11517 AIRPORT RD 2025-07-24 - Laserfiche WebLink

• This technique works with standard hydromulch(1,500 pounds per acre minimum)and BFM/MBFMs(3,000 pounds per acre minimum). • Areas to be permanently landscaped shall provide a healthy topsoil that reduces the need for fertilizers,improves overall topsoil quality, provides for better vegetal health and vitality,improves hydrologic characteristics,and reduces the need for irrigation.This can be accomplished in a number of ways: Recent research has shown that the best method to improve till soils is to amend these soils with compost.The optimum mixture is approximately two parts soil to one part compost. This equates to 4 • inches of compost mixed to a depth of 12 inches in till soils.Increasing • the concentration of compost beyond this level can have negative effects on vegetal health,while decreasing the concentrations can. reduce the benefits of amended soils.Please note:The compost should • • meet specifications for Grade A quality compost in Ecology Publication 94-038. Other soils,such as gravel or cobble outwash soils,may require different approaches. Organics and fines easily migrate throe•h the loose structure of these soils.Therefore,the importation of at least 6 inches of quality topsoil,underlain by some type of filter fabric to prevent the migration of fines,may be more appropriate for these soils. Areas that already have good topsoil,such as undisturbed areas, do not require soil amendments. • Areas that will be seeded only and not landscaped may need compost or meal-based mulch included in the hydroseed in order to establish vegetation. Native topsoil should be re-installed on the disturbed soil surface before application. • Seed that is installed as a temporary measure may be installed by hand if it will be covered by straw,mulch,or topsoil. Seed that is installed as a permanent measure may be installed by hand on small areas (usually less than 1 acre)that will be covered with mulch,topsoil,or erosion blankets. The seed mixes listed below include recommended • mixes for both temporary and permanent seeding. These mixes,with the exception of the wetland mix,shall be applied at a rate of 120 pounds per acre. This rate can be reduced if soil amendments or slow- release fertilizers are used. Local suppliers or the local conservation district should be consulted for their recommendations because the appropriate mix depends on a variety of factors,including location, exposure, soil type, slope,and expected foot traffic. Alternative seed mixes approved by the local authority may be used. 4-16 Volume II—Construction Stormwater Pollution Prevention February 2005