600 RIVERSIDE RD 2022-01-25 - Laserfiche WebLink

CITY OF EVERETT STORMWATER MANAGEMENT MANUAL 10. The terrace cross-section should be proportioned to fit the land slope. The ridge height should include a reasonable settlement factor. The ridge should have a minimum top width of 3 feet at the design height. The minimum cross -sectional area of the terrace channel should be 8 square feet for land slopes of 5 percent or less, 7 square feet for slopes from 5 to 8 percent, and 6 square feet for slopes steeper than 8 percent. The terrace can be constructed wide enough to be maintained using a small cat. Maintenance Standards Maintenance should be performed as needed. Terraces should be inspected regularly; at least once a year, and after large storm events. 3.2.16 BMP C140: Dust Control Purpose Dust control prevents wind transport of dust from disturbed soil surfaces onto roadways, drainage ways, and surface waters. Conditions of Use For use in areas (including roadways) subject to surface and air movement of dust where onsite and offsite impacts to roadways, drainage ways, or surface waters are likely. Design and Installation Specifications 1. Vegetate or mulch areas that will not receive vehicle traffic. In areas where planting, mulching, or paving is impractical, apply gravel or landscaping rock. 2. Limit dust generation by clearing only those areas where immediate activity will take place, leaving the remaining area(s) in the original condition, if stable. Maintain the original ground cover as long as practical. 3. Construct natural or artificial windbreaks or windscreens. These may be designed as enclosures for small dust sources. 4. Sprinkle the site with water until surface is wet. Repeat as needed. To prevent carryout of mud onto street, refer to Stabilized Construction Entrance (BMP C105). 5. Irrigation water can be used for dust control. Irrigation systems should be installed as a first step on sites where dust control is a concern. 6. Spray exposed soil areas with a dust palliative, following the manufacturer's instructions and cautions regarding handling and application. Oil based products are prohibited from use as a dust suppressant. The City may approve other dust palliatives such as calcium chloride or PAM. 7. PAM (BMP C126) added to water at a rate of 0.5 pounds per 1,000 gallons of water per acre and applied from a water truck is more effective than water alone. This is due to the increased infiltration of water into the soil and reduced evaporation. In addition, small soil particles are bonded together and are not as easily transported by wind. Adding PAM may actually reduce the quantity of water needed for dust control. PAM has also shown to be relatively affordable and thus an extremely cost-effective dust control method. Techniques that can be used for unpaved roads and lots include: 1. Lower speed limits. High vehicle speed increases the amount of dust stirred up from unpaved roads and lots. Volume 11— Construction Stormwater Pollution Prevention 3-28