Lead and Copper in Drinking Water

The Lead and Copper Rule

water pipes 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:​

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).

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

New!Upcoming Training
Fall 2023
MDE will be hosting a number of virtual training sessions for community water systems on the Lead and Copper Rule Revisions (LCRR) in the Fall of 2023. This training will focus on 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.​

There will be separate training sessions for small, medium, and large water systems (based on population served) as well as mobile home parks.

Training for "special" community water systems* and Non-Trasient Non-Community water systems will be held at a later time.

*Note: "Special" community water systems are facilities with live-in residents (such as nursing homes, correctional facilities, rehabilitaion centers, retirement homes, hospital with live-in patients, etc.) that have their own water sources (such as wells, springs, etc.).

​Links to MDE Service Line Inventory Spreadsheet and Guidance Documents:

Inventory Spreadsheet​​

​Water systems should use an appropriate MDE LCRR Service Line Inventory Spreadsheet that corresponds with the water systems' number of service connections as shown in the table below.

IMPORTANT ANNOUNCEMENT: Due to new information related to service lines​ that has recently come to WSP's attention​, the April 2023 version of the MDE LC​RR Service Line Inventory Spreadsheet ​will be updated and replaced by the October 2023 version. The April 2023 version of the inventory spreadsheet will become obsolete as of October 2023 and should not be used for reporting service line inventory information to MDE.

Water systems that have already begun using the April 2023 version of the inventory spreadsheet will need to transfer/replicate data properly (i.e., copy-paste data as values -- see Appendix F​) to the October 2023 version of the inventory spreadsheet. Instructions on how to transfer/replicate data properly will also be provided during our upcoming training sessions on the MDE LC​RR Service Line Inventory Spreadsheet​.​

Number of Service​​ Connections
MDE LC​RR Service Line Inventory Spreadsheet**
(April 2023)
Between 1 and ​​​​​​​5,000
MDE LCRR Service Line Inve​ntory Spreadsheet_50​​00 rows (will be replaced by the October 2023 version)
Between​ 5,001 and 10,000
MDE LCRR Service Line Inventory Spreadsheet_100​​00 rows (will be replaced by the October 2023 version)
Between​ 10,001 and 20,000
MDE LCRR Service Line Inventory Spreadsheet_200​​00 rows (will be replaced by the October 2023 version)
Between​ 20,001 and 30,000
MDE LCRR Service Line Inventory Spreadsheet_300​​00 rows​​​​ (will be replaced by the October 2023 version)
Between​ 30,001 and 45,000
MDE LCRR Service Line Inventory Spreadsheet_450​​00 rows​​​ (will be replaced by the October 2023 version)
Between​ 45,001​ and 85,000
MDE LCRR Service Line Inventory Spreadsheet_850​​00 rows (will be replaced by the October 2023 version)
Between​ 85,001 and 100,000
MDE LCRR Service Line Inventory Spreadsheet_1000​​00 rows (will be replaced by the October 2023 version)​​
More than 100,000
***​Instructions will be forthcoming***​​​
​​​**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.


Appendices A - G in PDF format

​​Appendices from MDE LCRR Service Line Inventory Spreadsheet that are a​vailable in PDF format (April 2023)​:

Coming Soon…
  • MDE LCRR Service Line Inventory Spreadsheet (With Examples) -- for reference ​only
  • LCRR “New” Water Systems Inventory Form
  • LCRR Customer LSL Notification Template 
  • LCRR Customer LSL Notification Certification Form
  • LCRR Template for PWS Written Statement Demonstrating No LSLs

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 Service Line Inventory) includes best practices and case studies for inventory development. 

EPA has committed to issuing additional guidance for small water systems and States. More information to come.

Association of State Drinking Water Administrators

The Association of State Drinking Water Administrators (ASDWA) has many resources that may be helpful to water systems:

  • Presentation slide decks and recordings from a 2022 ASDWA 8-part webinar series on various lead service line inventory topics (e.g., case studies, funding for inventory, inventory templates, and other tools) can be accessed at the ASDWA Lead Service Line Symposium page.
  • ASDWA also developed a framework for those starting the development of lead service line inventories prior to the release of EPA’s service line inventory guidance.
  • ASDWA’s Lead and Copper Rule webpage, which contains additional ASDWA papers, communications, webinars, and resources for the LCRR.
  • 2022-2023 ASDWA Webinar Series: Implementation Tools and Best Practices for Lead Service Line Inventories and Replacements​

Technical Assistance

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. 

For questions related to MDE’s service line inventory spreadsheet please contact the Lead and Copper in Drinking Water Division at Reporting.LeadCopperRule@maryland.gov.​​

Funding for Service Line Inventories and Lead Service Line Replacements

Opportunities for funding related to service line inventories and lead service line replacements may be found on MDE’s Water Infrastructure Financing Administration webpage.

In addition, the University of Maryland Environmental Finance Center 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 over the coming five years (from April 2023 through March 2028) at no cost to recipients through an award from the US Environmental Protection Agency.  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.​

New!​Lead and Copper Rule Improvements

On December 17, 2021, EPA published Docket No. EPA-HQ-OW-2021-0255 in the Federal Register. Within the Docket, EPA committed to propose and revise the LCRR by October 2024 with the Lead and Copper Rule Improvements (LCRI). The LCRI is expected to 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 or has lead interior pipes (lead is a dull gray metal that is soft enough to be easily scratched with a house key), you may want to test your water and have it analyzed by a State-certified laboratory.

The EPA provides information on testing your home's drinking water for lead and steps you can take if your home tests positive for lead.

Click here for a  list of Lead and Copper forms for testing ​your CWS or NTNCWS.

​For More Information

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


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