Partial lead service line replacement and why it matters

A partial lead service line replacement means only part of the pipe from the water main to the building gets replaced. That matters because some lead pipe stays in use, and the digging, cutting, and reconnection work can disturb old lead scale and temporarily raise lead levels at the tap. (epa.gov)

For many homeowners, a partial replacement feels like progress. But in plain terms, it can leave the main source of lead in place while also creating a period of higher short-term risk during and after the work. (epa.gov)

What a partial replacement is

A lead service line is the pipe that brings water from the main in the street to your home or building. EPA says that in homes with lead service lines, those lines are typically the most significant source of lead in the water. CDC also says lead pipes, faucets, and plumbing fixtures can increase the risk of lead exposure. (epa.gov)

A partial replacement happens when only one part of that service line is changed. In real life, that often means the utility replaces its side but the private side stays lead, or a private owner replaces their side while the utility side stays lead. If you are not sure what material you have, start with How to check your utility's service line inventory and How to tell if your water service line is lead.

The key issue is simple: a partial replacement is not a full fix. Under EPA's current rule, a lead service line counts as fully replaced only when the entire length of the line, both the system side and the customer side, is non-lead. (epa.gov)

Why a partial replacement can raise risk

The risk is not only that some lead pipe remains. The work itself can make lead release more likely for a time. EPA says lead service line replacement activities can break apart corrosion scales and cause temporary increases in lead in drinking water. CDC says a person's risk can increase while the work is ongoing and for up to six months after the work is completed. (epa.gov)

EPA's Science Advisory Board looked at the evidence on partial replacements and found that they pose short-term exposure risks similar to mandatory partial replacements, because they are expected to cause similar short-term increases in tap water lead levels. The Board also said galvanic corrosion associated with a partial replacement can be significant for at least several months, although the exact timing and size of the increase can differ from one water system to another. (epa.gov)

That is one reason the professional water utility association AWWA encourages utilities and local governments to identify and replace all lead service lines over time and to manage the risks that come from partial replacement. AWWA also notes that as long as lead remains in contact with drinking water, some risks remain. (awwa.org)

For homeowners, this is the practical takeaway: partial replacement may still be better than leaving a damaged line untouched in an emergency, but it is not the same as getting the lead out. Full replacement is the safer end goal.

What federal rules now require

EPA issued its final Lead and Copper Rule Improvements, or LCRI, on October 8, 2024. EPA says the rule requires drinking water systems across the country to identify and replace lead pipes within 10 years, strengthens testing, and improves communication with families about where lead pipes are and how replacements will happen. If you want the homeowner version, see The Lead and Copper Rule Improvements: what homeowners need to know. (epa.gov)

The rule builds on the earlier inventory requirement. EPA says water systems had to develop an initial service line inventory by October 16, 2024. Under the LCRI, systems must develop an updated baseline inventory by November 1, 2027, update that inventory every year, and make it publicly accessible. Water systems serving more than 50,000 people must make the public inventory available online. (epa.gov)

The LCRI also says water systems must fully replace all lead and certain galvanized lines that require replacement under their control within 10 years, unless the system qualifies for a deferred deadline or the state requires an even shorter deadline. EPA also says states must set shorter deadlines for individual systems when the state decides a faster timeline is feasible. (epa.gov)

Most important for this topic, EPA says partial replacements are prohibited unless they happen during an emergency repair or as part of planned infrastructure work that affects the service line, such as a water main replacement or meter replacement. EPA also says those partial replacements do not count toward a system's mandatory replacement rate. (epa.gov)

If a partial replacement does happen, the rule adds protections. EPA says the system must install a dielectric coupling between the old and new portions unless the new line is plastic. Before the line is put back into service, the system must provide notice, written flushing instructions, and a pitcher filter or point-of-use device certified by an ANSI-accredited certifier to reduce lead, along with six months of replacement cartridges and instructions for use. The system must also offer a follow-up tap sample between three months and six months after the replacement. (epa.gov)

What homeowners still may need to do

Even with stronger federal rules, utilities do not always control the whole service line. In some communities, the utility can replace its side easily but needs access, consent, permits, or funding arrangements before work can happen on the private side.

EPA's fact sheet says that when owner consent is needed for a full replacement, the water system must make a reasonable effort to get that consent. EPA defines that as at least four attempts using at least two different communication methods, such as a phone call, email, letter, text, or door hanger. EPA also says that within six months of a change in property ownership, the utility must offer full service line replacement to the new owner, and within one year it must make a reasonable effort to obtain the new owner's consent. (epa.gov)

This is where homeowner-side cost and logistics matter. If you may have to pay part of the private-side cost, read Who pays to replace the private side of a lead service line?, check Lead service line replacement grants, reimbursements and loans, and try the Lead line cost-share estimator.

Rules on permits, access, cost sharing, and who may do the work can vary by state, city, and utility, so confirm the details with your water utility, local plumbing inspection office, or state drinking water agency where appropriate.

Questions to ask before work starts

If your utility or contractor offers any lead service line work, ask these questions before you agree to the plan:

1. Is this a full replacement or a partial replacement? Ask which part of the line will be replaced and which part, if any, will stay in the ground.
2. What does the utility inventory show for my address? If the line is listed as lead, galvanized requiring replacement, or unknown, ask what evidence the utility used and whether the record has been updated. EPA requires annual updates and public access to inventories. (epa.gov)
3. Who pays for each side of the line? Ask whether the utility, city, or state has a grant, reimbursement, or low-cost financing option for the private side.
4. What protections will I get after the work? Ask for the written flushing steps, when and how you will receive a filter, and when the follow-up water test can be scheduled. EPA requires notice, flushing information, a lead-reducing filter or point-of-use device with six months of cartridges, and an offer of a sample three to six months after replacement. (epa.gov)
5. What will happen to my yard, sidewalk, basement, or wall? Get the restoration plan in writing if the job could affect landscaping, pavement, or interior access.
6. What is the path to a full replacement if this job is only partial? If the utility says a partial replacement is needed because of an emergency or another infrastructure project, ask what the next step is to remove the rest of the lead.

These questions help you separate a short-term repair from a real long-term fix.

If only a partial replacement happens anyway

Sometimes a partial replacement still happens because there is an emergency repair or another project that affects the line. If that is your situation, take the follow-up steps seriously.

• Use the filter the utility provides before you drink or cook with the water. EPA says the utility must provide a pitcher filter or point-of-use device certified by an ANSI-accredited certifier to reduce lead, plus six months of replacement cartridges and instructions. If you buy your own while you wait, CDC says to use a point-of-use filter certified by an independent testing organization to NSF/ANSI Standard 53 for lead removal and Standard 42 for particulate removal. (epa.gov)
• Follow the flushing instructions exactly. EPA requires written instructions for flushing service lines and premise plumbing after replacement. (epa.gov)
• Ask for the follow-up lead sample. EPA says the utility must offer to collect a tap sample between three months and six months after the replacement. (epa.gov)
• Use only cold tap water for drinking and cooking until you are confident the risk is under control. CDC says hot or warm tap water can have higher lead levels, and boiling does not reduce lead. (cdc.gov)
• Keep every notice and test result. If you later apply for funding or ask the utility to finish the job, good records help.

The bottom line is that risk management after a partial replacement matters, but it does not replace the need for a full replacement.

Frequently asked questions

Is replacing just the utility side enough?

Usually no. EPA says a lead service line counts as fully replaced only when the entire length of the line, both the customer side and the system side, is non-lead. A one-sided replacement may remove some lead, but it still leaves lead pipe in service and can trigger short-term lead release after the work. (epa.gov)

Can a utility still do a partial replacement under the current rule?

Yes, but only in limited situations. EPA says partial replacements are prohibited unless they happen as part of an emergency repair or in coordination with planned infrastructure work that affects the service line, such as water main or meter work. They also do not count toward the utility's mandatory replacement rate. (epa.gov)

What should I expect after any lead service line replacement?

EPA says the utility must provide notice that lead can temporarily increase, written flushing instructions, and a lead-reducing pitcher filter or point-of-use device with six months of replacement cartridges before the line is returned to service. The utility must also offer a follow-up lead test between three and six months after the work. (epa.gov)

What if my line is listed as unknown?

Do not assume unknown means safe. EPA says water systems must notify customers and people served by lines known to or potentially containing lead, including lead status unknown lines. Systems must update inventories every year, make them public, and identify the material of unknown service lines by the replacement deadline. Water systems serving more than 50,000 people must make the public inventory available online. (epa.gov)