Laserfiche WebLink
Verizon Communications-Stormwater Site Plan Everett,WA <br /> Erosion Control Evidence of erosion Determined by inspection.Properly designed Replace soil,plant material,and/or <br /> facilities with appropriate flow velocities should mulch layer in areas if erosion has <br /> not have erosion problems except perhaps in occurred.Reduce sediment transport <br /> extreme events.If erosion problems persist,the and clogging of infrastructure. <br /> following should be reassessed: Maintain desired plant survival and <br /> (1)flow volumes from contributing areas and appearance of facilities. <br /> bioretention cell sizing; <br /> (2)flow velocities and gradients within cell;and <br /> (3)flow dissipation and erosion protection <br /> strategies in the pretreatment area and flow <br /> entrance. <br /> Clean Under-drains Clogging Determined by inspection of clean-outs Jet clean or rotary cut debris/roots <br /> from under-drains.Maintain proper <br /> subsurface drainage,ponding depths, <br /> and dewatering rates. <br /> Clean Intersection of Blocked Flows Determined by inspection.Bioretention facilities Remove excess vegetation with a <br /> Pavement and should be designed with a proper elevation line trimmer,vacuum sweeper,rake <br /> Vegetation drop from pavement to vegetated area to prevent or shovel.Prevent accumulation of <br /> blockage of storm flows by vegetation into vegetation at pavement edge and <br /> infiltration area. maintain proper sheet flow of <br /> stormwater from paved/impervious <br /> areas to bioretention facility. <br /> Replace Vegetation Plants in poor Determined by inspection.If specific plants have a Reseed or replant bare spots or poor <br /> condition high mortality rate,assess the cause and replace performing plants.Maintain dense <br /> with appropriate species. vegetation cover to prevent erosion, <br /> encourage infiltration and exclude <br /> unwanted weed species. <br /> Replace Soil Contaminated Soils Determined by inspection(visual,infiltration, Remove vegetation(save as much <br /> pollutant,and soil fertility tests).Soil mixes for plant material as possible for <br /> bioretention facilities are designed to maintain replanting)and excavated soil with <br /> longterm fertility and pollutant processing backhoe,excavator or,if small <br /> capability,Estimates from metal attenuation facility,by hand.Maintain infiltration, <br /> research suggest that metal accumulation should soil fertility,and pollutant removal <br /> not present an environmental concern for at least capability. <br /> 20 years in,bioretention systems.Replacing mulch <br /> in bioretention facilities where heavy metal and <br /> hydrocarbon deposition is likely provides an <br /> additional level of protection for prolonged <br /> performance. <br /> Rebuild or Reinforce Damage Determined by inspection. Various activities to maintain walls, <br /> Structures intake and outfall pads,weirs,and <br /> other hardscape elements.Maintain <br /> proper drainage,and aesthetics and <br /> prevent erosion. <br /> Re-grade or Re- Disturbed Slope Determined by inspection. Maintain proper slope with hand <br /> contour Side Slopes tools,back hoe or excavator,replant <br /> exposed areas.Prevent erosion where <br /> side slopes have been disturbed by <br /> foot or auto traffic intrusion. <br /> Add Compost of Contaminated Once every one or two years.Compost amended Spread material by hand to minimize <br /> Mulch Compost landscapes are stormwater management facilities damage to plant material.Maintain <br /> and pesticide inputs should be eliminated or used organic matter content of soil, <br /> only in unusual circumstances.Landscape optimize soil moisture retention, <br /> management personnel should be trained to adjust prevent erosion,and enhance plant <br /> chemical applications accordingly. growth and survivability. <br /> PACLAND Job#50183001 Page 30 <br />