What's in Your Pipes?
- Achyut Manoj
- 5 days ago
- 7 min read
New Jersey has a law to replace every lead service line in the state by 2031. The system built to do that is running behind.
Turn on a tap anywhere in Bergen County and pressurized, treated, and tested water arrives almost instantly. The infrastructure making that possible is largely invisible, which is part of a major problem: much of Bergen County's water infrastructure is dangerously old and sometimes outdated. In somewhere around 350,000 New Jersey homes, the pipe connecting the street main to the house is still made of lead.
That pipe may have been installed before World War II and has been corroding since. The utility responsible for that corroding lead pipe may not even have a complete record of where it is.
A System Built in Layers
Municipal water delivery works in tiers. A treatment plant processes raw water and pumps it into a distribution network of large mains running beneath streets. "Water mains" are the primary underground pipes that distribute clean, pressurized drinking water throughout a municipality. Their role is akin to that of major arteries in our bodies.
From those mains, individual service lines branch off to each building: typically half an inch to an inch in diameter, running anywhere from 20 to 100 feet underground from the street to the foundation.
The service line is the last segment of that system and the one closest to the tap. Individual service lines are also the most likely to be made of lead.
Before 1986, lead was a standard service line material because it was cheap, easy to work with in the field, and flexible enough to handle slight ground movement without cracking. The Safe Drinking Water Act amendments that year (1986) banned lead pipe in new systems going forward, but neglected action towards lead piping already in the ground by 1986. New Jersey has an estimated 350,000 lead service lines still in service, accounting for roughly 75 percent of lead exposure in drinking water per the EPA. There is no safe level of lead exposure.
How the Problem Gets Managed, and Why That Is Not Enough
Lead pipe corrodes in contact with oxygenated water, releasing dissolved lead ions into the water stream. The rate of lead corrosion in service lines depends on that water's pH, chloride content relative to sulfate, and the type of disinfectant a utility uses.
That last variable has actually caused a major unintended problem in the past. Many utilities switched from "free chlorine" (a type of active, unbound chlorine that serves as a disinfectant in water to sanitize and kill harmful pathogens) to chloramines in the 2000s to comply with federal regulations limiting disinfection byproducts in treated water. Chloramines turned out to be more corrosive to lead pipe than free chlorine, and in several systems they destabilized mineral scale layers on the insides of pipe walls that had been preventing lead corrosion and leaching for years.
The Washington D.C. lead crisis in the early 2000s and the infamous Flint crisis in 2014 both followed that pattern, as subsequent research documented.
The standard engineering response to lead corrosion is orthophosphate treatment, which is when utilities add a phosphate compound to treated water in low doses. Phosphate compound molecules react with lead at the pipe wall to naturally and steadily form a thin protective mineral layer that limits how much lead dissolves into the stream.
Around 54 percent of U.S. utilities use this approach. Newark switched to orthophosphate in 2019 after lead levels spiked under its previous silicate-based inhibitor, which was releasing roughly six times more lead at comparable doses.
Orthophosphate treatment works, but it requires continuous precise phosphate content dosing. If phosphate compound concentrations drift or seasonal water chemistry shifts, the protective layer can break down.
Why Partial Replacement Backfires
For decades, when utilities replaced the public portion of a lead service line, they typically installed copper pipe on their side and left the homeowner's lead section in place. That seemed like a reasonable approach: do what you control and let the property owner handle the rest. But the engineering consequence was serious.
When copper and lead pipe are connected through water, they form a galvanic couple. Water conducts electricity between the two metals, and in that pairing lead is the less stable metal, so it corrodes preferentially. The corrosion concentrates at the junction between lead and copper piping, and produces not just tiny dissolved lead ions, but larger, solid particulates that break off from the pipe wall and travel downstream (down service lines and into buildings). Those particulates carry far higher lead concentrations than dissolved ions do, and standard lead testing at the tap measures dissolved lead in the water, not solid particles. That means the most concentrated form of lead that partial replacement produces can go entirely undetected in routine compliance testing.
Research in the Journal of the American Water Works Association found galvanic lead-copper connections increased lead release by 1.1 to 16 times compared to a full lead pipe. A long-term Virginia Tech study found partial replacements roughly 40 percent worse than leaving the full lead pipe in place. EPA's Lead and Copper Rule Improvements, finalized in October 2024, addressed this directly by requiring full replacement whenever utilities have legal access to the line.
What Goes In Instead
When a lead service line comes out, what replaces it is a real engineering decision with measurable consequences.
Copper remains in wide use, and it has a long track record in water systems. The galvanic interaction risk near any remaining lead in the distribution system is a legitimate drawback, and it has pushed utilities toward two alternative materials: high-density polyethylene (HDPE) and cross-linked polyethylene (PEX). Both materials are chemically inert, contain no metals, build up no corrosion scale, and cannot form galvanic couples with anything else in the piping system. No corrosion management is required because there's no risk of corrosion in the first place.
The water-grade version of HDPE is called PE4710. which features a tightly ordered molecular structure. That molecular structure gives PE4710 the strength and stability needed to withstand extreme loads, internal pressure, and environmental stresses underground, with a cited service life of 50 to 100 years. In July 2025, the American Water Works Association updated its PE4710 pipe standard to address lead service line replacement specifically, a signal from the industry's primary standards body about where replacement practice is heading.
PEX is just HDPE that has been crosslinked, meaning its molecular chains are permanently bonded into a rigid network that prevents the gradual crack growth that can eventually split standard plastic pipe under years of constant water pressure. It is also flexible enough to bend around underground obstacles without extra fittings, which reduces the number of joints in a replacement line and the number of points where leaks can develop. PEX now dominates residential replacement work, and North America became the largest regional PEX pipe market globally in 2025 at $1.64 billion, driven directly by replacement mandates. Any pipe in contact with drinking water must also hold NSF/ANSI/CAN Standard 61 certification, which limits what the material can leach into water over its service life.
The Regulatory Picture
New Jersey passed the Lead Service Line Replacement Law in July 2021, one of the first state mandates of its kind, requiring all community water systems to replace every lead service line by 2031 and file annual progress reports with NJDEP.
At the federal level, EPA finalized the Lead and Copper Rule Improvements (LCRI) in October 2024. It lowered the lead action level from 15 to 10 micrograms per liter, set a national 10-year replacement deadline, and for the first time required utilities to replace lead pipe on private property when they have legal access. Full compliance is due by November 2027.
The American Water Works Association challenged the LCRI in court over the feasibility of the replacement timeline, and oral argument is expected in fall 2026. The rule remains in effect while the case proceeds, although it's still a question whether the current administration defends it with the same commitment as the Biden EPA did.
Funding toward lead pipe replacement has arrived at a scale previously unavailable with the 2021 Infrastructure Investment and Jobs Act having already directed $15 billion. Then, in May 2024, the EPA announced $123 million for replacement in New Jersey. NJ was also selected in 2023 as one of four states for EPA's Lead Service Line Replacement Accelerators initiative, which provides direct technical support to communities working through the identification and replacement process.
What Is in the Way
The largest barrier is an ownership problem that nobody designed this infrastructure to solve.
Water mains still belong to individual utility companies, and the service line from the main to the curb stop is generally the utility's responsibility too. Everything from there into the building belongs to the homeowner.
A homeowner with a lead private-side line has historically had no legal obligation to replace it, and utilities have had no mechanism to compel them. NJ's 2021 law allowed municipalities to adopt ordinances permitting utilities to enter private property for replacement, but uptake across Bergen County has been uneven. Even after NJ extended the federal mandate to perform private-side replacement where utilities have access, when utilities don't have access, this problem is still not resolved.
Inventory is the other structural problem. Water systems were required to submit initial lead pipe inventories to EPA by October 16, 2024, but fewer than half of some states' systems met that deadline. Without accurate data on where the pipes are, the $123 million flowing through the NJ Drinking Water State Revolving Fund cannot be directed to the highest-priority replacements across hundreds of water systems.
The engineering debate is settled: we need full lead pipe replacement with inert materials, done in one operation rather than split across an ownership line. Infrastructure in NJ and Bergen County required to support that fix (property law, inventory data, funding distribution, municipal coordination) is what still needs to catch up. The 2031 deadline is five years away.
If you're interested in find out where lead service lines are located in NJ, visit this interactive map tool provided by the NJDEP.
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