Construction is set to start today on a new water treatment plant in the north-central Illinois city of Princeton.

The new 4 million-gallon-per-day plant should be finished by fall of 2013. The city's existing plant was built in 1930 with updates in 1964 and 1999. The project will cost $23.5 million. The city has taken on debt and passed rate increases to pay for the plant.

Supporters of the new plant say it's needed to support future growth in Princeton. Water superintendent Mike Eggers says the plan should last Princeton between 40 and 70 years.

Eggers calls the project "probably 1 of the largest, if not the largest, public works projects the city's ever done."