CGA is currently assisting the City of Eldora with further process adjustments/alterations to reduce Total Phosphorous concentration in plant effluent to further Iowa DNR’s commitment of the Iowa Nutrient Reduction Strategy.

Increasingly more stringent discharge standards made it necessary to upgrade the WWTP in the late 1990s. Preliminary engineering began about 1997 for replacing or upgrading the entire facility. The updated design included two one-million gallon equalization basins constructed in 2000. The remainder of the new WWTP construction was completed in 2005-2006.

Construction of the main facility included conversion of the two existing SBR tanks into an ISAM tank and a SAM tank. Three SBR tanks, an effluent tank, and two aerobic digesters were added to accommodate process flows. A new headworks building with stair screen, washing press and grit classifier replaced the old bar screen. Another new building houses the SBR blowers, a UV disinfection room and provides a separate control room for the SCADA system.


Both the equalization basins and the main plant replacement were funded by an Iowa SRF loan.