Groundwater Contaminants in Virginia and Treatment Technologies for Household Wells Virginia Master...

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


Treatments

• Disinfection by chlorine (most common)

• Reverse Osmosis not approved

Bacteria


Treatments

• Ozone

Bacteria


Treatments

• UV Light

Bacteria


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


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


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


MCL = .3 mg/L total iron Indicators

• Rusty color

• Sediment like mud

• Reddish or orange stains

• Metallic taste

Source• Natural deposits

Iron


3 Forms• Ferris – clear water

• Ferric – red water

• Organic slymes

Iron

Iron bacteria

Ferric water


Treatments

• Oxidizing filters

• Cation exchange

• Disinfection

• Oxidation/precipitation/filtration

Iron


MCL = .05 mg/L Indicators

• Dark brown stains

• Black stains

• Bitter metallic taste

• Sickness after inhalation


Manganese


Treatments• Oxidizing filters

• Cation exchange

• Disinfection/filtration

• Oxidation/precipitation/filtration

Manganese


MCL = 3 (threshold odor number) Indicators

• Rotten egg smell

• Musty

• Garlic

• Chemical

Odor


Sources• Chlorine – hydrogen sulfide

• Organic matter – gasoline contamination

• Methane gas – septic contamination

Odor


Treatments• Activated carbon

• Air stripping

• Oxidation/filtration

• Disinfection/filtration

Odor


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


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


MCL = 250 mg/L Indicators

• Medicinal taste

• Laxative effect

Source• Natural Deposits

Sulfate


Treatment• Reverse Osmosis

• Distillation

• Anion exchange

Sulfate


MCL = 500 mg/L Indicators

• Hard water

• Deposits on glasses and fixtures

• Colored water

• Staining

• Salty taste

TDS



• Brackish water intrusion

• Salt water intrusion

Treatment• Reverse osmosis

• Distillation

• Deionization by ion exchange

Taste


MCL = 10 mg/L Indicator

• Methemoglobinemia

Sources• Animal waste

• Fertilizer

• Natural deposits

• Septic tanks

• Sewage

Nitrate


Treatment• Chemical oxidation

• Anion exchange

• Reverse osmosis (preferred)

Nitrate


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


Treatment• Reverse Osmosis

• Distillation

• Cartridge-type filters

• New medias

• (pre-oxidize to convert Arsenic III to Arsenic V)

• Ion Exchange

Arsenic


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


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


Treatments• Raise pH of water

• Special lead filters

• Cation exchange softening

• Distillation

• Reverse Osmosis

Lead

Lead Removal Cartridge


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


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


Fluoride


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


Sources• Iron related bacteria

• Sulfur bacteria

Treatments• Chlorine feed followed by carbon filtration

• Ozonation followed by carbon filtration

Organic Slimes


No federal limit Indicators

• Staining of laundry and fixtures

• Odors

• Unpleasant solids in water

Sediment


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: [email protected]

USEPA Safe Drinking Water Hotline:800-426-4791www.epa.gov/safewater/hotline

Virginia Department of HealthOffice of Drinking Water804-786-6278

Groundwater Contaminants in Virginia and Treatment Technologies for Household Wells Virginia Master...

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