What are the most important test for well water?

Testing well water regularly is one of the most important things you can do as a homeowner to protect your health. Well water can contain harmful bacteria, chemicals, metals and other contaminants that can make you sick. Getting your water tested at least once a year, and whenever you notice changes in taste, smell or appearance, is critical to ensuring the safety of your drinking water.

In this article, we will discuss the most important tests you should have done on your well water and what they screen for. Understanding the different types of contaminants and their potential health effects can help you make informed decisions about necessary treatment options to provide clean, safe water for your household.

Common Well Water Contaminants

There are many potential contaminants that can be found in well water, some naturally occurring and others the result of human activities. Here are some of the most common:

Bacteria

Disease-causing bacteria like E. coli, Salmonella, and Shigella can make their way into well water from animal or human waste. These pathogens can cause gastrointestinal illness. Testing for total coliform bacteria alerts you to possible contamination.

Nitrates

Nitrates from fertilizer runoff, animal manure, or septic systems can contaminate groundwater. High levels of nitrates in drinking water have been linked with potential health risks for infants.

Heavy metals

Lead, arsenic, mercury, aluminum, cadmium and other heavy metals can dissolve into groundwater from natural mineral deposits or human activities. These metals can accumulate in the body and cause health problems at high concentrations.

Pesticides and herbicides

Common weed killers, insecticides, fungicides and other chemicals used in agriculture, industry or around the home can make their way into well water through the ground. Long-term exposure may increase health risks.

Petroleum products

Gasoline, oil and other fuels can leak into groundwater from storage tanks, spills or improper disposal. Benzene, toluene and other petroleum compounds can pollute wells.

Radon

Radon is a radioactive gas that occurs naturally in soil and rock. It can dissolve and accumulate in groundwater and expose people to cancer-causing radon gas when released from water into the air.

Chloride

High chloride levels indicate possible contamination from road salt, water softener backwash, animal waste or seawater intrusion in coastal areas. Corrosion and metallic taste are potential issues.

Recommended Annual Tests

At a minimum, well owners should test their water annually for the following:

Total coliform and E. coli

Testing for total coliform bacteria and E. coli provides a basic indication of the sanitary condition of your well. Presence of these bacteria signifies contamination and potential exposure to pathogens. Annual screening for total coliform and E. coli is recommended.

Nitrates

Nitrate is one of the most common groundwater contaminants. Annual testing is recommended to monitor levels, especially for families with young children and infants who are at higher risk from exposure to high nitrate concentrations.

pH

The pH indicates whether water is acidic, neutral or alkaline. Extreme high or low pH can cause corrosion of pipes and plumbing fixtures as well as affect the taste and safety of water. Annual pH testing is recommended.

Total dissolved solids (TDS)

TDS is a measure of the total amount of dissolved substances in water, such as salts and minerals. A high TDS indicates hard water and deposits in plumbing and appliances. Annual screening checks for changes.

Chloride

Test for chloride annually as an indicator of possible contamination from road salt, water softeners, animal waste or seawater intrusion. High chloride imparts a salty taste and can corrode pipes.

Hardness

A test for total hardness indicates the amount of dissolved calcium and magnesium in water. Hard water requires more soap to lather, can leave mineral deposits on fixtures, and can affect taste. An annual hardness test is wise.

Additional Recommended Tests

Beyond the basic annual tests, well owners should consider additional screening based on health status, known risks and water quality changes:

Heavy metals

A one-time baseline test for heavy metals like arsenic, lead, uranium and manganese can reveal if high levels are present due to natural geology or nearby mining/industry. These metals can cause health effects at high exposures. Retest if you notice changes in color, taste or smell.

Pesticides

If you live in an agricultural area where pesticides and herbicides are routinely used, consider testing for these chemicals. They can persist in groundwater and may have long-term health effects at high exposures.

Petroleum compounds

Test for gasoline components like benzene if you notice an oily sheen, fuel-like odor, or live near gas stations or buried fuel tanks. Benzene and other petroleum compounds have health risks at high levels.

Radon

Have a radon in water test done if radon in indoor air levels are elevated or if you live in a high radon zone. Radon in water becomes radon gas when released indoors during showering and other use. Long-term radon exposure may increase lung cancer risk.

Sediment

Test for turbidity or cloudiness after installing or repairing your well to check for sediment that could harbor bacteria. Disinfect and retest if turbidity is high until water clears.

How and Where to Test Your Well Water

Testing your well water is most effective if you follow these recommendations:

Use an accredited lab

Ensure you use a state-certified drinking water testing lab. Your county health department can often provide a list. The lab should follow approved sampling methods and quality control procedures to ensure accurate results.

Obtain proper sample bottles

Contact the testing lab to find out how much water is needed and if they provide shipping materials and sample bottles. Sterilized bacteriological bottles are essential for accurate bacterial tests.

Follow sampling instructions

Carefully follow the lab’s instructions for collecting samples to avoid contamination and ensure representative results. Flush pipes, use proper bottles, avoid overfilling, and ship quickly.

Sample at the tap

Collect samples from a frequently used kitchen or bathroom cold water tap, not at the well itself. This tests the water as it comes out for actual use and consumption.

Retest for bacteria after shock treating

If you shock chlorinate or disinfect your well and plumbing, wait several days for chlorine to dissipate before retesting total coliforms and E. coli to confirm bacteria removal.

Consider additional point-of-use testing

For a complete water quality picture, also test treated water from devices like softeners, filters, and at-tap purifiers to determine their performance.

Interpreting and Acting on Your Water Test Results

Once you get your well water test results back from the lab, here are some steps to take:

Compare results to standards

The lab report will indicate if any contaminant exceeds EPA or state health standards. Any detections above allowable limits require action to resolve.

Review for bacteria presence

Any total coliform or E. coli detected means disinfection and retesting to confirm bacteria removal before drinking the water. Don’t drink any water if E. coli is found.

Check nitrate levels

Nitrate over 10 ppm is unsafe for infants under 6 months. Limit use for pregnant women and young children. Install a treatment system if your water exceeds this level.

Evaluate any other detections

Detections of heavy metals, pesticides, petroleum compounds or other contaminants may require treatment or alternative water source depending on health risk factors.

Install necessary treatment

Bacteria or contaminants exceeding safe standards require installing effective water treatment you can maintain over the long-term, such as disinfection, filtration, softening, etc.

Flush and retest after plumbing work

Major plumbing repairs or well modifications call for thorough flushing and bacterial retesting to verify clean results post-construction before resuming drinking the water.

Check for taste and stain issues

Mineral levels outside optimum pH or hardness ranges may require adjustments or treatment for better taste and reduced staining. A water softener can address hard water concerns.

Maintaining Your Water Treatment System

If you need to install any kind of water filtration, disinfection or treatment system based on your test results, proper maintenance is essential for continued protection. Follow these tips:

Check and change filters/media

For systems with cartridge filters, membranes or media tanks, follow manufacturer specifications for checking, replacing and changing them out based on water usage or time.

Regularly test treatment effluent

Periodically sample water coming directly out of treatment systems like softeners, carbon filters and reverse osmosis units to confirm adequate contaminant reduction.

Disinfect mineral tanks annually

Mineral tanks in systems like water softeners should be sanitized yearly to control bacterial growth. Follow manufacturer directions to flush and add bleach or other cleaners.

Hire professionals as needed

Consider hiring a water treatment professional for major repairs or servicing of complex treatment systems. They have the expertise and equipment to keep systems running properly long-term.

Keep detailed records

Document equipment maintenance and replacements. Note dates of filter and media changes. Tracking service history helps spot issues and ensure routine tasks get done.

Special Considerations for Sensitive Populations

Some groups have higher vulnerability to water contaminants and require extra precautions:

Infants and young children

Children’s small body size and developing systems increase susceptibility to high nitrate levels, lead and certain bacteria that can cause illness. Consider additional testing for these if young kids will be drinking the well water.

Older adults

As immune function diminishes, older adults become more prone to illness from pathogens like Cryptosporidium and Giardia that can contaminate wells. Testing for these may be advisable if elderly residents drink the water.

Pregnant women

Pregnant women are at higher risk from toxins that could affect the developing fetus. Test for pesticides, volatile organic compounds, nitrate and heavy metals if pregnant women will use the well water.

Immunocompromised individuals

Those with weakened immune systems due to chemotherapy, organ transplants or conditions like HIV/AIDS have increased likelihood of becoming sick from well water bacteria and parasites. Test for Cryptosporidium, Giardia and total coliforms.

Bottled water may offer additional protection

For vulnerable groups, providing bottled water for drinking and cooking while using well water for other purposes may provide added protection from contaminants like bacteria and nitrates.

Emergency Warning Signs of Contamination

Certain situations require immediate action to protect health:

Bacteria positives

If total coliform or E. coli are detected in annual testing, or after water main repairs or well excavation work, immediately stop drinking the water and implement emergency disinfection procedures. Re-shock and retest.

Noticeable change in water

Sudden differences in taste, smell, color or clarity after a heavy storm or flood require emergency disinfection and testing to check for potential bacterial contamination. Don’t drink until tests show water is clean.

Nearby chemical spill

A proximate hazardous materials or petroleum spill requires prompt testing to determine if volatile organic compounds have entered groundwater. Stop drinking the water until tests confirm it’s safe.

Repeated bouts of gastrointestinal illness

If multiple family members experience stomach flu symptoms frequently, test for bacteria and parasites that could be sickening users. Shock chlorination may be needed along with additional treatment to remove pathogens.

Shock Chlorination of Contaminated Wells

If bacterial contamination is detected or suspected in your well, shock chlorination is an effective emergency disinfection method:

Check well construction and identify contamination sources

Inspect well components for defects allowing contaminant entry. Fix any cracks or faults. Check septic, pets, livestock, etc as possible bacterial sources.

Bypass any carbon filters or treatment systems

Chlorine will damage components like activated carbon. Set the system to by-pass before shocking the well.

Determine volume of water in well

Measure well diameter and depth to calculate gallons of water in the well for proper chlorine dose. An 8″ diameter, 100′ deep well contains about 100 gallons.

Add concentrated chlorine

For a 100 gallon well, mix a half gallon of laundry bleach (5.25% sodium hypochlorite) with a half gallon of water and pour down the well casing.

Recirculate and flush all taps

Attach a hose and spray water back down the well for 15 minutes. Then systematically run all faucets until smelling chlorine. Let sit overnight.

Flush pipes until chlorine odor and taste gone

The next day, flush all pipes until no chlorine smell or taste remains. This ensures chlorinated water is removed from the plumbing before use.

Retest for bacteria

Collect samples and retest for total coliform and E. coli after several days. Negative results indicate successful disinfection. Retreat if bacteria still present.

Conclusion

Safe well water is vital for the health of your household. Regular testing and addressing any contamination issues is crucial. The most important tests are total coliform, E. coli, nitrate, lead, arsenic and anything else of concern in your area. Look for noticeable changes, maintain treatment systems, and shock chlorinate when needed. With diligence and proper care, your well can provide clean water for years to come. Regular testing and prompt action gives you peace of mind knowing your water supply is in good condition.