Denver Water began addressing lead in drinking water long before the crisis in Flint hit the news in late 2015.
Today the water utility, Colorado’s oldest and largest, is four years into an initiative to remove lead service lines from homes throughout its service territory, which includes some 1.5 million people, about half in the city and county of Denver and half in surrounding suburbs. Denver Water was the first utility in the nation to win U.S. EPA approval for a program to permanently address lead exposure in drinking water by replacing all lead service lines.
The Lead Reduction Program aims to replace more than 64,000 services over 15 years at a cost of $670 million. It’s built on extensive communication with customers; on coordination among hundreds of utility employees, vendors and contractors; and on support from community advocacy organizations.
Alexis Woodrow became the utility’s Lead Reduction Program manager when the initiative launched in 2020. She had been with Denver Water since 2007, serving as a water resource planner working on long-term supply projections, as a process improvement facilitator and as a community relations specialist.
In 2016 she became involved in addressing sources of lead in tap water. In that role she dealt with public outreach, workflow around efficient service line replacement, and coordination with regulators. She talked about the Lead Reduction Program, its successes and the community’s response to it in an interview with Treatment Plant Operator.
TPO: What is Denver Water’s history with lead service lines?
Woodrow: The majority of lead service lines are within the city and county of Denver. Developing our inventory and estimating the number of lead service lines was a challenge, in part because property owners own the service line from the tap at the water main all the way into the home. For the first half of the 20th century, lead was used in a variety of products. In the second half, we began to see regulations on lead paint, leaded gasoline and lead in plumbing. We did our initial estimate based on homes built before or after 1951. We picked that year because while Denver Water began allowing other materials in 1949, we rarely see lead in homes built after 1951. Denver Water didn’t formally ban lead until 1971 and there wasn’t a federal ban on lead pipes until 1986. Historic evidence showed that lead service lines were not installed in our area after 1951.
TPO: What did your estimate show about the number of lead service lines?
Woodrow: Our initial estimate was 64,000 to 84,000. The reason for the range is there was limited data on customer-owned lead service lines and considerable uncertainty outside the city and county of Denver. Most suburbs were established after the 1950s, but we had some areas where houses were built before 1950. In some cases, there was a discrepancy between when the service line was tapped for a home and when that home was built. We included the upper threshold of 84,000 to be sure we covered everyone who might have a lead service line. The actual number looks to be much closer to 64,000.
TPO: What was observed about levels of lead in customers’ drinking water?
Woodrow: The federal Lead and Copper Rule, established under the Safe Drinking Water Act, was finalized in the early 1990s. It required water utilities to test lead and copper levels in drinking water in customers’ homes. There is no lead in the water we deliver to our customers, but lead can enter the water as it moves through service lines or household plumbing made of lead. In testing, the idea is to see lead levels below the action level set by the Lead and Copper Rule: the level in the 90th percentile home must be below 15 parts per billion. In 2012 we exceeded the action level — we were at 17 ppb.
TPO: What was done in response to that finding?
Woodrow: We launched a massive public outreach campaign to all of our customers via mail, phone calls, news stories and more. At the same time, we were evaluating our corrosion control treatment — how to chemically adjust treatment to reduce metals entering the water. We harvested lead lines, installed them at two of our treatment plants, and tried different treatment techniques to reduce the water’s corrosive properties. Since the 1990s, we had been elevating the pH of the water, which creates a coating on the interior of the pipe. We looked at raising the pH even more to create a stronger coating, or adding orthophosphate, which is a corrosion inhibitor.
TPO: What was the result of that investigation?
Woodrow: We produced a report for the Colorado Department of Public Health and Environment showing that both pH and orthophosphate were very good for reducing lead levels. Orthophosphate performed better, but we wanted to continue using pH because there were downstream consequences for adding orthophosphate. There is a cost to addressing phosphorus in streams and stormwater.
TPO: Were there local repercussions of news about the water crisis in Flint?
Woodrow: At the time Flint was happening, we had been communicating with our customers about lead in drinking water and had been doing so since the Lead and Copper Rule was enacted. But we increased our communication with customers beginning in 2016. We offered water-quality testing, and we looked at how other utilities were responding to the crisis. Our transmission and distribution crews started replacing lead service lines when they came across service line leaks and when they were doing main replacement projects.
TPO: What led to the decision to replace all lead service lines?
Woodrow: In 2018, a large stakeholder process was initiated, involving Department of Public Health and Environment, the EPA, Denver Water, wastewater entities, the city and county of Denver, watershed and environmental groups, all coming together saying, “We want to solve the public health problem; what is the best way to do it?” That is how the Lead Reduction program really came about. Let’s look at this holistically and let’s tackle the lead service lines because we know they are the largest contributors to lead in drinking water.
TPO: How was the Lead Reduction Program ultimately approved?
Woodrow: The program was conceived throughout 2018 and 2019. We put it into a plan and submitted it to the EPA and the Department of Public Health and Environment. They approved it in December 2019, and on Jan. 1, 2020, we launched the program. The idea was to replace all customer-owned lead service lines by 2034. We also provide customers with pitcher filters certified to remove lead and send replacement filters every six months to protect households until we replace their lead service lines.
TPO: Where does the funding for the program come from?
Woodrow: We replace lead lines and provide pitcher filters at no direct cost to the customer. We were able to use ratepayer resources and bond financing to spread the cost to all ratepayers. In addition to that, in 2022 Denver Water received $76 million from the Colorado State Revolving Fund, which is part of the Bipartisan Infrastructure Law, to use toward service line replacements in 2023, 2024 and 2025. We replace about 4,000 services a year using the ratepayer and bond financing. Starting in 2023, we replaced nearly 2,000 more per year using the federal funds and plan to replace another 4,000 service lines in 2024 and 2025.
TPO: What is the procedure for contacting homeowners about service line replacement?
Woodrow: When we launched the program, we sent notifications and filters to any customer who had a known or suspected lead service line. Now, customers slated to get a service line replaced receive a notice about three months in advance. They are asked to sign a consent form giving us permission to access their property to perform the replacement. If we don’t hear from them for a month or six weeks, we send a second notification. After that we might do some door-knocking or send an email.
TPO: What happens after the consent form is returned?
Woodrow: Our construction management field staff and our contractors do a pre-construction consultation with the customer where we look at the property to determine what needs to be done to replace the service line. It’s really helpful to walk the customer through the process in person. The customer agrees to a date for the work to be done.
TPO: What does the actual replacement process look like?
Woodrow: It’s a trenchless technology, either pulling the old service line out and replacing it with a copper service line, or directionally boring a new copper line and abandoning the lead line. There is a cut in the street, a cut in the tree lawn area to install a new meter pit, and then a small excavation to connect the line to the interior plumbing.
TPO: Why was trenchless technology chosen as the replacement method?
Woodrow: Trenchless technology allows for more efficient replacements. There were a lot of concerns among customers about landscaping. When people raise concerns, disruption to their yard is a big one.
TPO: Was there any triage or priority-setting to decide where in the service area to begin?
Woodrow: We spent a lot of time prioritizing. We looked at a lot of factors. Where are the lead lines the most densely concentrated? Who are the most vulnerable populations? We looked at socioeconomic and demographic data. We looked at areas where there are young families and families expecting children. We looked at low-income neighborhoods and historically underserved communities with other environmental stressors. We prioritized work in those areas.
TPO: Were there also physical constraints that had to be dealt with?
Woodrow: Yes. We also have to look at the feasibility of replacement. Are there construction constraints? Are there outsized water mains or conduits? We look at other city projects: We can’t do work on top of wastewater or transportation projects. We don’t want to dig up a road that was paved the year before.
TPO: What has been the community’s response to the lead service line initiative?
Woodrow: I would say overwhelmingly positive. The overwhelming majority of customers — 95% — consent to have their service line replaced. We definitely get a few unhappy customers. We launched the program in 2020 during the pandemic. People were staying home, being really concerned about their health and public health. Then we were talking about lead, which since Flint has been a hot-button issue. So, in communicating with our customers, there were some challenging conversations. But the community and our customers really do support the program. Some might not be happy with our restoration work, or they might have had an issue with communication or scheduling, but almost all think this program is the right thing to do.
TPO: In general, how would you rate the program’s results?
Woodrow: I am amazed at the success of the program. It’s a real team effort involving our staff, our contractors, our vendors, literally hundreds of people all working together for a good cause. And outreach to disproportionately affected communities, leveraging community advocates to help spread our message, has been helpful and inspiring.
TPO: What is the role of the community advocates?
Woodrow: Not every customer or community is open to working with government. If you are part of a historically underserved community, you might not view government as an entity that is trying to do the right thing; you’re less likely to allow us into your home to replace a service line or to use the pitcher filter we send you. Someone might not trust the government, but maybe they trust a community group that focuses, for example, on health access for Latino families. Different organizations have inroads in those kinds of communities. We did a lot of work with them, and they became our voices and advocates.
TPO: What does the future hold for the replacement program?
Woodrow: In 2021 the EPA issued the Lead and Copper Rule Revisions, which require public water systems to develop an inventory of lead service lines. There are increased notification requirements. There is also now a trigger level for lead or copper in drinking water in addition to the action level. The 90th percentile action level for lead of 15 ppb stays, but at the trigger level of 10 ppb, utilities need to look at their corrosion-control treatments. Relative to all this, we are in a fortunate position — our program sets us up nicely for the upcoming regulation.
