Rugby Water Treatment Plant Improvements

The City of Rugby, North Dakota, hired Interstate Engineering to perform design and construction engineering services for an upgrade to the existing water treatment plant.

Constructed in 1957, the existing water treatment plant consisted of a single train lime softening process system. The original plant capacity was approximately .89 Million gallons per day (MGD) and was fed from two wells approximately two miles east of Rugby. Due to declining water quality, the two wells have been disconnected from the potable supply and repurposed. In the mid-1970s, 1991, and 2005, the city developed six additional municipal wells. The new well fields are located on the Pleasant Lake Aquifer, approximately eight miles east of Rugby. In 1998 a second water treatment train was constructed which doubled the treatment capacity to 1,000 gallons per
minute (gpm).

The scope of this improvement project included new lime slakers, emergency power backup systems, and upgrades to the integrated control system. The existing lime slakers were extremely rusted and beyond the care of routine maintenance. The water treatment plant did not have emergency generator capabilities, so the addition of an emergency generator provided the capability to pump the 1,000,000 gallon ground storage reservoir to the elevated storage reservoir during an extended power outage. This capability would triple the available water to the community during an extended power outage. The existing control system has difficulty in maintaining communications with the remote well sites. The system lost communications with the wells daily. The loss of communication was due to outdated equipment at the remote well fields and in the plant.

The finished project replaced both lime slakers with 500 pounds per hour stainless steel units. These units work more efficiently and have created a much more consistent lime slurry to the water treatment system. A backup generator was installed on the water treatment plant site which allows the plant to operate in an extended power outage. An automatic transfer switch will intercept the building’s electrical service, thus allowing the generator to automatically provide power to the plant no matter what time of the day or night it is required. The generator was installed outside, in a factory weatherproof enclosure, and utilizes propane as its fuel source. New PLCs were installed throughout the water treatment plant, well fields, and water tower. These new controllers are more reliable than the existing PLCs and have reduced the issues the city has had with the telemetry failures.

The project was funded by a 60% MR&I Grant of $458,000 with a total project budget of $763,000. PKG Contracting was the general contractor, and Samson Electric was the Electrical Contractor. The total project came in under budget.

Interstate Engineering Team

Wade Senger, PE – Project Engineer
Jed Hastings – Observation
John Trebesch, PE – Design Engineer
Todd Langbehn – Drafter