Chatfield Wastewater Treatment Facility

Municipal Engineering Projects: +

Wastewater Treatment Facility Expansion – Chatfield, Minn.

Project Type: Wastewater Treatment Facility Expansion; Chatfield, MN

Client: City of Chatfield 

Recognition: 

ACEC/MN 2008 Grand Award 

The growth of the Chatfield community, along with the increase of infiltration of inflow from area stormwater, was taking a toll on the existing wastewater treatment facility.  With these factors affecting the ability of the system to accommodate the current flow rate, the City of Chatfield sought the engineering services of LHB and Donohue & Associates to design a new wastewater treatment facility.  During the pre-design/analysis process, LHB and Donohue were able to save Chatfield $5 million dollars off of the original estimate provided by another firm by adjusting the amount of flow capacity that was actually needed for the City. The new expansion includes a grit chamber in the headworks facility, a three ring oxidation ditch that removes the sludge and phosphorus from the wastewater as a part of the secondary treatment process. The oxidation ditch replaces the former trickling filter system and has been designed to accommodate future expansion and flow capacity. An additional benefit to the oxidation ditch is that by using this type of system, operators are able to reduce the amount of chemicals that are typically added to break down the phosphorus in the wastewater.  As a result, the process requires the use of fewer chemical additives and is safer for the environment. Another step in the treatment process calls for UV disinfection.  The new UV disinfection system will eliminate the need for dechlorination and the use of chlorine. Aerobically digested sludge will  be sent into established reed beds where further sludge process will occur. The new facility now accommodates 500,000 gallons of flow a day, or 220,000 gallons more than before the expansion.  LHB also provided the construction administration on the project.