Title: Drinking Water Quality Meeting Water Demand and Water Quality ChallengesEBMUD Perspectives Eileen M.
1Drinking Water QualityMeeting Water Demand
and Water Quality Challenges-EBMUD
PerspectivesEileen M. White, P.E.Manager of
Water Operations
September 12, 2006
2 from snowmelt to tap
- EBMUD, a large public community water system,
provides water service to 20 cities and 15
communities in two counties - 1.3 million customers
3EBMUDs Service Area
- 1,300,000 customers
- 3,944 miles of pipe
- 126 pumping plants
- 165 reservoirs/tanks
- 122 pressure zones
- Elevation MSL-1,450 ft
4Meeting Projected Water Demand (2030)281 MGD
5Water Conservation Program
35 MGD
17.6 MGD saved to date
District Programs 18 MGD goal
Natural Replacement 17 MGD goal
Fiscal Year
_at_ 5 million annual budget
6EBMUD RECYCLED WATER PROJECTS
7EBMUD Water System
- Mokelumne supply
- Lower treatment cost
- Excellent water quality
- More stable disinfection residual
- Less prone to nitrification
- East Bay supply
- Combination of Mokelumne local runoff
- Higher treatment cost
8 Sierra Snow Melt
- Snow melt provides 90 of our water source
- Pristine source allows us to produce superior
quality water
9Water Sources
- Mokelumne River Watershed
- 577 square mile protected watershed of the
Mokelumne River which collects snow melt from
Alpine, Amador and Calaveras counties - Supplies up to 325 million gallons of water daily
10Pardee Dam and Spillway
11Three Aqueducts
12Briones Reservoir
13San Pablo Reservoir
14General Challenges Facing Utilities
- Finite traditional good quality water sources
- Stringent and complex Drinking Water Regulations
- Maintain/Improve consumer confidence
- Infrastructure deterioration
- Infrastructure security
- Acceptable sustainable rate structure
- Climatic effects on water supply and quality
15Issues with Meeting Drinking Water Standards
- Regulations becoming more complicated to
implement - Challenge of simultaneous compliance of competing
standards - Uncertainty of scientific justification for
standards, e.g. Arsenic MCL - Utilities with high quality water sources may be
over-regulated because of minimum treatment
standard
16General Water Quality Challenges
- Pathogen Cryptospordium, Giardia, Virus
- Disinfection-By-Products THMs, HAA, Bromate
- Inorganics Arsenic, Perchlorate, Lead, Nitrate
- Organics SOC
- Potential Emerging Contaminants
- New/Rediscovered pathogens NDMA/Nitrosamines
- Endocrine Disruptors
- EPA UCMR Contaminants
- Contaminants with PHG or Notification levels
17Six Water Treatment Plants
- Three In-Line Treatment Plants
- Appropriate and efficient for high quality
supply - Three Conventional Treatment Plants
- Two plants have ozone/peroxide process for taste
and odor control
18Water Treatment Plant SchematicFull Treatment
Local Reservoir
X
Clear-wells
Filters
Distribution System
Ozone/ Peroxide
Aeration
Rapid Mix
Flocculation
Sedimentation
19Four Small Water Systems
- Pardee Recreation Area Water System
- 0.3 MGD ultrafiltration membrane
- Pardee Center Water System
- 0.1 MG ultrafiltration membrane
- Camanche Northshore Recreation Area
- 0.3 MGD groundwater wells
- Camanche Southshore Recreation Area
- 0.5 MGD direct-filtration
20EBMUD Water Treatment Approach
- EBMUD provides the highest quality water possible
to our customers - Protect the quality of sources so we can more
easily protect future generations
21Current Technologies
- Conventional Filtration
- Membrane Filtration
- Enhanced Coagulation
- Lime Softening
- Activated Carbon Granular or Powdered
- Ultraviolet Disinfection
- Ozone
22Current Technologies (contd)
- Mixed Oxidant
- Chlorine Dioxide
- Chloramines
- Corrosion Control Treatment
- Ion-Exchange/Activated Alumina
- Reverse Osmosis
- Biofiltration
23Emerging Technologies
- Improvement of membrane technology
- Coagulation Membrane Filtration, low pressure
reverse osmosis - Improvement of UV technology
- Mercury-free low-pressure lamp
- MIEX DOC removal process
24Water Delivery Alternatives
- Dual Distribution
- Point of Use/Point of Entrance Treatment
- Bottled Water
- Central Treatment and Distribution
25Summary
- Drinking water regulations are becoming more
stringent and complex to implement - Advancing water treatment technology produces
higher quality drinking water - Appropriate treatment technology will depend on
water quality and specific system conditions - Goal is to provide high quality water while
minimizing cost to customers
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27Water Quality Data
28Centralized Treatment vs. Distributed Treatment