Post on 19-Jan-2016
Groundwater Contaminants in Virginia and Treatment Technologies
for Household Wells
Virginia Master Well Owner Network October 30, 2008
Presented by: Mike Heatwole, CWS VISales ManagerMay Supply CompanyHarrisonburg, VA
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
• 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
Test the well immediately if the following occurs:
Well Testing
Test the well once a year for:• Coliform bacteria
• Nitrate/Nitrite
• Lead (if an olderhome)
• Iron
• Manganese
• 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?
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
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) = • 1¢ in $10,000
• 1 second in 11 days
Conversion factors:• PPM = GPG x 17.1
• mg/L = GPG x 17.1
• GPG = PPM/17.1
• GPG = Mg/L/17.1
Common Water Problems
May or may not be pathogenic Indicator
• Gastrointestinal disorders such as cramps, diarrhea and nausea
Source• Contaminated source water with human or
animal waste
Bacteria
Common Water Problems
Treatments
• Disinfection by chlorine (most common)
• Reverse Osmosis not approved
Bacteria
Common Water Problems
Treatments
• Ozone
Bacteria
Common Water Problems
Treatments
• UV Light
Bacteria
Common Water Problems
Treatments
• Distillation
Bacteria
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. Find the source of contamination and eliminate it.
2. Find the source of contamination and correct it.
3. Find a new source of water.
4. Boil the water.
5. Use chemical disinfection in the water.
6. Use Ultraviolet Light to treat the water.
A Disinfectant Should…
1. Destroy all types of pathogens.
2. Destroy all types of pathogens in the time available.
3. Function properly at all times.
4. Function within the temperature range.
5. Not cause water to become toxic or unpalatable.
6. Be safe and easy to handle.
7. Have a determinable concentration.
8. Provide residual protection.
Construction of UVs
Typical UV System
Advantages of UV Light
1. Automatic
2. No taste or odor
3. Low contact time
4. Practical
5. Does not create THMs
6. Low cost to operate
7. More effective than chlorine
8. Compact and easy to maintain
9. EPA-endorsed technology
Disadvantages of a UV Light
1. Shielding by turbidity
2. Tube coating may occur
3. No residual
4. The bulb gradually loses power
5. No way to test residual or dosage
Options to Consider
UV monitor• Measures UV output
Flow control• Prevents overrun of water
Hour meter• Alerts to bulb change
Solenoid valve• Shuts off flow is a failure occurs
Wiper
Final Installation
Always disinfect water lines after system is installed.
Always do a final test for customer to ensure safety.
Maintenance of UVs
Change bulbs once a year Clean quartz sleeve regularly Inspect unit Change O-rings
Common Water Problems
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
Hardness
Common Water Problems
Indicators• 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
Hardness
Softener
Advantages• Saves on:
• Soaps and cleaning supplies
• Plumbing
• energy
Disadvantages• Sends water to drain
• Watch use in alternative septics
Common Water Problems
MCL = .3 mg/L total iron Indicators
• Rusty color
• Sediment like mud
• Reddish or orange stains
• Metallic taste
Source• Natural deposits
Iron
Common Water Problems
3 Forms• Ferris – clear water
• Ferric – red water
• Organic slymes
Iron
Iron bacteria
Ferric water
Common Water Problems
Treatments
• Oxidizing filters
• Cation exchange
• Disinfection
• Oxidation/precipitation/filtration
Iron
Common Water Problems
MCL = .05 mg/L Indicators
• Dark brown stains
• Black stains
• Bitter metallic taste
• Sickness after inhalation
Source• Natural deposits
Manganese
Common Water Problems
Treatments• Oxidizing filters
• Cation exchange
• Disinfection/filtration
• Oxidation/precipitation/filtration
Manganese
Common Water Problems
MCL = 3 (threshold odor number) Indicators
• Rotten egg smell
• Musty
• Garlic
• Chemical
Odor
Common Water Problems
Sources• Chlorine – hydrogen sulfide
• Organic matter – gasoline contamination
• Methane gas – septic contamination
Odor
Common Water Problems
Treatments• Activated carbon
• Air stripping
• Oxidation/filtration
• Disinfection/filtration
Odor
Common Water Problems
MCL = 6.5 – 8.8 Indicators
• Low pH: sour and metallic taste, corrosion
• High pH: slippery feel, bitter and soda taste, deposits
Not to be confused with Alkalinity
pH
Common Water Problems
Source• Particular balance of acids and alkalinity
existing in all natural waters
Treatments• Increase by feeding soda ash or neutralizing
filter (calcite or calcite/magnesium)
• Decrease by feeding white vinegar or citric acid
pH
Common Water Problems
MCL = 250 mg/L Indicators
• Medicinal taste
• Laxative effect
Source• Natural Deposits
Sulfate
Common Water Problems
Treatment• Reverse Osmosis
• Distillation
• Anion exchange
Sulfate
Common Water Problems
MCL = 500 mg/L Indicators
• Hard water
• Deposits on glasses and fixtures
• Colored water
• Staining
• Salty taste
TDS
Common Water Problems
Source• Natural deposits
• Brackish water intrusion
• Salt water intrusion
Treatment• Reverse osmosis
• Distillation
• Deionization by ion exchange
Taste
Common Water Problems
MCL = 10 mg/L Indicator
• Methemoglobinemia
Sources• Animal waste
• Fertilizer
• Natural deposits
• Septic tanks
• Sewage
Nitrate
Common Water Problems
Treatment• Chemical oxidation
• Anion exchange
• Reverse osmosis (preferred)
Nitrate
Common Water Problems
MCL = 50 PPB • As of January 2006, it will be 10 PPB
2 Types• Organic and inorganic (most dangerous)
Sources• Naturally Occurring
Builds up in the body
Arsenic
Common Water Problems
Treatment• Reverse Osmosis
• Distillation
• Cartridge-type filters
• New medias
• (pre-oxidize to convert Arsenic III to Arsenic V)
• Ion Exchange
Arsenic
Common Water Problems
No federal limit Is a gas, and must be tested on-site Indicators
• Can be poisonous
• Can burn
• Causes corrosion Treatment
• Chlorine/filtration
• Air stripping
Sulphur
Common Water Problems
MCL = 0.015 (MCLG = 0.0) Indicators
• Causes delay in physical and mental development
• High blood pressure or kidney problems in adults
Sources• Old solder
• Corrosion of plumbing systems
• Erosion of natural deposits
Lead
Common Water Problems
Treatments• Raise pH of water
• Special lead filters
• Cation exchange softening
• Distillation
• Reverse Osmosis
Lead
Lead Removal Cartridge
Common Water Problems
MCL = 5 pCi/L (picocuries per liter) (MCLG = 0) Indicators
• Causes increased risk of cancer
Sources• Erosion of natural deposits
Treatment• Granular activated carbon
• Aeration
Radon
Common Water Problems
MCLG = 4.0 MCL – 4.0 Indicators
• Mottled teeth (Fluoride is added to strengthen teeth)
• Bone disease, pain and tenderness
Fluoride
Sources• Aluminum factories
• fertilizer
Treatment• Activated Alumina filters
• Distillation
• Reverse Osmosis
Common Water Problems
Fluoride
Common Water Problems
No federal limit Indicators
• Red or clear film in back of toilets – oily residue
• Rotten egg smell
• Can plug pumps and water systems
Organic Slimes
Common Water Problems
Sources• Iron related bacteria
• Sulfur bacteria
Treatments• Chlorine feed followed by carbon filtration
• Ozonation followed by carbon filtration
Organic Slimes
Common Water Problems
No federal limit Indicators
• Staining of laundry and fixtures
• Odors
• Unpleasant solids in water
Sediment
Common Water Problems
Sources• Poor well construction
• Surface water influx
Treatment• Cartridge or automatic filters
• Alum feed/retention/filtration
Sediment
For Additional Information
Water Quality Association4151 Naperville RoadLisle, IL 60532ph: 630-505-0160fax: 630-505-9637www.wqa.org
Water Systems Council1101 30th Street NW, Suite 500Washington DC 20007ph: 202-625-4387
fax: 202-625-4363www.wellcarehotline.org
Local Health Departments-in the phone book under Government
National Groundwater Association
South Atlantic Well Drillers AssociationPO Box 1290New Market, VA 22844540-740-3329
American Ground Water Trust16 Centre Street, PO Box 1796Concord, NH 03301ph: 603-228-5444fax: 603-228-6557trustinfo@aqwt.org
USEPA Safe Drinking Water Hotline:800-426-4791www.epa.gov/safewater/hotline
Virginia Department of HealthOffice of Drinking Water804-786-6278