Storm water Management Guidebook:
Anacostia Waterfront Development Zone Site (AWDZ site) - A site within the Anacostia Waterfront Development Zone that undergoes a major regulated project that is publicly owned or publicly financed.
Animal confinement area - An area, including a structure, used to stable, kennel, enclose, or otherwise confine animals, not including confinement of a domestic animal on a residential property.
Applicant - A person or their agent who applies for approval pursuant to this chapter.
As-built plan - A set of architectural, engineering, or site drawings, sometimes including specifications that certifies, describes, delineates, and presents details of a completed construction project.
Athletic playing fields - Compacted land cover and synthetic surfaces that are constructed primarily for use for athletic activities at schools and public parks. Compacted land cover and synthetic surfaces for which athletic activities are not the primary use are not considered athletic playing fields, unless these areas are necessary to support use of an adjacent area that is primarily used for athletic activities.
Best Management Practice (BMP) - Structural or nonstructural practice that minimizes the impact of stormwater runoff on receiving waterbodies and other environmental resources, especially by reducing runoff volume and the pollutant loads carried in that runoff.
Buffer - An area along a stream, river, or other natural feature that provides protection for that feature.
Building permit - Authorization for construction activity issued by the District of Columbia Department of Consumer and Regulatory Affairs.
Clearing - The removal of trees and brush from the land excluding the ordinary mowing of grass, pruning of trees or other forms of long-term landscape maintenance.
Combined sewer overflow (CSO) - The discharge of untreated effluent into a water body as a result of the combined volume of storm water and sanitary water exceeding the capacity of the combined sewer system and wastewater treatment plant.
Combined sewer system (CSS) - Sewer system in which storm water runoff is conveyed together with sanitary wastewater through sewer lines to a wastewater treatment plant.
Common plan of development - Multiple, separate, and distinct land-disturbing, substantial improvement, or other construction activities taking place under, or to further, a single, larger plan, although they may be taking place at different times on different schedules.
Compacted cover - An area of land that is functionally permeable, but where permeability is impeded by increased soil bulk density as compared to natural cover, such as through grading, construction, or other activity and will require regular human inputs such as periodic planting, irrigation, mowing, or fertilization. Examples include landscaped planting beds, lawns, or managed turf.
Control measure - Technique, method, device, or material used to prevent, reduce, or limit discharge.
Construction - Activity conducted for the:
Construction Codes - The District of Columbia's Construction Codes administered by the District of Columbia Department of Consumer and Regulatory Affairs, and ordinarily consisting of the Building Code, Residential Code, Electrical Code, Fuel Gas Code, Mechanical Code, Plumbing Code, Property Maintenance Code, Fire Safety Code, Energy Conservation Code, and waivers thereto authorized and duly granted by the District of Columbia's code official.
CRIAC - DC Water's Clean Rivers Impervious Surface Area Charge or Clean Rivers Impervious Area Charge.
Critical area stabilization - Stabilization of areas highly susceptible to erosion, including down-slopes and side-slopes, through the use of brick bats, straw, erosion control blanket mats, gabions, vegetation, and other control measures.
Cut - An act by which soil or rock is dug into, quarried, uncovered, removed, displaced, or relocated and the conditions resulting from those actions.
DC Water - The District of Columbia Water and Sewer Authority.
Demolition - The removal of part or all of a building, structure, or built land cover.
Department - The District Department of the Environment, except that the term "department" shall simply mean the word "department" when the context clearly shows that the term is so used in the title of a statute or a publication.
Department of Consumer and Regulatory Affairs (DCRA) - The District of Columbia Department of Consumer and Regulatory Affairs.
Department's submittal database - An online platform managed by the Department and accessible to the public that the Department uses to receive applications and make approval determinations.
Detention - Controlling the peak discharge rate of stormwater from a site.
Dewatering - Removing water from an area or the environment using an approved technology or method, such as pumping.
Director - The Director of the District Department of the Environment.
District - The District of Columbia.
Drainage area - Area contributing runoff to a single point.
Easement - A right acquired by a person to use another person's land for a special purpose.
Electronic media - Means of communication via electronic equipment, including the internet.
Equivalent Residential Unit (ERU) -A measure of impervious area based on one thousand (1,000) square feet of impervious surface area, taking account of a statistical median of residential properties. The number of ERUs is determined based on the amount of impervious area and the customer's classification as residential, multi- family, or non-residential.
Erosion - The process by which the ground surface, including soil and deposited material, is worn away by the action of wind, water, ice, or gravity.
Excavation - An act by which soil or rock is cut into, dug, quarried, uncovered, removed, displaced or relocated and the conditions resulting from those actions.
Exposed area - Land that has been disturbed or land over which unstabilized soil or other erodible material is placed.
Grading - Causing disturbance of the earth, including excavating, filling, stockpiling of earth materials, grubbing, root mat or topsoil disturbance, or any combination of them.
Impervious cover - A surface area which has been compacted or covered with a layer of material that impedes or prevents the infiltration of water into the ground, examples include conventional streets, parking lots, rooftops, sidewalks, pathways with compacted sub-base, and any concrete, asphalt, or compacted gravel surface and other similar surfaces.
Infiltration - The passage or movement of surface water through the soil profile.
Land cover - Surface of land that is impervious, compacted, or natural.
Land cover change - Conversion of land cover from one type to another, typically in order to comply with a requirement of this chapter or to earn certification of a Stormwater Retention Credit.
Land-disturbing activity - Movement of earth, land, or sediment that disturbs the land surface and the related use of pervious land to support that movement. Land-disturbing activity includes stripping, grading, grubbing, trenching, excavating, transporting, and filling of land, as well as the use of pervious adjacent land for movement and storage of construction vehicles and materials. Land-disturbing activity does not include repaving or remilling that does not expose the underlying soil.
Low Impact Development (LID) - A land planning and engineering design approach to manage stormwater runoff within a development footprint. It emphasizes conservation, the use of on-site natural features, and structural best management practices to store, infiltrate, evapotranspire, retain, and detain rainfall as close to its source as possible with the goal of mimicking the runoff characteristics of natural cover.
Major land-disturbing activity - Activity that disturbs, or is part of a common plan of development that disturbs, a land area of five thousand square feet (5,000 ft 2) or greater, and:
Multiple distinct areas that each disturb less than five thousand square feet (5,000 ft2) of land and that are in separate, non-adjacent sites do not constitute a major land-disturbing activity.
Major regulated project - A major land-disturbing activity or a major substantial improvement activity.
Major substantial improvement activity - Substantial improvement activity and associated land-disturbing activity, including such activities that are part of a common plan of development, for which the combined footprint of improved building and land-disturbing activity is five thousand square feet (5,000 ft 2) or greater, and:
A major substantial improvement activity may include a substantial improvement activity that is not associated with land disturbance.
Market value of a structure - Assessed value of the structure for the most recent year, as recorded in the real property assessment database maintained by the District of Columbia's Office of Tax and Revenue.
Natural cover - Land area that is dominated by vegetation and does not require regular human inputs such as irrigation, mowing, or fertilization to persist in a healthy condition. Examples include forest, meadow, or pasture.
Nonstructural Best Management Practice (BMP) - A land use, development, or management strategy to minimize the impact of stormwater runoff including conservation of natural cover or disconnection of impervious surface.
Off-site retention - Use of a stormwater retention credit or payment of in-lieu fee in order to achieve an off-site retention volume under these regulations.
Off-Site Retention Volume (Offv) - A portion of a required stormwater retention volume or required Water Quality Treatment Volume that is not retained on site.
On-site retention - Retention of a site's stormwater on that site or via conveyance to a shared best management practice on another site.
On-site stormwater management - Retention, detention, or treatment of stormwater on site or via conveyance to a shared best management practice.
Original Stormwater Retention Credit (SRC) owner - A person who is indicated as the proposed SRC owner in an application to the Department for the certification of an SRC. The proposed SRC owner becomes the original SRC owner upon the Department's certification of the SRC.
Owner - The person who owns real estate or other property, or that person's agent.
Peak discharge - The maximum rate of flow of water at a given point and time resulting from a storm event.
Person - A legal entity, including an individual, partnership, firm, association, joint venture, public or private corporation, trust, estate, commission, board, public or private institution, cooperative, the District government and its agencies, and the federal government and its agencies.
Permeable athletic track - A surface, including a surface made of synthetic material, located at a school or public park that is used for athletic purposes including biking, running, and walking, and that allows the infiltration of water into the ground.
Permeable playground surface - A surface, including a surface made of synthetic material, located under a playground area at a school or public park, that allows the infiltration of water into the ground.
Post-development - Describing conditions that may be reasonably expected to exist after completion of land development activity on a site.
Practice - A system, device, material, technique, process, or procedure that is used to control, reduce, or eliminate an impact from stormwater; except where the context indicates its more typical use as a term describing a custom, application, or usual way of doing something.
Pre-development - Describing conditions of meadow land and its relationship to stormwater before human disturbance of the land.
Pre-project - Describing conditions, including land covers, on a site that exist before the construction described in a stormwater management plan has begun.
Publicly-owned or publicly-financed project - A project:
Public Right of Way (PROW) - The surface, the air space above the surface (including air space immediately adjacent to a private structure located on public space or in a public right of way), and the area below the surface of any public street, bridge, tunnel, highway, railway track, lane, path, alley, sidewalk, or boulevard.
Public Space - All the publicly owned property between the property lines on a street, park, or other public property as such property lines are shown on the records of the District. This includes any roadway, tree space, sidewalk, or parking between such property lines, but it excludes adjacent parks and other public property that is not associated with the public right of way
Raze - The complete removal of a building or other structure down to the ground or to its foundation.
Record drawing - The final annotated set of engineering drawings for a construction project, which includes all deviations, field changes, approved changes, constructed depths of footing and structural elements, and horizontal and vertical locations of utility facilities referenced to survey data.
Responsible person - Construction personnel knowledgeable in the principles and practices of erosion and sediment control and certified by a Department-approved soil erosion and sedimentation control training program to assess conditions at the construction site that would impact the effectiveness of a soil erosion or sediment control measure on the site.
Retention - Keeping a volume of stormwater runoff on site through infiltration, evapo-transpiration, storage for non-potable use, or some combination of these.
Retention capacity - The volume of stormwater that can be retained by a best management practice or land cover.
Retention failure - Failure to retain a volume of stormwater for which there is an obligation to achieve retention, including retention that an applicant promises to achieve in order to receive Department-certified Stormwater Retention Credits. Retention failure may result from a failure in construction, operation, or maintenance; a change in stormwater flow; or a fraud, misrepresentation, or error in an underlying premise in an application.
Retrofit - A best management practice or land cover installed in a previously developed area to improve stormwater quality or reduce stormwater quantity relative to current conditions.
Runoff - That portion of precipitation (including snow-melt) which travels over the land surface, and also from rooftops, either as sheet flow or as channel flow, in small trickles and streams, into the main water courses.
Sediment - Soil, including soil transported or deposited by human activity or the action of wind, water, ice, or gravity.
Sedimentation - The deposition or transportation of soil or other surface materials from one place to another as a result of an erosion process.
Shared Best Management Practice (S-BMP) - A Best Management Practice (BMP), or combination of BMPs, providing stormwater management for stormwater conveyed from another site or sites.
Site - A tract, lot or parcel of land, or a combination of tracts, lots, or parcels of land for which development is undertaken as part of a unit, sub-division, or project. The mere divestiture of ownership or control does not remove a property from inclusion in a site.
Site Drainage Area (SDA) - The area that drains to a point on a site from which stormwater discharges.
Single- or two -family house -An individual house, townhouse, or rowhouse designed and used for occupancy by one or two families. An individual house, townhouse, or rowhouse that has been physically altered for use by more than one or two families is not considered a single- or two- family house.
Site Drainage Area (SDA) - The area that drains storm water from the site to a single discharge point or sheet flows from a single area off the site.
Soil - All earth material of whatever origin that overlies bedrock and may include the decomposed zone of bedrock which can be readily excavated by mechanical equipment.
Soil Erosion and Sediment Control Plan - A set of drawings, calculations, specifications, details, and supporting documents related to minimizing or eliminating erosion and off-site sedimentation caused by stormwater on a construction site. It includes information on construction, installation, operation, and maintenance.
Soils report - A geotechnical report addressing all erosion and sediment control-related soil attributes, including but not limited to site soil drainage and stability.
Storm sewer - A system of pipes or other conduits which carries or stores intercepted surface runoff, street water, and other wash waters, or drainage, but excludes domestic sewage and industrial wastes.
Stormwater - Flow of water that results from runoff, snow melt runoff, and surface runoff and drainage.
Stormwater Management - A system to control stormwater runoff with structural and nonstructural best management practices, including:
Storm water Management Guidebook (SWMG) - The current manual published by the Department, and available on the Department's website, containing design criteria, specifications, and equations to be used for planning, design, construction, operation, and maintenance of a site and each best management practice on the site.
Stormwater Management Plan (SWMP) - A set of drawings, calculations, specifications, details, and supporting documents related to the management of stormwater for a site. A SWMP includes information on construction, installation, operation, and maintenance.
Stormwater Pollution Prevention Plan (SWPPP) - A document that identifies potential sources of stormwater pollution at a construction site, describes practices to reduce pollutants in stormwater discharge from the site, and may identify procedures to achieve compliance.
Storm water Retention Credit (SRC) - One gallon (1 gal.) of retention for one (1) year, as certified by the Department.
Stormwater Retention Credit Ceiling - Maximum retention for which the Department will certify a Stormwater Retention Credit, calculated using the Stormwater Retention Volume (SWRv) equation with P equal to 1.7 inches.
StormwaterRetention Volume (SWRv) - Volume of stormwater from a site for which the site is required to achieve retention.
Stripping - An activity which removes or significantly disturbs the vegetative surface cover including clearing, grubbing of stumps and rock mat, and top soil removal.
Substantial improvement - A repair, alteration, addition, or improvement of a building or structure, the cost of which equals or exceeds fifty percent (50%) of the market value of the structure before the improvement or repair is started.
Structural best management practice - A practice engineered to minimize the impact of stormwater runoff, including a bioretention, green roof, permeable paving system, system to capture stormwater for non-potable uses, etc.
Supplemental review - A review that the Department conducts after the review it conducts for a first re-submission of a plan.
Swale - A narrow low-lying stretch of land which gathers or carries surface water runoff.
Transition Period One (TP1) - The one hundred and eighty (180) day period of time starting upon publication of the notice of adoption as final in the D.C. Register of the stormwater retention rulemaking. TP1 ends at the close of business on January 15, 2014.
Transition Period Two A (TP2A) - For a major land-disturbing activity, the three hundred and sixty-five (365) day period of time starting at the completion of Transition Period One. TP2A ends at the close of business on January 15, 2015.
Transition Period Two B (TP2B) - For a major substantial improvement activity, the five hundred and forty-five (545) day period of time starting at the completion of Transition Period One. TP2B ends at the close of business on July 14, 2015.
Waste material - Construction debris, dredged spoils, solid waste, sewage, garbage, sludge, chemical wastes, biological materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial or municipal waste.
D.C. Mun. Regs. tit. 21, r. 21-599