Post on 01-Jan-2016
Drinking Water ClinicInterpretation Meeting
Erin Ling and Brian BenhamVirginia Tech Biological Systems Engineering, Virginia Cooperative Extension
Why are we here?Why are we here?
• Caring for your private water system• Well location, protection, and construction
• Well maintenance and care
• Drinking water regulations – knowing how much is too much
• Water testing – what’s in your water?
• Dealing with problems
• Additional resources
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Private Water Supplies in VirginiaPrivate Water Supplies in Virginia1.7 million Virginians rely on wells, springs or
cisterns (22% of the population)
In the U.S. municipal water supplies are regulated by the EPA under the Safe Drinking Water Act; private supplies are not!
Homeowners relying on private water supplies:◦ Are responsible for all aspects of water system management
◦ May lack knowledge and resources to effectively manage
◦ Usually don’t worry about maintenance until problems arise
Groundwater is a shared resource – our actions can affect others’ water supplies too!
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How does water move to my well?How does water move to my well?(Bedrock/drilled well)(Bedrock/drilled well)
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In a bedrock well, groundwater moves through fractures, or cracks in the bedrock
Water can come from many different directions, depths, and sources into one well
It can take water hours, days, or years to move through to bedrock
Well casing extends through loose “overburden” and into the bedrock, where an “open” borehole continues underground
Water can come from any fractures that intersect the open borehole
How does water move to my well?How does water move to my well?(Bored or water table well)(Bored or water table well)
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In drilled or bored wells in sandy aquifers, groundwater fills up the pore spaces between grains of sediment or sand
In shallow wells, water moves relatively quickly from the surface down into the water table; with deeper wells, it takes more time.
There are a large range of depths of wells reaching aquifers at varying levels
Proper well locationProper well locationWell should be at least:◦ 10 feet from building foundation
(50 feet if termite treated)
◦ 50 feet from road
◦ 50 feet from sewers and septic tanks
◦ 100 feet from pastures, on-lot sewage system drainfields, cesspools or barnyards
Upslope from potential contaminationNot in an area that receives runoff
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Proper well constructionProper well constructionContract a licensed driller:
◦ Valid Class A, B or C contractor license with WWP (Water Well and Pump) classification
Well casing ◦ Minimum of 20’ for bored, 50 – 100’ deep for
drilled, depending on class of well
◦ Extends 12” above ground
Grouting to a minimum of 20’
Sanitary well cap or sealed concrete cover
Ground slopes away from well
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The Finished Product – Drilled WellThe Finished Product – Drilled Well
8http://www.omafra.gov.on.ca/english/environment/06-117.htm
Grout sealGrout seal
Sealed, sanitary well capSealed, sanitary well cap
Casing extending >12” above ground surface
Casing extending >12” above ground surface Ground sloping away
from casing
Ground sloping away from casing
Well Maintenance TipsWell Maintenance TipsDo not use fertilizers, pesticides, oil, or paint near well
Keep area around well clean and accessible
Keep careful records ◦ original contract, water test results and any
maintenance or repair information
Every year:◦ Conduct thorough visual inspection of well
◦ Check cap for cracks, wear and tear, tightness
Every 1-3 years have well inspected by a qualified professional (with WWSP classification)
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Private Water Supply RegulationsPrivate Water Supply Regulations
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• Virginia Private Well Regulationso 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 Apply to PUBLIC systems
o Primary (health) and Secondary (nuisance)
o Can be used as guidance for private systems to know “how much is too much”
EPA Drinking Water StandardsEPA Drinking Water Standards
Primary Standards• Also called Maximum
Contaminant Level (MCL)
• Cause health problems
• Enforced for public systems
• Over 80 contaminants
• For example: o Nitrate
o Lead
o Coliform
o Most organic chemicals and pesticides
Secondary Standards Also called SMCL or RMCL
Cause aesthetic problems:o Staining
o Taste
o Odor
Can naturally occur in ground water
About 15, including:o Iron
o Sulfate
o Manganese
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Testing water qualityTesting water qualityWhy 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?What should I test for?
Every year test for coliform bacteria◦ Simple, relatively inexpensive test
◦ 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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Conditions or nearby activities of concernConditions or nearby activities of concernConditions or Nearby Activities Test for:
Recurring gastro-intestinal illness Coliform bacteria, E. Coli
Household plumbing contains metals pH, lead, copper
Corrosion of pipes and plumbing Corrosivity, pH, lead
Nearby areas of intensive agriculture Nitrate, pesticides, coliform bacteria
Coal or other mining operations Metals, pH, corrosivity
Dump, junkyard or landfill VOCs, TDS, pH, sulfate, chloride, metals
Odor of gasoline or fuel oil VOCs
Objectionable taste or smell of water Hydrogen sulfide, corrosivity, metals
Stained plumbing fixtures or laundry Iron, copper, manganese
Salty taste Chloride, TDS, sodium
Scaly residues, soaps don’t lather Hardness
Rapid wear of water equipment pH, corrosivity
Water is cloudy, frothy or colored Colors, detergents
14Adapted from “Drinking Water for Household Wells”, EPA, 2002
If you need help figuring out what to test for, call Erin!
Understanding test resultsUnderstanding test resultsMost 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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How much? How much? 4 drops of ink in a 55 gallon barrel of water results in an“ink concentration”of 1 mg/L or ppm!
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Sources of potential contaminants or issues of concern
pH/corrosivity hardnessnitrate
fluoride
TDSiron
manganese sulfatechloride
sodium
Surface water contamination: nitrate, bacteria
Source may be plumbing materials or existing water treatment device:sodiumcopperleadbacteria
Some are found in groundwater naturally, either due to human activities on or below ground:
well
Where a contaminant comes from affects how we can deal with it!
arsenic
Options for problem waterOptions for problem water1. If possible, control the source of pollution
◦ Divert runoff, maintain septic system
2. Improve maintenance of water system◦ Install sanitary well cap, slope the ground
3. Treat the water to reduce contaminant concentration◦ Match the treatment option to the pollutant
◦ Consult a professional
4. Develop a new source of water◦ Deeper well, develop spring, connect to public
water
17http://static.howstuffworks.com/gif/septic-tank-cleaning-1.jpg, http://www.shipewelldrilling.com/Pictures/well_drilling_rig.jpg, http://www.clearflow.ca/REVERSE_OSMOSIS2.jpg
Treatment ConsiderationsTreatment Considerations Be sure to explore ALL of your options
Always have water tested by a certified lab
Be aware of unscrupulous businesses – look for National Sanitation Foundation (NSF) and Water Quality Association (WQA) certifications, consult Better Business Bureau (BBB)
Point of Use (POU) vs. Point of Entry (POE)
Weigh benefits and limitations of a device:◦ Cost
◦ Maintenance requirements
◦ Warranty
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SAMPLE Test ReportSAMPLE Test Report
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TestHousehold
Water SampleMaximum Recommended
Level or RangeIron (mg/L) ND 0.3Manganese (mg/L) 0.073** 0.05Hardness (mg/L) 44.7 180Sulfate (mg/L) 1.2 250Fluoride (mg/L ND 2Total Dissolved Solids (mg/L) 84.5 500pH 5.8** 6.5 to 8.5Sodium (mg/L) 8.1 20Nitrate-N (mg/L) ND 10Total Coliform Bacteria Present** AbsentE. Coli Bacteria Absent AbsentFirst Draw Data:
Arsenic (mg/L) ND 0.01Copper (mg/L) 1.1** 1.3
Lead (mg/L) 0.007 0.015Flush Data:
Arsenic (mg/L) ND 0.01Copper (mg/L) ND 1.3
Lead (mg/L) ND 0.015
** = exceeds recommended
level
** = exceeds recommended
level
ND = not detected by instrument;
may be expressed as
>0.001
ND = not detected by instrument;
may be expressed as
>0.001
Coliform BacteriaColiform BacteriaCannot be smelled, tasted or seenColiform bacteria is an indicator
organism – means disease-causing bacteria may be present
Public standard is 0 colony forming units (cfu)/100 mL (ABSENT)
If present, test for fecal coliform or E. coli presence – indicator that sewage or animal waste is present.
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If Coliform Bacteria are PRESENTIf Coliform Bacteria are PRESENTDon’t panic!Examine well for pathways surface water can
enter well (cracks in casing), make sure sanitary well cap is installed and secure, ground slopes away from well, etc.
Consider shock chlorinationRetest after shock chlorinationLong term treatment options: ozonation, UV
light, continuous chlorination
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If If E. Coli E. Coli Bacteria are PRESENTBacteria are PRESENTTake immediate steps to addressShock chlorinateRetest waterIn the meantime, consider boiling or use
another source of water for drinking or cooking
Check for potential contamination sourcesConsider long-term treatment options: UV
light, ozonation, continuous disinfection
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pHpH Measure of the
acidity or alkalinity of a substance (0 – 14) scale
Logarithmic scale: pH = 5 is 100 times more acidic than pH = 7
Good indicator of general water quality
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Increasing acidity
Increasing alkalinity
Neutral
Lemon juice
Vinegar
Recommended pH range 6.5 – 8.5
Milk
Battery acid
Ammonia
Milk of magnesia
Baking sodaSea water
Lye
Distilled water
Coffee
Bleach
Gastric acid
Corrosive WaterCorrosive 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
24http://www.bushman.cc/photos/Copper_Water_Pipe_Corrosion.jpg; http://www.cee.vt.edu/ewr/environmental/teach/wtprimer/corrosion/corrosion.html
Corrosive Water: Metals of concernCorrosive Water: Metals of concern Lead
◦ Many serious health effects, especially in children and infants
Developmental, neurological, reproductive and renal
◦ EPA MCL is 0 mg/L with a health action level of 0.015 mg/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
25http://www.gravitaexim.com/images/Lead-pipe.jpg
Addressing Lead or Copper in WaterAddressing Lead or Copper in Water Options to consider:
◦ Discuss test results with your physician if concerned!
◦ Metals will be highest with corrosive water and contact time with
pipes. Flushing pipes may address problem. Make sure that water
runs until it is as cold as it gets before drinking
◦ Activated carbon filter (e.g. Brita) MAKE SURE IT IS LABELED TO REMOVE LEAD
MAKE SURE TO CHANGE AS DIRECTED
◦ Address corrosivity of water – if pH < 6.5, can use acid neutralizing
filter; however, corrosivity can be caused by other factors as well
◦ Reverse Osmosis
◦ Use another source of water known to be safe
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Iron and ManganeseIron and Manganese Nuisance - not health concern
SMCL: Iron = 0.3 mg/L; Mn = 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 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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FluorideFluoride Occurs naturally in varying levels
◦ Naturally high levels of F in E. Virginia groundwater
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
28http://www.willamettedental.com/en_us/ALL/patients/pps/retailproducts_prettysmile.gif; http://en.wikipedia.org/wiki/Dental_fluorosis
SodiumSodium Low levels occur naturally; high levels may be
from man-made source
◦ Road salt storage or application
◦ Industrial waste
◦ Sewage, fertilizers or animal waste
◦ WATER SOFTENER
Sodium: EPA recommendation for people on low-sodium diets: 20 mg/L
Consider other sources of salt in diet and discuss with Dr.
Higher levels may indicate contamination – test for bacteria or other contaminants
Salty taste; and may accelerate corrosion of pipes and water heaters
Treat using distillation, reverse osmosis, demineralization
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Hardness/ScalingHardness/Scaling
Hardness Rating Grains per Gallon mg/L
Soft Less than 1.0 Less than 17.1
Slightly-Moderately Hard 1.0-7.0 17.1-120
Hard 7.0-10.5 120-180
Very Hard Over 10.5 Over 180
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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
Nitrate (NONitrate (NO33-N)-N)
Serious health concern for infants
◦ Methemoglobinemia or “blue baby syndrome”
Nitrate nitrite during digestion and blood cannot carry oxygen
◦ MCL 10 mg/L NO3-N or 45 mg/L of NO3
If 3-5 mg/L, use do not use water for infants under 6 months
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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Total Dissolved Solids (TDS)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
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
32http://en.wikipedia.org/wiki/Total_dissolved_solids
ArsenicArsenicOccurs naturally in some rocks; more common in
groundwater supplies when water tables rise and fall frequently
Used in wood preservatives, paints, pesticides, etc.
Linked to many types of cancer, stomach pain, paralysis, and blindness
EPA primary standard is 0.010 mg/L
Reverse osmosis to remove
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Virginia Master Well Owner Network Virginia Master Well Owner Network Training WorkshopTraining Workshop
Want to learn more about
your private water supply?
Visit www.wellwater.bse.vt.edu
Contact Erin Ling
wellwater@vt.edu
540-231-9058
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Help Others!
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Virginia Household Water Quality ProgramVirginia Master Well Owner Network
Erin Ling (wellwater@vt.edu) Brian Benham (benham@vt.edu)
www.wellwater.bse.vt.eduEmail: wellwater@vt.edu
Ph: 540-231-9058
Treatment OptionsTreatment OptionsPrimary Problem Treatment Method Notes
Corrosive water, copper, lead, leaks
Acid neutralization Uses limestone chips or soda ash to increase water pH and hardness to prevent corrosion
Arsenic, fluoride Activated alumina Water pH must be less than 8.5 Pretreatment with oxidation may be necessary to achieve good arsenic removal
Hydrogen sulfide, methane, volatile organics, radon
Aeration Expensive and susceptible to cogging by other pollutants but very effective when multiple gases are present
Sulfate, nitrate, arsenic Anion exchange Increases chloride concentration in treated water. May make water more corrosive.
Chlorine, pesticides, herbicides, radon, miscellaneous tastes and odors, volatile organics
Carbon filter Disinfection should be used on water supplies with bacterial contamination because bacteria can multiply in filter. Carbon must be replaced periodically.
36Adapted from Tips for Buying Water Treatment Equipment by Stephanie Clemens and Bryan Swistock, Penn State University
Treatment OptionsTreatment OptionsPrimary Problem Treatment Method Notes
Bacteria, iron and manganese
Chlorination Water must be clear for chlorine to work. Requires tank for storage and contact time.
Removes everything except volatile organics, pesticides, herbicides
Distillation Produces small amounts of bland-tasting water. Space needed to store treated water.
Iron, manganese, hydrogen sulfide
Oxidizing filters Periodic addition of chemicals and backwashing is necessary. Good option when all three are present.
Bacteria, metals, odors, tastes
Ozone Expensive to purchase and operate but very effective at removing multiple pollutants.
All dissolved pollutants Reverse osmosis Produces small amounts of water and some waste water. Will not remove most organic pollutants or bacteria
37Adapted from Tips for Buying Water Treatment Equipment by Stephanie Clemens and Bryan Swistock, Penn State University
Treatment OptionsTreatment OptionsPrimary Problem Treatment Method Notes
Soil, sand, other particles Sediment filter Must be routinely changed or backwashed
Removes scale or hardness and limited amounts of dissolved iron and manganese
Softener Causes increase in water sodium level. Water may become more corrosive after softening.
Bacteria Ultraviolet light Water must be free of sediment to kill bacteria effectively. Change bulb annually.
38Adapted from Tips for Buying Water Treatment Equipment by Stephanie Clemens and Bryan Swistock, Penn State University