Drinking Water Quality Meeting Water Demand and Water Quality ChallengesEBMUD Perspectives Eileen M.

1
Drinking 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

3
EBMUDs 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

4
Meeting Projected Water Demand (2030)281 MGD
5
Water 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
6
EBMUD RECYCLED WATER PROJECTS
7
EBMUD 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

9
Water 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

10
Pardee Dam and Spillway
11
Three Aqueducts
12
Briones Reservoir
13
San Pablo Reservoir
14
General 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

15
Issues 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

16
General 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

17
Six 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

18
Water Treatment Plant SchematicFull Treatment
Local Reservoir
X
Clear-wells
Filters
Distribution System
Ozone/ Peroxide
Aeration
Rapid Mix
Flocculation
Sedimentation
19
Four 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

20
EBMUD 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

21
Current Technologies

• Conventional Filtration
• Membrane Filtration
• Enhanced Coagulation
• Lime Softening
• Activated Carbon Granular or Powdered
• Ultraviolet Disinfection
• Ozone

22
Current Technologies (contd)

• Mixed Oxidant
• Chlorine Dioxide
• Chloramines
• Corrosion Control Treatment
• Ion-Exchange/Activated Alumina
• Reverse Osmosis
• Biofiltration

23
Emerging 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

24
Water Delivery Alternatives

• Dual Distribution
• Point of Use/Point of Entrance Treatment
• Bottled Water
• Central Treatment and Distribution

25
Summary

• 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

26
(No Transcript)
27
Water Quality Data
28
Centralized Treatment vs. Distributed Treatment