3214 BROADWAY BROADWAY KINECT APARTMENTS 2021-08-11

CITY OF EVERETT STORMWATER MANAGEMENT MANUAL 3. If erosion occurs due to poorly controlled drainage,the problem shall be fixed and the eroded area protected. 411 3.2.10 BMP C123: Plastic Covering Purpose Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas. Conditions of Use • 1. Plastic covering may be used on disturbed areas that require cover measures for less than 30 days, 11. except as stated below.2. Plastic is particularly useful for protecting cut and fill slopes and stockpiles. Note: The relatively rapid breakdown of most polyethylene sheeting makes it unsuitable for long-term(greater than 6 months)applications. • 3. Clear plastic sheeting can be used over newly-seeded areas to create a greenhouse effect and • encourage grass growth if the hydroseed was installed too late in the season to establish 75 percent grass cover, or if the wet season started earlier than normal. Clear plastic should not be used for this purpose during the summer months because the resulting high temperatures can kill the grass. 4. Due to rapid runoff caused by plastic sheeting,this method shall not be used upslope of areas that 1110 might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable . slopes. • 5. While plastic is inexpensive to purchase,the added cost of installation,maintenance,removal, and disposal can make this an expensive material. • 6. Whenever plastic is used to protect slopes,water collection measures must be installed at the base of the slope. These measures include plastic-covered berms, channels,and pipes used to covey clean rainwater away from bare soil and disturbed areas. At no time is clean runoff from a plastic - covered slope to be mixed with dirty runoff from a project. • 7. Other uses for plastic include: a. Temporary ditch liner • b. Pond liner in temporary sediment pond c. Liner for bermed temporary fuel storage area if plastic is not reactive to the type of fuel being stored d. Emergency slope protection during heavy rains - e. Temporary drainpipe("elephant trunk")used to direct water. Design and Installation Specifications • 1. Plastic sheeting shall have a minimum thickness of 0.06 millimeters.2. If erosion at the toe of a slope is likely,a gravel berm,riprap, or other suitable protection shall be • installed at the toe of the slope in order to reduce the velocity of runoff. 3. Plastic slope cover must be installed as follows: a. Run plastic up and down slope,not across slope b. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet ID Volume 11— Construction Stormwater Pollution Prevention 3-18