A-1 Landscaping and Construction, Inc. 7/20/2016

1 This work consists of installing a flexible, impenetrable barrier to prevent sediment from 2 construction activities from entering adjacent water bodies. This curtain is weighted at the 3 bottom to achieve closure and supported at the top through a flotation system. 4 5 Materials ' 6 Turbidity curtain shall be a Type II which is usually used in areas where there may be small to 7 moderate current running (up to 2 knots or 3.5 feet per second) and / or wind and wave action 8 can affect the curtain. Materials should be of bright colors. 9 Floats (Expanded Polystyrene Billets within Fabric Pockets) 10 Galvanized Steel Ballast Chain 11 Pre-manufactured Turbidity Barrier 12 13 Construction Requirements 14 Turbidity curtains should be oriented parallel to the direction of flow to the extent it can be. The 15 curtain height shall provide sufficient slack to allow the top of the curtain to rise to the maximum 16 expected high-water level (including waves) while the bottom maintains continuous contact with 17 the bottom of the water body. The bottom edge of the curtain shall have a weight system 18 capable of holding the bottom of the curtain down and conforming to the bottom of the water 19 body, so as to prohibit escape of turbid water under the curtain. The turbidity curtain shall be 20 located beyond the lateral limits of the construction site and firmly anchored in place. The 21 alignment should be set as close to the work area as possible but not so close as to be 22 disturbed by construction equipment. The height of the curtain shall be a minimum 20 percent 23 greater than the depth of the water to allow for water level fluctuations. The area of proposed 24 installation of the curtain shall be inspected for obstacles and impediments that could damage 25 the curtain or impair its effectiveness to retain sediment. Supplemental anchors of the turbidity 26 curtain toe shall be used, as needed, depending on water surface disturbances such as boats 27 and wave action by winds. 28 29 Monitoring 30 The turbidity curtain shall be inspected daily and repaired or replaced immediately if 31 damage or failure is noticed. If the curtain is oriented in a manner that faces the 32 prevailing winds, frequent checks of the anchorage shall be made. While inspecting, look 33 for areas where turbid water is escaping into the larger water body. The contractor shall 34 be responsible for maintenance of the filter curtain for the duration of the project in order 35 to ensure the continuous protection of the watercourse. When the curtain is no longer 36 required as determined by the inspector, the curtain and related components shall be 37 removed in such a manner as to minimize turbidity. Remaining sediment shall be , 38 sufficiently settled before removing the curtain. Sediment may be removed and the 39 original depth restored. Any spoils must be hauled away or taken to upland area and be 40 stabilized. Any floating construction or natural debris shall be immediately removed to 41 prevent damage to the curtain. 42 43 Measurement 44 Turbidity curtain will be measured by the linear foot. 45 46 Payment 47 "Turbidity Curtain", per linear foot. 48 49 The unit contract price per linear foot for "Turbidity Curtain" shall be full pay for all equipment, 50 labor, and materials to perform the work as specified, including installation, maintenance and 51 removal. 52 53 RIVERFRONT DEVELOPMENT NORTH WETLAND COMPLEX 116