Alton Wastewater System Enhancements

Wastewater Treatment and Collection System Improvements for the City of Alton

The City of Alton established its wastewater collection infrastructure in the 1960s. Predominantly made up of vitrified clay pipe, this system had, unfortunately, succumbed to the inevitable state of disrepair that comes with time. Significant amounts of Inflow and Infiltration (I&I) were observed during stormwater episodes, primarily due to natural degradation of collection pipe, wyes, and service connections. Furthermore, the wastewater treatment facility, having outlived its projected operational lifespan, required the replacement of a substantial portion of its original equipment.

Recognizing the pressing need for system revitalization, the City of Alton entrusted Heartland Engineering with the role of spearheading the plan to overhaul major components of both the treatment and collection systems. A significant financial boost was provided when the city, with the assistance of Heartland staff, successfully procured a $5,000,000 grant through the American Rescue Plan Act (ARPA).

The design strategy encompassed a comprehensive refurbishment of the treatment plant. Notable enhancements included the integration of dissolved oxygen probes and variable frequency drives for the oxidation ditch, along with the replacement of rotors, bearings, and shafts. Furthermore, significant portions of supplementary equipment, such as the UV and tertiary treatment apparatus were refurbished or replaced.

Complementing the plant rehabilitation, Heartland Engineering is also committed resources towards  rehabilitating the collection network, emphasizing the resolution of I&I. The system was video inspected with all inspection results being made available on the City’s Geographic Information Systems (GIS) site. The inspection allowed our design team to pinpoint zones where repairs are necessary. Remedial actions included in-situ lining techniques to repair the original clay conduits along with dig & replace methods for areas where the damage was more extensive. Sewer wyes will underwent pressure testing followed by grouting to seal voids. Engineering design of the project was completed in the spring of 2024. Heartland also administered the bidding and construction process, with the construction contract being awarded in July 2024 and final completion taking place in March 2026.