2007/08/15 Council Agenda Packet

EXHIBIT A SCOPE OF WORK 1. Work to Be Performed Conduct studies,design and construction management for proposed improvements to the intake pipelines and recovery water discharge at the City of Everett water filtration plant. The project will be conducted in three phases (planning/predesign,design and construction management)as described below. The basis of this proposal is for the following two capital improvement projects at Lake Chaplain,which may be designed and constructed separately or jointly: • Extension of the existing twin gravity intakes from approximately 30 foot depth to approximately 60 foot depth(length 500 to 1,000 lineal feet),and • Extension of the recovery water discharge outfall(length up to 7,000 lineal feet)into Lake Chaplain. These intake and outfall extension projects would be constructed of HDPE pipe with bolt-on precast concrete anchors. PLANNING/PREDESIGN Design Criteria The City of Everett would furnish the following design information: • Design flow rates for the gravity intake lines and the recovery water discharge • Lake Chaplain inflow and outflow design criteria • Hydraulic design criteria(pump data,allowable HGL,Lake Chaplain water surface elevations) • Requirements for intake screening or configuration • Record drawings for gravity intakes,siphon intake and recovery water piping • UW reservoir analysis and bathymetric data. Field Studies The following field activities will be conducted in support of the planning and design tasks. • • UW bathymetry will be used for planning and design. Final bathymetry will be obtained by the contractor prior to construction and for record drawings. Two ADCP current meters will be placed in Lake Chaplain from mid-August through September. The locations will be approximately 2,000 feet on either side of the point of inflow to Lake Chaplain,in approximately 60 feet of water. Each meter will be set to record current velocity at 10 minute intervals in 5-foot depth bins. The meters will be anchored with precast concrete weights,ground lines and surface floats. The City of Everett boat and operator will be used for the deployment and recovery of the meters. • Wind speed and air temperature will be monitored continuously by City of Everett at a station near the top of the levee during the current meter deployment. • City staff will measure water temperature profiles at six stations spaced along the axis,twice weekly during the current meter deployment. • Side scan sonar and subbottom and seismic profiling will be conducted along the axis of the lake. This work will be staged from the City of Everett boat(with operator). The product of the side scan will be a surficial features map(analogous to an aerial photograph),and the product of the subbottom and seismic profiling will be to map surficial sediment thicknesses and engineering properties. • The existing twin gravity intakes will be inspected and videotaped by divers. Inflow shall be shut down during this dive. The City shall provide staging for the dive from their vessel. • An inspection dive of the current meter anchors shall be conducted. The purpose of this dive shall be to inspect the current meter mooring and determine soil bearing and settlement criteria from the concrete anchors(to be used in design of the pipeline anchors). The City shall provide staging for the dive from their vessel. r3 Page 10 of 14