Montana Department of Environmental Quality About Us Permitting & Operator Assistance Public Participation

Drinking Water

Program Overview

Public Water Systems are legally defined as entities that provide water to 25 or more people for more than 60 days a year or have 15 or more service connections. In Montana this includes cities, towns, water districts, subdivisions, HOAs, campgrounds, restaurants, bars and other businesses. The Public Water Supply Bureau at DEQ regulates public water systems in Montana to ensure that the water being served meets federal Safe Drinking Water Act and state laws and regulations. Private wells are not regulated under these regulations.  

Rivers, lakes, springs and wells provide water to PWS that are often treated before serving to the public. The number of people served, the type of source water, and type of contaminants determines the frequency of drinking water testing.

If you are a certified operator or are looking to become certified, visit our Permitting and Operator Assistance page for more information on forms, monitoring schedules, checking your CECs, and other applicable requirements.

Compliance and Reporting

Compliance and reporting is critical to maintaining both Montana’s public water supply and the health of Montana lakes, rivers, streams and wetlands. DEQ conducts a variety of inspections and requires mandatory reporting to ensure compliance and protection of public health and Montana waters.

Private Water Wells and Septic Systems

Private water wells and septic systems require homeowners to take more control of their water quality. Well and septic owners have a responsibility to themselves, their families, and their neighbors to protect ground water from contamination and to ensure that water systems provide good quality drinking water.


Public Water Supply Bureau

Main Number (406) 444-4400

Bureau Chief
Greg Olsen (406) 444-0493

Several online resources exist to help you find out about levels of regulated contaminants in your treated water for the preceding calendar year.

Consult your annual Consumer Confidence Report (CCR) through the U.S. Environmental Protection Agency (EPA), or search the Drinking Water Watch, which can be searched by county or several other parameters.

Summary data regarding compliance for all public water supply systems in Montana can be viewed in Montana's 2020 Annual Public Water System Compliance Report

Contaminants in Drinking Water

EPA sets legal limits on over 90 contaminants in drinking water. The legal limit for a contaminant reflects the level that protects human health and that water systems can achieve using the best available technology. EPA rules also set water-testing schedules and methods that water systems must follow.

The National Primary Drinking Water Regulations are legally enforceable standards for drinking water. These standards establish maximum levels of contaminants allowed in drinking water to protect public health.

National Primary Drinking Water Regulations

The National Secondary Drinking Water Regulations are non-mandatory standards that serve as guidelines for drinking water contaminants that are not considered a risk to human health.

National Secondary Drinking Water Standards

Water System Rule Summaries

Individual Montana Drinking Water Rules


Public Water Supply Bureau: 444-4400

Source Water Delineation and Assessment

DEQ conducts Source Water Assessments (also known as Source Water Delineation and Assessment Reports) that analyze existing and potential threats to the drinking water of public water supplies.

Each Source Water Assessment includes four major elements:

1. Identify the Source(s) of Water used by Public Water Systems

Source water protection areas are delineated for ground water and surface water sources. This technical process considers characteristics of the aquifer or watershed and the public water system intake. It then identifies the land area that contributes recharge to the hydrologic or hydrogeologic system above or upgradient from the public water system well or intake structure. These protection areas are part of a source water delineation and assessment report (SWDAR) and are shown graphically on a map. Check out examples of completed reports on the Internet

2. Identify and Inventory Potential Contaminant Sources

Potential contaminant sources within the source water protection area are identified and described in the assessment report. Regulated contaminants of concern in Montana include nitrate, microbial contaminants, and certain fuels, solvents, herbicides, pesticides, and metals. Potential contaminants sources include septic systems, animal feeding operations, underground storage tanks, floor drains and sumps, and certain land use activities.

3. Assess the Susceptibility of Public Water Systems to Potential Contaminant Sources

A susceptibility assessment consists of evaluating the setting of the well or intake and the relative hazard posed by potential contaminant sources. A determination of relative susceptibility for each significant potential contaminant source identified within the source water protection area will be in the assessment report.

4. Make Results of the Delineation and Assessment Available to the Public

Source water assessments must be made available to the public; this is accomplished by completing a technical report that addresses items one through three above. Various media are used to distribute the reports including the Source Water Assessment Program (SWAP) Internet site, state library, and excerpts in the consumer confidence reports.

Review Source Water Assessment Reports

Source Water Delineation and Assessment Form Instructions:

Source Water Protection Delineation - PWS-6

Certification of Source Water Protection Plans

Water Quality Districts Program

Local water quality districts  are formed by county governments. Legislation describes district organization and specifies the authorities that can be exercised at the local level. The Montana Department of Environmental Quality provides support to local water quality district programs but does not have an active management role in their activities. Districts have been formed in Missoula, Lewis & Clark, Silver Bow, and Gallatin Counties. These groups serve as local government districts with a governing board of directors, and funding obtained from fees collected annually with county taxes, similar to funding mechanisms for other county districts.

Local Water Quality Districts


Montana has developed health-based guidance values for Manganese in drinking water. Information on the health effects of Manganese is an evolving science, and Montana is using a guidance value approach to help Montana families take voluntary steps to ensure that their drinking water is safe. Because they are guidance values, there are no new or additional regulatory requirements for homeowners or public water systems.


Private water wells and septic systems require homeowners to take more control of their water quality. Well and septic owners have a responsibility to themselves, their families, and their neighbors to protect ground water from contamination and to ensure that water systems provide good quality drinking water.

Stay Well by Checking Your Well

All well owners should conduct an annual water well "check-up" that includes a wellhead and pressure tank inspection. Conducting an annual well check-up of your water system is an important step to take to ensure proper operation of a well. A check-up can prolong your system’s years of service as you monitor water quality.

Annual check-up checklist:

  • At a minimum, test your water for coliform bacteria and nitrates. You can also test for any additional contaminants that may be specific for your area. You should also have your water tested if there is a: change in taste, odor, or appearance; after the well system is serviced; or after a flooding event.
  • Inspect your well parts to ensure they are in good repair. Look for problems such as cracked, corroded, or damaged well casing or settling and cracking of the ground surface around the well casing. If any of these problems are present, your well can become a conduit for contamination to ground water.
  • Check to make sure your well cap is not broken or missing. If your well does not have a sanitary cap (a two-part cap with a rubber seal), it is recommended that you replace it with a sanitary well cap.
  • Inspect your pressure tank and associated plumbing by looking for things like leaks or corrosion, which could lead to future problems.
  • Survey the area around your well to make sure there are no hazardous materials nearby (paint, motor oil, household chemicals, etc.) which could spill and contaminate your well water.

Don’t Wish for Safe Water…Test for It!

What to do After a Flood

Maintaining a Private Septic System

Lead in Schools

Montana Department of Public Health and Human Services (DPHHS) has rolled out a Lead Reduction in Schools Drinking Water Rule. This rule was enacted to protect school children by minimizing lead levels in drinking water provided at Montana’s schools.

Children are the most susceptible to lead exposure and spend a large amount of their childhood in schools. It is extremely important that schools are providing safe drinking water.

Montana Department of Environmental Quality (DEQ) is partnering with DPHHS to provide sampling and remediation technical assistance and guidance to schools.

Montana Department of Public Health and Human Services (DPHHS) has rolled out a Lead Reduction in Schools Drinking Water Rule. This rule was enacted to protect school children by minimizing lead levels in drinking water provided at Montana’s schools.

Children are the most susceptible to lead exposure and spend a large amount of their childhood in schools. It is extremely important that schools are providing safe drinking water.

DPHHS is partnering with Montana Department of Environmental Quality (DEQ) to provide sampling and remediation technical assistance and guidance to schools.

The requirements for schools are as follows:

  1. Starting January 17, 2020, all schools regulated through the Montana Office of Public Instruction (OPI) will be required to sample: all drinking water fountains; kitchen fixtures that can be used for human consumption; and a representative subset of the remaining fixtures. Schools will have two years to complete the sampling.
  2. Create and maintain a simple schematic and inventory of plumbing materials, all fixtures, and those that are used for human consumption. Schools are required to prepare a simple sketch or drawing (also could be aerial photo) showing the locations of all their water fixtures. Schools will also prepare a plumbing inventory including list of all fixtures, plumbing types, maintenance or repair history, and general school information. The inventory information will be used to create a sampling plan.
  3. Create and implement a water flushing plan. Schools will be required to flush their water systems any time a school has been inactive for greater than three days. Water flushing is an effective way for schools to improve their water quality. It removes stagnant water from pipes and fixtures that may contain higher concentrations of lead.
  4. Follow-up actions will be required depending the results of the sampling. Results will be placed into one of three bins (categories)
    • Bin 1 – Lead concentrations greater than 15.0 micrograms per Liter (µg/L) – fixture must be immediately removed from service.
    • Bin 2 – Lead concentrations greater than 5.0 µg/L less than 15.0 µg/L – fixture must be fixed, replaced or removed from service.
    • Bin 3 – Lead concentrations less than 5.0 µg/L – no action is required.
  5. Routine sampling required following the initial sampling event.
  6. Schools are required to make test results publicly available. Sample results with remediation status will also be available on the DEQ website. (Link, under construction)

Montana DEQ will provide assistance and guidance documents to help schools with these requirements.

Background and Sources of Lead in Drinking Water

Lead is unusual among drinking water contaminants in that it seldom occurs naturally in water supplies like groundwater, rivers, and lakes. Lead enters drinking water primarily as a result of the corrosion, or wearing away, of materials containing lead in the water distribution system and facility plumbing. Corrosion can release lead from pipes, solder, fixtures, and other plumbing materials that the water comes in contact with on its way from the water source to the tap. The extent to which corrosion of plumbing materials occurs can affect the amount of lead that is present in the drinking water. Most lead in school drinking water results from corrosion of older plumbing materials containing lead. Primary contributors are interior lead solder (commonly used until 1988) and lead pipe and lead solder, leaded brass fittings, valves, and various drinking water outlets (e.g., water fountains and faucets) that contain lead. It is also important to note that brass and galvanized plumbing components can contain lead.

When water is stagnant for several hours or more in lead pipes or plumbing systems containing lead, the lead may leach into the drinking water. Schools can be particularly susceptible to higher lead concentrations due to their extended periods of no water use (e.g., holidays, weekends, and winter/spring/summer breaks).

Health Effects of Lead


Are all schools required to sample for lead in their drinking water?
All schools that meet the definition below are required to collect samples. This includes public and private schools with the exception of home schools. “School" means a building or structure or portion thereof occupied for the teaching of individuals, the curriculum of which satisfies the basic instructional program approved by the Board of Public Education for pupils in any combination of Kindergarten through Grade 12, but excludes home schools as that term is defined in 20-5-102(2)(e), MCA.

How will schools afford to pay for the sampling?
State of Montana will provide funding for the sample analysis through a grant from the US EPA to assist with testing for lead in drinking water at schools.

Why did Montana go with an action level of 5.0 ug/L?
The EPA and the Centers for Disease Control and Prevention (CDC) agree that there is no known safe level of lead in a child's blood. School aged children, especially those six years of age and under, are the most susceptible to the effects of lead. Montana is using 5.0 ug/L because it is the practical quantitation level (PQL) for lead. The PQL is the concentration at which a given analysis will be sufficiently precise to yield a satisfactory quantitative result. Or simply put it is the lowest concentration at which lead can be accurately measured in water.

How do I find out if my child’s school has tested the drinking water for lead?
Contact your school administrator to learn about previous or ongoing efforts to test for and reduce lead in drinking water. You can also check the status of the school sampling on the DEQ Lead Reduction in Schools Drinking Water Program webpage.

Is lead in drinking water the only potential source of lead exposure for kids?
No. Children can be exposed to lead from paint, dust, soil, air, and food, as well as drinking water. Lead can also be brought into homes on clothes and shoes after exposure from leaded dirt, and industrial processes that involves lead. Be sure to change and wash clothes, remove shoes, and shower to avoid tracking lead into the home from soil, work sites, or hobbies. If a child has an elevated blood lead level, it is likely due to lead exposures from a combination of sources.

What should I do if I am concerned about my child’s exposure to lead?
There is no safe blood lead level. In children, even low levels of exposure have been linked to damage to the central and peripheral nervous system, learning disabilities, shorter stature, and impaired hearing. If you are concerned about your child’s exposure to lead, contact a health provider to learn more about blood lead testing. The only way to determine a child’s lead level is to have the child’s blood tested.

There are two state grants available to schools to help with funding for the lead reduction in school drinking water program.

The lead sampling grant covers the laboratory costs associated with the initial lead sampling as funding permits. Schools do not need to apply for this grant. As long as the school submits their samples to a Montana certified laboratory for lead, the laboratory will submit the invoice directly to DEQ for review and payment. For the invoice to be paid, the school must have already submitted their plumbing history, inventory and floorplans to DEQ for approval. Only public schools are eligible for this grant. When contacting the laboratory, make sure to tell them this is part of the lead in school program.

DEQ partnered with Montana Office of Public Instruction (OPI) to develop a remediation grant program. The grant program will be implemented through OPI. If your school requires remediation, you will receive an email with directions on how to apply for the reimbursement of up to $1,000 per school. Funding for this reimbursement grant is limited and is based on first come first serve basis.

There are other sources of funding for remediation activities ranging from grants to low interest loans based on eligibility requirements. A document summarizing these options will be posted under the guidance section of the Lead in School webpage shortly.

Program Introduction

Program Requirements

Getting Started


Lead In Schools Contact

Lead Reduction in School Drinking Water Rule Manager
Greg Montgomery (406) 444-5312
1520 E 6th Ave
Helena, MT 59601

Public Water Supply Emergency, Safety, and Preparedness

In an emergency, make sure you notify 911 and your local authorities first. Then proceed to contact our program through the Disaster and Emergency Services duty officer program at 406-324-4777, which notifies the DEQ duty officer, or contact our offices directly during business hours.

For more information related to emergency preparedness, security, or safety, or if you have questions or comments about these resources contact Kirk Yoder.

The information below is intended to provide resources and information for public water systems related to emergency preparedness, security, and safety.

State & Federal Laws

Emergency Preparedness

Being prepared to respond to threats and incidents is not just a plan.

Safety & Security

As there are numerous safety considerations there is no comprehensive list for all public water systems. The Safety and Health Bureau should be consulted in Montana if an assessment is needed to determine safety hazards and requirements.


The American Water Works Association has tools, provides standards, and has links to additional resources for physical security and cypersecurity planning. Vulnerability Assessments are considered a critical starting point of security planning and overall preparedness.

The following are technical assistance providers that can help with Vulnerability Assessments and developing Emergency Response Plans

Vulnerability Assessments can be a critical part of security planning and overall emergency preparedness

PWS Emergency Contact

Kirk Yoder (406) 444-7494
1520 E 6th Ave
Helena, MT 59601