Transcript No Slide Title

Drinking Water and the Lake
• There are 40+ plants utilizing Lake Michigan
Water
• Illinois, Wisconsin, Michigan, Indiana
• Sizes of 1 MGD to 1 BGD
• Designed for 100 year Lake lows and highs
Numerous Treatment Processes
• Filtration
– Sand, anthracite, granular activated carbon,
membranes
• Disinfectantion
– Chlorine gas, bleach, chloramines, ozone,
investigating ultra-violet disinfection
Excellent Water Source
Regulated substances include:
–
–
–
–
Arsenic is 50 times lower than standard
Barium is 10 times lower than standard
Nitrate is 20 times lower than standard
Bacteria routinely exceed standards
Over 360 other compounds are monitored and
not detected.
Climatic Change Factors
• Source water
– Water level
– Water quality
– Water temperature
• Water demand
– Precipitation
– Temperature
Lake Level
Impacts
• High Water Levels
– Some shore facilities may require flood
protection
– Ability to supply water to plant may improve
• Low Water Levels
– Improved protection of shore facilities
– Some intake may require extension
Typically 1000 – 5000’ out into the Lake
Typically 25 – 40’
Primary Water Quality Impacts
• Algal mass
– Impacts how often filters require cleaning
– Taste and odors in the Lake
• Turbidity
– Impacts treatment chemical usage
– Sludge removal operations
– Filter runs
Water Temperature
• Water Production
– Ice formation on intakes slows flow
• Water Treatment
– Coagulation and flocculation
– Disinfection
Water Demand
• Water production can double in the Summer
• Sustained hot dry weather increases demand
• Water plants sized and expanded to meet
maximum flow day
Global Warming Impacts
• Water Treatment
– Providers are confident that potential
challenges are surmountable
• Water Production
– Some intakes may require extension to deeper
water
– Most providers cautiously optimistic about
impact of a one meter drop in Lake level
West Shore Water Producers
Association
www.wswpa.com