Low Pressure Area Improvements, Alderwood Water & Wastewater District.
To implement a pressure upgrade of a 440-acre area in their water system, AWWD commissioned PACE to model, plan, design, and observe construction of a complex transfer between two established pressure zones. The recommended transfer was accomplished through the installation of more than 15,000 lineal feet of 12-inch and 18-inch transmission main and looping mains to isolate the area. The work was further complicated by the requirement to maintain both domestic service and fire flows during the transfer process. In addition to the need to coordinate the construction between a number of affected jurisdictions, including Snohomish County, WSDOT, WDFW, the City of Everett, and the District, the project employed two types of trenchless technology dictated by natural and man-made conditions. A 120 lineal foot augered/jacked casing under SR 522 permitted installation of one 18-inch line. At a separate location, a 250 lineal foot horizontal directional drill (HDD) allowed installation of a 14-inch HDPE line under Swamp Creek, a salmon-bearing stream.  Survey work was performed to enable the design.

Olympus Lift Station, Coal Creek Utility District.
PACE prepared the design modifications to relocate and upsize Coal Creek Utility District's Olympus Pump Station.  This station required relocation due to widening of Coal Creek Parkway, and was also upsized to accommodate build-out flows within its service area.  The new custom-designed station is sized to handle flows of 2,500 gpm and includes three pumps, standby emergency power, a 100,000-gallon overflow wetwell, and state-of-the-art controls.  The existing 8" forcemain was also upsized to 12" to handle increased flows.  PACE conducted various hydraulic studies and models to simulate flow through this station.