For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
BEST MANAGEMENT PRACTICES (BMPs).
(1) The most effective and practicable means of erosion prevention and sediment control, and water quality management practices that are the most effective and practicable means of to control, prevent, and minimize degradation of surface water, including avoidance of impacts,
construction-phasing, minimizing the length of time soil areas are exposed, prohibitions, pollution prevention through good housekeeping, and other management practices published by state or designated area-wide planning agencies.
(2) Individual BMPs found in this permit are described in the current versions of Protecting Water Quality in Urban Areas, MPCA and The Minnesota Stormwater Manual, MPCA. BMPs must be adapted to the site and can be adopted from other sources. However, they must be similar in purpose and at least as effective and stringent as MPCA's BMPs. (Other sources include manufacturers specifications, Storm Water Management for Construction Activities: Developing Pollution Prevention Plans and Best Management Practices, U.S. Environmental Protection Agency 1992, and Erosion Control Design Manual, Minnesota Department of Transportation, et al., 1993).
CONSTRUCTION ACTIVITY. Includes construction activity as defined in 40 C.F.R. § 122.26(b)(14)(x) and small construction activity as defined in 40 C.F.R. § 122.26(b)(15) and CONSTRUCTION ACTIVITY as defined by Minn. Rule 7090.0080, subp. 4. This includes a disturbance to the land that results in a change in the topography, existing soil cover (both vegetative and non-vegetative), or the existing soil topography that may result in accelerated stormwater runoff, leading to soil erosion and movement of sediment into surface waters or drainage systems. Examples of construction activity may include clearing, grading, filling, and excavating. CONSTRUCTION ACTIVITY includes the disturbance of less than one acre of total land area that is a part of a larger common plan of development or sale if the larger common plan will ultimately disturb one acre or more. CONSTRUCTION ACTIVITY does not include a disturbance to the land of less than five acres for the purpose of routine maintenance that is performed to maintain the original line and grade, hydraulic capacity, or original purpose of the facility.
DEWATERING. The removal of surface or ground water to dry and/or solidify a construction site to enable construction activity. Dewatering may require a Minnesota Department of Natural Recourses water appropriation permit and, if dewatering water is contaminated, discharge of such water may require an individual MPCA NPDES/SDS permit.
ENERGY DISSIPATION. Methods employed at pipe outlets to prevent erosion caused by the rapid discharge of water scouring soils. Examples include, but are not limited to: concrete aprons, riprap, splash pads, and gabions that are designed to prevent erosion.
EROSION PREVENTION. Measures employed to prevent erosion. Examples include but not limited to: soil stabilization practices, limited grading, mulch, temporary erosion protection or permanent cover, and construction phasing.
INFEASIBLE. Not technologically possible or not economically practicable and achievable in light of the best industry practices. Page 13 of 14 October 2013 | wq-strm4-59q .
INITIATED IMMEDIATELY. Taking an action to commence stabilization as soon as practicable, but no later than the end of the work day, following the day when the earth-disturbing activities have temporarily or permanently ceased, if the permittee(s) know that construction work on that portion of the site will be temporarily ceased for 14 or more additional calendar days or seven calendar days where Appendix A.C.1.a applies. The following activities can be taken to initiate stabilization:
(1) Prepping the soil for vegetative or non-vegetative stabilization;
(2) Applying mulch or other non-vegetative product to the exposed soil area;
(3) Seeding or planting the exposed area;
(4) Starting any of the activities in (1) through (3), above, on a portion of the area to be stabilized, but not on the entire area; and
(5) Finalizing arrangements to have stabilization product fully installed in compliance with the applicable deadline for completing stabilization .
PERMANENT COVER. Surface types that will prevent soil failure under erosive conditions. Examples include: gravel, asphalt, concrete, rip rap, roof tops, perennial cover, or other landscaped material that will permanently arrest soil erosion. A uniform perennial vegetative cover (i.e. evenly distributed, without large bare areas) with a density of 70% of the native background vegetative cover for the area must be established on all unpaved areas and areas not covered by permanent structures, or equivalent permanent stabilization measures. PERMANENT COVER does not include the practices listed under temporary erosion protection.
PROJECT(S). All construction activity that is planned and/or conducted under a particular permit. The project will occur on the site or sites described in the permit application, and in the associated plans, specifications and contract documents.
PUBLIC WATERS. All water basins and watercourses that are described in M.S. § 103G.005, subd. 15, as it may be amended from time to time.
NATURAL BUFFER. An area of undisturbed cover surrounding surface waters within which construction activities are restricted. NATURAL BUFFER includes the vegetation, exposed rock, or barren ground that exists prior to commencement of earth-disturbing activities.
NORMAL WETTED PERIMETER. Te area of a conveyance, such as a ditch, channel, or pipe that is in contact with water during flow events that are expected to occur from a two-year 24-hour storm event.
PERMITTEE. Ay owner or operator of a construction site that is providing information to the City of Dilworth in order to prove that their stormwater BMP design for during and post construction activities adequately addresses all requirements of this chapter.
STABILIZE, STABILIZED, STABILIZATION. The exposed ground surface has been covered by appropriate materials such as mulch, staked sod, riprap, erosion control blanket, mats or other material that prevents erosion from occurring. Grass, agricultural crop or other seeding alone is not stabilization. Mulch materials must achieve approximately 90% ground coverage (typically 2-ton/acre).
SEDIMENT CONTROL. Methods employed to prevent sediment from leaving the site. SEDIMENT CONTROL practices include silt fences, sediment traps, earth dikes, drainage swales, check dams, subsurface drains, bio rolls, rock logs, compost logs, storm drain inlet protection, and temporary or permanent sedimentation basins. A floating silt curtain placed in the water is not a sediment control BMP to satisfy perimeter control requirements, except as provided for in the SEDIMENT CONTROL part.
STEEP SLOPES. Slopes that are 1:3 (V:H) (33.3%) or steeper in grade.
STORMWATER. Defined under Minn. Rule 7077.0105, subpart 41(b), and includes precipitation runoff, stormwater runoff, snowmelt runoff, and any other surface runoff and drainage.
SURFACE WATER or WATERS. All streams, lakes, ponds, marshes, wetlands, reservoirs, springs, rivers, drainage systems, waterways, watercourses, and irrigation systems whether natural or artificial, public or private, except that surface waters do not include treatment basins or ponds that were constructed from upland development.
TEMPORARY EROSION PROTECTION. Methods employed to prevent erosion during construction activities. Examples of temporary erosion protection include, but are not limited to: straw, wood fiber blanket, wood chips, vegetation, mulch, and rolled erosion control products.
WATERS OF THE STATE. (As defined in M.S. § 115.01, subd. 22, as it may be amended from time to time) means all streams, lakes, ponds, marshes, watercourses, waterways, wells, springs, reservoirs, aquifers, irrigation systems, drainage systems and all other bodies or accumulations of water, surface or underground, natural or artificial, public or private, which are contained within, flow through, or border upon the state or any portion thereof.
(Ord. 15-02, passed 2-9-2015)