Transcript NSF Water Systems

Water Quality
Consumer Confidence Reports
Drinking Water Problems
Treatment Technologies
Water Quality
• 1996 Amended Safe Drinking Water Act
– Requires all community water systems
provide customers with an annual quality
report.
• Must contain the following:
– Source of the water
– Levels of any contaminants found in local drinking
supply
– Likely source of any detected contaminants and
susceptibility of water supply to potential
contamination
Water Quality
– EPA Maximum Contaminant Levels
– Any violation of drinking water related rules
– An educational statement regarding Cryptosporidium
and the need for certain vulnerable populations to
avoid exposure
– Also included:
» Measurements of color, odor, PH level, hardness,
alkalinity, temperature, silica, sodium and
potassium.
Water Quality Reports
• Common Units of Measurement
– mg/L (Milligrams per Liter)
• One of most common units of measure
– ppm (Parts per Million)
• Equivalent to mg/L
– MFL (Million Fibers per Liter)
• Used to measure asbestos
– NTU (Nephelometric Turbidity Units)
• Measure of turbidity, or clarity, of the water
Water Quality Reports
– pCi/L (Pico Curies per Liter)
• Measurement of radioactivity
• Used for radium, uranium, and radon
– gpg (Grains per Gallon)
• Refers to hardness of water
– Can be reported in mg/L (1 gpg = 17.1 mg/L
• Very hard water – more than 10 gpg
• Very soft water – less than 1 gpg
– MCL (Maximum Contaminant Level)
• Max level allowable in public drinking water
supplies.
Water Quality Reports
• Common Abbreviations
– AL (Action Level)
• Conc. of lead or copper in water
• Violations do NOT require public notifications
• Most high levels due to household pipes &
faucets
– MCLG (Maximum Contaminant Level
Goal)
• Max level at which no known or anticipated
health threat exists
Water Quality Reports
– NA (Not analyzed)
• Can mean water source deemed non-vulnerable
to a specific contaminant
• Testing not required
– ND (Not Detected)
• None of the tested contaminant was found
– TT (Treatment Technique)
• The set of procedures that public water suppliers
must follow to ensure a contaminant is controlled
in the drinking water
Water Quality Reports
– Contaminant or Parameter
• The particular substance being analyzed
– Unit
• The unit of measure
– Violation
• Indicates a contaminant that exceeded an MCL
– Source
– Amount Detected
• Indicates the potential source of a contaminant
Water Quality Reports
• Interpreting Your Report
– ID the contaminant and compare the level
shown in the “amount detected” column
against the level shown in the “MCL”
column.
– Also compare it to the MCLG column.
• MCLG is a goal not a requirement. “MCL” is a
requirement.
Regulatory Bodies
• EPA does not establish standards
• Pre 1991
– Industry self-regulated
• National Sanitation Foundation (NSF)
– Established in 1968
– 1991 accredited by ANSI (American
National Standards Institute) and RVC
(European equivalent)
– 1996 became WHO Collaborative Center for
Drinking Water Safety and Treatment
NSF
– Independent, non-profit third party testing
body
– Responsible to:
• Consumer user sector
• Regulatory sector (government)
• Manufacturer sector
– Test any equipment used in food preparation
and storage, including water
• Now the drinking water system industry
standard nationally & worldwide
Standards
• Test Under Materials Guidelines
– These determine that all product
components are safe and not leaching off
trace toxins
• Test Under Structural Guidelines
– These make sure the unit will not explode,
crack, disintegrate, etc.
Standards
• Six ANSI/NSF Standards for POU and POE
Treatment Technologies
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# 42: DWTU’s - Aesthetic Effects
#44: Cation Exchange Water Softeners
#53: DWTU’s - Health Effects
#55: UV Microbiological Water Treatment
Systems
– #58: RO Drinking Water Treatment Systems
– #62: Drinking Water Distillation Systems
Standards
• Each standard requires:
– verification of ALL contaminant reduction
claims made by the
manufacturer/assembler;
– structural integrity testing of the product;
– toxicological assessment and acceptance of
ALL materials used in fabrication
Standards
• Requirements con’t.
– extraction testing and health effects
assessments of all chemicals at the levels
leached to water in contact with the
products; and
– review and prior acceptance of all labeling
and sales literature with the products
Standards
• NSF Two Main Standards for Water
Filtration Devices:
– #42: Aesthetic effects
• Covers taste, odor and chlorine removal
– #53: Health effects
• Covers most every pollutant including:
– Chemicals, Pesticides, Herbicides, Cysts (Giardia &
Cryptosporidia), Turbidity, Lead, Asbestos & Radon
• Each substance is tested individually with each
test a separate expense
Standards
• NSF Testing Methods
– Filters are tested for 100% removal of a
substance (such as lead) for twice the rated
filter capacity
• Example: if a filter is rated for 500 gallons by
NSF then it removed lead for 1,000 gallons at a
100% removal level.
You and Water
• Water
• regulates body temperature
• serves as a solvent for minerals, vitamins, amino
acids, glucose, etc.
• carries oxygen
• lubricates joints
• is necessary for chemical reactions in the body
• acts as a shock absorber
• removes waste products
Water
• Consumer Information
– Municipal water supplies regulated by EPA and
individual states.
– Well Water
• Required to be evaluated for microbiological
contamination only at time well is installed.
• Up to well owner to monitor and ensure water quality
Water
– Basic Water Testing
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Total coliform testing *
Nitrates/nitrites
A hardness test
pH
– If water is less than 7.0pH may have trouble with leaching
copper and lead from residential plumbing
• Arsenic *
• BTEX and MTBE analysis *
– If a gas station is within ¼ mile
• * should be tested at least annually
Water
• Possibly radon
• Pesticides
– If living near a golf course, orchard or agricultural area
– Testing for Odor & Color Problems
• Hydrogen sulfide and methane analysis
– Rotten egg odor
• Iron bacteria analysis
– Musty or moldy odor
• Iron level
– Problems with red staining of fixtures
• Manganese
– Problems with brown or black staining of white laundry
Water
– Compare test results with EPA or state
drinking water regulations to see if
contaminants exceed recommended levels.
System Selection
• Points to Consider When Purchasing a
Drinking Water System
• Verify that the technology is safe and effective
– Tested and certified by NSF
• What contaminants is the device certified to
remove
• What is the flow rate in gallons per minute
(GPM) for the unit
• How often do you need to change the filter
– Cost of replacing the filter
– Is changing the filter user friendly
System Selection
• Customer satisfaction guarantee and/or product
warranty
• Company Longevity
– Best advice - stick with recognized industry leaders
with at least 15 years experience or more
Drinking Water Problems
• Chlorine
– Known poison
– Long-term exposure risk is unknown
– Reacts with organic material to form
trihalomethanes (THM’s)
• Examples include chloroform, broomcorn and
dichlorobromethane
Drinking Water Problems
• Chloramine
– A chlorine/ammonia compound
• Used by some municipalities when the level of
chlorine is at the highest acceptable level but
more disinfection is needed
• Represented as totally safe yet with a disclaimer
to not give chloramine treated water to animals
and not to use it in fish tanks.
Drinking Water Problems
• Bacteria
– Municipal water pipe systems can contain
bacteria anywhere between the purification
plant and your home
– Spring or well supplies can be contaminated
from animals dying or defecating in the
source or become contaminated from nearby
septic systems or ground water
contamination
Drinking Water Problems
• Lead
– A cumulative toxin that stays in tissues
permanently (especially the brain)
– Also affects a person in relation to their body
weight
– Main sources
• Lead pipes and lead solder
– Houses older than 20 years and less than 5 years at risk
– Houses in areas of soft (low mineral levels) tend to
corrode the lead from pipes more easily
Drinking Water Problems
• Asbestos
– Potential carcinogen
– So small as to be unfeasible to remove it at a
treatment plant
– Sources
• Naturally occurring in water coming from areas
that have a lot of serpentine rock
• Asbestos-lined water pipes
Water Drinking Problems
• Chemical Pollution
– For the most part odorless, colorless,
tasteless, so undetectable
– Chlorine most predominant
– Some of most dangerous chemicals are
present only in trace amounts (ppb) but
highly toxic even at minute levels
– Sources
• Usually industrial or commercial
Drinking Water Problems
• Chemical Pollution
– Volatile Organic Contaminants (VOC’s)
• Includes various plastics, gasoline and petroleum products
– Herbicides
• Dioxin (2-4D) and lindane
– Pesticides
• DDT, malathione
– THM’s
• Trihalmethanes (previously covered)
Drinking Water Problems
• Cysts
– Worms, parasites and protozoa
– Biggest offenders
• Giardia
– 7-14 microns
– Cysts are chlorine resistant and hard to kill
• Cryptosporidia
– 3-5 microns
– Cysts are chlorine resistant and hard to kill
Drinking Water Problems
• Cysts
– Municipal utilities are unable to completely
remove these cysts
– Milwaukee
• Huge outbreak in 1993, over 100 people died
– San Francisco
• Repeatedly tested positive for giardia
Drinking Water Treatment Technologies
• NSF evaluates the following technologies
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Adsorption (ANSI/NSF 42 & 53)
Softeners (ANSI/NSF 44)
Ultraviolet Treatment (ANSI/NSF 55)
Reverse Osmosis (ANSI/NSF 58)
Distillers (ANSI/NSF 62)
Styles of Devices
• POE (Point-of-Entry)
• POU (Point-of-Use)
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Personal Water Bottle
Pour-through
Faucet-Mount
Counter-top Manual Fill
Counter-top Connected to sink faucet
Plumbed-in
Plumbed in to separate tap
In Home Purification
• Removing all contaminants at the kitchen
or bathrooms taps just before consuming
is the most logical, efficient and
economical solution to drinking water
purification
– This allows only the drinking water to be
filtered rather than all household water
– No possibility of re-contamination after
purification
Technologies Available
• Granulated Activated Carbon (GAC)
• Long history of being used to absorb impurities
• Most powerful absorbent known
– One pound =a surface area of 125 acres
• Slight electro-positive charge added to it to
increase absorbent
– Used extensively in most of the commonly
encountered water filters today
• rated as taste and odor filters or pre-filters
designed to remove initial dirt, rocks, sediment
Technologies Available
• Granulated Activated Carbon
– Very few are effective at true filtration
• Will not remove substances of health concern
– Problems
• Channeling
– Water takes path of least resistance and makes its own
channels through the filter
– Reduces contact time to media allowing impurities to seep
through
Technologies Available
• Granulated Activated Carbon
– Problems
• Bacterial Growth
– Some heterotrophic bacteria are trapped in filter.
– Filter acts as an excellent growth medium (warm,
moist & oxygen rich)
– No barriers to prevent bacteria from coming out in the
water
– Some companies use silver nitrate (a known poison) to
aid in keeping growth down
Technologies Available
• Granulated Activated Carbon
– Problems
• Effectiveness decreases rapidly
– Most have minimum amount of GAC so they become
saturated quickly.
Technologies Available
• Distillation
• Heats water to vapor point
– So in theory
• Chemical pollution and other contaminants
vaporized and separated from vaporized water
– Uses
• Used in rare situations where large amounts of
trace minerals (calcium, magnesium, etc.) must
be removed to improve taste
– Some people periodically drink mineral-free water for
specific health regimens such as dissolving kidney &
gall stones
Technologies Available
• Distillation
– Uses and Risks
• Termed “aggressive” by EPA because of ability to
leach minerals
– Mineral free (soft) water can be detrimental to health
of bones, teeth and tissues if consumed over a long
period
– Other Disadvantages
• Requires electricity and adequate water
– Wastes gallons for every gallon produced
• Expensive
Technologies Available
• Distillation
– Problems
• Units require periodic and extensive maintenance
to the piping (not user friendly)
• Requires a holding tank which can possibly be
recontaminated and allow bacterial growth
• Not effective at removing VOC’s because many
re-condense back into liquid (just like water)
– Usually needs to be combined with a GAC filter to
remove additional chemicals
• Have been shown to blow vaporized
contaminants out into surrounding air
Technologies Available
• Reverse Osmosis
– A separation process that makes use of a
semi-permeable membrane
• Some contaminants can get through so a GAC
filter is added at end of process
• Better taste than distillation because water is
well-oxygenated (tastes closer to spring water)
• Unit of choice if extreme mineralization or high
nitrate levels in the water (agricultural areas)
Technologies Available
• Reverse Osmosis
– Disadvantages
• Waste 3 to 10 gallons of water for every gallon
produced
• Like distillation, produces essentially mineral
free water
– Mineral supplements recommended to counterbalance
leaching effect of drinking mineral-free, aggressive
water
Available Technologies
• Ultraviolet Light
– Uses UV light to kill bacteria
• Normally combined with carbon technology to
give more complete purification
– Disadvantages
• Only effective on bacteria, viruses and some
algae
• Does NOT eliminate protozoa such as
cryptosporidia and giardia
Available Technologies
• Ultraviolet Light
• Incomplete purification
– Less effective when organic matter is present
– No residual disinfection down the line
» Only good at the spot where the light is located
• Limited application
– Not effective against chemicals, lead or asbestos
• Expensive to purchase and maintain
Available Technologies
• Ozonation
– Super-oxygenate water to kill bacteria with
adequate contact time
– Disadvantages
• Only addresses bacterial contamination
• Needs to be combined with carbon filtration to be
effective
• Expensive to purchase and maintain
• Can create by-products in the treated water
Available Technologies
• Solid Carbon Block Filters
– Technology has combined absorption
capability of carbon with a solid block of
material to selectively strain particles out of
water being forced through it
• Density of the block determines how finely water
is cleaned
• Better brands have a three part filter and are
designed to prevent any possibility of “bypass”
due to high pressure failure
Available Technologies
• Solid Carbon Block Filters
– Advantages
• Mechanical straining
– Strains out dirt, sediment, rust, algae, cryptosporidia,
asbestos and particulate matter through water
pressure - no electricity required
» Even works on a simple hand pump
• Chemical bonding
– Carbon bonds to most chemical known to man
– When water is forced through the solid carbon block it
is forced to slow down so it increases the contact time
with the carbon
Available Technologies
• Solid Carbon Block Filters
» More contact time better reduction of toxins,
pesticides, THM’s, chlorine, bad tastes and odors
» Heavy metals like lead are absorbed
• Dissolved calcium and magnesium do not bond to
carbon
• Bacteria are strained out and remove on outside
of block
– Due to density of block, lack of oxygen and space
bacteria cannot breed in the carbon block
Available Technologies
• Convenient
– No storage, filters on demand
• Inexpensive
– Cost of a unit plus maintenance works out to about $60
/ year
– Water costs about 4-8 cents / gallon to make
• Filters are user friendly replaceable
• Lasts 8-12 months (dependent on amount of
sediment and dirt)
Available Technologies
• Solid Carbon Block Filters
– Disadvantage
• Will not remove nitrates or sulfides (agricultural
fertilization by-products)
– In areas these are a problem RO technology can take
care of the problem
Available Technologies
• Bottled Water
– Booming business
– Required to test to same standards as
municipal water suppliers
• Also allowed to have a minimum contaminant
level (same as municipal suppliers)
– Scoop on bottled water
• Expensive
• Inconvenient
Available Technologies
• Bottled Water
• No laws requiring it to be purer than tap water
• 1991, U.S. House Energy and Commerce
Commission study showed:
– 25% of “gourmet” waters drawn from same sources as
cities
– 31% exceeded tap water limits for microbiological
contaminants
– 25% could not document water source
– Any bottled water sold within state borders is not
subject to regulation by the FDA
Available Technologies
• Bottled Water
• 1985 University of Delaware study
– Found 24 out of 37 popular mineral waters were out of
line with at least one of the 31 standards for drinking
water
• Due to nature of bottling and handling it is
difficult to avoid casual contamination
• Air that bubbles up through home water
dispensers is contaminated with bacteria and
dust
• Bottled water companies recommend keeping
water out of direct sunlight
Water
• Bottled Water
– Regulated by U.S. FDA
• Regulates bottled water as a food
• Requires every product be fully tested annually
for chemical, physical and radiological
contaminants
– NSF Certification Program
• Verifies that the bottling facility and its products
meet the requirements of FDA regulations.
Bottled Water
• Types
– Artesian Water
• From a confined aquifer that has been tapped & the
water level stands above the top of the aquifer
– Ground Water
• From a subsurface saturated zone that is under
pressure
– Fluoridated
• Contains fluoride added within the limitations
established in the Code of Federal Regulations
Bottled Water
– Mineral Water
• Contains at least 250ppm total dissolved solids.
• Source tapped by bore holes or springs.
• Originates from a geologically and physically protected
underground water source.
• No minerals may be added to this water
– Purified Water
• Produced by distillation, deionization, reverse osmosis,
or other suitable processes
• May be referred to as “demineralized water”
Bottled Water
– Sparkling Water
• Contains the same amount of carbon dioxide that it
had at emergence from the source.
• CO2 maybe removed and replenished after treatment.
– Spring Water
• Comes from an underground formation from which
water flows naturally to the Earth’s surface.
– Sterile Water
• Meets the requirements for “sterility tests” in the U.S.
– Well Water
• Taken from a hole bored, drilled or otherwise
constructed in the ground.
Summary
• Consumer Protection
– Over 517 different brands of filters on the
market today
– Look for NSF certifications
– Remember the two main standards used for
water filtration devices
Summary
• NSF Two Main Standards for Water
Filtration Devices:
– #42: Aesthetic effects
• Covers taste, odor and chlorine removal
• Also rates on percent removal
– Class I: 75% or greater Chlorine removal
– Class II: 50-74% Chlorine removal
– Class III: 25-49% Chlorine removal
Summary
– #53: Health effects
• Covers most every pollutant, with many of them,
like lead and asbestos, being extremely hard to
remove due to size or chemical structure.
• The substances rated for are tested for
individually with each test a separate expense
– Chemicals (VOC’s, THM’s), Pesticides, Herbicides,
Cysts (Giardia & Cryptosporidia), Turbidity, Lead,
Asbestos & Radon
Summary
• Remember that NSF does not rate or
compare one unit over any other, it
simply certifies that product bearing the
registered NSF mark meets minimum
requirements of the applicable Standard