The City of Walker had a 2-cell controlled discharge lagoon to treat the community’s wastewater. The existing lagoon system was permitted to discharge every 180 days during the spring and fall based on receiving stream flow. Due to excessive wastewater flow, the existing controlled discharge lagoon system needs to discharge more frequently than every 180 days. The excessive flow was expected to be due to infiltration and/or inflow.
HR Green completed a Wastewater Facility Plan in 2009 to evaluate potential options for the City including: 1) expanding their existing controlled discharge lagoon system, 2) converting the existing lagoons into a continuous discharge aerated lagoon system, and 3) constructing a new mechanical treatment plant. Converting the existing lagoons to a continuous discharge aerated lagoon system was the recommended alternative.
HR Green worked with the City of Walker to apply for various grants and other funding sources. The City was awarded a $585,000 IJOBS grant for the project. Construction of the plant upgrade began in April 2012 and was completed in November 2012. The new wastewater system consists of a new raw sewage lift station, conversion of the controlled discharge lagoons into an aerated continuous discharge lagoon, a settling cell, a SAGR system, and a UV disinfection system. The system began operations in October 2012 and has been consistently meeting the new ammonia and bacteria limits set in the NPDES permit.