Membrane Microfiltration Water Treatment Plant
Enaville, ID

J-U-B has been working with Shoshone County Water District for over a decade to improve their aging infrastructure and meet Idaho Department of Environmental Quality water quality requirements. The Water District serves 4 separate communities that span over 13 miles and contain infrastructure dating back to the early 1900s. Most recently, in 2011, J‑U-B worked with the District to meet the requirements of the Surface Water Treatment Rule complete construction of the first 5.6 mgd phase of a 6.8 mgd membrane microfiltration (MF) surface water treatment plant for their sole water supply.

The Issues. Following seasonal flooding, the State of Idaho determined that the Enaville Well water source was “Ground Water Under the Direct Influence of Surface Water” (GWUDI). Consequently, the District has implemented a Surface Water Treatment Rule (SWTR) compliance project, including a new treatment facility to comply with the Safe Drinking Water Act’s SWTR and the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). Membrane microfiltration was chosen as the core treatment process.

Addressing the issues. In the spring of 2011 commissioning was completed for the Districts 5.6 mgd MF water treatment plant. The MF plant utilizes GE-Zenon ZW1000 microfiltration equipment and includes treatment and recycling of backwash and chemical cleaning wastewater, lime addition for pipeline corrosion and pH control, hypochlorite disinfection, low- and high-pressure compressed air support systems, and membrane chemical feed and cleaning equipment. The total cost for the facility was $13.1 million.

In combination with adding filtration, the District implemented a consumption based metering program to reduce system demands. J-U-B assisted in design and construction management for the installation of nearly 2700 domestic water meters and drive-by radio read meter system.

Results and Benefits.  The Enaville well and microfiltration water treatment plant are now protecting public health for the 5,000 rate payers of the Central Shoshone County Water District. The Enaville Well is a spectacular water source with capacity to serve the District’s entire service area and potential growth areas.

Addition of automated meter reading and localized service line replacement has resulted in a 45% reduction in peak summertime water demand. This has reduced the need for expansion of the treatment facility, and significantly reduced operating expenses for the District.

Unique and memorable. Over the last ten years, J-U-B has also helped the District with planning efforts that led to replacement of two tanks, a well capacity upgrade, and adding a radio read metering system to the entire district. J-U-B has helped the District obtain funding for over $19 million in projects, with close to 40 percent grant funding. Project highlights include:

  • Pilot study of three MF equipment suppliers to develop full scale design parameters
  • Prequalification of MF equipment vendors.
  • Procurement of $2.2 million of MF equipment.
  • 3-D design of process equipment.
  • Backwash recycling to increase plant efficiency
  • Optimized MF chemical cleaning waste minimization and neutralization
  • Lime addition for corrosion control
  • Funding through 2009 American Recovery and Reinvestment Act (ARRA)

Project Awards or Recognitions.

ACEC of Idaho, 2012 1st Place Award Winner – Water Resources

AWWA 2011, Excellence in Engineering – Best Medium Water Works Project

 “…J-U-B has taken care of Central Shoshone County Water District’s engineering needs since 2000. Our latest project, our new water treatment, plant exemplifies this. J-U-B helped guide the Water District through acquiring funding, preliminary planning, negotiations with regulatory agencies, design, and construction of this facility. We believe this project addresses our fundamental needs at a cost that is affordable to our rate payers.”

– Duane Little, District Board Chairman