Drinking Water Safety and Protection (and the Virginia Master Well Owner Network) Erin James Ling, M.S. Virginia Tech Biological Systems Engineering Virginia Cooperative Extension Photo credit: Va Department of Health Office of Drinking Water Where does your water come from? Public or private supply? Bottled? Groundwater? Surface water? Both? Who manages your water system and water quality? Is there a source water protection plan in place for your water supply? What do you know about your water quality? 2 Today’s Presentation • Public vs. Private Water Supplies • Drinking Water Regulations • Source Water Protection • How to care for private water systems • Well location, protection, and construction • Well maintenance and care • Water testing – What’s in your water? • Dealing with water problems • Virginia Household Water Quality Program • Virginia Master Well Owner Network 3 Public vs. Private Water Supplies PUBLIC SYSTEMS: Community water systems may be run by local government, PSA, HOA or private company Considered public system if serving more than 15 service connections/25 people more than 60 days of the year Non-community systems: ◦ Transient (e.g. campground) ◦ Non-transient (e.g. school or restaurant) PRIVATE SYSTEMS: Wells are considered private if they serve fewer than 25 people Water well construction, location and application regulations vary from state to state (monitoring generally NOT required) Owner is responsible for maintenance, routine water testing, dealing with problems Regulated under Safe Drinking Water Act 4 Public vs. Private Supplies in Va PUBLIC SYSTEMS 38 of Virginia’s 95 counties completely reliant on groundwater; 55 counties draw more than half of supply from groundwater Of Virginia’s 2,900 public supplies, more than 2,300 rely on groundwater; many are small and remote with no alternative to groundwater 80% of Virginia’s population relied on public water supplies in 2008 Monitoring of water quality required at the treatment plant; lead and copper levels must be monitored from tap water samples throughout community PRIVATE SYSTEMS Majority of households in 60 of Virginia’s 95 counties rely on private water supply systems (> 1,500,000 households) In 52 counties, the number of households using private wells is increasing faster than the number connecting to public systems Homeowners relying on private water supplies: Are responsible for all aspects of water system management Often lack knowledge and resources to effectively manage Usually don’t worry about maintenance until problems arise 5 Safe Drinking Water Act Passed by Congress in 1974 to protect public health by regulating the nation’s public water supply Authorized EPA to set health-based drinking water standards to protect against natural and man-made contaminants Original focus on treatment to create safe water; 1996 amendments included ◦ Source water protection efforts including surface water systems ◦ Evaluation of susceptibility to contamination ◦ Operator training ◦ Funding for water system improvements ◦ Increased public information 6 EPA Drinking Water Standards Primary Standards Secondary Standards • Also called Maximum Contaminant Level (MCL) • Cause health problems • Enforced for public systems • 80+ contaminants, including o Nitrate o Lead o Coliform bacteria o Most organic chemicals and pesticides Also called SMCL or RMCL Cause aesthetic problems: o Staining o Taste o Odor Can naturally occur in ground water States can choose to enforce About 15, including: o Iron o pH http://www.epa.gov/safewater/contaminants/index.html 7 Consumer Confidence Reports SDWA requires all community water systems to provide annual reports about the water they distribute From Town of Blacksburg 2008 Report 8 Virginia Drinking Water Regs • Virginia maintains “primacy” to regulate public drinking water supplies • • Virginia Water Control Law (1992) / Virginia Water Control Board Virginia Waterworks Regulations (1995) Virginia Department of Health Office of Drinking Water ◦ Monitors drinking water quality ◦ Provides technical assistance ◦ Finances improvements and seeks funding ◦ Enforces drinking water regulations for Virginia Public Water Supply Law and Safe Drinking Water Act ◦ Central office and 6 field offices ◦ Source Water Assessment Program (required by SDWA) 9 Virginia Drinking Water Regs • Virginia maintains “primacy” to regulate public drinking water supplies • • Virginia Water Control Law (1992) / Virginia Water Control Board Virginia Waterworks Regulations (1995) Virginia Department of Health Office of Drinking Water 10 Source Water Protection Basic concepts apply to public and private sources; consider interaction between the two Groundwater systems: Wellhead Protection ◦ Understand of groundwater flow to determine recharge areas; complex in Virginia due to geology • Surface water systems: Watershed Protection Three basic steps: 1. Delineate assessment boundaries of a drinking water source 2. Perform inventory of land use activities 3. Determine relative susceptibility of the drinking water source to these activities; may include contingency plans or conservation measures to ensure adequate supply Community involvement essential for success 11 Land use-related Contaminant Sources Common Land use-related Contaminants Agriculture Nutrients Bacteria Pesticides Herbicides Sediment Mining Iron Manganese pH Sediment Chemicals Residential Development Bacteria Nutrients Sediment Pesticides Herbicides Chemicals Oil Roads Chlorides Industry or Landfill Hydrocarbons VOC’s Travel-time example http://ga.water.usgs.gov/edu/pesticidesgw.html 14 Contaminant Source Proximity – How close is too close? Be concerned about land uses and potential contaminate sources visible from home In situations where groundwater travel-times are shorter, activities further away may impact water quality ◦ Fractured bedrock ◦ Limestone geology (karst) ◦ Gravel aquifers that transmit water easily How does water move to a well? (Bedrock/drilled well) In this part of Virginia, 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 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 16 How does water move to a well? (Shallow/bored well) In the Virginia coastal plain, shallow wells drilled in sandy soils are common Because of shorter travel time, water is more susceptible to contamination Well casing extends to bottom of well to below saturated zone Well screen filters sediment from water 17 Well should be at least: ◦ 5 feet from property boundary ◦ 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 Photo credit: Swistock, Penn State Univ Proper private well location Upslope from potential contamination Not in an area that receives runoff 18 Proper private well construction Contract 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 12” Photo credits: SAIF Water Wells ; Penn State University Grouting to a minimum of 20’ Sanitary well cap or sealed concrete cover Ground slopes away from well 19 The Finished Product – Drilled Well http://www.omafra.gov.on.ca/english/environment/06-117.htm 20 The Finished Product – Bored Well http://www.omafra.gov.on.ca/english/environment/06-117.htm 21 Private Well Maintenance Tips Do not use fertilizers, pesticides, oil, or paint around 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 10 years have well inspected by a qualified professional (with WWP classification) 22 Private Water Supply Regulations • Virginia Private Well Regs 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 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” 23 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 24 What should I test for? Public and private water supply users should consider testing for metals Private supply users: ◦ Every year test for coliform bacteria 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 and water condition Residential Development Bacteria Nitrates Sediment Lawn Chemicals 25 How do I test my water? Participate in a VAHWQP drinking water clinic (private water supply users) Choose a certified laboratory ◦ List available at http://www.vdh.state.va.us/DrinkingWater/laboratories/ Use containers provided and follow directions ◦ Sample bottles often contain fixers- do not rinse ◦ Be aware of time requirements to get samples to lab 26 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 ◦ Bacteria ◦ Radon, hardness, pH 1 ppm = about 4 drops in a 55 gallon barrel! Compare to EPA standards: http://www.epa.gov/safewater/contaminants/index.html 27 Sources of contamination or issues of concern well Surface water contamination: nitrate, bacteria Source may be plumbing materials or existing water treatment device: sodium copper lead bacteria Where the condition or contaminant comes from affects how we can deal with it! Water moves via fractures or cracks in bedrock Some contaminants are found in groundwater naturally, and some are there due human activities. TDS iron hardness 28 Options for problem water 1. If possible, control the source of pollution ◦ Divert runoff from well, 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 29 http://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 Home Treatment Considerations Be sure to explore ALL of your options Always have water tested by a certified lab Be aware of dishonest businesses – look for NSF (National Sanitation Foundation) and WQA (Water Quality Association) certifications, consult BBB If it sounds too good to be true…it probably is! Point of Use (POU) vs. Point of Entry (POE) Weigh benefits and limitations of device ◦ Cost ◦ Maintenance ◦ Warranty 30 What is the VAHWQP? Established in 1989 County-based Drinking Water Clinics Coordinated with local Extension Agents Kickoff Meeting Homeowners collect sample; samples analyzed at VT lab Interpretation Meeting: test results and advice for dealing with water problems provided • The Virginia Master Well Owner Network 31 Virginia Master Well Owner Network (VAMWON) Includes extension agents and volunteers Training workshops across VA • Groundwater hydrology • Proper well location, • • • • • construction and maintenance Land use impacts and wellhead protection Water testing and interpretation Solving water problems Education and outreach ideas Water conservation VAMWON volunteer outreach: Fairs and home shows Speak to church or civic groups One-on-one conversations with neighbors and friends Write an article for local paper Help with drinking water clinic 32 VAMWON Volunteer Policy Qualifications: ◦ Attend VAMWON training and achieve 80% on post-test ◦ Agree to a goal of making 100 educational contacts annually ◦ Communicate effectively and diplomatically ◦ Not work or own a business affiliated with private water systems ◦ Option to recertify after two years Guidelines: ◦ Unpaid, volunteer work only ◦ Provide general educational information ◦ Do not give professional advice or make specific recommendations ◦ Refer specific questions to qualified professional 33 VAMWON Responsibilities VAMWON Agents ◦ Conduct county-based drinking water clinics ◦ Educate local private water system owners VAMWON Volunteers ◦ Assist VAMWON agents with drinking water clinics ◦ Outreach to church, service, and civic organizations ◦ Staff VAMWON booth at fairs, clinics, ag and home shows ◦ Maintain water system as a good practices demonstration site ◦ Contribute to VAHWQP newsletter and website ◦ Assist with evaluating program impacts 34 Building Capacity through VAMWON • Agents conduct county-based drinking water clinics • Agents better informed to address water quality concerns Sustaining relationships: building capacity to improve water quality Virginia Master Well Owner VCE Agents Private Water System Owners Virginia Master Well Owner Volunteers • Community-based outreach • Peer-to-peer education • Develop relationships through collaborative education and outreach • Continuing VAMWON training opportunities • Share innovative education delivery methods 35 Interested in learning more? Come to a drinking water clinic Join Virginia Master Well Owner Network! ◦ Learn more about your own water system and how to protect your water quality and share info with others ◦ Receive 7 hours MG continuing education credits ◦ Apply today at: www.wellwater.bse.vt.edu or call Erin ◦ At VAMWON training workshop: Free water conservation devices for home and garden Resource binder Reduced cost of sample analysis (when a drinking water clinic is held in your county) 36 Upcoming Events in 2010 41 VAMWON agents, 32 volunteers trained so far VAMWON Training Workshops ◦ Volunteer: Aug 28 (Giles Co) and Oct 30 (Charlottesville) ◦ VCE Agent: Oct 29-30 (Charlottesville) Drinking Water Clinics ◦ 10 counties scheduled for 2010 ◦ 1200 participants during 2009 = 2010 drinking water clinic = 2010 Vol VAMWON workshop = 2010 Agt VAMWON workshop 37 VAMWON Training Workshop August 28, 2010 9 am – 4 pm Giles County OR October 30, 2010 9 am – 4 pm Charlottesville Visit www.wellwater.bse.vt.edu Or contact Erin Ling 540-231-9058 / wellwater@vt.edu 38 Erin James Ling Virginia Household Water Quality Program Virginia Master Well Owner Network Website: www.wellwater.bse.vt.edu Email: wellwater@vt.edu Ph: 540-231-9058 39 Resources Private Water Supply Protection in VA: www.wellwater.bse.vt.edu Office of Drinking Water Source Water Protection: http://www.vdh.virginia.gov/drinkingwater/source/swpp.htm Virginia Department of Health: www.vdh.state.va.us EPA SafeWater/Drinking Water Regulations: http://www.epa.gov/safewater/contaminants/index.html Virginia Rural Water Association: http://vrwa.org/index.php Virginia Cooperative Extension Offices: www.ext.vt.edu National Groundwater Association Well Owner: http://www.wellowner.org/ National Sanitation Foundation: www.nsf.org Water Quality Association: www.wqa.org 40 Conserve water! Protect your water quantity and quality Reduce the load to septic or sewer system Save $$$$ Save ENERGY used to move or heat water Protect resources for future generations Little effort produces significant results 41 Where is water used in the home? 69-100 gallons/person/day 42 Ways to conserve INDOORS Toilets ◦ Check for leaks by putting food coloring in tank ◦ Reduce number of flushes per day 1 less flush per person/day in US would save enough water to create a lake one sq. mile 4 ft deep every day! ◦ Toilets made before 1993 3-8 gallons per flush; newer toilets use 1.6 gpf ◦ Improved toilets can save a family 14,000-17,000 gallons per year ◦ Install toilet tummy or 2 liter bottles in tank Turn off water when brushing teeth or shaving! 43 Ways to conserve INDOORS Shower and Bath ◦ ◦ ◦ ◦ ◦ Reduce time spent in shower – get a timer! Install low-flow shower head – 2.5 gpm or less Bathe small kids together Reconsider baths – 50 or more gallons! Consider collecting water for plants, etc. Houseplants ◦ Collect water from washing produce, cooking, or cleaning fish tank to water plants ◦ Put discarded ice cubes in a plant rather than the sink 44 Ways to conserve INDOORS Kitchen ◦ Dishwashers New ones work! Don’t pre-wash dishes Run only when full ◦ Faucets Fix Leaks! One drip per second 2,700 gal/year Install low-flow faucet aerators Turn it off when not in use (washing dishes) ◦ Consider composting rather than garbage disposal ◦ Use as little water as possible when cooking 45 Ways to conserve INDOORS Laundry ◦ Consider purchasing energy efficient model (23 gallons per load compared to 40) ◦ Use cold setting whenever possible ◦ Pre-treat stains to avoid re-washing ◦ Only wash full loads, or adjust load size setting 46 Ways to conserve OUTSIDE Xeriscape – landscape in ways that do not require irrigation ◦ Plant species appropriate to your area (native), in practical areas of the yard ◦ Use mulch, manure and compost ◦ Group plants by water need ◦ If watering is necessary, do so in the morning hours ◦ Harvest rainwater using a cistern 47 Ways to conserve OUTSIDE Check for leaks – hoses, etc. Use the broom instead of hose to clean Install fewer impermeable surfaces Take the car to a carwash that recycles water Install backflow protector on all outdoor faucets and use backflow practices 48 Achieving Water Conservation Changes in Habits ◦ Little or no additional cost ◦ Quick effect ◦ Often temporary Water saving appliances or fixtures ◦ ◦ ◦ ◦ Can be expensive Most are easily installed Very effective Often permanent 49 Effect of Water Conservation 25 Without Conservation 20 With Conservation 15 10 5 0 Toilet Washer Shower Faucets Dishwasher Normal use = 68 gallons per day per person Conservation use = 38 gallons per day per person 50 Photo credits: www.water-research.net, www.britannica.com Coliform Bacteria Cannot be smelled, tasted or seen Coliform bacteria is an indicator organism – means diseasecausing 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. 51 If Coliform Bacteria are PRESENT Don’t panic! Recommend RETEST ◦ To use VT lab, cost is $9 + overnight shipping Samples MUST be sent overnight for test to work Contact Hope White 540-231-4334 to have a kit mailed ◦ To use a local certified lab – email ejames@vt.edu for a list Examine well or spring Consider shock chlorination Long term treatment: ozonation, UV light, continuous chlorination 52 http://www.kimicontrol.com/microorg/escherichia_coli.jpg If E. Coli Bacteria are PRESENT Take immediate steps to address Shock chlorinate Retest water In the meantime, consider boiling or use another source of water for drinking or cooking Check for potential contamination sources Consider long-term treatment options: UV light, ozonation, continuous disinfection 53 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 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 54 www.goodcleanwater.com/fyi.htm Hardness 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 Treat using water softener Hardness Rating Grains per Gallon mg/L Less than 1.0 Less than 17.1 Slightly Hard 1.0-3.5 17.1-60 Moderately Hard 3.5-7.0 60-120 Hard 7.0-10.5 120-180 Over 10.5 Over 180 Soft Very Hard 55 Conditions or nearby activities of concern Conditions or Nearby Activities Test for: Recurring gastro-intestinal illness Coliform bacteria Household plumbing contains lead pH, lead, copper Radon in indoor air Radon 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 Adapted from “Drinking Water for Household Wells”, EPA, 2002 56 General Water Quality Indicators Indicator Acceptable Limit Indication Coliform bacteria < I coliform/100 ml Possible bacterial or viral contamination from human or animal waste pH 6.5 to 8.5 Important overall measure of water quality; pH can alter corrosivitiy and solubility of contaminants. Low pH: pitting of pipes and fixtures, metallic taste High pH: water has slippery feel, soda taste Total dissolved solids 500 mg/L Dissolved metals, like iron or manganese; hardness; salty, bitter taste or staining. 57 Opportunities for PARTNERSHIPS Train: 70 agents and 240 volunteers Build Capacity: • Agents conduct county drinking water clinics • Agents and volunteers make educational contacts • Establish relationships • • • • • DEQ, VDH, VASWCD, EPA, ? Expanded programming (septic, etc.) Information sharing Joint grant- writing opportunities Continuing education for VAMWON Revitalized! Resources • • • • • Website Newsletter Water Quality Resource Expert Panel Updated VCE water quality publications VAHWQP Coordinator o Needs assessment and scheduling of clinics o Targeted programming for underserved populations o Support for agents and volunteers By 2010 • • • • 5,400 + water samples analyzed 1,100+ underserved persons reached 18+ drinking water clinics conducted Establish capacity to continue providing drinking water clinics, education and outreach through VAMWON. 58 SAMPLE Test Report Household Water Sample Maximum or Recommended Level or Range 0.02 0.3 <0.001 0.05 Hardness (mg/L) 44.5 180 Sulfate (mg/L) 2.066 250 Chloride (mg/L) 30 250 Fluoride (mg/L) < 0.1 2.0 Total Dissolved Solids (mg/L) 102 500 6.2** 6.5 to 8.5 -2.98 ** -1 to 1 Copper (mg/L) 0.04 1.0 Sodium (mg/L) 7.8 20 4 10 PRESENT** ABSENT ABSENT ABSENT Test Iron (mg/L) Manganese (mg/L) pH Saturation Index Nitrate-N (mg/L) Total Coliform Bacteria E. Coli Bacteria ** measured value exceeds recommendation for household water 59 Corrosive (aggressive) water ◦ Corrodes metal in plumbing, causing damage, pitting ◦ Leaching of copper or lead into drinking water is a health concern! ◦ EPA recommends drinking water be non-corrosive ◦ Treat using acid neutralizing filter (with calcite or calcite/corosex blend) or soda ash injection 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, reduces efficiency of water heaters and appliances ◦ Treat using water softener, if necessary 60 http://www.bushman.cc/photos/Copper_Water_Pipe_Corrosion.jpg; www.watersoftening.org/effects_of_hard_water.htm Corrosive and Scaling Water 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 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 61 http://wi.water.usgs.gov/pubs/FS-221-95/p2.gif Nitrate (NO3-N) Serious health concern for infants ◦ Methemoglobinemia or “blue baby syndrome” Nitrate becomes nitrite in digestive system, 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 BOILING INCREASES concentration of nitrates!!! Treatment: distillation, reverse osmosis, ion exchange 62 http://www.cotrip.org/winterdriving/images/pic6.jpg 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 contaminants Salty taste; and may accelerate corrosion of pipes and water heaters Treat using distillation, reverse osmosis, demineralization 63 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 64 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 65 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 66 Spring Management Tips Make sure spring box is sealed to prevent insects, animals, and surface water from entering Fence livestock out of stream catchment area Disinfect springs after construction and test annually for bacteria 67 Cistern Management Tips Make sure cistern is constructed properly to ensure it is the proper size to meet your water demands. A minimum of 5,000 gallons is recommended. All cisterns require treatment. Most rely on rainwater that can be extremely corrosive to plumbing systems Water should be disinfected before it is consumed 68