GREAT LAKES RAW WATER INTAKE EXPANSION INVESTIGATION AND DESIGN CONSIDERATIONS ANALYSIS

摘要

To resolve ice blockage and water quality issues for Elyria Water Treatment Plant, a water intakestudy was conducted in the summer of 2007, focusing on developing and evaluating new intakealternatives. Information required for alternative development was acquired through public datasearch, offshore investigation, and model simulation. Model results and water column analysisindicated improved average raw water quality at the new intake site (3000 feet offshore)compared with the current intake site (1300 feet offshore). Water quality monitoring implied thatwater quality in the new site may be fluctuant during storm events.Based on lake conditions and intake requirements, two alternative intake designs wereinvestigated: 1) extending the existing intake pipe to 3000 feet offshore and installing a new crib;2) installing a new, larger intake pipe and crib. Economic and non-economic criteria wereadopted to evaluate and compare these two alternatives. The results of the alternative evaluationshowed that although the extension alternative has lower construction cost, the new intake pipealternative will significantly improve the system capacity, reliability, and flexibility. Designcriteria were also discussed in this study in order to provide a practical evaluation of the intakealternatives.