1998 - 2008 Water System Improvements, City of Kirkland
Roth Hill was selected by the City of Kirkland to provide complete design, permitting, and construction support services for its annual watermain replacement program for the tenth year in a row. Most of the projects involve the replacement of AC watermains that are typically aging and experiencing breaks, being undersized for fireflow conditions, or a combination of both. All projects involve working around existing utility conflicts as many mains being replaced have been in the ground for over 65 years and many other utilities have been constructed since that time. Roth Hill has provided topographic surveying, preliminary and final engineering design drawings, specifications, bidding/contract documents, and preparation of opinion of probable construction costs and construction record drawings once construction is complete. We also have provided construction administration and construction observation support as needed.
228th Street Water System Improvements, Alderwood Water & Wastewater District
Roth Hill provided a high degree of water and sewer utility coordination with the District, Snohomish County Public Works, Snohomish County PUD, and other franchise utilities for this water and sewer project done in conjunction with the County’s 1.8 mile road-widening project between 9th Avenue and Locust Way. During design, monthly utility coordination meetings were held at the County’s office to review progress of planned utility relocations, ensure coordination between the utilities and the County regarding existing and proposed utility locations, and discuss construction phasing issues. This project included over 11,000 linear feet of 6- to 16-inch DI watermains to replace existing mains that were in conflict with the proposed road alignment plus adding new mains as part of the District’s distribution system. Additionally, 2,200 linear feet of 8-inch gravity sanitary sewer pipe and associated side sewers were installed to permanently remove an existing sewer lift station and force main from service. Roth Hill provided water and sewer design, construction support, and construction record drawing preparation on this project.
Reservoir No. 2, Highland Water District
This project includes the design and construction of a new 610,000-gallon painted steel tank reservoir with a ring wall foundation. New piping will be installed to hydraulically connect this reservoir to the existing Reiner Road Reservoir and the District’s water system. This reservoir will more than double the water storage capacity of the District and will be used to supply the increasing water demand that is a result of growth within the District. Roth Hill is providing planning, surveying, design, loan funding, permitting and construction administration and observation services.
Auburn Intertie Phase 1, King County Water District No. 111
Roth Hill designed an intertie to connect King County Water District No. 111’s water system to the City of Auburn’s. This project consisted of 3,780 linear feet of 16-inch watermain, valves, fire hydrants and appurtenances. A temporary booster station was installed to serve one pressure zone and the transmission main. Design capacity was 1 MGD. The intertie agreement included the negotiation of the 1 MGD between the City and the District. Our design for the District was coordinated with the City of Auburn’s design. We acted as project coordinator, overall project cost accountant, along with coordinating with the City’s inspector and construction administrator.
Auburn Intertie Phase 2, King County Water District No. 111
As the District Engineer, Roth Hill represented the District during the second phase of the Auburn intertie project. This phase included negotiation and execution of a long-term supply agreement with three agencies: King County Water District No. 111, City of Auburn, and Covington Water District. The project construction included two deep-well supply stations, two booster pumps, approximately 10,000 linear feet of 16- and 20-inch diameter transmission main and a crossing of the Green River.
Pump Station No. 1 – New SPU Tap and Meter Vault Design, Soos Creek Water & Sewer District
The primary objective of this project is to improve the reliability of the District’s supply system by increasing the system’s redundancy. In addition to providing system redundancy, the project will increase the capacity of Pump Station No. 1 in order to augment its capacity as a backup supply in response to the District’s projected growth in the number of its future customers. Pump Station No. 1 will be abandoned and a new, larger Pump Station No. 1 on the north side of the SPU line at 114th Avenue will be built on a new site. The new Pump Station No. 1 will be designed to handle a much larger capacity than the existing station (approximately 5,000 gpm versus 1,000 gpm). The site relocation and increase in capacity necessitates a new tap of SPU’s 60-inch line to the north at 114th Avenue. Because of the future station’s increased pumping capacity and to reduce velocity and friction loss associated with the connection, the new tap is expected to be 20 or 24 inches in diameter.