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Advanced OperatorShort Schools
Production of Drinking Water
Cal Sawyer/Mark Anderson
Advanced OperatorShort Schools
Water Supply Treatment
Introduction to Potable Water
Virginia Department of Health
O rgan iza tion C hart
S ew ag e an d W ater S ervices W as tew ate r E n g in eerin g W ater S u p p ly E n g in eerin g
O ffice o f E n viron m en ta l H ea lth S ervices
http://www.vdh.state.va.us/onsite/index.htm
http://www.vdh.state.va.us/owp/index.htm
Advanced OperatorShort Schools
Public Waterworks Laws & Regulations
Federal Laws & Regulations
State Laws & Waterworks Regulations
Definition of Potable Water
Water fit for human consumption and domestic use which is sanitary and normally free of minerals, organic substances, and toxic agents
in excess of reasonable amounts for domestic usage and
normally adequate in quantity and quality for the minimum health requirements of the persons served.
Federal Laws Safe Drinking Water Act (SDWA) of 1974
- SDWA Amendments of 1986
- Lead Contamination Control Act of 1988
- SDWA Amendments of 1996 Code U.S. Public Health Service Drinking
Water Standards (1914) of Federal Regulations (40 CFR Part 141)
Virginia’s Laws
Title 32.1, Chapter 6, Article 2 of the 1950 Code of Virginia: “Public Water Supplies”
Waterworks Regulations Originally effective: Sept. 1, 1974 Latest revision: November 1995
Waterworks Regulations Definitions, Permit Procedures, Quality Standards,
Operation , Cross-Connection Control, and Design Requirements for water source,
treatment,
pumping,
storage, and
piping Administered by State Board of Health
Waterworks Regulations implemented
by Virginia Department of Health - Office of Water Programs
Division of Water Supply EngineeringCentral office in Richmond Six Engineering Field Offices: Abingdon, Culpeper, Danville, East Central Virginia (Richmond), Lexington, Southeast Virginia (Virginia Beach)
Division of Water Supply Engineering
Duties include : technical review of engineering plans, surveillance, investigating complaints, training, technical assistance, enforcement
Waterworks Regulations define…..
Types of Waterworks Community waterworks serves at least 15 connections
or at least 25 year-round residents Nontransient Noncommunity waterworks serves at
least 25 of the same people more than 6 months per year
Noncommunity waterworks is not a community waterworks but operates at least 60 days per year
Types of Water Systems
Public Water System– 271 million Americans receive drinking water
from public sources– 171,000 PWSs
Private Home Water System– 23 million Americans receive drinking water
from private sources
Public Water Systems
Community Water Systems– Publicly and investor-owned waterworks– 249 million Americans served by CWSs
Noncommunity Systems– Day care centers, elementary and other public/
schools– Factories– 6.1 million Americans served by NCWSs
Quantity Requirements
Per capita usage: 150 gpd Per residential connection : 400 gpd
Fire fighting (recommended):
A minimum residential fire flow of 500 gpm
Water pressure requirements:
A minimum pressure of 20 psi at the service connection, for all conditions
Quality Requirements
Types of health threats– acute– chronic
Maximum Contaminant Level (MCL)1o Primary MCL: based on health considerations
2o Secondary MCL: based on aesthetics
Quality Requirements
Bacteriological qualityFree of pathogens
Chemical qualityInorganic chemicals (1o & 2o contaminants)Organic chemicals (1o contaminants)
Radiological quality(1o contaminants) Physical quality (2o contaminants)
Multiple Barrier Approach
Source water protection Water treatment Distribution system Education
Multiple Barrier Approach
Source Water Protection Surface Sources Groundwater
Multiple Barrier Concept
Source water protection– Surface water– Groundwater
Treatment to remove contaminants and to disinfect
Distribution system Education and public awareness
What is the Nature of the Watershed?
Industrial Agricultural Forest Residential Sources of spills
Watershed Characteristics
Adequate source in quantity? Adequate source in quality? Are there sources of pollution? Is the highest quality water being drawn? Fluctuations in water quality
Watershed Protection
Size of owned/protected area of the watershed
How watershed is controlled Restricted area around intake
Determining the Areas to Be Protected
Is the aquifer recharge area protected?
Recharge Zone activities Well Head Protection Program Is the aquifer being used confined or
unconfined?– Information sources– USGS
Is the site subject to flooding?
Is the well located near a potential source of pollution?
Source Feet from Well
Watertight Sewers 50
Other sewers 100
Septic tanks 100
Sewage field, bed or pit 200
Animal pens and yards 200
Change Water Quality to:Improve safety for human consumptionImprove aesthetic appealProtect distribution system
Water Treatment Processes
Water Treatment
Advanced OperatorShort Schools
Drinking Water Treatment
Photo Credit: Virginia Department of Health
Drinking Water Contaminants
Biological– Bacteria– Protozoa– Viruses
Chemical Radiological
– Radon– Radionuclides
Potential Health Effects of Chemical Contaminants in Drinking Water
Chemical Cancer Developmental/Reproductive
Neurologic Other
Arsenic Skin, Internal SAB Peripheral CardiovascularImmunologicDermatologic
DBPs BladderColonLeukemia
SABLBW Defects
Fluoride FluorosisLead Internal Intelligence
behaviorHemoprotein,kidneys
Nitrate SAB Methemoglobinemia
Pesticides Leukemia LBWRadon LungSulfate Diarrhea
Table of Detected Contaminants
Contaminants subject to an MCL, Action Level or Treatment Technique
Unregulated contaminants Monitoring of contaminants as required by
the Information Collection Rule Likely source of contamination
Water Treatment
Purpose of water treatment Groundwater treatment components
– Iron and manganese removal, if needed– Disinfection, if needed
Surface Water Treatment components• Filtration
– Coagulation/flocculation/sedimentation
• Disinfection
Water Treatment
Produce potable water– Not sterile– Quality based on acceptable risks
• 1:10,000 - 1:10,000,000 of a healthy population
• Dependent on contaminant and its effects
Majority of treated water is not consumed– Fire fighting– Industrial, commercial, and irrigation
Water treatment (continued)
Purpose of water treatment Treatment components
• Disinfection• Filtration
– Coagulation/flocculation/sedimentation
Distribution System
Water mains Storage tanks Water meters Possibly, redisinfection
Distribution System Notes
Water is fine leaving the treatment plant Most waterborne diseases and illnesses
can be traced to the distribution system Cross connections
Etiologic Agent of Waterborne Disease Outbreaks(WBDO) in the U.S.
1995-1996
Bacterial20%
Chemical32%
Viral5%
Unidentified34%
Parasitic9%
Factors that affect whether WBDOs are recognized and investigated:
Size of outbreak Severity of disease caused by outbreak Public awareness that an outbreak may
be occurring Investigator's interest in studying the
etiologic agent Health department resources Routine laboratory testing for
pathogen
Sequence of events before an individual infection can be reported
Individual is infected
Did illness occur?yes
Did the ill person seek medical care?yes
Was the appropriate clinical test (stool, blood) ordered?
yes
Did the patient comply?yes
Was the laboratory proficient?yes
Was the clinical test positive?yes
Was the test result reported to the health agency?
Was the report timely?
What did the health agency do with the report?
yes
yes
no
no
no
no
no
no
no
no
Examination of One Contaminant
Cryptosporidium parvum oocysts Waterborne pathogen hard to identify
– Normally used indicators insufficient Resistant to disinfection by chlorination Difficult to remove by traditional treatment
processes unless running optimally
Outbreaks of Cryptosporidiosis in the U.S. (Drinking Water)
Year Location No. Ill Water source Filtered Disinfected Coliforms in treated water
1984 TX 2,000 artesian well no yes no
1987 GA 13,000 river yes yes no
1991 PA 550 ncs well no yes no
1992 OR spring no yes no
1992 OR river yes yes no
1993 WI >400,000 lake yes yes no
1994 NV ? lake yes yes no
1994 WA 113 well no no yes
1 4 7 10 13 16 19 22 25 28 31 3 6 9 12 15 18 21 24 27
0
10
20
30
40
Nu
mb
er o
f ca
ses
March April
Random Telephone Survey
(N = 436 cases)
Treated
water tu
rbid
ity (NT
U)
0
0.5
1
1.5
2
Water Plant Closed(Boil Water Advisory Issued)
Crypto Diagnosis Made
community vulnerable
Dates of Illness Onset & Water Turbidity(Milwaukee 1993)
Lessons Learned Passive, laboratory-based surveillance was
inadequate to detect the outbreak Public Health and Water Utilities need to form
partnerships Existing water quality standards were not adequate Communities cannot become complacent about
the quality of their source water Communities must invest resources in the
infrastructure and technology of their drinking water treatment plants
What is the Risk of Waterborne Cryptosporidum?
The level of risk from drinking water is unknown. In most situations this risk is thought to be very low. Risk probably varies from city to city depending on:
Quality of Source WaterQuality of Water Treatment
More risks from other modes of transmission Exposure to feces of infected humans or animal Sex involving contact with feces Eating contaminated food Swallowing contaminated recreational water
Who Is at Risk of Severe Cryptosporidiosis?
Patients with HIV/AIDS
People born with defective immune system(Examples on next slide)
Some people being given drugs to:Treat cancerPrevent organ transplant rejection
Populations with Impaired Immunity (Non-HIV)
Children with congenital immunodeficiencies Bone marrow and solid organ transplant recipients Cancer patients receiving radiation and/or chemotherapy Patients receiving chronic corticosteroid therapy Patients with diabetes, chronic pulmonary disease, sickle cell
anemia, asplenia Patients with indwelling catheters Burn and trauma victims Premature newborns (<32 weeks gestation) The elderly
Waterworks in Virginia
Noncommunity 2000 waterworks
Nontransient Noncommunity746 waterworks
Community 1587 waterworks
Total # systems = 4,330
46%
37%
17%
Public Water Systems
Must adhere to federal and state standards Must regularly test for microbial and
chemical contamination Must notify the public of a violation
Monitoring of Drinking Water
Only PWSs are required to monitor Some parameters continually monitored,
but most are not, e.g.,– Nitrate: annually– Radionuclides: once every 4 years– Bacteria: monthly– Inorganics & metals: annually/every 3 years
Monitoring Many tests
– Snapshot at the time when sample taken– Results are not in real time
Some contaminants are monitored by surrogates or indicators– Ease of detection– Indicator itself not a pathogen
Photo Credit: Virginia Department of Health
Private Home Water Systems
Most sources are wells or springs Most owners do not treat water
– Except for water softeners and– Iron and manganese removal
Most owners do not test water – bacterial contamination– nitrates– radiological
Bottled Water
Water quality standards for bottled water often less rigid than for public water supplies
FDA does not regulate in-state sales
Consumers need to make informed choices between bottled water or tap water
Photo Credit: Virginia Department of Health
Consumer Confidence ReportsCCR
Reports the quality of drinking water Refers consumers to their health care
provider First ones were mailed by October 1999
Purpose of the CCR
A means to raise consumers’ awareness of:– the sources of their drinking water– the importance of source water protection– what is involved to delivery safe drinking water– detected substances in their drinking water
A means for consumers, particularly those with special health needs, to make informed decisions regarding their drinking water
CCR to Address the Essential Elements:
Is the water safe to drink? Does it meet federal standards? What are the test results and how do they
compare with the standards? How might it affect me? What is the utility doing about it? Where can I go for more information?
Table of Detected Contaminants
Contaminants subject to an MCL, Action Level or Treatment Technique
Unregulated contaminants Monitoring of contaminants as required by
the Information Collection Rule Likely source of contamination
Role of Care Providers
Be familiar with drinking water quality characteristics in your community– Be aware of any MCL violations and the potential for
adverse health effects
– Be especially vigilant if your patient has a private well Use drinking water quality data to counsel at-risk
patient Report suspected waterborne disease outbreaks
Resources for Health Care Providers
World Wide Web– EPA
• http://www.epa.gov/OGWDW/wot/howcan.html
• www.epa.gov/OGWDW
– VDH• www.vdh.state.va.us/owp/index.
Safe Drinking Water Hotline– 1-800-426-4791
Drinking Water Cycle
Questions?
