Stormwater Treatment Retrofits

r furnishing the necessary labor, materials, equipment, tools, and guarantees thereof to construct the CIP 1 - Pennsylvania Place Bottleneck and CIP 1 - Stormwater Treatment Retrofits. CIP 1 - Pennsylvania Place Bottleneck: The City is contracting for a high-flow bypass stormwater pipe running along Coal Mines Trail to alleviate capacity concerns within the City storm drain system between East Pennsylvania Avenue and East Washington Avenue as identified in the City of Roslyn Stormwater Comprehensive Plan, July 2014, Gray & Osborne, Inc. (SCP). This bypass will route excess flows directly to Crystal Creek, beginning at East Washington Avenue and following the Coal Mines Trail eastward and then southeastward for approximately 1,660 feet. The undersized pipe in the existing trunk line will remain in place, conveying all lowflows and baseflows along the original route. The proposed bypass begins with a 7' x 9.5' x 14.5' cast-in-place concrete box structure with spring-assisted access hatch. The bypass structure contains an overflow weir that diverts high flows into a 36" HDPE pipe that travels 412' in length before transitioning to a 42" HDPE pipe for 1,286'. This pipe outfalls into a proposed ditch that has riprap lining for 23', then streambed cobble mix for 30' before outfalling into Crystal Creek. A small portion of the existing stream bank will be re-graded to provide an appropriate transition between the outfall ditch and Crystal Creek. The project also includes interception of an 8" storm drain where it intersects the bypass alignment, paving, replacement of gravel pathway along the pipe alignment, plantings, and installation of a split-rail fence and hand-placed boulders separating the existing path from the outfall ditch. This work is covered under a US Army Corps of Engineers (USACE) Nationwide Permit and a Washington Department of Fish and Wildlife (WDFW) Hydraulic Project Approval (HPA). An Archaeological Site Alteration and Excavation Permit by Washington State Department of Archaeology and Historic Preservation (DAHP) is pending. CIP 1 - Stormwater Treatment Retrofits: The City is contracting for stormwater treatment retrofits consisting of biofiltration swales to improve water quality within the local waterway, Crystal Creek. The City currently has limited Best Management Practices (BMPs) within the urbanized areas of the City. The BMPs will provide stormwater runoff treatment for the reduction of Total Suspended Solids (TSS) and other pollutants. Nine biofiltration swales will be constructed on Utah Avenue, 1st Street, A Street, Idaho Avenue, Washington Avenue, and the intersection of Pennsylvania Avenue and B Street. The outfalls from each biofiltration swale will be connected to the existing stormwater conveyance network. The connections to the existing stormwater conveyance network will be made using CPEP pipe, ranging from 6" to 15" in diameter. There will be approximately 560 linear feet of pipe required to connect the biofiltration swales to the existing stormwater conveyance network All in-water work shall be completed between July 16 and August 31,2023, to comply with the USACE Nationwide Permit, and the WDFWHPA. All remaining work shall be substantially complete within 60 working days of issuance of Notice to Proceed. All bidding and construction is to be performed in compliance with the Contract Provisions and Contract Plans for this project and any addenda issued thereto that are on file at the office of the City Clerk, City Hall, Roslyn, Washington. Proposals must be accompanied by a certified check, cashier's check, money order, or bid bond payable to the "City of Roslyn" and in an amount of not less than five percent (5%) of the total amount bid. The CIP 1 - Pennsylvania Place bottleneck Project is anticipated to be financed by the City and a grant from Kittitas County. The CIP 1 - Stormwater Treatment Retrofits Project is anticipated to be financed by the City and in part by a grant from the Washington State Department of Ecology. Neither the State of Washington nor any of its department or employees are, of shall be, a party to any contract or any subcontract resulting from this solicitation for bids. The City of Roslyn expressly reserves the right to reject any or all Proposals and to waive minor irregularities or informalities and to Award the Project to the lowest responsive, responsible bidder as it best serves the interests of the City. Award of the project will be contingent on financing and receipt of the Archaeological Site Alteration and Excavation Permit by DAHP which is anticipated mid-July 2022 Contract questions shall be directed only to the office of the Project Engineer: Kari Nichols, PE Mead & Hunt, Inc. Phone: 503-548-1496 Email: kari.nichols@meadhunt.com

Division 33 -

Utilities, Instrumentation and Control for Utilities, Water Utilities, Water Utility Distribution Piping, Water Utility Distribution Equipment, Disinfecting of Water Utility Distribution, Water Utility Storage Tanks.