Hydraulic Evaluation - Joseph F. Donovan Water Treatment Plant, Kankakee, IL

The Joseph F. Donovan Water Treatment Plant in Kankakee, Illinois, treats water from the Kankakee River for potable use throughout the Kankakee Area. Peak system demands occasionally approach the hydraulic limit of the facility.

In order to make the most economical use of this facility, CIWC hired NIES Engineering, Inc., to evaluate the hydraulic performance of the plant and identify hydraulic restrictions. Elimination of these restrictions will become a part of CIWC's capital improvement program at the plant as the need for additional capacity arises.

NIES employed two computer models of the treatment plant in order to evaluate its hydraulic performance. Precise calculation of the hydraulics through pretreatment was essential, as there is only two feet of available fall from the mixing basins to the filters.

Initially, a spreadsheet model was generated to simulate the hydraulics from low lift pumping, through pretreatment and into the gravity filters. This model was run at increasing plant throughput and a hydraulic profile was generated for each flow rate. These progressive hydraulic profiles were used to illustrate the impacts of various bottlenecks throughout the plant.

From this data, a program of recommended improvements was generated. An intricate network of filter effluent piping required the use of a more sophisticated hydraulic model. NIES utilized Cybernet™ software to evaluate the performance of the filter effluent piping. This model was run at varying filter loading rates to optimize flow through the piping network.

Key Points

• Improved Efficiency
• Computer Modeling
• Logical Improvements

Water Treatment Plant Modifications - East Plant Pressure Filters, City of La Porte, IN

The potable water system of La Porte, Indiana consists of two treatment plants, three elevated tanks, and seven wells. The goal for NIES Engineering, Inc. was to rehabilitate or replace the aging pressure filters in Plant 2, an unmanned 6 million gallon per day plant on the East end of town.

The approach adopted by NIES Engineering, Inc. was to analyze the condition of existing steel pressure filters and media then develop a cost analysis for available alternatives. Preliminary examination of one of the pressure filters revealed impacted media, substantial internal steel corrosion, and mineral deposits that explained the observed reduction in filter efficiency and plant capacity.

The options available were to replace the five pressure filters entirely, or rehab with either single or dual media and either water wash or combination air-water wash. The favored approach was to rehab the filters using Water Plant workers to assist in media removal. Original internal filter piping was replaced as was the underdrain plate.

The final dual media, water wash rehabilitated filters represented a cost savings over total replacement of more than 50%. External backwash piping was also replaced as were pneumatic operated valves. The whole Plant 2 system was integrated into a system wide radio controlled SCADA system that allowed full control from the Lake Street Plant. A new concrete backwash basin, high service pump replacement, fluoride pump replacements, and update of the chlorination facility completed the improvements.

The project was a success with all original goals accomplished. The City of La Porte now benefits from a reliable, unmanned, remote water plant that operates with high efficiency pumps and full control from the Lake Street Plant.

Key Points

• Improved Control
• Cost Effective Rehabilitation
• Extended Life
• Energy Efficient Pumping

Elevated Tank - City of La Porte, IN

Prior to the start of this project, the water system of La Porte, Indiana, consisted of two treatment plants, two elevated tanks, and seven wells. The goal for NIES Engineering, Inc. was to improve long-term supply in the East and southeast areas of the City that were anticipated to experience growth.

NIES Engineering, Inc. analyzed the existing distribution system, presented alternatives and recommendations, and designed the necessary improvements. Using computer modeling hydraulic network analysis (HNA), it was determined that the best solution was to locate a new ½ million gallon elevated tank on the southeast side of town. In addition, a new transmission main was planned and designed that would ultimately loop around to the south side of the distribution network, further reinforcing the water distribution system in this area.

The new elevated tank and transmission main gave the City the ability to supply water to the southeast side of town without filling the existing elevated tanks too quickly. The new elevated tank stabilized pressures in this area, provided additional operating and fire storage capacity and improved fire flow protection. Unique features of the project included an altitude control vault located within the elevated tank base to improve wintertime maintenance access, and the use of vibroflotation sand compaction techniques to consolidate loose sandy soils to a depth of 30 feet below the tank foundation.

The project was a success with all original goals accomplished. The City of La Porte now benefits from a reliable water supply to an area of town that continues to enjoy strong growth.

Key Points

• Improved Supply Pressure
• Supports Growth
• Fire Support Storage

Large Diameter Sewer Replacement - La Porte, IN

The Fox Street combined sewer, carrying both wastewater and stormwater flows, was originally built in 1910. Ninety years later, the 72-inch diameter sewer carried over 50% of the City’s wastewater south to the Treatment Plant. The sewer was believed to be in very poor condition based on experience with multiple cave-ins.

Remote TV inspection confirmed extensive sewer deterioration threatening complete failure which prompted the City’s decision to replace one mile of sewer with new reinforced concrete pipe (RCP). Several challenges added complexity to the project. The original sewer route deviated from the right-of-way, traversing underneath two commercial greenhouse buildings.

To keep disruption to greenhouse operations to a minimum, the new 78-inch sewer would need to follow a new path within the right-of-way, where other utilities were already located. The RCP sewer was constructed using an open-cut trench and at the north end of the project this trench was more than 30 feet deep. This required a wide excavated area and replacement of more than 2,000 feet of incidental water main.

All project construction was achieved with minimum disruption to residents and local businesses. There was considerable public interest in the job due to the shear size of the construction equipment and RCP sewer pipe (each eight foot long section weighed over eight tons). Site visitors included newspaper photographers, students from a local school and city officials.

NIES Engineering helped to secure State Revolving Fund (SRF) financing for the project by completing Program Application and a Preliminary Engineering Study. We provided assistance in every phase of the project including field surveying, preparation of plans and specifications, reviewing bids, contractor selection and on-site construction inspection. We completed all phases of the project on time and within budget.

The City of La Porte has now significantly improved the reliability and capacity of a major section of the combined sewer system.

Key Points

• SRF Funding
• Cost Effective
• Cooperation