AYER -- Department of Public Works Superintendent Mark Wetzel told selectmen last week that he had received six bids for the Groton School Road Wastewater Pumping Station.

One bid was significantly lower than the others, and that bidder eventually requested that it be withdrawn. The second lowest bid was from Ricciardi Bros. of Worcester, whose references Wetzel said he had checked.

The original project bid made last winter came in at $620,000, but only $450,000 had been appropriated by the town for the job, Wetzel said. He then sat down with the engineer to drastically change the design for the system, which serves the Nashoba Valley Medical Center, Madigan Lane and part of Groton Road, and feeds the whole Groton School Road area.

The existing pump station on Groton School Road is more than 40 years old and at the end of its design life. Its pumps and controls are also below grade, with limited access by ladder to a very confined space.

The replacement will consist of a new wet well and pump station building, 70 feet of new gravity sewer and 45 feet of force main. The pumps and controls will be located above grade, providing safer access for maintenance. A new meter chamber will allow the DPW to track the water flow more accurately.

The selectmen unanimously approved the award of the $420,000 contract for the new pumping station to Ricciardi Bros.