3301 SEAWAY BLVD 2020-01-21 - Laserfiche WebLink

3.3 Mitigation Measures Prior to Construction 1. Construction management plans must be reviewed and approved by the Directors of the Planning and Community Development Department and the Engineering and Public Services Department prior to the issuance of permits allowing construction of any facilities located within 50 feet of an environmentally sensitive area(steep slope, stream,wetland,landslide hazard area,etc.)and associated buffer. The construction management plan must include the following minimum measures: a. Specific erosion controls to be implemented prior to authorizing any construction activities which will impact an environmentally sensitive area as defined by the City's environmentally sensitive area regulations. b. For any facilities on or adjacent to erosion or landslide hazard areas,the construction management plan must address all mitigation measures identified in the geotechnical report approved by the Planning Director. c. Implementation of best management practices to control erosion both during and after construction, including compliance with the City of Everett's Design and Construction Standards and Specifications Manual and the Stormwater Management Manual. d. Construction schedule,status update reporting requirements,and contingency provisions to become effective if the schedule is not met. 2. Any water quality enhancement or detention facilities proposed near steep slopes will require detailed geotechnical analysis and design that documents and ensures their safety. 3. Prior to issuance of grading permits for removing earth from a site,the applicant must demonstrate that permits have been obtained for placement of the earth off-site. During Construction/Earthwork 4. All earthwork within a geologically hazardous area or its required buffer must be performed under the supervision of a professional civil or geotechnical engineer. The engineer must provide certification to the City that all work was done in compliance with requirements set forth in the City approved geotechnical report. •5. In order to minimize erosion during construction,all soil piles shall be covered with plastic sheeting or other impervious covering staked to the groupd or anchored with rocks or sandbags. Berms,earthen or otherwise, must be constructed at the perimeter of excavated areas to prevent adjacent site runoff from entering the excavations. 6 Temporary slopes within native glacial soils shall be limited to a maximum angle of 1/2 foot horizontal (H)to 1 foot vertical(V). Temporary slopes within fill soils shall be limited to a maximum angle of 1 H:1 V. Temporary slopes must be covered with an impermeable membrane,such as visqueen or mulch, in order to prevent precipitation from coming In contact with the soils. Permanent slopes steeper than 25%shall be designed by a professional civil or geotechnical engineer. The design should present appropriate erosion control measures which may include: hydroseeding,erosion control blankets, rip-rap,jute matting,and visqueen. 7. Grading/filling must not adversely affect the hydrology of streams and existing or created wetlands. 8. Grading/filling on-site shall not adversely affect adjoining sites.