Transcript Bacteria - Virginia Household Water Quality Program

Groundwater Contaminants in
Virginia and Treatment
Technologies for Household Wells
Presented by: Mike Heatwole, CWS VI
Sales Manager
May Supply Company
Harrisonburg, VA
Virginia Master Well Owner Network s October 30, 2008
Well Testing

If you own a well or private water supply,
it is your responsibility to have it tested

Testing is only mandatory at the time of
property exchange
Well Testing

Test the well immediately if the following occurs:
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•
•
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Water changes color
Water develops a
taste
Water develops a
smell
A natural disaster or
heavy flooding
No known results
•
•
•
•
Someone in the
household is pregnant or
nursing
Unexplained illness
occurs
Known contaminants are
in the area
A spill occurs in the area
Well Testing

Test the well once a year for:
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Coliform bacteria
Nitrate/Nitrite
Lead (if an older
home)
Iron
Manganese
•
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Hardness
pH
Sulfate
TDS
Alkalinity
Well Testing

Test for the following if:
• Well is near gas stations
• VOCs
• Well is in bedrock
• Arsenic
• Radon
• Flouride
Where Do I Get My Water Tested?
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Check with a local testing laboratory
Purchase your own test kit
Check with your well driller or pump installer
Check with local water treatment dealers, who
may offer free testing – be prepared for a sales
pitch!
Local wholesaler or supplier who has testing
capabilities
Water Testing Considerations
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Some tests require special containers
and collection procedures
Some labs offer sample collection
services
Keep a record of all test results
Some tests are best performed on-site
Have the results explained clearly
What Does the Test Measure?

Common measurements:
• MCL = Maximum Contaminant Level
measured in:
•
mg/L (milligrams per liter) or PPM (part per million)
• MCLG = maximum contaminant goal

1 part per billion (PPB)=
• 1¢ in $10,000,000
• 1 second in 30 years
What Does the Test Measure?

1 part per million (PPM) =

Conversion factors:
• 1¢ in $10,000
• 1 second in 11 days
• PPM = GPG x 17.1
• mg/L = GPG x 17.1
• GPG = PPM/17.1
• GPG = Mg/L/17.1
Common Water Problems
Bacteria


May or may not be pathogenic
Indicator
• Gastrointestinal disorders such as cramps,
diarrhea and nausea

Source
• Contaminated source water with human or
animal waste
Common Water Problems
Bacteria

Treatments
• Disinfection by chlorine (most common)
• Reverse Osmosis not approved
Common Water Problems
Bacteria

Treatments
• Ozone
Common Water Problems
Bacteria

Treatments
• UV Light
Common Water Problems
Bacteria

Treatments
• Distillation
What Is UV Light?
Electromagnetic Spectrum
How Does UV Light Destroy
Microorganisms?


UV Light does not kill microorganisms
UV Light is absorbed by
microorganisms, shifting electrons and
breaking bonds in their deoxyribonucleic
acid (DNA). This keeps the organism
from reproducing, minimizing the risk
and spread of disease.
How Does UV Light Destroy
Microorganisms?
Mode of Action of Ultraviolet Light
Are There Other Ways To
Disinfect the Water?
1.
2.
3.
4.
5.
6.
Find the source of contamination and
eliminate it.
Find the source of contamination and correct
it.
Find a new source of water.
Boil the water.
Use chemical disinfection in the water.
Use Ultraviolet Light to treat the water.
A Disinfectant Should…
1.
2.
3.
4.
5.
6.
7.
8.
Destroy all types of pathogens.
Destroy all types of pathogens in the time available.
Function properly at all times.
Function within the temperature range.
Not cause water to become toxic or unpalatable.
Be safe and easy to handle.
Have a determinable concentration.
Provide residual protection.
Construction of UVs
Typical UV System
Advantages of UV Light
1.
2.
3.
4.
5.
6.
7.
8.
9.
Automatic
No taste or odor
Low contact time
Practical
Does not create THMs
Low cost to operate
More effective than chlorine
Compact and easy to maintain
EPA-endorsed technology
Disadvantages of a UV Light
1.
2.
3.
4.
5.
Shielding by turbidity
Tube coating may occur
No residual
The bulb gradually loses power
No way to test residual or dosage
Options to Consider
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UV monitor
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Measures UV output
Flow control
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Prevents overrun of water
Hour meter
•
Alerts to bulb change
Solenoid valve
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Shuts off flow is a failure occurs
Wiper
Final Installation
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
Always disinfect water lines after system
is installed.
Always do a final test for customer to
ensure safety.
Maintenance of UVs
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Change bulbs once a year
Clean quartz sleeve regularly
Inspect unit
Change O-rings
Common Water Problems
Hardness
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No federal limit
Soft = less than 17.1 PPM
Slightly Hard = 17.1 - 60 PPM
Moderately Hard = 60 – 120 PPM
Hard = 120 – 180 PPM
Very Hard = 180+ PPM
Common Water Problems
Hardness
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Indicators
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White scale and deposits
Soap curd and lime scum residue
Consumes soap and makes cleaning more difficult
Source
•
Calcium (limestone) and magnesium salts in rain
water
Treatment
•
Water softener
Softener
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Advantages
• Saves on:
• Soaps and cleaning supplies
• Plumbing
• energy

Disadvantages
• Sends water to drain
• Watch use in
alternative septics
Common Water Problems
Iron
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MCL = .3 mg/L total iron
Indicators
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Rusty color
Sediment like mud
Reddish or orange stains
Metallic taste
Source
•
Natural deposits
Common Water Problems
Iron
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3 Forms
• Ferris – clear water
• Ferric – red water
• Organic slymes
Ferric water
Iron bacteria
Common Water Problems
Iron

Treatments
• Oxidizing filters
• Cation exchange
• Disinfection
• Oxidation/precipitation/filtration
Common Water Problems
Manganese
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MCL = .05 mg/L
Indicators
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Dark brown stains
Black stains
Bitter metallic taste
Sickness after inhalation
Source
•
Natural deposits
Common Water Problems
Manganese
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Treatments
• Oxidizing filters
• Cation exchange
• Disinfection/filtration
• Oxidation/precipitation/filtration
Common Water Problems
Odor
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MCL = 3 (threshold odor number)
Indicators
• Rotten egg smell
• Musty
• Garlic
• Chemical
Common Water Problems
Odor
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Sources
• Chlorine – hydrogen sulfide
• Organic matter – gasoline contamination
• Methane gas – septic contamination
Common Water Problems
Odor
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Treatments
• Activated carbon
• Air stripping
• Oxidation/filtration
• Disinfection/filtration
Common Water Problems
pH
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MCL = 6.5 – 8.8
Indicators
• Low pH: sour and metallic taste, corrosion
• High pH: slippery feel, bitter and soda taste,
deposits
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Not to be confused with Alkalinity
Common Water Problems
pH
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Source
• Particular balance of acids and alkalinity
existing in all natural waters
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Treatments
• Increase by feeding soda ash or neutralizing
•
filter (calcite or calcite/magnesium)
Decrease by feeding white vinegar or citric
acid
Common Water Problems
Sulfate
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MCL = 250 mg/L
Indicators

Source
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• Medicinal taste
• Laxative effect
• Natural Deposits
Common Water Problems
Sulfate
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Treatment
• Reverse Osmosis
• Distillation
• Anion exchange
Common Water Problems
TDS
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MCL = 500 mg/L
Indicators
• Hard water
• Deposits on glasses and fixtures
• Colored water
• Staining
• Salty taste
Common Water Problems
Taste
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Source
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Natural deposits
Brackish water intrusion
Salt water intrusion
Treatment
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Reverse osmosis
Distillation
Deionization by ion exchange
Common Water Problems
Nitrate
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MCL = 10 mg/L
Indicator
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Methemoglobinemia
Sources
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Animal waste
Fertilizer
Natural deposits
Septic tanks
Sewage
Common Water Problems
Nitrate
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Treatment
• Chemical oxidation
• Anion exchange
• Reverse osmosis (preferred)
Common Water Problems
Arsenic
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MCL = 50 PPB
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2 Types
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Sources
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Builds up in the body
• As of January 2006, it will be 10 PPB
• Organic and inorganic (most dangerous)
• Naturally Occurring
Common Water Problems
Arsenic
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Treatment
• Reverse Osmosis
• Distillation
• Cartridge-type filters
• New medias
• (pre-oxidize to convert Arsenic III to
•
Arsenic V)
Ion Exchange
Common Water Problems
Sulphur
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No federal limit
Is a gas, and must be tested on-site
Indicators
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Can be poisonous
Can burn
Causes corrosion
Treatment
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Chlorine/filtration
Air stripping
Common Water Problems
Lead
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MCL = 0.015 (MCLG = 0.0)
Indicators
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Causes delay in physical and mental development
High blood pressure or kidney problems in adults
Sources
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Old solder
Corrosion of plumbing systems
Erosion of natural deposits
Common Water Problems
Lead
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Treatments
• Raise pH of water
• Special lead filters
• Cation exchange softening
• Distillation
• Reverse Osmosis
Lead Removal Cartridge
Common Water Problems
Radon
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MCL = 5 pCi/L (picocuries per liter) (MCLG = 0)
Indicators
•
Causes increased risk of cancer
Sources
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Erosion of natural deposits
Treatment
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Granular activated carbon
Aeration
Common Water Problems
Fluoride
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MCLG = 4.0
MCL – 4.0
Indicators
• Mottled teeth (Fluoride is added to
•
strengthen teeth)
Bone disease, pain and tenderness
Common Water Problems
Fluoride
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Sources
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Treatment
• Aluminum factories
• fertilizer
• Activated Alumina filters
• Distillation
• Reverse Osmosis
Common Water Problems
Organic Slimes
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No federal limit
Indicators
• Red or clear film in back of toilets – oily
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•
residue
Rotten egg smell
Can plug pumps and water systems
Common Water Problems
Organic Slimes
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Sources
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Treatments
• Iron related bacteria
• Sulfur bacteria
• Chlorine feed followed by carbon filtration
• Ozonation followed by carbon filtration
Common Water Problems
Sediment
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
No federal limit
Indicators
• Staining of laundry and fixtures
• Odors
• Unpleasant solids in water
Common Water Problems
Sediment

Sources

Treatment
• Poor well construction
• Surface water influx
• Cartridge or automatic filters
• Alum feed/retention/filtration
For Additional Information
Water Quality Association
4151 Naperville Road
Lisle, IL 60532
ph: 630-505-0160
fax: 630-505-9637
www.wqa.org
Water Systems Council
1101 30th Street NW, Suite 500
Washington DC 20007
ph: 202-625-4387
fax: 202-625-4363
www.wellcarehotline.org
Local Health Departments
-in the phone book under Government
National Groundwater Association
South Atlantic Well Drillers Association
PO Box 1290
New Market, VA 22844
540-740-3329
American Ground Water Trust
16 Centre Street, PO Box 1796
Concord, NH 03301
ph: 603-228-5444
fax: 603-228-6557
[email protected]
USEPA Safe Drinking Water Hotline:
800-426-4791
www.epa.gov/safewater/hotline
Virginia Department of Health
Office of Drinking Water
804-786-6278