City Council authorized the issuance and sale of notes at its June 28 meeting, for replacing the screw pumps located at the Wastewater Treatment Plant. The maximum principal amount of the notes is $580,000, which shall be issued in the anticipation of the issuance of bonds. The estimated maximum maturity of the bonds is 20 years, with an annual interest rate of 6%.
The two screw pumps are an important part of treating an average of 2.7 million gallons of wastewater per day. After wastewater collects at the plant, it goes through a screening system and then the pumps carry the water at an upward incline to the grit tanks. From there, gravity carries the water as it goes through the remainder of the treatment process: aeration, two phases of clarification, a tertiary lagoon, chlorination and de-chlorination.
The pumps have been in operation at the plant for 30 years but their rated useful life is 25 years. According to Plant Superintendent Doug Beugly, despite their age the screw pumps have required little maintenance over the years.
The city has decided to purchase new screw pumps, rather than a submersible pump alternative, because screw pumps are more reliable and use less electricity.
Council previously passed a separate ordinance to authorize bidding for the replacement project. Associated controls and equipment will be replaced as well.