Transcript Water Resources Extension at Penn State University

Water Quality Contaminants
of Concern
Erin James
Virginia Master Well Owner Network Training
Sources of potential contaminants or
issues of concern
well
Surface water contamination: nitrate, bacteria
Source may be plumbing
materials or existing water
treatment device:
sodium
copper
lead
bacteria
Often found in groundwater naturally, may
be due to man’s activities on or below
ground:
TDS
iron
hardness
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Testing water quality
 Why test?
 Protect family’s health and safety
 Many contaminants undetectable by human senses
 Preventive measures often more effective and less
expensive
 Legal protection
 When to test?
 Routine tests every 1-3 years
 Pregnant woman or infant in the home
 Recurring gastrointestinal illness
 Change in taste, appearance, odor of water
 Any services or repairs are done
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What should I test for?
 Every year test for coliform bacteria
 Simple, inexpensive test ($15-20)
 Indicates possible contamination from human or animal
waste
 Every three years test:
 pH (secondary std: 6.5 – 8.5)
 Total Dissolved Solids (TDS; secondary std 500 mg/L)
 Other contaminants based on local land uses nearby
and condition of water
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Understanding test results
 Most results provided as concentrations:
 mg/L (milligrams per liter) ≈ ppm (parts per million)
 µg/L = (micrograms per liter) ≈ ppb (parts per billion)
 Other units unique to test
 Radon, hardness, pH
 Compare to EPA standards:
http://www.epa.gov/safewater/contaminants/index.html
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Private Water Supply Regulations
• Virginia Private Well Regulations
o Specify application, inspection and
construction requirements
o No requirements for maintenance or
water testing after construction of well –
responsibility of the owner!
• EPA National Drinking
Water Standards
o
o
o
Apply to PUBLIC systems
Primary (health) and Secondary
(nuisance)
Can be used as guidance for private
systems to know “how much is too
much”
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EPA Drinking Water Standards
Primary Standards
Secondary Standards
• Also called Maximum
Contaminant Level (MCL)
• Cause health problems
• Enforced for public systems
• Over 80 contaminants
• For example:
 Also called SMCL or RMCL
Nitrate
o Lead
o Coliform
o Most organic chemicals and
pesticides
o
 Cause aesthetic problems:
Staining
o Taste
o Odor
o
 Can naturally occur in ground
water
 About 15 contaminants including:
Iron
o Fluoride
o Chloride
o
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Tests for Specific Health Concerns
Situation
Recommended Tests
Family members or guests with
recurring incidents of
gastrointestinal illness
Coliform bacteria, nitrate,
sulfate
Household plumbing contains
pH, corrosion index, lead,
lead pipes, fittings or solder joints copper, cadmium, zinc
or brass
Household with pregnant woman Coliform bacteria, nitrate
or young infant
Family member on
recommended low-sodium diet
Sodium
Adapted from Household Water Testing. 2000. Blake Ross, Kathleen Parrott, and Janice Woodward (VCE pub 356-485)
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Tests based on nearby land use
If you suspect or observe
Recommended Tests
Leaking fuel tank
Hydrocarbon scan
Coal mining
TDS, iron, sulfate, pH, corrosivity,
manganese, aluminum
Gas or oil drilling
TDS, chloride, sodium, barium, lead, pH,
corrosivity, strontium
Road salt storage or application
TDS, chloride, sodium
Landfill or dump
TDS, pH, chemical oxygen demand, VOC
scan, heavy metals
Land application of sludge
Total coliform, nitrate, heavy metals
Septic system
Fecal coliform/E. coli, nitrate, surfactants
Intensive agricultural use
Total coliform, nitrate, pesticide scan, pH, TDS
Adapted from Household Water Testing. 2000. Blake Ross, Kathleen Parrott, and Janice Woodward (VCE pub 356-485)
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Nuisance Problems
Symptom
Description
Recommended Tests
Stained plumbing
fixtures
Red or brown
Reddish-brown slime
Black
Green or Blue
Chalky white
Iron
Iron bacteria
Manganese
Copper
Hardness
Off-color water
Cloudy
Black
Brown or yellow
Turbidity, suspended solids
Hydrogen sulfide, Mn
Iron, tannic acid
Unusual taste or odor
Rotten egg
Metallic
Salty
Septic, musty, earthy
Alkali, bitter
Gasoline or oil
Soapy
Hydrogen sulfide
pH, corrosivity, Fe, Cu, Zn, Pb
TDS, chloride, sodium
Coliform, methane
pH, TDS
Hydrocarbon scan
Surfactants or detergents
Corrosive water
Deposits, pitting of
plumbing
Corrosivity, pH, copper, lead
Adapted from Household Water Testing. 2000. Blake Ross, Kathleen Parrott, and Janice Woodward (VCE pub 356-485)
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If Coliform Bacteria are PRESENT
 Don’t panic!
 Recommend RETEST
 Use certified lab
 Follow with test for E. Coli bacteria
 Take this as an opportunity to examine well or
spring for damage or needed improvements
 Consider shock chlorination
 Long term treatment options: ozonation, UV light,
continuous chlorination
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http://www.kimicontrol.com/microorg/escherichia_coli.jp
If E. Coli Bacteria are PRESENT
 Take immediate steps to address
 Shock chlorinate
 Retest water
 In the meantime, consider boiling for at least 3
minutes or use another source of water for
drinking or cooking
 Check for potential contamination sources,
examine well or spring
 Consider long-term treatment options: UV light,
ozonation, continuous disinfection
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http://wi.water.usgs.gov/pubs/FS-221-95/p2.gif
Nitrate (NO3-N)
 Serious health concern for infants < 6 mo
 Methemoglobinemia or “blue baby syndrome”
 Nitrate
 nitrite during digestion and blood cannot carry oxygen
 Sources include fertilizer, animal manure, sewage
 NO3 dissolves and moves easily through soil
 Test in spring months; levels change over time
 BOILING INCREASES concentration of nitrates!!!
 Treatment: distillation, reverse osmosis, ion exchange
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0
1
pH
 Measure of whether a
more acidic
substance is acidic or
alkaline
Neutral
 pH of 5 is 100 times more
water quality
Vinegar
5
Coffee
6
Milk
7
Distilled water
8
acidic than pH of 7
(logarithmic scale)
 Good indicator of general
3
4
 Scale:
0 (acidic) to 14 (alkaline)
2
Battery acid
Gastric acid
Lemon juice
9
Baking soda
Sea water
10
more alkaline
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Milk of magnesia
12
Ammonia
13
Bleach
Lye
14
Recommended
pH range
6.5 – 8.5
Corrosive and Scaling Water
 Measure of alkalinity, TDS, and pH
 Corrosive (aggressive) water
 Corrodes metal in plumbing, causing damage, pitting
 Leaching of copper or lead into drinking water – health
concern!
 EPA recommends drinking water be non-corrosive
 Scaling water
 Contains high levels of minerals
 Forms scale on inside of pipes and appliances, lime
deposits on shower heads and taps
 Can lead to clogging of pipes, reduced efficiency of heaters
and appliances
http://www.bushman.cc/photos/Copper_Water_Pipe_Corrosion.jpg; www.watersoftening.org/effects_of_hard_water.htm
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Corrosive and Scaling Water
 Usually a measure of alkalinity, TDS, and pH; often
reported as a Saturation Index (varies by lab)
Langelier Saturation
Index (LSI)
Description
Recommendation
-5 to -3
Severe corrosion
Treatment recommended
-3 to -1
Moderate corrosion
Consider treatment
1- to 1
Balanced
Treatment not needed
1 to 3
Moderate scaling
Consider treatment
3 to 5
Severe scaling
Treatment recommended
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Corrosive Water
 Also called aggressive water
 Corrodes metal plumbing – can leach metals, causes pitting and
leaks, reduces length of appliance life
 Most commonly caused by low pH; other contributing factors include
alkalinity, temperature, TDS levels
 EPA recommends drinking water be non-corrosive
 Excess copper or lead in drinking water is a health concern
 Depending on pH, treat with acid neutralizing filter or soda ash
injection
http://www.bushman.cc/photos/Copper_Water_Pipe_Corrosion.jpg; http://www.cee.vt.edu/ewr/environmental/teach/wtprimer/corrosion/corrosion.html
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Corrosive Water: Metals of concern
 Lead
 Many serious health effects, especially in children and infants
Developmental, neurological, reproductive and renal
 EPA MCL is 0 µg/L with a health action level of 15 µg/L.
 Sources include:




Pipes in older homes (pre-1930)
Solder in homes built prior to 1986
“Lead-free” brass fixtures (<8%) – even in NEW homes!
 Copper
 High levels can cause nausea, vomiting, stomach cramps; infants and
children particularly sensitive
 EPA MCL is 1.3 mg/L
 Nuisance effects noticeable at 1.0 mg/L
http://www.gravitaexim.com/images/Lead-pipe.jpg
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www.goodcleanwater.com/fyi.htm; www.watersoftening.org/effects_of_hard_water.htm;
Hardness/Scaling
 Hard water contains high levels of
calcium and magnesium ions
 Dissolved into water during contact with
limestone and other minerals
 Not a health risk – nuisance
 Decreased cleaning action of soaps, detergents
 Scale build-up in pipes and on appliances
 Reduced efficiency and lifespan of water heaters
 No EPA standard for public systems
 Treat using water softener
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Total Dissolved Solids (TDS)
 Water is a great solvent – dissolves many compounds as
it travels over and under ground
 TDS is a measure of all dissolved impurities < 2µm dia
 Natural sources: limestone, salt deposits, other minerals
 Man-made sources:
 Septic systems and sewage
 Run off from agricultural or urban land
 Road salt, industrial sources
 General indicator of water quality;
test at least every three years
 EPA SMCL is 500 mg/L
 Treat using distillation or reverse osmosis
http://en.wikipedia.org/wiki/Total_dissolved_solids
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Fluoride
 Occurs naturally in varying levels
 Naturally high levels of F in E. Virginia groundwater (3-6 mg/L)
 Added to many public water systems for reduced dental
caries and strong teeth and bones
 Health concerns:
 Long term exposure: links to bone cancer
 Shorter term exposure: dental or skeletal fluorosis
 EPA MCL 4.0 mg/L and SMCL 2.0 mg/L
 Optimum levels for public systems 0.8 - 1.2 mg/L
 Limited use for children up to 8 years
 Treatment (reverse osmosis) removes ALL fluoride
http://www.willamettedental.com/en_us/ALL/patients/pps/retailproducts_prettysmile.gif; http://en.wikipedia.org/wiki/Dental_fluorosis
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/www.cotrip.org/winterdriving/images/pic6.jpg; /www.apswater.com/images/fleck%205600.jpg
Sodium and Chloride
 Low levels occur naturally; high levels
usually from
man-made source
 Road salt storage or application
 Sewage, fertilizers or animal waste
 WATER SOFTENER
 Sodium: EPA MCL for those onlow-sodium diets: 20 mg/L
 Chloride: EPA SMCL of 250 mg/L
 Higher levels may indicate contamination – test for
bacteria or other contaminants
 Salty taste; increased corrosion of pipes and water heaters
 Treat using distillation, reverse osmosis, demineralization
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http://www.freedrinkingwater.com/images-water-quality/chemicals/water%20in%20reddish-brown.jpg
Iron and Manganese
 Nuisance - not health concern
 SMCL: Iron = 0.3 mg/L
Manganese = 0.05 mg/L
 Red-brown/black staining, particles,
metallic taste
 Treatment depends on type/form of iron
 Ferrous: water initially clear  orange-brown
or black solid particles
 Ferric: solid particles apparent immediately,
or water has a tint
 Iron/Manganese bacteria: not a health concern; feed on Fe
and Mn, forming red-brown or black-brown slime
 Treatment: water softener, aeration and filtration, ozonation,
distillation
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thepipelinefixation.blogspot.com
Hydrogen Sulfide
 Colorless gas; rotten egg smell
 Not regulated by EPA – people can detect low levels
 Naturally present in shale, sandstone, near coal or oil
fields
 Sulfur-reducing bacteria produce (not a health risk)
 Treatment depends on concentration, so must test
 Only noticeable in hot water?
 Bacteria could be thriving in your water heater
 Sulfates may be converted to H2S chemically in your
water heater during a reaction with your magnesium
corrosion control rod
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What do you recall about…..
 Iron and manganese
 Bacteria
 Hardness
 Corrosive and Scaling Water
 Hydrogen Sulfide
 Nitrate
 Sodium
 TDS
 Fluoride
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