Lead and Copper in Drinking Water

The Lead and Copper Rule​​​

water pipesThe federal Lead and Copper Rule (LCR)​, effective in Maryland starting in the early 1990s, requires public water systems (both Community Water Systems (CWS) and Non-Transient Non-Community Water Systems (NTNCWS)) to test for lead and copper in drinking water at customers' taps at high risk sites (Tier 1 sites) located throughout their water distribution system.  If testing reveals that lead and/or copper levels exceed the Action Levels established by the US Environmental Protection Agency (EPA) in 10 percent of samples collected during a particular monitoring period, water systems are required to perform certain actions, such as optimizing corrosion control treatment, notifying the public (if the lead Action Level is exceeded), and replacing Lead Service Lines (if present) to reduce exposure to lead and copper at customers' taps. ​


Minor Revisions of 2000​
Short Term Revisions​
Lead and Copper Rule Revisions​

Service Line Inventories​

MDE Tra​inings​​​​

MDE Service Line Inventory Reporting Forms and Guidance Documents​

​​MDE LCRR Service Line Inventory Spreadsheet​​​
MDE LCRR Service Line Inventory Spreadsheet​'s Appen​dices A - G​​
New!MDE LCRR ​Service Line Inventory Certification Form for “New” Water Systems​​​​
Other Documents/Forms/Guidance​​

​​Service Line Inventory Guidance from the US Environmental Protection Agency​
Association of State Drinking Water Administrators (ASDWA)
Funding and Technical Assistance for Service Line Inventories and Lead Service Line Replacements​​
Lead and Copper Rule Improvements​
How do I know if my tap water is lead free?
Lead and Copper Rule Te​sting Forms​
​For More Information​​​


In 1991, the United States Environmental Protection Agency (EPA) published the ​Lead and Copper Rule (LCR) to minimize lead and copper in drinking water. The Rule replaced the previous Maximum Contaminant Level (MCL) standard of 50 ppb, measured at the entry point to the distribution system, with an Action Level (AL) of 0.015 mg/L for lead and 1.3 mg/L for copper based on 90th percentile level of required compliance monitoring values. The Lead and Copper Rule differs from other Safe Drinking Water Act regulations in that it replaced compliance determination based on an MCL with a three-pronged approach to reducing lead and copper levels:

  1. Treatment technique requirements, including corrosion control and source water treatment;​
  2. Lead service line replacement program;
  3. Public Education for lead.

Lead and copper enter drinking water primarily through plumbing materials. Exposure to lead and copper may cause health problems ranging from stomach distress to brain damage. The Rule established a Maximum Contaminant Level Goal (MCLG) of zero (0) for lead in drinking water and a treatment technique to reduce corrosion of lead and copper within the water distribution system. The treatment technique for the Rule requires water systems to monitor drinking water at customer taps. If lead or copper concentrations exceed the AL in more than 10% of customer taps sampled, the system must undertake a number of additional actions to control corrosion. If the AL for lead is exceeded, the system must inform the public about steps they should take to protect their health including running the water to flush out the lead, using cold water for cooking and preparing baby formula, and identifying if their home plumbing fixtures contain lead. Exceeding the AL is not considered a violation. The LCR applies to all Community Water Systems (CWS) and Non-Transient Non-Community Water Systems (NTNCWS).​

Since 1991, the LCR has undergone various revisions.​

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Minor Revisions of 2000

On January 12, 2000, EPA published minor revisions to the 1991 Rule making a number of substantial changes including: 

  • Requirements that when systems replace lead service lines they are to:
    • Replace the portion of the lead service line that they own.
    • Notify residents of the potential for temporary increases in lead levels and measures they can take to reduce lead levels if the system replaces only that part of a lead service line that it owns.
  • Authority for states to invalidate tap samples under certain circumstances.
  • Requirements that systems on reduced monitoring report to the state primacy agency any changes in treatment or the addition of a new water source.

Short Term Revisions

In ​​2007, EPA revised the Lead and Copper Rule to enhance implementation in the areas of monitoring,

  • Required educational statement about lead in drinking water be included in all Consumer Confidence Reports.
  • Changed notification of state primacy agency of anticipated changes in treatment or source water that could increase corrosion of lead from simply notification to prior notice and approval.
  • Changed definition of monitoring and compliance periods to require all compliance samples be taken within the same calendar year.
  • Required water systems above the lead action level to return to standard monitoring if they are on a reduced monitoring schedule.
  • Added flexibility and improved the readability of required public education language.
  • Expanded public education material delivery strategies to better reach consumers and disseminate information to at-risk populations.

New! Lead and Copper Rule Revisions

Service Line Inventories

EPA published the Lead and Copper Rule Revisions (LCRR) in January 2021, which requires all Community Water Systems (CWS) and Non-Transient Non-Community Water Systems (NTNCWS) to submit an initial service line inventory to the Primacy Agency by October 16, 2024. Water systems must develop an inventory to identify the material(s) of service lines connected to the public water distribution system and categorize the service line materials as “Lead”, “Galvanized Requiring Replacement (GRR)”, “Non-lead”, or “Lead Status Unknown” (see link to MDE guidance below). Additionally, there are certain requirements for the water systems to make their information publicly accessible and to notify all persons served by the water system at the service connection with a lead, GRR, or lead status unknown service line​​.

To comply with the service line inventory requirements of the LCRR, Maryland’s public water systems are required to use one of the service line inventory reporting forms provided by MDE to document and report their initial inventory and inventory updates.  Water systems must submit their initial inventory and inventory updates to MDE.

Fall 2023
During the Fall of 2023, MDE hosted the first round of virtual trainings for community water systems on how to complete the MDE LCRR Service Line Inventory Spreadsheet, which must be used by Maryland's water systems to document, track, and organize their service line inventory and report to MDE. The Fall 2023 training concluded on December 15, 2023, and focused on community water systems (both privately owned and publicly owned, including mobile home parks, towns, and cities).

Spring 2024
Training for non-transient non-community water systems (e.g., schools and businesses) and “special" community water systems* (e.g., retirement facilities, nursing homes, correctional facilities, etc.), which typically have a small number of service lines and own the entire length of the service line, will be held in the Spring of 2024.  The Spring 2024 training will conclude on April 11, 2024.

Future Training
MDE plans on hosting additional training related to transferring data from previous versions of LCRR Service Line Inventory Spreadsheets (i.e., April 2023 and December 2023) to the current version of the spreadsheet (i.e., March 2024), as well as training related to the Lead and Copper Rule Improvements (expected to be finalized by the EPA in October 2024).
MDE has developed two types of service line inventory reporting forms and water systems must use one of these forms to document their service line inventory:

  • For water systems that MEET the definition of a “new” water system ONLY:
MDE LCRR Service Line Inventory Certification Form for “New” Water Systems - Initial Inventory​

  • For water systems that DO NOT meet the definition of a “new” water system:

    MDE LCRR Service Line Inventory Spreadsheet​

    • ​Water systems that meet the definition of a “new” water system may choose to use this form instead of MDE LCRR Service Line Inventory Certification Form for “New” Water Systems

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Water systems should use an appropriate MDE LCRR Service Line Inventory Spreadsheet that corresponds to the number of service connections in their water distribution system(s) as shown in the table below.

**ALERT** (March 15, 2024)

​​The newly updated version of MDE’s LCRR Service Line Inventory Spreadsheet (March 2024) is now available for download.  This new version of the inventory spreadsheet incorporates anticipated changes related to the US EPA’s recently proposed Lead and Copper Rule Improvements.  Older versions of the inventory spreadsheet (i.e., April 2023 and December 2023) are obsolete and should not be used for reporting service line inventory information to MDE.

MDE will work with water systems that have started populating data on the older versions of the inventory spreadsheet (April 2023 or December 2023) to transfer the data to the new version of the spreadsheet (March 2024).  It is important that data be transferred/replicated properly (i.e., copy-paste data as values -- see Appendix F​) to the new version of the inventory spreadsheet.  If your water system would like additional assistance on how to transfer/replicate data properly, please reach out to MDE's Water Supply Program via email at​​ <Reporting.LeadCopperRule@maryland.gov​>.​

Number of Service​​ Connections
MDE LC​RR Service Line Inventory Spreadsheet**
(March 2024)
500 or fewer
MDE LCRR Service Line Inve​ntory Spreadsheet_50​​0 rows​​​
Between​ 501 and 5,000
MDE LCRR Service Line Inve​ntory Spreadsheet_50​​00 rows​​
Between​ 5,001 and 10,000
MDE LCRR Service Line Inventory Spreadsheet_100​​00 rows
Between​ 10,001 and 20,000​
MDE LCRR Service Line Inventory Spreadsheet_2​00​​00 rows​​​​
​Between​ 20,001 and 30,000​
MDE LCRR Service Line Inventory Spreadsheet_300​​00 rows​​​​​​
Between​ 30,001 and 45,000​
MDE LCRR Service Line Inventory Spreadsheet_450​​00 rows​​​​
Between​ 65,001​ and 85,000
​​​MDE LCRR Service Line Inventory Spreadsheet_850​​00 rows
Between​ 85,001 and 100,000
MDE​ LCRR Service Line Inventory Spreadsheet_1000​​00 rows
More than 100,000
***​Contact MDE for instructions***​​​
​​**Note: Inventory spreadsheets with higher number of rows​ are larger (in size) and may take several seconds to a few minutes to open and edit (after downloaded).​​​

After downloading the Excel spreadsheet from MDE's website, you may need to enable editing of the spreadsheet as well as unblock and enable macros.  Follow the steps in Ena​ble Editing, Unblock and Enable Macros Instructions​ to enable editing and unblock and enable macros.​​

Microsoft Excel has a useful feature (called "Freeze Panes") that can help water systems view a large spreadsheet by keeping an area of a particular worksheet visible while you scroll to another area of the same worksheet.  Follow the steps in Freeze/Unfreeze Rows and Columns in a Worksheet Instructions​​ to apply "Freeze Panes" or "Unfreeze Panes" features to your spreadsheet.  Note that the spreadsheet you downloaded may already have Freeze Panes applied.​  In addition, the zoom level on the spreadsheet is defaulted to 100%, which may restrict viewing area and/or the number of rows you see if you open the spreadsheet on smaller computer screen.  To increase your viewing area, you may decrease the zoom level (i.e., "zoom out") and/or adjust the height of certain rows (Note: Please be mindful when adjusting row heights as doing so may cut off necessary text).  If these methods are not sufficient, you may try to unfreeze panes.

MDE LCRR Service Line ​Inventory Spreadsheet's Appendices A - G:

New!​MDE LCRR Service Line Inventory Certification Form for “New” Water Systems
​This certification form is only to be used by public water systems (Community and Non-Transient Non-Community) that meet MDE's definition of a "New" water system​.  For the purpose of the LCRR service line inventory, MDE Water Supply Program defines a “new” water system as a public water system that contains only Non-Lead service lines in its water distribution system and meets the following criteria:

  • ​​All pertinent records have demonstrated that all service line pipes* (i.e., the entire length of service line pipes connecting water mains** to buildings) were installed on or after May 17, 1972***, with no reuse of pipes (rigid or flexible), fittings, or meters installed before May 17, 1972,

  • ​All pertinent records have demonstrated that all service line pipes were installed on or after the date of local ordinance (that did not include lead pipe as an acceptable material to be used for water service pipes) that was in effect prior to May 17, 1972, with no reuse of pipes (rigid or flexible)​, fittings, or meters installed before the effective date of the local ordinance.

*Note that service lines do not include pipes that have been severed AND abandoned outside the building as they would not be connected to the building inlet.

**For water systems that do not have water mains, the service line would be from the well(s) to the building(s).  If there is a well house/building or treatment plant/building after the well(s), then the service line would be from the well house/building or treatment plant/building to the building/structure served.​

*​**May 17, 1972, is the effective date on which lead pipe was not included as one of the acceptable materials to be used for water service pipes under Maryland law (COMAR

The ​​certification form​​ can be downloaded below:

T​he completed certification form should be submitted to MDE at:  Reporting.LeadCopperRule@maryland.gov

Please be sure to include “New Water System Service Line Inventory Form” in the subject line of the email AND Water System Name and PWSID in the body of the email.​

Coming Soon…
  • MDE LCRR Service Line Inventory Spreadsheet (With Examples) -- for reference ​only
  • LCRR Customer LSL Notification Template 
  • LCRR Customer LSL Notification Certification Form
  • LCRR Template for PWS Written Statement Demonstrating No LSLs
  • Recording of LCRR Service Line Inventory Spreadsheet Training​

Service Line Inventory ​Guidance from the US Environmental Protection Agency

In August 2022, EPA released Guidance for Developing and Maintaining a Service Line Inventory to support water systems. The guidance (Guidance for Developing and Maintaining a Servic​e Line Inventory) includes best practices and case studies for inventory development. 

In June 2023, EPA released the Small Entity Compliance Guide to support water systems, particularly small water systems, in complying with the LCRR initial inventory requirements.  The guidance ​(Developing and Maintaining a Service Line Inventory: Small Entity Compliance Guide) explains the inventory-related actions small community and non-transient non-community water systems are required to take under the LCRR.

​Visit EPA's website​ for more information on EPA's service line inventory guidance.​

Association of State Drinking Water Administrators (ASDWA)

ASDWA has many resources that may be helpful to water systems:

Funding and Technical Assistance for Service Line Inventories and Lead Service Line Replacements​

  • MDE’s Water Infrastructure Financing Administration has opportunities for funding related to service line inventories and lead service line replacements. More information may be found on MDE’s Water Infrastructure Financing Administration webpage.

  • On November 4, 2022, EPA announced a selection of Environmental Finance Centers (EFCs) that will help communities across the country access federal funding for infrastructure projects that improve public health and environmental protection, including service line inventories and lead service line replacements. The current regional and national EFCs that provide assistance for water infrastructure projects include University of Mary​land, Rural Community Assistance Program (RCAP), Environmental Policy Innovation Center (EPIC), U.S. Water Alliance​, and Moonshot Missions​. The selected EFCs will help underserved communities that have historically struggled to access federal funding receive the support they need to access resources for water infrastructure improvements.  For more information on EFCs, visit EPA’s Environmental Finance Centers webpage.
    • ​In addition, the University of Maryland EFC is providing direct support to municipalities, tribes, and water utilities in Maryland to help them access federal and state funding to address water infrastructure needs across drinking water, wastewater, stormwater, and source water. This assistance will be delivered through March 2028 at no cost to recipients through an award from EPA. Available services include assistance identifying water challenges; developing plans; building technical, financial, and managerial capacity; and completing funding application materials. Assistance is available on a need basis, with priority given to historically underserved and disadvantaged communities. To request assistance, contact Michelle Kokolis​ at mkokolis@umd.edu.​
  • The Maryland Rural Water Association (MRWA) has Circuit Riders who are available to assist small water systems (population under 10,000) with completing their service line inventories.  Please visit their website or contact them at info@md-rwa.org​ for additional information.​

New!Lead and Copper Rule Improvements

On December 6, 2023, the proposed Lead and Copper Rule Improvements (LCRI), were published in the Federal Register. The proposal builds on the 2021 Lead and Copper Rule Revisions (LCRR) and the 1991 Lead and Copper Rule (LCR).​ The LCRI will delay the implementation of portions of the LCRR beyond the October 16, 2024, compliance date, however, EPA maintains the October 16, 2024, compliance date for the lead service line inventories. Water systems are to keep their current tap sampling plans until the LCRR comes into effect on October 16, 2024. For more information on the LCRI, see https://www.epa.gov/ground-water-and-drinking-water/lead-and-copper-rule-improvements.​

How do I know if my tap water is lead free?

Whether you receive water from a public water system or from your own private well, testing your home's drinking water is the only way to confirm if lead is present. Most water systems, based on their number of customers, test for lead at a certain number of high-risk homes within their service area as part of their regulatory water monitoring requirements. These tests provide a system-wide snap shot of whether or not corrosion is being controlled within the distribution system, but do not reflect conditions at every customer tap served by that water system. If your home is served by a lead service line, has lead interior pipes (lead is a dull gray metal that is soft enough to be easily scratched with a house key), or if you are concerned about lead levels in your drinking water, you may want to consider  testing your water and havinge it analyzed by a State-certified laboratory.

Information on testing your home's drinking water for lead and steps you can take if you are concerned about lead in your home​ ​can be found on EPA's website.

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Lead and Copper Rule Testing Forms

​Click here for a list of Lead​ and Copper forms fo​r testing ​your ​CWS or NTNCW​S​​​.

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For More Information

Please contact the Water Supply Program at Reporting.LeadCopperRule@maryland.gov​ or 410-537-3702​.

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