Drinking Water

 Below are some of our representative projects, sorted alphabetically.

City of Lynnwood, 212th Street Emergency Water Project

On November 1st, 2015, an aging 8-inch asbestos concrete water main broke near Hall Lake on 212th Street SW in Lynnwood. Skillings Connolly provided the design and construction management for the temporary emergency water system intertie between the City of Lynnwood and City of Mountlake Terrace, pavement repair and restoration, and the replacement of the remaining AC water main. The water system intertie provided continuous water service to the customers along 212th while the existing AC water main was taken out of service and replaced.

This project has been awarded the Public Works Project of the Year Award for Disaster or Emergency Construction/Repair projects less than $5 Million. 

 Clearwood Community Association, On-Call Water System Repair and Improvement

Clearwood Community operates and maintains a water system serving 1,350 customers.  We have provided them with a variety of engineering services such as surveying and design for the replacement of 4,700 lineal feet of six-inch water main with eight-inch service lines on narrow, rolling residential streets with steep grades.  The project included preparation of plans, profile, and detail sheets, as well as cost estimates, specifications, and coordination with the homeowner’s association. Bidding support and post-construction record documents were also provided.  Our design required careful coordination with Puget Sound Energy as the water main and new underground electrical transmission lines were constructed simultaneously.  The water system construction was designed to be installed in sections to minimize shut down periods for homeowners when the new water main was brought on-line.  The design also included installation of new Air-Vac assemblies meter setters with PRVs and hydrants.

Other assignments have included comprehensive planning, design, and commissioning of a new 450 gpm well, a 400,000-gallon reservoir, and water main extensions.  We have also performed design, construction, and commissioning of the system’s water pH adjustment facilities, which treats the water with a 25% solution of sodium hydroxide.

Thousand Trails,
Resort Water System Evaluation

Skillings Connolly provided a water system plan evaluation report for replacement of their existing 60 GPM water treatment plant, supplying potable water to a full campground and maintaining the 50,000-gallon reservoir.  We evaluated several water treatment options, identified three manufacturers, and prepared a budgetary cost estimate for each option.  Our review compared each option’s ability to meet all treatment requirements along with:  the relative size of the units for the smallest footprint, the lowest capital cost, and the earliest delivery schedule.  The recommended option met all of these criteria, so we suggested an initial pilot study for the system.

  • Summit Water and Supply Company,
    Tank 4 Replacement

Summit Water desired to replace the existing 150,000 gallon concrete tank with a welded steel tank of the same diameter with a capacity of approximately 200,000 gallons.  The new tank provided additional standby storage and greater redundancy for providing peak and fire flows throughout the 522 Pressure Zone. The existing Tank 4 is a 150,000 gallon tank constructed of vertical concrete panels and was erected in 1961.  The seams between the vertical panels used wood to seal the joints.  When the tank was taken out-of-service for maintenance, the wood dried out and became ineffective in preventing leaks due to repeated wet/dry cycles.

Skillings Connolly for the designed the new 0.20 MG Welded Steel Tank.  This consisted of preparing the plans and details for the reservoir, site development, erosion control, grading and drainage piping design, water piping connections, and associated improvements. Skillings Connolly also was responsible for the supervison of geotechnical investigations, surveying, design engineering, bidding documents, contractor submittal reviews and assistance during construction.

  • Summit Water and Supply Company, Well 16 Project Report and Water System Modeling

Summit Water & Supply Company (Summit) serves about 15,000 people in central Pierce County.  As engineer of record for this public water system, Skillings Connolly prepared comprehensive plans, specifications and designs, water demand forecasts, and water rights applications.  We also evaluated regional supply options and possible implementation strategies, conducted cost of service and other financial studies, developed proposed water rates and fees, and designed water treatment facilities for disinfection and corrosion control.

First, a 5000 gpm pumping station was developed to meet build-out demands.  At the client’s request, Skillings Connolly developed a design for a 2500 gpm pump station as an initial capacity.  This station was configured to consist of two Goulds with 1750 gpm, 75 hp VFD vertical turbine pumps, with allowance for a third pump by installing a spare “can” for future use.  The tank fill and discharge are controlled by Summit’s Supervisory Control and Data Acquisition (SCADA) system, which allows the tank to operate as an additional source for the system during peak periods.  Valves with electronic control interface coupled with the pump’s VFD controllers provide a set flow rate while maintaining back pressure and altitude control. Skillings Connolly supervised construction and startup of these facilities. We also recently undertook a rate study which included a cost of service and other financial studies, which was used to develop a water rate structure with associated fee schedule

  • Thurston County,
    Tilley Rd Maintenance Facility

Thurston County expanded their public works maintenance facility located on a 44-acre site west of Tilley Road (SR 121).  As a subconsultant to KMB Design Groups, Inc., Skillings Connolly worked on the master plan as well as the PS&E for site development.

This LEED Gold candidate project included parking lots and a new office building, maintenance shop, Emergency Operations Center (EOC), fueling station, plaza, fountain, and a 9000 sf stormwater pond.  Our site design also included other stormwater innovations such as permeable paving, a demonstration rain garden, and diverted roof runoff, which is collected in several 10,000 gallon storage tanks to provide irrigation water.  We prepared drainage, septic, and water reports in conjunction with the SEPA documentation; gathered existing record data and provided the survey work for the compilation of a base map; performed a Level 1 Traffic Impact Analysis (TIA) and a Level of Service Analysis (LOS); and provided engineering of a large onsite septic system; water system for domestic use, fire flow, and re-use; drainage collection, conveyance, treatment, and disposal; erosion control, grading, paving, and access roads.  In addition, we coordinated with utility companies and received approval from the Department of Health for the Class “A” Water System Report.  The water system design included a new well, domestic booster pump system, distribution piping, and expansion of the site’s fire suppression capabilities.  Skillings Connolly also provided services in connection with WSDOT approval of new accesses and frontage improvements to the state highway.  This included preparation of a PFA and detailed construction plans for the necessary upgrades to the highway.