In 2009, the city of Ames, Iowa, decided to build a new municipal water treatment plant after concluding that renovation and expansion of the existing plant would be more difficult and expensive than starting fresh.
The city’s existing plant, built in 1924 with a filtration system installed in 1927, was originally an iron removal facility with the capacity to handle two million gallons per day (MGD). The plant underwent several modifications and modernizations, becoming a lime-softening facility in 1932. Over time, the plant was modernized and expanded in stages, but at its current capacity of 12 MGD could not provide for the city’s future water needs.
Ames, with a population of approximately 62,000, is located on the fast-growing I-35 corridor leading to the capital city of Des Moines, just 30 miles away. Ames is the home of Iowa State University of Science and Technology (ISU), with its nationally recognized engineering, agriculture, and veterinary medicine schools, the headquarters of the Iowa Department of Transportation, and the U.S. Department of Agriculture’s national Animal and Plant Health Inspection Services.
Taking into account the region’s future needs, the Ames City Council and Water & Pollution Control Department concluded that a new plant would best provide the necessary capacity for expansion.
Other concerns about the existing plant included crowded working conditions, lack of a sprinkler system, and the fact that multiple expansions had made it difficult to access the core of the plant for maintenance.
Also, due to the way the plant is constructed, complete shutdown is necessary for any major repairs, which would leave the community without access to water.
New Site, Similar Technology – But More Modern
When it became clear that the cost to renovate, modernize, and expand the existing facility would exceed the cost of constructing a new treatment plant, the Ames City Council and Water Pollution found a new site at 1800 East 13th Street. It’s just across the Skunk River from the existing facility, located at 300 East 5th Street, close enough that the new plant can utilize the existing wells and distribution system but will have an initial capacity of 15 MGD.
Designs were completed and approved in the spring of 2014, and construction on the plant broke ground the following October. The project was funded through a low-interest loan from Iowa’s Drinking Water State Revolving Fund, with repayment coming from utility revenues.
WesTech’s portion of the project commenced at the design stage, working closely with architects, and the builder, Knutson Construction. WesTech also provided onsite supervision, start-up assistance, and operator training.
WesTech was the clear choice to provide water treatment technology, both from the standpoint of excellence and that of history; the current plant features filtration equipment built by General Filter, founded in Ames in 1935. Along with Microfloc, General Filter was purchased by WesTech in 2012 and continues as the Ames office of the company.
Taste was an important issue for Ames. The city prides itself on the clean, fresh taste of its water. In fact, Ames has won numerous awards for the taste of its water, including a national taste test sponsored by the American Water Works Association (AWWA), a fact the city took into account when deciding on the type of plant to build.
For this reason, the city and its residents preferred not to make any significant changes in the plant’s equipment and technology and elected to go with a traditional lime softening plant. As Water Plant Supervisor Lyle Hammes describes it, the plant will operate in much the same way but with new, more modern and efficient equipment.
Changes Include Indoor Clarifiers, MULTICRETE II Underdrains
While the city wanted to keep its existing process unchanged, compliance with updated regulations from the Department of Natural Resources (DNR) required some modifications, the most substantial of which was the need to put the clarifiers inside the plant. Although having the clarifiers indoors is common in colder areas, it is atypical for Iowa plants.
In collaboration with the engineering firm and architect, WesTech was able to position equipment so that operators can observe the operation of both the clarifiers and the filters from the same operation floor, allowing them to make ongoing adjustments in both systems.
Construction and installation of the water filtration system began in 2015 with WesTech providing the aerators, filters, and clarifiers.
Having met with plant operators to identify water treatment concerns and specifications, WesTech application engineers identified the best system and components based on those criteria.
WesTech’s design features three Solids CONTACT CLARIFIERs™ in 58-square-foot basins for initial removal of solids. Three 9-foot-diameter aluminum cascade aerators for iron oxidation were chosen for their durability and low maintenance.
WesTech also supplied and engineered eight potable water mixed media filters with MULTICRETE™ II filter underdrains. Engineered Stainless Steel Design (ESSD®) washtroughs were installed to remove particles collected by the filtering media. While the original plant featured a series of filter underdrains from different suppliers, WesTech’s MULTICRETE II underdrains had shown the best performance, making the company the clear choice for new equipment.
Designed with a reinforcing rebar skeleton, color-coded piping, spinning pumps, and an attractive modern design, the water treatment plant also features a state-of-the-art control system.
At every stage, WesTech worked closely with the design team, consulting engineer, and contractor, Knutson Construction, resulting in an extremely smooth process. While some delays are always inevitable in a project of this size, construction stayed on schedule at every stage. Start up of WesTech’s equipment took place in mid-July.
On August 26, the City of Ames will hold an Open House, during which time the public can tour the plant. The City’s Public Art Commission is currently holding an art contest, with cash prizes to be awarded for Best of Show and People’s Choice.
Throughout the construction process, civic engagement in the design of the new plant has been extremely high. From the beginning, the Ames City Council and Water & Pollution Control Department sought input from the community, and especially those who would be working at and operating the plant. This involvement has contributed to a palpable sense of community pride in the new facility.
That pride has extended to WesTech’s Ames staff, who have found it extremely rewarding to work on a project that directly benefits their community. With the new water treatment plant located just a few miles from WesTech’s Ames office, engineers and staff were given an open invitation to visit the plant and made several trips to watch the installation of equipment.
From engineers and project managers to office and support staff, the 50-plus members of WesTech’s Ames office have appreciated the opportunity to showcase their company’s products and technology to friends, family, and their entire community.