College of Engineering Unit:
The Lena Water Treatment Plant (LWTP) is a critical infrastructure project aimed at transitioning the Community of Lena from reliance on well water to utilizing surface water sourced from the nearby Snake River. This transition is necessitated by the need to ensure a sustainable and high-quality water supply that meets the stringent drinking water standards set by the US Environmental Protection Agency (EPA) and the Idaho Department of Environmental Quality (DEQ). The LWTP must adhere to the drinking water standards mandated by these agencies, ensuring that the treated water is safe and suitable for community use.
The facility will treat raw water sourced from the Snake River, with the goal of demonstrating the capability to deliver a finished water flow rate of 3.5 million gallons per day (MGD). Additionally, the discharge to the municipal sewer system must not exceed 300,000 gallons per day (gpd) and 500 gallons per minute (gpm). To ensure reliability and continuous supply, the raw water reservoirs will provide three days of storage at maximum day flow, even with one reservoir out of service. The project will also include the cost for chemical feed systems, although their design is excluded.
The LWTP project encompasses several key components and constraints. The incoming raw water pipeline will be a 24-inch High-Density Polyethylene (HDPE) pipe with a Standard Dimension Ratio (SDR) of 17, situated within 25 feet of the raw water reservoir. The plant will integrate processes to treat and store raw water, meeting the required storage and flow criteria. All operations must comply with EPA and DEQ regulations regarding water quality and discharge limits.
As part of the 10% engineering deliverable phase, a series of critical documents will be prepared. These include a Process Flow Diagram, which provides a detailed representation of the water treatment process, illustrating the flow of water through various treatment stages. Additionally, a Process and Instrumentation Diagram (P&ID) for the raw water reservoir will be created, depicting the instrumentation and control devices used within the reservoir. A comprehensive process layout will show the arrangement of treatment processes and designated areas within the plant, while a hydraulic profile will detail the hydraulic gradients and flow characteristics throughout the treatment plant. An equipment list will inventory all equipment with power ratings exceeding one horsepower, and a detailed project cost estimate will cover all aspects of the design and construction of the LWTP.
In conclusion, the Lena Water Treatment Plant project is a pivotal development for the Community of Lena, aiming to secure a reliable and high-quality water supply from the Snake River. Through meticulous planning, adherence to regulatory standards, and efficient design, the LWTP will ensure that Lena's residents have access to safe and clean drinking water for years to come.