7007 SEAWAY BLVD 2016-01-01 MF Import

newly graded area end the existlng standing pool of Narbeck Swamp. If the area would�have been graded per the plan, ft would have risked having the Narbeck waters breach into the graded area, ceusing erosion during construction and potentially aftering the outlet of the swamp. The alteretion resulted in the final grades being approximately two feet shallower than was called for in the plans. 10) Again, due to winter construction, rounded river rock was added to two cells ' located where the old access road �rossed the creek. When the culveR for this road was removed and the cells dug as propo�ed, the creek water had to be pumped around the work area. Streambed gravel was added to the cells and new channel to prevent turbidity in the stream. 11) An 18-inch culvert pipe was placed in the overflow area of the leaky berm. Construction scheduling caused the overflow area to be installed before tho � desired activation of the leaky berm. This culvert and ax�mpanying con*rol valve � were added to the origintl plans as a means of controlling the !iming of leaky berm activation. Delaying full adivation of the system until plants are fuily rooted � and seasonal rainfalls have abated will minimize the potential for erosion. The system will become fully charged when the culvert valve is closed and ali flow is � diverted through the leaky berm. F 12) Site grading started on August 13, 1996 with all parties having construction � goals of minimizing pot�ntial for erosion by completing most of the excavation ; betore Fall rafns. On October 22, 1998, Snohomish County Airport directed the general contractor to immediately start double shifts to include 7-day work weeks. Overtime, equipment and lighting costs of 514,000 were paid by Snohomish County to complete excavation before Fall rains. Snohomish County Airport prevented erosion and sedimentation by directing this acceleration of earthwork and funding the extra costs. 46