City of Newport
Newport, Oregon, USA
HDR provided design and construction engineering services for a new water membrane filtration facility in Newport, Oregon. The plant's capacity was upgraded from 4 to 6 million gallons per day (MGD), expandable to 10 MGD. The new treatment system design includes an intake pump station, a pressurized flocculation system, membrane filters, granular activated carbon (GAC) to improve water taste and odor, and a clearwell for disinfection. A membrane backwash system minimizes waste, increasing water recovery to more than 99.5 percent.
Source water is obtained from the Upper and Lower Big Creek Reservoirs—two eutrophic lakes with challenging water-quality conditions (seasonal iron, manganese, and algae). Pretreatment with sodium permanganate, sodium hydroxide, and aluminum chlorohydrate is necessary.
Other major elements of the project included a siphon diversion from the Lower Big Creek Reservoir to the intake pump station; a raw water pipeline from the intake pump station to the new water treatment plant; additional treated water storage (clearwell) to meet disinfection requirements; a new pumping system to deliver treated water to the city's distribution system; implementation of a new SCADA/control system for the new treatment processes and to allow for periodic unattended operation; new laboratory and office space; and new chemical dosing and cleaning systems.
The project encountered several challenges during design and construction (water quality, site constraints, unfavorable soil conditions, dam seismic stability issues, and funding shortages). The total project budget was just under $20 million. HDR worked closely with the CM/GC contractor and the city to resolve all issues and produce a state-of-the-art membrane filtration facility.
- Membrane backwash system provides more than 99.5 percent water recovery.
- Granular activated carbon improves water taste and odor.
- Siphon diversion from the Lower Big Creek Reservoir to the intake pump station overcame seismic stability issues.