Drinking water is one of our most valuable and vulnerable resources. In Idaho 95% of our drinking water comes from groundwater which is precipitation, surface water, and irrigation water that has been absorbed into the ground where is collects.
Contaminants in Idaho’s groundwater can come from natural sources or human activities. These contaminants may affect the safety of your drinking water, especially if you rely on a private well because private wells are not regulated.
Do you know where your drinking water comes from or what’s in it?
About 30% of Idaho residents use private wells as their main source of drinking water. Unlike public water systems, private wells are not regularly tested or monitored. This means you may be drinking water with harmful contaminants without knowing it.
If you own a private well, you are responsible for making sure your water is safe to drink.
Contaminants in groundwater can cause health problems. These may include short-term symptoms or long-term health and developmental effects. Some contaminants occur in such small amounts that you cannot taste, see, or smell them. The only way to know what’s in your water is to test it.
When and What to Test For
Regular testing helps protect your health and your family's health. Here's how often you should test your well water:
• Once a year: Test for bacteria and nitrates
• Every 3 to 5 years: Test for other contaminants, including metals and chemicals
Use the Groundwater Quality Near Me map to find out what contaminants may be present in your area. This can help you decide what to test for.
If your water test results show unsafe levels of contaminants:
• Contact the Environmental Health Program at the Idaho Department of Health and Welfare
○ Email: EH@dhw.idaho.gov
○ Phone: 1-800-445-8647
• Our team can help you understand your results and recommend the best way to fix the problem.
• You can also review our well water testing flow charts to better understand your next steps.
How to Take a Water Sample
Idaho Private Well Water Project
The Environmental Health Program at the Idaho Department of Health and Welfare works to help Idaho residents protect their health. This project focuses on helping private well owners understand the importance of regular well water testing and treatment. The goal is to provide education and support so that well owners can take steps to keep their drinking water safe.
What the Project Does
The Idaho Private Well Water Project helps private well owners:
● Learn about the health risks that can come from drinking untreated or contaminated well water
● Understand how to care for and maintain their well
● Receive free well water testing
This is a joint effort between the Department of Health and Welfare and the Idaho Department of Environmental Quality (DEQ).
As part of this project, information about the aquifers that well owners use is collected. This includes:
● Depth to the aquifer
● Chemicals or other substances found in the aquifer
● Possible sources of contamination
This information supports aquifer protection and helps with decisions about public water treatment systems.
Who is Eligible to Participate?
Anyone that can get a water sample with 48 hours to the Idaho Bureau of Laboratories in Boise or IAS EnviroChem laboratory in Pocatello.
How the Free Water Testing Works
Free testing is available if you agree to share your test results on the Groundwater Quality Near Me Map, managed by the Department of Health and Welfare. Your well’s general location will be shown on the map, but not the exact location.
Your name, address, and other personal information will not be shared.
How to Participate
● Fill out the initial survey to let us know you are interested in joining the project. Initial Survey for the Private Well Water Project
● After we receive your survey, we will contact you with instructions on how to proceed.
● Later, we will ask you to complete a follow-up survey to help us understand your experience and gather feedback.
Is my well water safe from these contaminants? / ¿Es seguro mi agua de pozo de estos contaminantes?
Nitrate is a chemical commonly found in fertilizers, manure, and liquid waste from septic systems. Natural bacteria in soil can convert nitrogen into nitrate. Rain or irrigation water can then carry the nitrate through the soil into groundwater.
High levels of nitrate in drinking water can be harmful. Nitrates reduce the ability of blood to carry oxygen, which can be especially dangerous for infants and pregnant people.
Additional Resources:
How to Take a Water Sample:
Private Well Water Testing Video
Pruebas de Agua de Pozos Privados
What to Do if Your Nitrate Levels Are High?
If your test results show high nitrate levels, review the next steps using our nitrate sampling flow chart.
Need Help Treating Your Water?
Water Treatment Options to learn how to remove contaminants from your drinking water.
Total Coliform (TC) Bacteria are commonly found in soil, surface water, on plants, and in the intestines of humans and warm-blooded animals. TC bacteria are an indicator that contamination has entered the water. Most TC bacteria are not harmful. However, some can make you sick. A person that has been exposed to these bacteria may have an upset stomach, vomiting, fever, or diarrhea. Children and the elderly are more at risk from these bacteria.
Las bacterias coliformes totales (TC) se encuentran comúnmente en el suelo, en aguas superficiales, en plantas y en los intestinos de los humanos y de los animales de sangre caliente. Las bacterias TC son un indicador de que la contaminación ha entrado en el agua. La mayoría de las bacterias TC no son dañinas. Sin embargo, algunos pueden enfermarte. Una persona que ha estado expuesta a estas bacterias puede tener malestar estomacal, vómitos, fiebre o diarrea. Los niños y los ancianos están más en riesgo por estas bacterias.
For more information, please review our Bacteria Brochure Folleto de bacterias
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken a total coliform water sample that has come back present, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
Arsenic is a chemical element that naturally occurs in the earth’s mineral deposits and dissolves in groundwater. Arsenic in drinking water may have harmful health effects depending on how much you consume and how sensitive you are to it. Long-term exposure to low levels of inorganic arsenic in drinking water is known to cause human health problems including: cancer, thickening and discoloration of the skin, problems with blood vessels, high blood pressure, heart disease, nerve effects including numbness and/or pain.
El arsénico es un elemento químico que se encuentra de forma natural en los depósitos minerales de la tierra y se disuelve en las aguas subterráneas. El arsénico en el agua potable puede tener efectos perjudiciales para la salud dependiendo de cuánto consumas y de cuán sensible seas a él. La exposición a largo plazo a bajos niveles de arsénico inorgánico en el agua potable se sabe que causa problemas de salud en los seres humanos, incluyendo: cáncer, engrosamiento y decoloración de la piel, problemas con los vasos sanguíneos, hipertensión, enfermedades del corazón, efectos en los nervios que incluyen entumecimiento y/o dolor.
For more information, please review our Arsenic Brochure Folleto de arsénico
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken an arsenic water sample that has come back elevated, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
Fluoride is a naturally occurring mineral that is released from rocks into the soil, water, and air. Fluoride helps protect your teeth by strengthening the outer enamel surface. If you get too little fluoride, your teeth might weaken and develop cavities. Cavities can lead to pain, tooth loss, infections, and other health problems.
Excess amounts of fluoride ions in drinking water can cause dental fluorosis, skeletal fluorosis, arthritis, bone damage, osteoporosis, muscular damage, fatigue, joint-related problems, and chronicle issues.
El fluoruro es un mineral que ocurre de forma natural y se libera de las rocas al suelo, agua y aire. El flúor ayuda a proteger tus dientes al fortalecer la superficie externa del esmalte. Si recibes muy poco flúor, tus dientes pueden debilitarse y desarrollar caries. Las caries pueden provocar dolor, pérdida de dientes, infecciones y otros problemas de salud.
Cantidades excesivas de iones de flúor en el agua potable pueden causar fluorosis dental, fluorosis esquelética, artritis, daño óseo, osteoporosis, daño muscular, fatiga, problemas articulares y problemas crónicos.
For more information, please review our Fluoride Brochure Folleto sobre fluoruro
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken a fluoride water sample that has come back above or below recommended levels, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
Manganese is a naturally occurring mineral in rocks and soil in regions of Idaho and can be found in drinking water sources. You might suspect manganese is in your water if it is discolored (brownish red), causes staining of plumbing fixtures or clothing, or has an off-taste or odor. Children and adults who drink water with high levels of manganese for a long time may have problems with memory, attention, and motor skills. Infants (babies under one year old) may develop learning and behavior problems if they drink water with too much manganese in it.
El manganeso es un mineral que se encuentra de forma natural en las rocas y el suelo en regiones de Idaho y se puede encontrar en fuentes de agua potable. Podrías sospechar que hay manganeso en tu agua si está descolorida (marrón rojizo), causa manchas en los grifos o la ropa, o tiene un sabor u olor extraño. Los niños y adultos que beben agua con altos niveles de manganeso durante mucho tiempo pueden tener problemas de memoria, atención y habilidades motoras. Los bebés (menores de un año) pueden desarrollar problemas de aprendizaje y comportamiento si beben agua con demasiado manganeso.
For more information, please review our Manganese Informational Sheet.
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken a manganese water sample that has come back elevated, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
Selenium is a trace mineral needed in small amounts for good health. Short-term ingestion of high concentrations of selenium may cause nausea, vomiting, and diarrhea.
El selenio es un mineral traza que se necesita en pequeñas cantidades para una buena salud. La ingestión a corto plazo de altas concentraciones de selenio puede causar náuseas, vómitos y diarrea.
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken a selenium water sample that has come back elevated, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
pH is a measurement of how acidic/alkaline water is. In its purest form, water has a pH of 7, which is at the exact center of the pH
scale. A change in pH can change the chemical state of contaminants. Most water for use has a pH of between 6.5 and 8.5.
The danger of more acidic water – when the pH is less than 6.5 – is that it can leach metals from the well and from the pipes that bring you water. These metals include lead, manganese, copper and iron, and they can be toxic in large amounts.
When the PH of water becomes more basic - when the pH is greater than 8.5, water taste can become more bitter. This elevated pH can also lead to calcium and magnesium carbonate building up in your pipes. While this higher pH doesn't pose any health risks, it can cause skin to become dry, itchy and irritated.
El pH es una medida de cuán ácida o alcalina es el agua. En su forma más pura, el agua tiene un pH de 7, que se encuentra exactamente en el centro de la escala de pH. Un cambio en el pH puede alterar el estado químico de los contaminantes. La mayoría del agua para uso tiene un pH entre 6.5 y 8.5.
El peligro de un agua más ácida – cuando el pH es inferior a 6.5 – es que puede lixiviar metales del pozo y de las tuberías que te traen agua. Estos metales incluyen plomo, manganeso, cobre y hierro, y pueden ser tóxicos en grandes cantidades.
Cuando el pH del agua se vuelve más básico - cuando el pH es superior a 8.5, el sabor del agua puede volverse más amargo. Este pH elevado también puede provocar la acumulación de carbonato de calcio y magnesio en tus tuberías. Aunque este pH más alto no representa riesgos para la salud, puede causar que la piel se vuelva seca, con picazón e irritada.
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken the pH of a water sample that has come back below 6.6 or above 8.5, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
Sulfates are a group of mineral salts that are natural or human-made. These salts can be found in soil, air, and water. People who are not used to drinking water with high sulfate can get diarrhea and dehydration from drinking the water. Infants are often more sensitive to sulfate than adults.
Los sulfatos son un grupo de sales minerales que son naturales o creadas por el ser humano. Estas sales se pueden encontrar en el suelo, el aire y el agua.Las personas que no están acostumbradas a beber agua con alto contenido de sulfato pueden sufrir diarrea y deshidratación al consumirla. Los bebés suelen ser más sensibles al sulfato que los adultos.
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken a sulfate water sample that has come back elevated, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
Uranium is a naturally occurring, mildly radioactive compound commonly found in rocks, soil, and water. Uranium in well water is caused by uranium in the rock where the well is drilled. Exposure to elevated levels of uranium over a long period of time can damage your kidneys. However, the kidney can recover from this damage after exposure is reduced or eliminated.
El uranio es un compuesto radiactivo natural, ligeramente radiactivo, que se encuentra comúnmente en rocas, suelo y agua. El uranio en el agua de los pozos es causado por el uranio en la roca donde se perfora el pozo.La exposición a niveles elevados de uranio durante un largo período de tiempo puede dañar tus riñones. Sin embargo, el riñón puede recuperarse de este daño una vez que se reduce o elimina la exposición.
For more information, please review our Uranium Brochure Uranio En El Agua De
Mi Pozo
Learn how to take a proper water sample by watching this video (Pruebas de Agua de Pozos Privados), or would you rather read the instructions here.
You have taken a uranium water sample that has come back elevated, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
Lead can enter drinking water when a chemical reaction occurs in plumbing materials that contain lead. Corrosion is more severe when water has high acidity or low mineral content. Household plumbing fixtures, welding solder, and pipe fittings made prior to 1986 are more likely to contain lead. High levels of lead in tap water can cause health effects if the lead in the water enters the blood and causes high blood lead level. It can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of the body.
El plomo puede entrar en el agua potable cuando ocurre una reacción química en los materiales de plomería que contienen plomo. La corrosión es más severa cuando el agua tiene alta acidez o bajo contenido mineral. Los accesorios de fontanería del hogar, la soldadura de soldadura y las conexiones de tuberías fabricados antes de 1986 tienen más probabilidades de contener plomo.Los altos niveles de plomo en el agua del grifo pueden causar efectos en la salud si el plomo en el agua entra en la sangre y provoca un alto nivel de plomo en la sangre.Puede causar daño al cerebro y a los riñones, y puede interferir con la producción de glóbulos rojos que transportan oxígeno a todas las partes del cuerpo.
For more information, please review our Lead Facts Sheet, Lead in your Drinking Water brochure, Hoja informativa sobre el plomo, Plomo en su Agua Potable
Learn how to take a proper water sample by watching this video (Pruebas de Plomo y Cobre en el Agua).
You have taken a lead water sample that has come back elevated, what next? Review our sampling flow chart here.
You need more information on how to treat your water for contaminants? We have information for you here.
About PFAS
Per- and polyfluoroalkyl substances (PFAS) is the name for a group of thousands of man-made chemicals that have been used in industry and consumer products worldwide since the 1940s. Exposure to PFAS chemicals from products and the environment over long periods of time may cause harmful health effects.
PFAS chemicals have been used in non-stick cookware, water-repellent clothing, stain resistant fabrics and carpets, some cosmetics, some firefighting foams, and products that resist grease, water, and oil. During their production, use, and disposal, PFAS can enter the soil, water, and air. Most PFAS do not break down, so they stay in the environment for long periods of time. PFAS are found in the blood of people and animals all over the world. Learn more about how PFAS can impact your health and how to reduce exposure.
Acerca de las PFAS
Sustancias perfluoroalquiladas y polifluoroalquiladas (PFAS) es el nombre de un grupo de miles de sustancias químicas artificiales que se han utilizado en la industria y en productos de consumo en todo el mundo desde la década de 1940. La exposición a las sustancias químicas PFAS de los productos y del medio ambiente durante largos períodos de tiempo puede causar efectos nocivos para la salud.
Los productos químicos PFAS se han utilizado en utensilios de cocina antiadherentes, ropa repelente al agua, telas y alfombras resistentes a las manchas, algunos cosméticos, algunas espumas contra incendios y productos resistentes a la grasa, el agua y el aceite. Durante su producción, uso y eliminación, las PFAS pueden ingresar al suelo, al agua y al aire. La mayoría de las PFAS no se descomponen, por lo que permanecen en el medio ambiente durante largos períodos de tiempo. Las PFAS se encuentran en la sangre de personas y animales de todo el mundo. Obtenga más información sobre cómo las PFAS pueden afectar su salud y cómo reducir la exposición.
For more information, please review our PFAS Brochure Sustancias
perfluoroalquiladas y polifluoroalquiladas (PFAS) EN EL AGUA POTABLE
S) EN EL AGUA POTABL
OR
Please visit our PFAS website for more information
Por favor, visite nuestro sitio web sobre PFAS para más información.
Private wells can be a safe and reliable source of drinking water. In Idaho private well owners are responsible for ensuring their water is safe to drink. All private well owners should test their drinking water to ensure that it is safe to drink and regularly maintain their wellhead.
Some private wells may have high levels of contamination from bacteria, naturally occurring, or man-made chemicals that can be harmful to your health. Use the resources below to find out what to test for, how often to test, and how to keep your water safe. To learn the best ways to take a water sample, please review the videos linked in the above contaminant list or directly below.
Learn how to take a proper water sample by watching this video Pruebas de Agua de Pozos Privados, or would you rather read the instructions here.
Learn how to take a proper water sample for lead and copper by watching this video Pruebas de Plomo y Cobre en el Agua.
Ground Water Quality Near Me
The Idaho Department of Health and Welfare created the interactive map below to make private well owners aware of existing ground water quality data in their area and promote regular ground water quality testing. Ground water quality at privately owned wells is not regulated by the State of Idaho. Private well owners are responsible for maintaining their well and ensuring the water is safe to drink, which can be accomplished through periodic testing.
View the map here
About the Map
Private wells displayed on the map were sampled by the Idaho Department of Water Resources , the Idaho Department of Environmental Quality , the Idaho State Department of Agriculture , and private well owners between 2004-2020. Each well contains the most recent sampling results for up to nine chemicals, the year it was sampled, the sampling agency, and the well depth if it is known.
Agencies may have additional data that has not been included as part of this map. Additionally, more recent data may exist for certain chemicals that were unavailable at the time this map was published. Contact the individual sampling agencies for more information.
Find a location and set your search radius
Enter an address or place of interest in the search field in the panel to the left of the map. The map will default to locating wells within a two mile radius of your location. Use the text box or slider to expand the search radius in miles. Alternatively, click the set location icon , located next to the magnifying glass icon, and click on the map to set a location if the address is unknown.
View results
Wells found within the designated search radius are listed below the slider. Wells over a primary drinking water standard are titled as Primary Standard Exceeded. Click on individual search results, or click directly on a well symbol to see the data.
Note multiple agencies may have sampled the same well, but assigned a different site ID. Additionally, the same agency may have sampled the same well for different chemicals in different years. Use the arrow in the pop up window after clicking on a well to view all available data.
Drinking Water Standards
Primary
Arsenic, fluoride, nitrate, selenium, and uranium have primary drinking water standards. Public drinking water systems are regulated by DEQ and are required to comply with these, and other standards not represented here, to protect human health. The units of measure (e.g., ug/L or mg/L) provided in the following table may not match the units of measure on the laboratory report provided to you. If this is the case, results will need to be converted to make the best use of this table. If you need assistance converting or interpreting results, call the laboratory that did the analysis or IDHW's Environmental Health Hotline at 1-800-445-8647 or radon@dhw.idaho.gov.
Chemical |
Primary Standard |
Health Effects |
| Arsenic | 10 ug/L | Long term exposure to arsenic from drinking water can cause cancer and skin lesions. |
| Fluoride | 4 mg/L | Depending on the length and amount of exposure, fluoride can stain teeth, increase risk of broken bones, or cause pain and tenderness in joints and bones. |
| Nitrate | 10 mg/L | Nitrate can be converted to nitrite in humans where it lessens the ability of blood to carry oxygen. This is of greatest concern for infants, pregnant, and nursing women. |
| Selenium | 0.05 mg/L | Prolonged exposure to elevated levels of selenium can cause fingernail or hair loss, numbness in extremities or circulation problems. |
| Uranium | 30 ug/L | The greatest risk is kidney damage, especially for young children because their bodies are still developing. |
| Bacteria* | ZERO |
Most coliform bacteria do not cause disease, but they can indicate the presence of other harmful bacteria such as Escherichia coli (E. coli). E. coli can cause nausea, vomiting, fever, and diarrhea. * Monitoring results related to bacteria were not included in this map because the presence of bacteria is typically a result of site specific conditions rather than a wide scale problem. |
Secondary
Chloride, fluoride, iron, manganese, and sulfate have secondary drinking water standards. These guidelines were established by EPA to manage aesthetic considerations of drinking water such as taste, color and odor. These contaminants are not considered to present a risk to human health at the secondary levels.
Chemical |
Secondary Standard |
Health Effects |
| Chloride | 250 mg/L | Salty taste |
| Fluoride | 2 mg/L | Tooth discoloration |
| Iron | 0.3 mg/L | Rust color, sediment, metallic taste, reddish or orange staining |
| Manganese | 0.05 mg/L | Black to brown color, black staining, or bitter metallic taste |
| Sulfate | 250 mg/L | Salty taste |
Water Quality Testing
Water samples can be taken by homeowners and submitted to a laboratory for testing. Click here for a list of Idaho-certified laboratories . The laboratory, your DEQ regional office , or public health district can tell you how to obtain the necessary sample containers, how to take the sample, and how quickly you must get the sample to the laboratory. If you do not want to take the samples yourself, an environmental consultant can conduct the sampling for you.
Testing Frequency
Testing |
Chemical |
| Once a Year | Bacteria, Nitrate |
| Once every 3-5 years | Arsenic, Fluoride, Selenium, Uranium |
| If your water tastes, smells, or looks strange | Chloride, Manganese, Sulfate |
| If you live in an agricultural area and/or have underground tanks with petroleum | Pesticides, Petroleum |
| If you have a formula-fed infant under 6 months | Manganese |
Fix a Problem
If there is a problem with your drinking water, you may need to disinfect your well, repair your system, find an alternative drinking water source, and/or install a water treatment device to remove contaminants. When installing a treatment system, look for NSF International certified treatment devices. You need more information on how to treat your water for contaminants? We have information for you here.
Treatment Resources
Protecting Your Wellhead
Well maintenance and managing potential sources of contamination are very important to keep your water safe.
Inspect the well and surrounding area regularly:
- Are the well casing, well cap, and surface seals intact and in good shape? Is the top of the well at least 18 inches above the ground?
- Is the area around the well sloped to drain surface water away from the well?
- Are irrigation valves set properly to prevent backflow?
Fertilizers, animal waste, pesticides, septic systems and other potential sources of contamination should be located and managed so they do not contaminate the well.
- Avoid mixing or using fertilizers, herbicides, fuels, motor oil, and other pollutants near the well.
- Do not pile snow, leaves, or other materials around the well.
- Take care when working around the well to avoid damaging the casing.
- Properly locate and manage septic systems.
Contribute Data
Private well owners utilizing the Idaho Bureau of Laboratories (IBL) as their testing laboratory have the opportunity to participate in citizen science by allowing their results to be displayed publicly on this map. Citizen science is the voluntary involvement of the public in scientific research, in this case data collection. This work helps professional scientists and other private well owners to better understand ground water quality in Idaho.
If you own a private well, consider becoming a citizen scientists by granting permission on IBL’s submission form to display your tests results on this map. There are more than 3,000 wells displayed on the map currently. Note data collected by citizen scientists may not have been collected under a Quality Assurance Project Plan (QAPP), a written document that outlines the procedures a monitoring project will use to ensure the samples collected are of high enough quality to meet project needs. Using a QAPP is not required to display your results, but resources are available online. Click here for more information.