Most of the drinking water in Idaho (public and private) comes from groundwater through wells and springs. There are some surface water systems that pull water from lakes and rivers.  Well drilling permits and water rights are administered by the Idaho Department of Water Resources (IDWR).  Public water systems are tested regularly, but private water systems (this includes unregulated community systems) have no regulations associated with testing them.  Private water sources can be required to be tested under other regulations or requirements if the water is being used for small daycare’s, small food processors, bottled water plants, foster/care homes, and house sales if required by lender or buyer.

Idaho’s Public Drinking Water Program is administered by the Idaho Department of Environmental Quality (IDEQ).  A public water system is defined under IDAPA 58.01.08 (Idaho Rules for Public Drinking Water Systems).  A public water system is a water system meant for human consumption (includes restroom access), has at least 15 connections, and/or regularly serves an average of 25 people a day for at least 60 days out of the year.

IDEQ contracts with the seven (7) Idaho Public Health Districts to work with non-community public water systems (schools, restaurants, businesses, RV parks, etc.) and community water systems under 25 connections.

If you would like look up information about public water systems, you can go to the PWS Switchboard.  There is information on there about both Idaho and Federal rules, sampling and monitoring data for specific water systems, guidance documents, training opportunities, and drinking water operator information.

If you need to contact SWDH about a public water system, call 208-455-5400.

Private Water Supply

Most private water supplies consist of a single well that serves a single residence. The Idaho Department of Water Resources (IDWR) regulates and permits all wells in the state of Idaho. Private water supplies are the sole responsibility of the system owner to maintain and to ensure safe potable water.

The Private Water Program that SWDH administers consists of education, technical assistance, and water sampling, for a nominal fee. Residents can choose to collect their own water samples as well. SWDH can provide guidance on what tests would be beneficial, and what the results mean to public health.


Private Water Sample by an Environmental Health Specialist – $100 plus lab testing fees*

Mortgage Surveys – A mortgage survey is a survey of a property’s wastewater disposal and potable water systems (typically septic system and well).

Mortgage Survey with a bacteriological sample (coliform presence/absence) – $240.00

Mortgage Survey with bacteriological, plus other requested water tests – $240 + lab testing fees*.

The most common tests are coliform bacteria presence/absence ($18), nitrate ($19), nitrite ($19), arsenic ($21), fluoride ($19), uranium ($44), and lead ($21).  Other inorganics commonly tested, iron ($13), manganese ($13), sodium ($13), pH ($10), hardness ($22), and total dissolved solids ($15).

For residents that choose to collect their own water samples and would like to utilize the district courier service to transport the water samples to the State Lab, SWDH charges a $10.00 fee. Please note that this fee is only to transport the sample to the State Lab, the testing fees from the State Lab still apply and the lab will send a bill to you directly.

If you have further questions, please contact SWDH at 208-455-5400.

Related Links

Idaho Department of Health & Welfare – Well Water (includes brochures about various drinking water contaminants in English and Spanish)

Lead Testing of Drinking Water Samples

These instructions are meant for private citizens who are checking their drinking water for lead.  These instructions follow the same protocols done by public water systems doing “first-draw” sampling for regulatory purposes.

Brief History

Most lead exposure in drinking water comes from internal plumbing materials within a home or building.  By the 1930’s, lead pipes were no longer being used normally.  You should have the pipes checked if your plumbing pre-dates that timeframe.  If the pre-1930 plumbing is inaccessible (such as a buried service line), the samples may have to be taken differently than the normal “first-draw” sample.  Lead solder was common with copper pipes until 1986, when it was banned.  There was some overlap until 1988 when enforcement at the State level began.   In 2014, a national mandate went through allowing no more than 0.25% of lead by weight in any pipe, fixture, or fittings that comes into contact with drinking water.  Faucets that were manufactured prior to 2014 could still have a higher lead content.

Sample Locations

Generally, a person’s typical high dose would be first thing in the morning (or after returning home at the end of the day).  Collect a sample from an indoor cold water tap that is regularly used for drinking water, like the kitchen or a bathroom sink tap.  Do not use outside or laundry taps as they are not normal drinking water locations.  The sample should be collected after the water has set motionless for at least 6 hours. If testing a non-residential location, focus on taps that would likely be used for drinking purposes like water fountains and breakroom areas.

Sampling Vacant Locations

If the house or building is vacant, it will be difficult to get accurate levels.  Flushing the tap, the day before or allowing a tap to sit longer than 12 hours will not give a typical exposure.  This should be kept in mind for anyone receiving test results from a location that had been sitting vacant when sampled.  If sampling a vacant location, it is recommended the sampler note this fact on the lab form and (if known) how long the water has sit static or when it was last flushed out.

Taking the Sample(s)

  1. Obtain the proper sample bottle(s) from a Certified Drinking Water Laboratory.
  2. Choose the location(s) where the sample(s) will be taken. Do not do extra flushing the day before as this will not depict typical exposure.  Do not remove the faucet aerator.
  3. Do not use the tap for at least 6 hours prior to the sample being taken.
  4. Open the bottle and place under the tap. Turn on the cold water and fill the bottle with a strong flow of water. Replace the lid and make sure it is secure.
  5. Fill out the paperwork and make sure date and time collected are noted. Write on bottle to indicate it is for lead testing and some other data like a last name or address.  If more than one tap was tested, make sure to note on bottle which location the sample was taken.
  6. If unable to deliver to lab immediately, place bottle(s) in refrigerator or cooler with ice packs. It is best not to take longer than 3 days to submit the sample(s) to the laboratory.


If the lab results exceed 0.015 milligrams per liter (mg/L), then the lead levels are higher than what is recommended.  Many publications use “parts per billion” (ppb) as a measurement;  0.015 mg/L equals 15 ppb.


  • Only use cold water for cooking and drinking purposes. Warmer water can make the lead leach out faster than cold water. Hot water taps may have a higher lead content than the cold water if there is potential lead content in the plumbing after the hot water heater.
  • Summer months may have higher lead levels than during winter months.
  • Whole house water treatment may make the water more corrosive than the raw water. This includes water softeners.  If a new unit is installed, testing may need to be done more than once over the next several months.
  • Reverse osmosis and several other filtration treatments will remove lead from the water.
  • IMPORTANT: Never use metal pipes or fittings after reverse osmosis or distiller treatments.  Water that comes after a reverse osmosis or distiller will aggressively leach lead and copper out of the pipes or fittings.
  • The National Sanitation Foundation (NSF) has a “Consumer Guide to NSF Certified Lead Filtration Devices for Reduction of Lead in Drinking Water” on their website at: http://www.nsf.org/consumer-resources/health-and-safety-tips/water-quality-treatment-tips/lead-in-drinking-water.

Please contact Southwest District Health at 208-455-5400 if you have any questions or need help locating a certified drinking water laboratory.