Drinking Water for a Central Illinois Community

Farnsworth Group was retained by the City to prepare a comprehensive planning report to evaluate various alternatives for upgrades or replacement of the plant.  Based on the results of this report, the City authorized Farnsworth Group to design, permit and provide construction engineering design services.

The City of Princeton, IL provides potable water service to more than 7,600 residents. Over the past several years, the City’s water demands had increased to the point that the existing water treatment plant was being operated 24/7 in order to keep up with the demands, which were close to reaching the plant’s maximum capacity. The existing 1.6 MGD lime-softening water treatment plant was originally constructed in the 1930’s. Located in a land-locked downtown location, the aging facilities were also in need of some major repairs and upgrades. 

Our team designed the recommended alternative of a new 4.0 MGD lime-softening water treatment plant, a new well field and new water main piping from the new wells to the new plant. The project was separated into two phases in order to take full advantage of funding opportunities through the ARRA economic stimulus.

The Phase I portion of the project generally included the following components:

• four (4) new groundwater wells – 1,000 gpm each
• filter backwash lagoon, lime sludge lagoons
• site piping and connections
• emergency generator for the new plant

The Phase II portion included the new 4.0 MGD lime-softening water treatment plant with two parallel process trains – aeration, detention, solids contact softening, recarbonation, rapid sand filtration and two (2) 500,000-gallon finished water ground storage tanks. The plant provides bulk chemical storage and feeding systems, including a lime system, which allows the City to purchase dry calcium hydroxide and produce their own liquid lime slurry on site.