Engineering Evaluation of Water Supply
Location: Paragould, Ark.
Client: Paragould Light, Water & Cable
Completion Date: August 2004
Burns & McDonnell performed an engineering valuation of Paragould Light, Water & Cable's (PLWC’s) Fifth Avenue Water Treatment Plant to address several technical issues. The plant was upgraded in the late 1990s and has experienced problems with the flocculation/clarification system, filters and various support systems.
Water demands were examined back to the early 1980s to assess peak capacity needs into the future. A 20-year planning period was selected for the evaluation. Based upon historical trends and recent growth patterns in the community, the plant’s 6-million-gallon-per-day (MGD) rating is marginal for needs expected in the next few years.
- Plant performance evaluation
- Long range forecast
- Regulatory review
- Alternatives development
- Evaluation of improvements
- Cost estimating
- Construction phasing
One particular problem was performance of the cone clarifiers. Raw water for the plant comes from several deep groundwater wells and exhibits low turbidity and low hardness. The settled water turbidities from these units were difficult to control. Burns & McDonnell performed a treatability study with various coagulants and polymers to identify what worked best. The units would likely function better if raw water turbidities were higher.
Burns & McDonnell prepared a long-range forecast of water system demands to the year 2025. A regulatory review of state and federal requirements on public water supplies was included, so that the plant will comply with future regulations. Operational and facility improvements to meet these demands and regulations were identified. Improvements were also needed to aeration, rapid mix/flow splitting, clarification and filtration. Various support systems, including backwash pumps, high service pumps and other components were also targeted for improvements.
An evaluation of the existing water supply system, including the wells, treatment plant and storage/distribution system was included in the study. An analysis of design criteria for the future plant was developed along with alternatives for achieving those criteria. Recommendations were presented, along with an analysis of phasing options for implementing plant improvements. Cost estimates were developed to aid in budgetary planning.