6133 LAKE CHAPLAIN RD 2025-08-19

Glossary 19 Definitions are arranged alphabetically by term. For a complete list of definitions, please see the SWMMWW:fortress.wa.gov/ecy/ershare/wq/Permits/Flare/2019SWMMWW/2019SWMMWW.htm Best Management The schedules of activities, prohibitions of practices, maintenance procedures,and structural Practice(BMP) and/or managerial practices,that when used singly or in combination, prevent or reduce the release of pollutants and other adverse impacts to waters of Washington State. Compaction The densification,settlement, or packing of soil in such a way that permeability of the soil is reduced. Compost Organic material that has undergone biological degradation and transformation under controlled conditions designed to promote aerobic decomposition at a solid waste facility in compliance with the requirements of Chapter 173-350 WAC,or biosolids composted in compliance with Chapter 173-308 WAC. Composting is a form of organic material recycling. Critical Area At a minimum,areas which include wetlands,areas with a critical recharging effect on aquifers used for potable water,fish and wildlife habitat conservation areas,frequently flooded areas,geologically hazardous areas,including unstable slopes, and associated areas and ecosystems. Dispersion Release of surface and stormwater runoff such that the flow spreads over a wide area and is located so as not to allow flow to concentrate anywhere upstream of drainage channel with erodible underlying granular soils. Hard Surface An impervious surface,a permeable pavement,or a vegetated roof. Impervious A non-vegetated surface area which either prevents or retards the entry of water into the Surface soil mantle as under natural conditions prior to development.A non-vegetated surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops,walkways, patios, driveways, parking lots or storage areas,concrete or asphalt paving,gravel roads, packed earthen materials,and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater. Open, uncovered retention/detention facilities shall not be considered as impervious surfaces for the purposes of determining whether the thresholds for application of Minimum Requirements are exceeded. Open, uncovered retention/ detention facilities shall be considered impervious surfaces for purposes of runoff modeling. Land Disturbing Any activity that results in a change in the existing soil cover(both vegetative and non- Activity vegetative) and/or the existing soil topography. Land disturbing activities include,but are not limited to clearing,grading,filling,and excavation.Compaction that is associated with stabilization of structures and road construction shallalso be considered a land disturbing activity.Vegetation maintenance practices, including landscape maintenance and gardening, are not considered land-disturbing activity.Stormwater facility maintenance is not considered land disturbing activity if conducted according to established standards and procedures. City of Everett Public Works Small Project Stormwater Site Plan/Report—Sept.2023 Page 29 of 40