Transcript Chloramines in Drinking Water

Secondary Disinfection with Chloramines
Charlotte Smith
Charlotte Smith & Associates, Inc.
Groveland Community Services District
Community Education Meeting
December 16, 2006
copywrite: Charlotte Smith & Associates, Inc.
Bacteria, viruses, parasites and organic molecules
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GCSD Adds Chlorine to Disinfect the Water
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Chlorinated-organic molecules (e.g. THMs) are Formed
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Add Chlorine and Ammonia-N to the Water
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Chlorine Binds to Ammonia-N Instead of DBP (e.g.THM)
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Chloramine:
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Organic molecule remains un-chlorinated
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Questions & Answers
I’ll go first
Why does Federal Law Require
Addition of Disinfectants
to
Drinking Water ?
• Microbes (including E. Coli, Hepatitis, Polio, Giardia,
Cryptospordium) exist in the environment. These
microbes can find their way into lakes and reservoirs
that are drinking water sources.
• The Safe Drinking Water Act sets both minimum
and maximum levels for disinfectants in drinking
water to protect customers from disease-causing
organisms.
How are Disinfectants Used
in Drinking Water ?
• By Law, “primary” and “secondary” disinfection
must be applied to drinking water which uses surface
water as the source of supply.
• “Primary disinfectants” are used to kill microbes.
Ranked by ability to kill bacteria: primary disinfectants
include ozone, ultraviolet light, chlorine dioxide, chlorine and
chloramine.
• “Secondary disinfectants” are used to maintain the
quality of water in the distribution system.
Secondary disinfectants are chlorine and chloramine. Chlorine
dioxide is allowed but not often used for this purpose.
How Do Utilities Select Disinfectants ?
• Disinfection selection must conform to public health
laws. All aspects of disinfection of public water systems
including chemicals used, concentrations, training and
licensing of operators are regulated.
• Disinfectant selection is also based on source water
quality, size of the system, and whether it’s being used for
primary or secondary disinfection.
What is the Best Disinfectant ?
• Chlorine, ozone, UV and chlorine dioxide are better
than chloramine for primary disinfection (to kill
microbes).
• Chloramine is best for secondary disinfection:
Chloramine is more protective against biofilm (slime) in distribution
systems and the bacteria that causes Legionnaires Disease
(Legionnella) than chlorine.
• GCSD will use chlorine and UV for primary disinfection and
chloramine for secondary disinfection.
What is the Negative Aspect of Drinking
Water that Contains a Chlorine Based
Disinfectant ?
• Disinfection by-products (such as trihalomethanes)
result from disinfectants combining with naturally
occurring organic matter in the water.
• Disinfection by-products at high levels are suspected
carcinogens.
Can GCSD Water Meet Drinking Water
Standards for DBP if they Continue to Use
Free Chlorine for Secondary Disinfection ?
No.
GCSD water would
not meet future
regulations for
disinfection byproducts.
Can GCSD Water Meet Drinking Water
Standards for DBPs if They Use Chloramine ?
Yes.
GCSD water would meet
Safe Drinking Water Act
levels for DBP
(Trihalomethanes and
Haloacetic Acids)
Can Very Concentrated Chlorine or Ammonia
Solutions Used for Laundry or Cleaning Cause
Health Problems such as Skin Irritation?
• Yes. That’s why Sodium Hypochlorite (chlorine solution) and
Ammonium Hydroxide (ammonia solution) used as cleaning
solutions should be handled carefully and not mixed together.
• OSHA requires a Material Safety Data Sheet (MSDS) for very
concentrated solutions of these chemicals – to protect the
workers.
• An MSDS does not relate to drinking water because of the
extremely low concentration of these chemicals in water. There
is about 25,000 to 100,000 times less chlorine in drinking water
than household bleach.
The Washington Post has Reported Increased Lead Levels in
Washington DC After They Switched to Chloramines.
Will GCSD Customers Experience Higher Lead Levels in the Future
?
• Lead comes from lead pipes and solder in homes.
•DC has 23,000 lead service pipes. If your home does not
have a lead service it is not comparable to this situation.
Note: Customers should check the Annual Water Quality Report
known as the “Consumer Confidence Report” for Lead Levels,
for a District-wide picture of this issue.
Can Dialysis Patients Drink
Chlorinated or Chloraminated Water ?
• Dialysis patients can drink chlorinated or
chloraminated water even though neither can be in the
water used for cleansing their blood.
• Food and beverages that we digest don’t come in
direct contact with the blood stream.
Is Chloraminated Water Safe for
Children and the Elderly ?
Yes. Some cities in the US have been using
chloramines since the 1920s.
Is Chloraminated Water Safe for
Pets and Wildlife ?
Yes. The levels in drinking water are safe for animals.
When should Customers Replace Home
Plumbing Parts ?
• Plumbing parts should be replaced when they wear
out. Non-chloramine resistant parts will wear out
faster. Therefore, it’s wise to replace parts with
chloramine resistant ones.
Where Can Consumers Find Information
on Bottled Water or
Home Devices such as Filters?
• Home filters are not regulated. The National
Sanitation Foundation website provides some
information.
www.nsf.org
• The Food and Drug Administration regulates bottled
waters. Consumers of bottled water should contact
the FDA or the manufacturer. www.fda.gov
What are Reliable Information Sources ?
• Details About Your Drinking Water:
The water utility and GCSD water quality www.gcsd.org
• Drinking Water Standards:
USEPA www.epa.gov
California Department of Health Services www.dhs.ca.gov
• Public Health Issues:
Centers for Disease Control www.cdc.gov
State and County Health Departments www.tuolumnecounty.ca.gov
• Personal Health Issues:
Clinical specialist (e.g. dermatologists, nephrologists)
• Other: Peer reviewed scientific literature www.awwa.org
Your Turn