Lead Service Line (LSL) Inventory: Getting Started - PUB3058

This fact sheet provides public drinking water systems with general guidelines for developing a lead service line inventory and for communicating the inventory process with their customers.  

Terms and Abbreviations

AL - Action Level
ALE - Action Level Exceedance
Cu - Copper
Customer/ Owner - The owner of a building/private property, owner’s agent, residents, and tenants
DWSRF - Drinking Water State Revolving Fund
CWS - Community Water System
LCR - Lead and Copper Rule 
LCRI - Lead and Copper Rule Improvements
LCRR - Lead and Copper Rule Revisions 
LSL - Lead Service Line
LSLI - Lead Service Line Inventory
LSLR - Lead Service Line Replacement
NTNCWS - Non-Transient Non-Community Water System
Pb - Lead
POU - ”Point of Use” device such as a water filter
PWS - Public Water System
TL - Trigger Level
TNCWS - Transient Non-Community Water System

Definition of a Service Line 

A service line is an underground pipe that carries potable drinking water from the water main to the customer’s home or building. The service line may have split ownership, where the water system owns one portion of the line and the customer owns the other. Refer to a water system’s specific requirements to determine where the water system-owned and customer-owned portion of the service line begins and ends.

The most common ownership boundary in Missouri is at the meter. In this situation, the water system owns the portion of the service line from the water main to the water meter and the customer owns the service line from the meter to the home or building. Other common ownership boundaries are the curb stop, property line, easement or right-of-way. Customer-owned service lines may be from the property line or meter to the indoor shut-off valve where premise plumbing begins. Ownership boundaries are different for each water system. Research your records to determine what applies in your specific situation.

Inventory Requirement

All community and non-transient non-community water systems are required to create and submit an inventory.  The LCRR do not apply to private wells or TNCWS. It also does not apply to private (indoor) premise plumbing. However, water systems may want to consider premise-plumbing materials when identifying locations for future tap sampling required by the LCRR. 

Inventory Deadline

Initial Inventory

Public water systems need to submit their initial LSLI to the Missouri Department of Natural Resources' Public Drinking Water Branch by Oct. 16, 2024. The department developed an Excel spreadsheet that systems must use to submit the LSLI. The spreadsheet is available in several versions, based on the systems size, and is downloadable from the department's Lead Service Line Inventory webpage. 

The “initial LSLI” does not need to be 100% complete with all service line materials identified. However, each service line must be included in the inventory. The system can list the service lines they have not yet examined as “unknown”. Enter data for only one PWS identification (PWSID) number per spreadsheet (orange cell in the MO_LSLI tab), and each horizontal line/row of the spreadsheet must be a single and specific service line. A water system must save the Excel LSLI document based on the unique PWSID. While the goal is to identify all service lines, service lines remaining unidentified are to be listed in the LSLI as “unknown: possibly lead”. 

Updated Inventory

The PWS must submit an updated LSLI to the department on either an annual or a three-year schedule, consistent with the system’s lead and copper tap sampling schedule. Essentially, if you are sampling for lead and copper, you are also required to submit an updated LSLI. For systems with a six-month standard monitoring schedule, the updated LSLI will be due on an annual basis.

Updates to the LSLI are to include all newly identified service line materials and all replacements completed. Systems on a nine-year lead and copper monitoring schedule previously submitted information stating they are lead and copper free. Water systems that previously indicated they do not have lead must still submit a LSLI. 

Funding Assistance Opportunities

The Bipartisan Infrastructure Law included significant funding for identifying and replacing lead service lines. The department’s Financial Assistance Center is responsible for dispersing these funds through the Drinking Water State Revolving Fund program. To learn more about available LSLI funding opportunities (both loans and grants), visit Water Financial Assistance Opportunities. You may also contact the Financial Assistance Center at 573-751-1192 or by email at fac@dnr.mo.gov.

Communication with Customers

Developing the Lead Service Line Inventory

It is vital that water systems communicate the purpose and necessity of developing an accurate lead service line inventory with their customers. Educating your customers can help build trust with them as well as help them understand the risks that lead poses in drinking water. These communication efforts can help you gain your customers support for the inventory, as well as get them to be more engaged in providing the information you will need to develop a complete inventory for your system. The department developed documents to help water systems engage their customers, which are available for download on the department's Lead Service Line Inventory webpage.

While customers may be nervous about participating in lead sampling or inspections offered by a water system, please assure the customer they will not “get in trouble” if lead is detected by tap sampling or an LSL is found. There are no fines or penalties for identifying an LSL. Removing a customer-owned LSL is currently a voluntary choice. Identifying the service line material is the first step to make an informed decision. The majority of customers would like to know if their service line is an LSL.

The majority of service lines are “non-lead” and the goal is to identify as many service lines as possible before the initial LSLI is due. In most cases, the PWS must obtain permission to look at the customer-owned portion of the service line. If a customer does not want to allow water system personnel to perform an identification, the customer can self-identify their own service line. However, the PWS should have the right of “easement” to inspect the water system-owned service line and access to the water meter. Ultimately, public water systems will need to identify the materials used for all service lines in their distribution system in future inventory updates.  

After Submitting the Initial Lead Service Line Inventory

Within 30 days of submitting the initial LSLI, water systems must notify all customers that have a lead, galvanized requiring replacement, or unknown service line, and provide the following information:

• Health effects of lead
• How to reduce the level of lead in drinking water
• For lead and galvanized requiring replacement service lines, information about opportunities to replace the service line.  

Systems are required to inform customers with unknown service lines because the service line material could possibly be lead. 

Public Accessibility to the Lead Service Line Inventory

Water systems greater than 50,000 persons are required to make the publicly accessible inventory available online. Water systems with a population of 50,000 persons or less are required to make the publicly accessible inventory available upon request. Instructions to access the service line inventory must be included in the Consumer Confidence Report (CCR).

Procedure for Performing a Lead Service Line Inventory

The PWS will need to identify the exact service line construction material for each service line to complete the inventory. The first step of the process should be researching service line records. If records are not available or are incomplete, the next step would be to perform a basic on-site visual examination. Systems may alternatively consider performing tap water analysis if this is appropriate for their specific situation. If the previous steps have been unsuccessful, the final step would be excavation. This is the most costly of the methods, but it is also the most accurate and may be necessary to verify the accuracy of the system’s records. Below you will find additional guidance on these steps. 

Records Review

Begin by checking the definition used by your system for the ownership boundary of the service line. Also identify the date the water system banned the use of lead in the water system. Missouri’s lead ban was effective Jan. 1, 1989, but the water system may have banned lead before this date.

Next, determine if records exist that accurately identifies service line material. Begin with researching service line records at the water system level to determine the materials used during construction. If those records are not available or are incomplete, the system should proceed with records research at the local or county level. Use all available records. Tap cards, meter installations, as-built plans and specifications, statement of work complete, distribution system maps, plumbing permits, building permits, occupancy inspections and tax records are all possible sources for identification. You may also use Information gathered from the records review for creating predictive models. Predictive models use this information to “predict” areas that are more or less likely to have lead service lines.

To ensure the accuracy of records used, for each type of record, the system should perform additional verification, such as visual examination. If paper records are very old, plumbing may have changed. Water system operators may know the PWS-owned portion of service line materials, and the customer may know what the service line material is for their portion. For small water systems, the system may also be able to contact local contractors and plumbers for records concerning the material used in the customer-owned portion of the service line. In general, systems should visually verify 10% of each record type. If 95% of visual examinations are accurate, the records can be trusted. 

Visual Examination

Public water systems who cannot identify their service lines using records will need to use a more hands-on method to identify their service line material, such as basic on-site visual examination. Examples of basic on-site examination include: 

• Customer self-identification - Customers can examine their service line at the point it enters their home or building. Water systems can provide materials to aid customers in identifying the service line material composition. The customer must complete a form or affidavit that states how they performed the identification, sign it and provide a picture for the water system to verify. The department has developed information that can assist with customer identification, which is located on the department’s Lead Service Line webpage.
• PWS examination at point of entry - Water system staff can obtain customer permission to visually examining the service line at the point it enters the home or building. However, customers can refuse entry to homes or buildings or even potholing on their property where easements and rights-of way do not exist.
• PWS examination at meter pit - Water system staff can examine the meter pit to identify the service line material composition if connectors are not present.

The PWS should have access to the meter for replacement or inspections, even if it is inside a building. Evaluating the pipe in the meter pit on both sides of ownership can help identify the construction materials of the pipe if connectors are not used.

In addition, you can evaluate where the service line enters through the basement or foundation. Customers may be willing to self-identify their portion of the service line. They could do a scratch/ magnet test, sign a form or affidavit and take a picture for water system verification and records. The department's Do you have a Lead Service Line? - PUB3046 fact sheet outlines steps the customer can take to determine their service line composition. If the service line pipe is galvanized steel or iron, check to see if a lead service line was ever present upstream of this galvanized service line. If there was lead, it meets the definition of galvanized requiring replacement.

Tap Water Sampling

Water sampling at the customer tap can identify a lead service line. Systems can perform identification through flush, sequential or profile sampling. Sampling of this type, however, has limitations according to water chemistry. Water systems that have hard water, use a corrosion inhibitor or use calcium carbonate stabilization will have a coating on the interior of pipe that keeps water from contacting lead. In this situation, lead cannot leach enough to identify a lead service line.

Excavation

After the water system has exhausted all other methods, excavation is the final method used to identify service line material. The following methods are EPA-approved identification methods for completing a LSLI:  

• Open-trench Potholing - Normally, the open trench method exposes 3-5 feet of service line on each side of the water meter and exposes more of the service line than other methods. Connectors may extend several feet from each side of the meter. With only connectors visible, you may not see the actual service line material in a meter pit. If the service line entering the customer’s building is of a different material than at the meter, it is likely that someone previously repaired or spliced the line. Drawbacks of the excavation method are increased labor, time, and cost, as well as the need for repairs to yards, sidewalks, retaining walls, driveways, etc. 
• Hydro-vacuum (hydro-vac) Excavation - Hydro-vac excavation is less invasive, but exposes less of the service line. Because it exposes less of the service line, it is more likely for this process to miss lead materials that may be present. Hydro-vac excavation tends to be more cost effective. The excavation can be bell-shaped at the bottom of the pit to expose additional length of service line, reducing property damage. Although it can be expensive to purchase a hydro-vac truck, water systems can hire a contractor to provide hydro-vac services.

EPA recommends three locations for visual examination and identification: where the service line enters the home or building and both sides of the ownership boundary. The most common ownership boundary in Missouri is the water meter. Other examples of ownership boundaries are the corporation stop, curb stop, property line, water main, right-of way or easement. Again, systems should check their records for each specific situation. If the boundary is at the meter, systems should pothole at least 4 to 5 feet on each side of the meter to ensure identification beyond connectors. 

Non-traditional or Emerging Identification Methods  

There are a number of non-traditional methods available to water systems for conducting their LSLIs. However, systems should take caution to ensure any non-traditional method used will be effective for their system, as these methods can have questionable reliability. Some examples of non-traditional methods and potential reliability issues include the following:

• Resistivity - Radar and electrical resistivity can have problems if material or connectors are different material types.
• Sequential Sampling - Sequential sampling may indicate presence of LSL, but does not guarantee absence of LSL because calcium scales, corrosion control treatment, or water chemistry may “mask” the presence of a LSL.
• Camera Scope - An internal pipe camera scope might dislodge scales from inside of pipes, and can be hard to identify material composition with mineral build-up.

Due to these reasons, non-traditional or emerging identification methods may not be accurate in certain circumstances. If scientific research determines certain methods are inaccurate or have low accuracy, water systems will have to reinvestigate effected service lines.

Lead Service Line Disturbance

A temporary release of lead can occur any time someone disturbs a lead service line by construction, excavation, service shut-off, connector replacement or partial or full LSLR. Open trench excavation used for lead service line identification will constitute a disturbance if the excavation reveals the presence of a lead service line. Hydro-vac excavation may or may not cause a disturbance. EPA currently does not have enough information from scientific study to conclude that there is no disturbance. Therefore, EPA is recommending that systems consider hydro-vac excavation a disturbance until there is evidence it is not.

Notification

Any time a LSL is disturbed or replaced, the PWS must provide notification to the owner, owner’s authorized agent and any residents of where the LSL disturbance occurred, indicating a potential increase of lead in drinking water, the health effects of lead and actions consumers can take to minimize exposure (flushing and filters). The PWS must complete the notification within 24 hours of the line returning to service. For multi-family residences, the PWS can post customer notification at a conspicuous location.

Point of Use Device

After these disturbances occur, the LCRR requires the PWS provide a Point of Use (POU) device, such as a pitcher filter, and a six-month supply of filters. Brand choices can vary, but filters must be NSF/ ANSI 53 certified to reduce lead to less than five parts per billion (ppb). The meaning of filter certification labels found in the performance data sheet. 

• NSF/ ANSI 42 - Filters class 1 particulates 
• NSF/ ANSI 53 - 2019 standard establishing <5 ppb (ug/L) lead (Pb) REQUIRED BY RULE
• NSF/ ANSI 61 - Faucet, fittings, and valves do not contain Lead
• NSF/ ANSI 372 - Lead free components (<0.25% lead in pipes and <0.2% in solder)

The PWS must direct the customer to use filtered water for all cooking and drinking water needs for six months. Normal resolution time of a disturbance is three months. A lead and copper tap sample collected after three months can determine if the disturbance has resolved. If resolved, the system no longer needs to provide the filter. The PWS must ensure the POU manufacturer certifies the filter to last six-months (usually 120 filtered gallons) or supply enough filters to meet this requirement. The PWS must account for the number of water users (people) at the home or building to ensure the POU device is able to handle the volume for six months.

Additional Information:

• Lead service line identification: A review of strategies and approaches - Cornwell, David A. et al. (June 10, 2021)
• Federal Register 86 FR 4198, Jan. 15, 2021 - Lead Service Line Inventory and Replacement Requirements: 40 CFR Part 141.84
• History of Lead Regulation in Drinking Water Supplies - North Dakota Department of Environmental Quality
• How to Identify Lead Free Certification Marks for Drinking Water System & Plumbing Products - EPA

Important Dates Related to Lead in Plumbing: 

• June 19, 1986: EPA promulgated the Safe Drinking Water Act (SDWA) Lead Ban
• Jan. 1, 1989:  Missouri Lead Ban became effective 
  • Lead pipes (100% Pb reduced to 8%) and solder (50% Pb reduced to 0.2%)
  • “Lead free” pipes and fixtures containing up to 8% lead remain classified as “non-Lead”
• Jan. 4, 2014: 2011 Reduction of Lead in Drinking Water Act (RLDWA) became effective. The Act amends the 1986 SDWA to define “lead free” water pipes and fittings < 0.25% lead (instead of 8%)