Date
Tuesday, September 10, 2024
Time
4:15 PM - 4:45 PM
Location Name
M111
Name
Upgrades to “Old Faithful”: Residuals Management and Improvements at Crescent Hill WTP
Track
Drinking Water Quality
Description

Louisville Water’s Crescent Hill Water Treatment Plant (CHWTP) in Louisville Kentucky is the largest water treatment plant in the State. For over 50 years, solids residuals from plant processes have been successfully managed through a complex system of pipelines which convey the residuals to the B.E. Payne Lagoons approximately nine miles away. The advantage of this system is the drastic reduction in O&M cost for residuals management at the CHWTP. However, this critical system is aging and is reaching the end of its useful life. It presents a single point of failure in the event of an emergency. To address concerns for operational flexibility and system redundancy, Louisville Water and HDR undertook the design of a fully redundant solids conveyance system at the CHWTP. Historical data collection and field assessments of the existing system revealed a delicate balance of hydraulic designs within a network of holding tanks, pumping stations, force mains, gravity drains, and gravity force mains with pipe sizes ranging from 12 inches to 36 inches. A detailed hydraulic capacity assessment of the system was conducted using standard hydraulic calculations, computational fluid dynamic modeling, and a time-varying hydraulic model. This assessment was then used to design a redundant pipeline system that would meet or exceed the capacity of the existing system. The existing pipeline corridor is heavily congested with critical infrastructure and traverses long distances of cross-country and difficult to access areas. Multiple discussions with internal and external stakeholders (USACE, CSX, Louisville Metro, Public Works) solidified a pipeline alignment and provided a roadmap for successful pipeline construction including multiple trenchless crossings (traditional bore and jack, HDD) and the rehabilitation of existing pipelines for reuse. A collaborative public engagement plan was implemented to quantify the social and environmental impacts for the project and ensure risks were acknowledged and addressed. This kind of engagement resulted in a design change to repurpose an existing 36-IN Raw Water Main in order to minimize impacts to residents along Zorn Avenue. A significant amount of collaboration centered around operation and maintenance needs for Louisville Water after completion of construction. Implementing an operation and maintenance strategy for a wastewater system at a water utility required extensive discussions to ensure typical operating conditions were understood and any process emergencies could be detected and quickly addressed. This collaboration resulted in the inclusion of appropriate flow, pressure, and level instrumentation, cross connections, air release valves, flushing and drain assemblies and other appurtenances that ensured optimal system performance for years to come. The proposed presentation will outline the key elements of the project and highlight the benefits of: detailed field assessments and hydraulic evaluations to implement complex pipeline system improvements, proactive engagement with stakeholders to address installation challenges and reduce social and environmental impacts, and collaborative approaches to develop attainable operation and maintenance procedures for utility assets. Through careful assessment and extensive collaboration, Louisville Water has implemented a cost-effective design that provides essential redundancy and improvements to the existing solids conveyance system while addressing and mitigating public and environmental impacts.