The biological iron removal process uses naturally occurring bacteria to catalyze the oxidation of dissolved iron. Chemical oxidants, such as chlorine or potassium permanganate that are traditionally used in conventional iron removal processes, are eliminated. Reported advantages of the biological process when compared with conventional chemical oxidation processes include reduced chemical use, higher filtration rates, and the ability to efficiently treat source waters that contain high concentrations of iron (greater than 6 milligrams per liter [mg/L]). The City of Florence (City), Oregon, has chosen the biological iron removal process for expansion of its existing water treatment plant facility. The City currently practices conventional chemical oxidation to reduce dissolved iron levels in its source water from about 7 mg/L to below the secondary maximum contaminant level of 0.3 mg/L.