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Lead & Copper Rule

Program Overview

The Environmental Protection Agency (EPA) has been working on long-term revisions to the Lead and Copper Rule for a number of years. The following is a statement from the Association of State Drinking Water Administrators (ASDWA) regarding the delays in the revisions:

In a Federal Register notice published June 16, 2021, EPA has delayed the effective date of the final Lead and Copper Rule Revisions (LCRR) originally published on January 15, 2021. The effective date of this rule is delayed until December 16, 2021. Additionally, the compliance date for the final rule is delayed until October 16, 2024. Extending the compliance deadline ensures states have the full three years provided by the Safe Drinking Water Act to adopt laws and regulations to obtain primacy for the rule and so water systems have adequate time to take any necessary actions to meet the compliance deadlines in the rule. 



1520 E 6th Ave
Helena, MT 59601

Lead & Copper Rule Manager

George Williams (406) 444-3276

Lead & Copper Rule Manager

Matt Schmidt (406) 444-6652

Lead in School Rule Manager

Greg Montgomery (406) 444-5312

Questions, Comments and Documentation can be emailed to: 

Lead Service Line Inventories

The most significant new requirement in the LCRR is the Lead Service Line Inventory. Service line inventories help water systems take action to address a potential significant source of lead in drinking water - lead service lines (LSLs). Establishing an inventory of service line materials and identifying the location of LSLs is a key step in getting them replaced and protecting public health.

All Community and Non-Community Non-Transient Water Systems are required to submit their initial service line inventories by October 16, 2024.

Completed inventories should be submitted online by signing into DEQ's online services portal through the button below.

Submit an Inventory

DEQ has developed a number of guidance documents, templates, and forms to help water systems with this requirement. Funding is also available for inventories, planning and lead service line replacement activities. The documents below are intended to assist water systems in preparing their inventories.

Technical Assistance

DEQ has partnered with the Montana Department of Commerce to provide a Technical Assistance Program to assist water systems complete their inventories. If you would like assistance in completing your inventory please click on the link to complete the application for assistance.

LSL Inventory Technical Assistance Program


Additional Information & Resources


A small amount of copper is essential for good health. The Food and Drug Administration recommends a dietary allowance of 2 milligrams (mg) of copper a day. Major food sources of copper are shellfish, nuts, grains, leafy vegetables, mushrooms, chocolate, liver, and some fruits. Exposure to high doses of copper can cause health problems. Short-term exposure to high levels of copper can cause gastrointestinal distress. Long-term exposure and severe cases of copper poisoning can cause anemia and disrupt liver and kidney functions. While some of the copper you consume rapidly enters the bloodstream, your body is very good at preventing high levels of copper from entering the bloodstream; it will excrete excess copper after several days. Individuals with Wilson’s or Menke’s disease (genetic disorders resulting in abnormal copper absorption and metabolism) are at higher risk from copper exposure than the general public.


Lead is a toxic metal that can be harmful to human health even at low exposure levels. Lead is persistent, and it can bioaccumulate in the body over time.

Young children, infants, and fetuses are particularly vulnerable to lead because the physical and behavioral effects of lead occur at lower exposure levels in children than in adults. A dose of lead that would have little effect on an adult can have a significant effect on a child. In children, low levels of exposure have been linked to damage to the central and peripheral nervous system, learning disabilities, shorter stature, impaired hearing, and impaired formation and function of blood cells.

It is important to recognize all the ways a child can be exposed to lead. Children are exposed to lead in paint, dust, soil, air, and food, as well as drinking water. If the level of lead in a child's blood is at or above the CDC action level of 5 micrograms per deciliter, it may be due to lead exposures from a combination of sources. EPA estimates that drinking water can make up 20 percent or more of a person’s total exposure to lead. Infants who consume mostly mixed formula can receive 40 percent to 60 percent of their exposure to lead from drinking water.

Pregnant Women

Lead can accumulate in our bodies over time, where it is stored in bones along with calcium. During pregnancy, lead is released from bones as maternal calcium and is used to help form the bones of the fetus. This is particularly true if a woman does not have enough dietary calcium. Lead can also cross the placental barrier exposing the fetus to lead. This can result in serious effects to the mother and her developing fetus, including:

  • Reduced growth of the fetus
  • Premature birth

Find out more about lead's effects on pregnancy:

Lead can also be transmitted through breast milk. Read more on lead exposure in pregnancy and lactating women (PDF) (302 pp, 4.3 MB, About PDF).


Lead is also harmful to adults. Adults exposed to lead can suffer from:

  • Cardiovascular effects, increased blood pressure and incidence of hypertension
  • Decreased kidney function
  • Reproductive problems (in both men and women)

Related Information

Can I shower in lead-contaminated water?
Yes. Bathing and showering should be safe for you and your children, even if the water contains lead over EPA’s action level. Human skin does not absorb lead in water.

This information applies to most situations and to a large majority of the population, but individual circumstances may vary. Some situations, such as cases involving highly corrosive water, may require additional recommendations or more stringent actions. Your local water authority is a valuable resource for testing and identifying lead contamination in your tap water. Many public water authorities have websites that include data on drinking water quality, including results of lead testing. Links to such data can be found on the EPA Consumer Confidence Report website.

Lead and copper are unusual among drinking water contaminants in that they seldom occur naturally in water supplies like rivers and lakes. Lead and copper enter drinking water primarily as a result of the corrosion, or wearing away, of materials containing lead and/or copper in the water distribution system and facility/residential plumbing. These materials include lead-based solder used to join copper pipe, brass and chrome-plated brass faucets, and in some cases, pipes made of lead that connect facilities to water mains (service lines). In 1986, Congress banned the use of lead solder containing greater than 0.2% lead, and restricted the lead content of faucets, pipes and other plumbing materials to 8.0%. In 2011, the Reduction of Lead in Drinking Water Act further reduced the allowable lead content in water-bearing materials with a new definition of “lead-free” products. The new definition of “lead-free” is a weighted average of 0.25% lead calculated across the wetted surfaces of a pipe, pipe fitting, and fixture and 0.2% lead for solder and flux.

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

  • For Public Water Systems (PWS)

    PWSs should have an understanding of their water chemistry and how it will interact the distribution system plumbing.


    Customers should learn about the water they are receiving from their local water supply utility. This can be done by reading the annual consumer confidence report (CCR) which is prepared by all community water systems. Customers can also perform the following activities which will minimize your potential exposure to lead and copper in your drinking water.

    • Use only cold water for drinking and cooking. Hot water can be more corrosive than cold water.
    • Flushing your water system after any extended period of non-use like vacations. Flushing is an easy and effective way of reducing the potential of lead and copper exposure in your drinking water. Flush each faucet or fixture that is used for drinking and food preparation for a couple minutes prior to use.
    • Routine inspection of your plumbing system for signs of corrosion. Corrosion can be caused by a number of things such as dissimilar materials (copper pipe connected to brass fitting) and electrical grounding (electrical system being ground to copper pipe).
    • Routine inspection of faucet aerators. Check your aerators on a regular basis. The aerator is located at the end of the faucet and should be able to unscrew. Particulates can collect in the aerator, reducing your flow and increasing potential for lead and copper exposure.

For detailed information for how to maintain compliance with the Lead & Copper Rule see the EPA document Lead and Copper Monitoring and Reporting Guidance for Public Water Systems.

The Lead & Copper Rule applies to Community and Non Transient/Non Community Public Water Systems. Systems must have a site sampling plan that indicates the sample locations as well as backup locations. The number of sample locations is dependent on the system’s population.

Table 1

>100,000 100 50
10,001 to 100,000 60 30
3,301 to 10,000 40 20
501 to 3,300 20 10
101 to 500 10 5
100 or less 5 5

The lead and copper regulations require you to sample at locations that may be particularly susceptible to high lead or copper concentrations. The LCR establishes a tiering system for prioritizing sampling sites. A materials evaluation is required to help classify sampling sites into tiers. You must perform a materials evaluation before you begin lead and copper tap monitoring. Table 2 below, defines the tiering system for prioritizing sampling sites.

Table 2

Tier 1 sampling sites are single family structures with copper pipes with lead solder installed after 1982 (but before the effective date of your State’s lead ban) or contain lead pipes; and/or that are served by a lead service line. Note: When multiple-family residences (MFRs) comprise at least 20% of the structures served by a water system, the system may count them as Tier 1 sites. Tier 1 sampling sites consist of buildings: with copper pipes with lead solder installed after 1982 (but before the effective date of your State’s lead ban) or contain lead pipes; and/or that are served by a lead service line.
Tier 2 sampling sites consist of buildings, including MFRs: with copper pipes with lead solder installed after 1982 (but before effective date of your State’s lead ban) or contain lead pipes; and/or that are served by a lead service line. Tier 2 sampling sites consist of buildings with copper pipes with lead solder installed before 1983. Tier 2 sites shall complete its sampling pool with representative sites throughout the distribution system.
Tier 3 sampling sites are single family structures w/ copper pipes having lead solder installed before 1983. Used if all Tier 1 and Tier 2 sites have been exhausted. Tier 3 sites shall complete its sampling pool with representative sites throughout the distribution system. Tier 3 Not applicable.
Note: All States were required to ban the use of lead solder in all public water systems, and all homes and buildings connected to such systems by June 1988 (most States adopted the ban in 1987 or 1988). Contact the Drinking Water Program in your State to find out the effective date. Note: 40 CFR 141.86(8) Any water system whose distribution system contains lead service lines shall draw 50% of the samples it collects during each monitoring period from sites that contain lead pipes, or copper pipes with lead solder, and 50 % percent of the samples from sites served by a lead service line.

Once monitoring begins, you must use the same sites, unless a site is no longer accessible to you or no longer fits the requirements of a priority site (e.g., the lead service lines that served the site have been replaced ).

Monitoring frequency is determined by a number of factors and are generally in two categories (Standard and Reduced).

Standard Monitoring- Samples are collected within a 6-month window (January-June and July-December). Systems will need 2 consecutive rounds of 6-month data with results less than the action level for lead and copper. All new systems and systems that have a change in source or treatment must be on standard monitoring. Systems that have an action level exceedance will also have to go to standard monitoring.

Reduced Monitoring- If a system has 2 consecutive rounds of 6-month data with results less than the action level for lead and copper, the system would be a candidate for reduced monitoring of either annual or triennial sampling. Systems would also have the number of samples reduced. Refer to Table 1.

Action Level (AL)

In 1991, EPA published a regulation to control lead and copper in drinking water. This regulation is known as the Lead and Copper Rule (also referred to as the LCR). Since 1991 the LCR has undergone various revisions, see the Rule History section below.

The treatment technique for the rule requires systems to monitor drinking water at customer taps. If lead concentrations exceed an action level of 0.015 milligrams per Liter (mg/L) or copper concentrations exceed an action level of 1.3 mg/L in more than 10% of customer taps sampled, the system must undertake a number of additional actions to control corrosion

Under Construction
  • Montana Rural Water – LCRR & Service Line Inventory Workshops (MRWS & DEQ)
  • Join us for a half-day workshop featuring MT Rural Water and DEQ on the Lead and Copper Rule Revisions, including a deep dive on the
    foundational Lead Service Line Inventory. We’ll highlight how other systems are tackling the rule as well as review some of the tools available to support your compliance journey.

    • May 1, 2023 – Billings 9am-12pm
    • May 2, 2023 – Miles City 9am-12pm
    • May 3, 2023 – Glasgow 9am-12pm
    • May 4, 2023 – Havre 9am-12pm

           Click Here to Register