Plant History

The Dorr-Leighton Wastewater Treatment Plant was constructed in 1978 to serve approximately
240 homes in the Village of Moline. The flow into the new facility was approximately 55,000
gallons per day, a little over 50% of design (100,000 gallons per day) until the early 1990’s. The
facility discharged approximately 16 million gallons from its two (2) wastewater stabilization
ponds into Green Lake Creek annually, again approximately 50% of design (37 million gallons).
Area growth pressure threatened an expansion as a large mobile home development and
industrial park were considered by the Townships. These two (2) projects alone, without any
further area growth, consumed the remaining system capacity and a decision to expand was
imminent. Both Townships continued to monitor the situation and began to seek funding and
design services for an expanded facility.
The first DLWA system expansion was constructed in 1999. The new facility employed a higher
level of treatment using aeration and naturally occurring microorganisms. The process called
“sequencing batch reactors (SBR’s) was installed along with chemical phosphorus removal and
biosolids storage for the generated solids from treating the wastewater. The new facility was
designed for an average of 250,000 gallons per day of flow. Area growth continued through
2015-16 and again, flows and growth seemed to point to the need for a second system expansion
as daily flows approached 200,000 gallons per day and over 1300 single family home units
(REU’s). Over the next three (3) years, the Authority secured financing from the US Department
of Agriculture for a low interest loan and design services were initiated and construction
contracts were bid in early 2020.
In April 2020, the current facility expansion began in spite of Covid 19 pandemic. The project
was deemed an “essential service” project and the contractor was willing to start/continue work.
The project is planned for completion in late 2021-early 2022 and will treat approximately
550,000 gallons when finished. The Projects webpage  lists the construction progress.