Wastewater / Treatment
Wastewater Treatment Plant Improvements / Hopedale, Illinois
Maurer-Stutz, Inc. was retained by the Village of Hopedale to conduct a comprehensive study and analysis of its existing wastewater treatment facilities. Due to aging facilities and the need to improve efficiency of treatment systems, numerous improvements were recommended at the treatment plant.
Maurer-Stutz, Inc. was also retained by the Village to design the recommended improvements, which included an automated bar screen facility, parallel oxidation ditches, secondary clarifiers, enhancements to an existing treatment tank for aerobic digestion, blower improvements, drying beds, effluent pumps, and a standby generator. All improvements were designed to fit on the existing Village owned site.
All treatment plant facilities were designed for an increase in design average flow from 0.20 mgd to 0.26 mgd and an increase in peak design flow from 0.40 mgd to 0.93 mgd.
Wastewater Treatment Plant – UV Disinfection / Canton, Illinois
Upon renewal of the City’s NPDES permit for their Wastewater Treatment Plant, EPA imposed a disinfection limit on the treated effluent from the plant. Previously the plant had been exempt from disinfecting their effuent.
After researching several options, the City decided to proceed with an ultraviolet disinfection system. Tertiary filters were removed from the existing filter building and the filter building was retrofitted with the UV system. The system is composed of 4 banks of UV bulbs in series. The system is flow paced based on a flow meter on the influent line. The system has a maximum flow capacity of 13.5 mgd.
Wastewater Treatment Facilities Planning Study / City of Lewistown, Illinois
The Lewistown Treatment Plant was cited by the Illinois Environmental Protection Agency (IEPA) for several violation notices. The compliance commitment agreement between IEPA and the City required that these items be addressed and/or improved.
The City of Lewistown hired Maurer-Stutz, Inc. to evaluate the various violation notice items and to design improvements where necessary. The items included the following: evaluation of clarifier capacity, evaluation of drying bed capacity, evaluation of the flow split between full treatment and excess flow treatment during storm events, and design of a disinfection system for overflows from the excess flow treatment facilities.
Flow monitoring and sampling were undertaken at the plant to determine if first flush flows were being captured and given full treatment before any diversion into the excess flow treatment facilities occurred. Maurer-Stutz, Inc. worked closely with the City and the City attorney in developing a plan of action with IEPA to address the violation notice items. Maurer-Stutz promoted a plan that would minimize expenditures, yet satisfy IEPA’s requirements.
Treatment Plant Reactor, Clarifier, and Anoxic Tank Structural Design / Morton, Illinois
Due to growth in subdivisions and housing, the Village of Morton needed to increase the capacity of its Sewage Treatment Plant. Structural design was completed for two clarifiers, an anoxic tank with an attached splitter box, and an oxidation ditch biological reactor with attached effluent boxes. Temporary sheet piling was also designed for use during construction due to the close proximity of adjacent existing structures.
The elevation of the ground water table was expected to be very high, which required that a high lateral pressure be applied to the reinforced concrete tank walls, resulting in very thick walls and large buoyant forces. To reduce the design lateral pressure and buoyancy, non-cohesive, well-drained soils were used as the backfill adjacent to the walls and for the base under the slab, and pressure relief valves were placed in the base slab of the reactor.
The structures were curved, which presented special considerations for the design and detailing of the structure.