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Water Quality Contaminants of Concern

Water Quality Contaminants of Concern

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Water Quality Contaminants of Concern

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  1. Water Quality Contaminants of Concern Erin James Virginia Tech Biological Systems Engineering Virginia Master Well Owner Network Training October 29-30, 2008 Harrisonburg Virginia

  2. Overview • General recommendations of VAHWQP and VAMWON • EPA public drinking water standards • General water quality indicators • Specific health concerns, nuisance problems, or nearby landuses • Specific contaminants common in VA

  3. General VAHWQP Recommendations • Test every year for bacteria • Test every three years for pH, TDS, any local pollutants • Test before new nearby activity - legal protection! • Test if there are infants or people with compromised immune systems in your home • Test if change in odor, appearance or taste • Always recommend testing through a certified lab

  4. EPA Drinking Water Standards Primary Standards • Also called Maximum Contaminant Level (MCL) • Cause health problems • Enforced for public systems • Over 80 contaminants • For example: • Nitrate • Lead • Coliform • Most organic chemicals and pesticides Secondary Standards • Also called SMCL or RMCL • Cause aesthetic problems: • Staining • Taste • Odor • Can naturally occur in ground water • About 15 contaminants including: • Iron • Fluoride • Chloride http://www.epa.gov/safewater/contaminants/index.html

  5. General Water Quality Indicators Adapted from Interpreting your Water Test Report. 2001. Blake Ross and Kathleen Parrott (VCE pub 356-489)

  6. Tests for Specific Health Concerns Adapted from Household Water Testing. 2000. Blake Ross, Kathleen Parrott, and Janice Woodward (VCE pub 356-485)

  7. Coliform Bacteria • Cannot be smelled, tasted or seen • Coliform bacteria is an indicator organism – means disease-causing bacteria may be present • Public standard is 0 cfu/100mL • If present, test for fecal coliform or E. coli presence – strong indicator that sewage or animal waste is present. Photo credits: www.water-research.net, www.britannica.com

  8. Nuisance Problems Adapted from Household Water Testing. 2000. Blake Ross, Kathleen Parrott, and Janice Woodward (VCE pub 356-485)

  9. Nuisance problems http://www.process-controls.com/techsales/Dynamic_Descaler/images/before_1.jpg, www.tamhil.com/english/content.asp?id=24

  10. Nuisance problems Photo credits: www.ehrenner.com/Chloronation.html, www.bookofjoe.com/2006/01/13/index.html, cleanwellwater.com/acidic_water_bluegreen_stains

  11. Nuisance problems Photo credits: Midland Corrosion Associates, www.awqinc.com/ph.html, www.ehrenner.com/Chloronation.html, http://www.copper.org/applications/plumbing/techcorner/images/erosion_corrosion.jpg

  12. Tests for Specific Contamination Adapted from Household Water Testing. 2000. Blake Ross, Kathleen Parrott, and Janice Woodward (VCE pub 356-485)

  13. Conditions or nearby activities of concern Adapted from “Drinking Water for Household Wells”, EPA, 2002

  14. Most common contaminants in Virginia • Iron and manganese • Bacteria • Hardness • Corrosive and Scaling Water • Hydrogen Sulfide • Nitrate • Sodium • TDS • Fluoride

  15. 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 bacteria – not a health concern; feed on Fe and Mn, forming red-brown or black-brown slime http://www.freedrinkingwater.com/images-water-quality/chemicals/water%20in%20reddish-brown.jpg

  16. Bacteria • Coliform an indicator of potential for other pathogens: • Dysentery, Hepatitis, Typhoid, Cholera, Giardia, Cryptosporidia • Sources: • Human and animal waste (septic tank, barnyard runoff) • Insects, small animals in poorly sealed wells • Flooding; older or shallow wells without air-tight seal • Laboratory test: • EPA MCL for public supplies is 0 cfu/100mL • Reported as presence/absence, cfu (colony forming units)/100 mL, or MPN (most probable number) http://bcn.boulder.co.us/basin/data/BACT/info/FColi.html

  17. Hardness www.goodcleanwater.com/fyi.htm • Hard water contains high levels of calcium and magnesium ions • Dissolved into water during contact with limestone, 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

  18. 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

  19. Corrosive and Scaling Water • Usually a measure of alkalinity, TDS, and pH; often reported as a Saturation Index (varies by lab)

  20. Corrosive Water: Metals of concern • Lead • Many serious health effects, esp in children and infants • Developmental, neurological, reproductive and renal • EPA MCL is 0 µg/L with an HAL (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

  21. Hydrogen Sulfide thepipelinefixation.blogspot.com • Colorless gas; rotten egg smell • Not regulated by EPA – most people can detect at very low levels • Naturally present in shale, sandstone, near coal or oil fields • Produced by sulfur-reducing bacteria (not a health risk) • Treatment depends on concentration, so you 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

  22. Nitrate (NO3) • Serious health concern for infants • Methemoglobinemia or “blue baby syndrome” • Nitrate becomes nitrite in digestive system, which forms methemoglobin rather than hemoglobin (does not carry oxygen) • EPA MCL 10 mg/L NO3-N (nitrate nitrogen) or 45 mg/L of NO3 (nitrate) • If levels approach 3-5 mg/L, use another source of 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 • NOTE that BOILING INCREASES concentration of nitrates!!! http://wi.water.usgs.gov/pubs/FS-221-95/p2.gif

  23. Sodium and Chloride • Low levels occur naturally • Higher levels usually from man-made source • Road salt storage or application • Industrial waste • Sewage, fertilizers or animal waste • In coastal areas, salt water intrusion • Sodium: EPA MCL for people on low-sodium diets: 20 mg/L • Chloride: EPA SMCL of 250 mg/L • Higher levels may indicate contamination – test for bacteria or other chemicals • Salty taste; and may accelerate corrosion of pipes and water heaters http://www.cotrip.org/winterdriving/images/pic6.jpg

  24. 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 http://en.wikipedia.org/wiki/Total_dissolved_solids

  25. Fluoride • 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 http://www.willamettedental.com/en_us/ALL/patients/pps/retailproducts_prettysmile.gif; http://en.wikipedia.org/wiki/Dental_fluorosis

  26. What do you recall about….. • Iron and manganese • Bacteria • Hardness • Corrosive and Scaling Water • Hydrogen Sulfide • Nitrate • Sodium • TDS • Fluoride