Caldwell Wastewater Treatment Plant

"Improving Wastewater Treatment Processes"

How can a city in Idaho process and clean its wastewater in an affordable and easy to maintain manner?

MWH's approach for Caldwell, Idaho helped accomplished this goal. The project was honored with an "Outstanding Civil Engineering Achievement (OCEA) Award" from the American Society of Civil Engineers, Southern Idaho.

The $13 million Caldwell Wastewater Treatment Plant Improvements Project was cited by OCEA judges to be a "significant contribution to civil engineering processes and society."

As Caldwell's mayor Garret Nancolas explained, "This state-of-the-art facility will help ensure the economic growth and the continued prosperity of our community for the next 15 years."

Ultraviolet Disinfection Facility

The award-winning facility includes:

• New treatment facilities
• An emergency power system
• Advanced instrumentation and control system
• An operations building and landscaping
• A new pump station and piping to connect the new facilities with existing ones.

Phase 2 of the upgraded treatment plant is currently under construction.

The project will include a new ultraviolet disinfection facility that eliminates the need for chlorine. The low-pressure, high-intensity UV facility is one of the first of its kind in the Northwestern United States. It will feature an automatic cleaning mechanism and high-output, high-efficiency lamps.

Also included in Phase 2: A new access bridge over Indian Creek, and replacement of two 45-year-old clarifier mechanisms.

This innovative facility is improving the water quality of Idaho's Boise River and other downstream rivers. Water leaving the plant is 60 percent cleaner than with the old facility. As a result, the rivers will be more fishable, swimmable and enjoyable for many years to come.