Lead Abatement: Treat the Water or Replace the Pipes?

In light of the crises in Flint, Michigan, water utilities around the country are asking, 'What's the best way to handle lead?'
Lead Abatement: Treat the Water or Replace the Pipes?
Lead pipes are an issue, especially in older cities of the East and Midwest. While many utilities have undertaken programs to replace lead piping in their own water systems, the problem goes deeper.

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It’s a tough question.

Replace all the lead pipe in your drinking water system, including home service laterals, or add corrosion-control chemicals at the plant to prevent leaching of lead into the water supply.

The discussion has intensified since the lead poisoning debacle in Flint, Michigan. Unfortunately, the national discussion has focused mostly on politics and finger-pointing.

Lead pipes are an issue, especially in older cities of the East and Midwest. While many utilities have undertaken programs to replace lead piping in their own water systems, the problem goes deeper. That’s because the replacements in many cases don’t include the line from the home to the street. Traditionally, replacing those pipes has been the responsibility of the homeowner.

Costs can be $5,000 or more, not counting the disruption of sidewalks, lawns, gardens and driveways. Up to now, many homeowners have been reluctant to do it.

An alternative approach is to treat the water at the treatment plant, either adjusting the pH to prevent corrosivity (something Flint failed to do) or adding chemicals to coat the inside of lead pipes and prevent the lead from leaching into the drinking water supply.

The current U.S. EPA Lead and Copper Rule does not provide much guidance on what to do, except that utilities are required to test regularly at a selected number of taps for lead levels that exceed 15 ppm, which the EPA considers the threshold of safety. Ninety percent of those tests must register below the threshold, otherwise corrective action is required.

But the rule is not without its critics, who question whether any lead level above 0 ppm is safe for human consumption. They also point out the required testing protocol does nothing to protect the 10 percent of taps that might record lead amounts above 15 ppm, or those that were not in the test sample to begin with.

“There is no safe level of lead,” the Lead and Copper Working Group of the National Water Advisory Council reported to the EPA last December. The group stated that although the current Lead and Copper Rule should remain as a “treatment technique rule,” it should “require proactive lead service line (LSL) replacement programs, which set replacement goals, effectively engage customers in implementing those goals, and provide improved access to information about LSLs, in place of current requirements in which LSLs must be replaced only after a lead action level exceedance.”

Translation: Utilities should be required to replace lead service lines.

As for costs, the council recommended water utilities incorporate lead line replacement expenses as part of their capital improvement programs and urged states to include the costs of lead line replacement in their state drinking water revolving funds. The working group also advocated the adoption of creative financing measures.

Even without such regulatory pressure, many water utilities have embarked on programs to remove the lead service lines they are responsible for. Some have gone further, replacing not only mainlines but also service lines from the curb to the house.

Line replacement programs

Louisville, Kentucky
Since the early 1990s, Louisville Water has replaced most of its lead service lines with copper, while controlling pH and alkalinity in the water produced at its two treatment plants (240 mgd combined capacity). The goal is to ensure the water is safe and stable as it’s pumped through 4,200 miles of pipe to some 850,000 customers.

Kelley Dearing Smith, communications director, says the replacement program began in the early 1990s and that fewer than 8,000 lead service lines remain. The utility expects to complete the job by early 2025.

“In 2014 alone, we spent $1.5 million to replace approximately 670 lines,” she says.

To produce stable water from the Ohio River, Louisville adds slaked lime to adjust pH and alkalinity and plans to switch from ferric chloride to ferric sulfate to reduce chlorides. The city spends more than $800,000 annually on softening and corrosion control, Dearing Smith says.

“If you have high chlorides, you can still have the potential for corrosion despite pH adjustment,” says Dr. Rengao Song, the utility’s manager of water quality and research. He says the move to ferric sulfate will cost the utility an additional $300,000 annually, but follows more than a year of study and will be worth it: “You can replace all of the pipes, but the water chemistry has to be right. You have to do both in order to get the job done.”

Song also cautions that it is not enough to know just the quality of the water leaving the treatment plant. It’s critical to know the quality of the water in the distribution system. To that end, Louisville collects water-quality data in the distribution system and at commercial and industrial sites. The data is collected during sampling related to the Total Coliform Rule, the cross-connection program and the water tank monitoring program. “That enables us to know exactly what the water looks like in the distribution system,” Song says.

Even a comprehensive corrosion control program such as Louisville’s does not get at the lead pipes or internal plumbing on property owners’ sites. “That’s something we’re looking at,” says Dearing Smith. “How do we do it, what would be fair from a budget standpoint? It’s uncharted territory.”

Lansing, Michigan
In Lansing, the Board of Water and Light (BWL) owns all the service lines in its distribution system, including the lines from the curb to the house. That unique arrangement has let the utility replace nearly all of its lead pipe since 2004. BWL provides about 19 mgd of water to 55,000 customers through 800 miles of mains.

According to Stephen Serkaian, executive director for public affairs, the utility has replaced more than 13,500 lines in the past 11 years and has just 650 to go. “We expect to be out of the lead service business in the next 15 to 18 months,” he says.

The cost has been about $42 million; the final tab is estimated at $44 to $45 million, funded through the utility’s capital improvement budget.

To facilitate line replacement, the utility employs a trenchless method, pulling the old line straight out from the street-side and inserting new copper line back through the existing hole. The replacement program capitalized on a major combined sewer overflow project that exposed many water mains.

The utility has prioritized its program, first replacing pipes serving schools and day care centers, then homes with sensitive populations, and then areas where other infrastructure projects were taking place or areas with large concentrations of lead service lines.

“Following Flint, any resistance by the homeowner has gone by the wayside,” Serkaian says.

BWL also adds phosphate compounds during treatment to control corrosion.

Madison, Wisconsin
Madison might be the only U.S. city to have replaced all lead lines, including customer-owned services, while using no anticorrosion chemicals in treatment. Joe Grande, water-quality manager, says that since 1995, Madison has replaced some 8,000 utility-owned lead service lines, while plumbing contractors hired by customers replaced about 6,200 private service connections. The utility made grants of $3.8 million to property owners, using money generated by renting antenna space on its water towers.

The project took 11 years to complete and cost the utility about $15.5 million. Madison replaced lines instead of adding chemicals to avoid introducing more phosphorus through wastewater discharges to local lakes already overburdened with nutrients. In addition, Grande says, some chemicals showed tendencies to clog meters and lines.

An early barrier to line replacement was the use of public money on private property, but the utility persuaded local and state officials to change policies and approve the funding. Property owners were eligible for grants of up to $1,000 from the utility to have their lines replaced. Grande notes that the finances worked out favorably for all. The average cost for private line replacement was less than $1,500, and the average property owner grant was about $670. That compares to estimates he’s heard from other utilities of $3,500 to $6,500 per line and higher.

Grande says the decision to replace all lines yielded efficiencies that translated to cost savings: “Our contractors could ramp up staff and coordinate with the various neighborhoods. Plus, the initial excavation made by the utility was left open until the private contractor did the work. Our customers benefitted from those efficiencies.”

Installation methods added to the savings. Rather than excavate open trenches or pull old pipes, Madison used a process called bulleting. “We excavated a hole in the area between the street and sidewalk, then shot the new pipe beneath the surface to the house using a pressure technique,” Grande says.

Treatment approaches

Akron, Ohio
The City of Akron Water Supply Board uses zinc orthophosphate for corrosion control and sodium hydroxide (caustic soda) for pH adjustment to comply with lead and copper regulations and provide 35 mgd of safe drinking water to its 90,000 service connections and 300,000 customers.

Jeff Bronowski, water supply manager, says that although the city stopped installing lead pipes in the 1940s and has been replacing lead pipes when the opportunities arise, treatment with chemicals has been the mainstay of the city’s lead abatement program for the past 10 years.

He says the city spends about $130,000 a year on zinc orthophosphate and just over $400,000 a year for caustic soda. The zinc orthophosphate is a corrosion inhibitor that forms a protective barrier to prevent lead in pipes and household plumbing from dissolving. The caustic soda maintains a pH level of 7.0 to 7.6.

“In 1992, we began testing for lead and copper,” Bronowski says. “We’ve remained in compliance with EPA standards during each monitoring period, testing at the tap after the waterline has been inactive for at least six hours.” Only two samples have been reported above the action levels since 2003.

Akron draws its raw water from a reservoir fed by the Cuyahoga River well upstream of the industrial areas of Akron and Cleveland. In addition, the city owns 20,000 acres of land around the reservoir, protecting its water supply from the effects of development.

Plant City, Florida
Plant City, in west central Florida, includes historic neighborhoods with many homes built before the 1980s, when lead was used in household plumbing. Some older city water mains are made of ductile iron with lead-filled joints. The water utility adds polyphosphate to its water to sequester iron and control corrosion of lead and copper by coating the inner pipe walls.

Plant City draws its raw water through four wells drilled into the Floridan Aquifer. The oldest well and a 250,000-gallon elevated storage tank were built in 1965. The installation was upgraded in 1997 with a high-service pump station and a 750,000-gallon ground storage basin. Well depths vary from 734 feet to just over 1,200 feet.

Produced water flows by gravity from the elevated tanks, and by pumps from the ground storage tank, into a 135-mile looped distribution system. The system serves 12,900 metered customers.

Total water production is 5.3 mgd, and permitted capacity is 14.2 mgd.

Steve Saffels, utilities superintendent says the utility spends an average of $60,000 per year on polyphosphate, added at an average concentration of 2 mg/L. He notes the feed rate differs depending on the water quality at each well site. The city’s most recent water-quality report indicates zero instances of lead exceeding the EPA action level of 15 ppb in tap water sampling, and a 90th percentile result of 2.7 ppb.

A big bill
A 2013 report by the American Water Works Association (“Buried No Longer – Confronting America’s Infrastructure”) describes the enormity of the lead pipe replacement challenge, noting that more than 1 million miles of pipes beneath the streets are nearing the end of their useful life. The report put the replacement cost at $1 trillion over the next 25 years or more, but noted that most Americans pay less than $3.75 per 1,000 gallons of safe tap water.

“Delaying the investment can result in degrading water service, increasing water service disruptions and increasing expenditures for emergency repairs,” the report stated. “Ultimately, we will have to face the need to ‘catch up’ with past deferred investments, and the more we delay, the harder the job will be when the day of reckoning comes.”

Where will the money come from? The recently passed Water Infrastructure Financing and Innovation Act (WIFIA) could help. Enacted in 2014 as part of the Water Resources and Reform Development Act, WIFIA provides low-interest federal loans for up to 49 percent of the costs for large drinking water, wastewater, stormwater and water reuse projects. A recent addition to the law allows tax-exempt bonds to fund the remaining 51 percent of a project.

On the other hand, WIFIA does nothing to help small utilities, which make up most of the water providers in the country.

So back to the question: treat or replace? Irrespective of any new regulations, utilities must consider the annual operating costs of corrosion control versus the capital expense of service line replacement. Creative financing programs like that used by Madison could help.

In the final analysis, the answer may be: both.

“We are focused on eliminating any factors that can contribute to a decrease in water quality,” says Dearing Smith of Louisville. “Over 20 years ago, we made a very strategic decision to begin eliminating our lead service lines, and we feel comfortable in that program and its role in minimizing that risk.” At the same time, the utility’s risk reduction program includes water chemistry and stabilization: “optimizing the water quality,” in Dr. Song’s words.


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