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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 Master Well Owner Network Training

  2. 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 sodium iron chloride hardness pH/corrosivity fluoride sulfate nitrate manganese

  3. 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

  4. 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

  5. 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

  6. Private Water Supply Regulations • Virginia Private Well Regulations • Specify application, inspection and construction requirements • No requirements for maintenance or water testing after construction of well – responsibility of the owner! • EPA National Drinking Water Standards • Apply to PUBLIC systems • Primary (health) and Secondary (nuisance) • Can be used as guidance for private systems to know “how much is too much”

  7. 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

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

  9. Tests based on nearby land use Adapted from Household Water Testing. 2000. Blake Ross, Kathleen Parrott, and Janice Woodward (VCE pub 356-485)

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

  11. 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

  12. If E. Coli Bacteria are PRESENT http://www.kimicontrol.com/microorg/escherichia_coli.jpg • 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

  13. Nitrate (NO3-N) http://wi.water.usgs.gov/pubs/FS-221-95/p2.gif • 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

  14. pH 0 Battery acid 1 Gastric acid 2 Lemon juice more acidic 3 Vinegar • Measure of whether a substance is acidic or alkaline • Scale: 0 (acidic) to 14 (alkaline) • pH of 5 is 100 times more acidic than pH of 7 (logarithmic scale) • Good indicator of general water quality 4 5 Coffee Recommended pH range 6.5 – 8.5 6 Milk Neutral Distilled water 7 8 Baking soda 9 Sea water 10 Milk of magnesia more alkaline 11 12 Ammonia Bleach 13 Lye 14

  15. 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

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

  17. 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

  18. 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

  19. 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 www.goodcleanwater.com/fyi.htm; www.watersoftening.org/effects_of_hard_water.htm; 20

  20. 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 21 http://en.wikipedia.org/wiki/Total_dissolved_solids

  21. 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

  22. 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 /www.cotrip.org/winterdriving/images/pic6.jpg; /www.apswater.com/images/fleck%205600.jpg

  23. 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 http://www.freedrinkingwater.com/images-water-quality/chemicals/water%20in%20reddish-brown.jpg

  24. Hydrogen Sulfide thepipelinefixation.blogspot.com • 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

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