Lead water pipes’ cheaper replacements carry hidden costs

Listen to this article

By Rajpreet Grewal, Laodong Guo and Melissa Scanlan
University of Wisconsin-Milwaukee

Flint, Michigan, made headlines in 2015 when tests found dangerously high levels of lead in drinking water. The city had switched its water supply to the Flint River a year earlier, and corrosive water had damaged old lead pipes, exposing thousands of people to lead contamination.

The result was a health crisis whose effects are still being felt today. And Flint was just the tip of the iceberg.

The U.S. Environmental Protection Agency estimates that 9.2 million service lines that deliver drinking water to U.S. homes and businesses are made of lead. The federal government considers replacing these lead pipes a top priority and has launched a number of initiatives to help, including the Infrastructure Act of 2021, which provides $15 billion over five years to replace lead pipes.

The EPA is now proposing to order the removal of all lead pipes across the United States within ten years. However, the agency is silent on what will replace the lead.

The buried lead pipes are concentrated in cities with high proportions of low-income populations. Seven of the 10 states with the most lead pipes are located along the Great Lakes, and research from the University of Wisconsin-Milwaukee shows that new federal funding will cover less than a fifth of the cost of replacing known lead pipes in that region alone. These cities could be unwittingly creating new environmental health risks.

The problem with lead pipes

There is no level of lead exposure that is considered safe for humans.

In children, lead exposure can affect organs and brain development and lead to reduced intelligence, behavioral problems and learning difficulties. Adults are also at risk. Even low levels of lead exposure can cause kidney problems and high blood pressure. According to a recent study, 170 million adults in the United States were exposed to high levels of lead in early childhood.

In 1986, Congress amended the Safe Drinking Water Act to prohibit the use of lead piping in the installation or repair of public water systems in homes and businesses that supply drinking water.

But many communities already had lead pipes that they expected to last for decades, and replacing them is expensive. The EPA estimates that replacing each lead line from a municipal water main to a home costs an average of $5,066.

Copper, iron and plastic are common replacement materials for lead pipes. Plastic, especially polyvinyl chloride or PVC, is becoming increasingly popular. Plastic is usually less expensive than other materials.

While most pipe materials cause problems in the long run, there may be hidden costs associated with using plastic pipes in drinking water systems that raise serious questions and health concerns.

Hidden health costs from plastic

One type of plastic, PVC, was first used in U.S. water systems in 1955 and became widely used in the 1970s. Other types of plastic pipe include cross-linked polyethylene (PEX), high-density polyethylene (HDPE), and chlorinated polyvinyl chloride (CPVC).

Scientific studies have shown that plastic pipes can attract metals and leach chemicals as well as micro- and nanoplastics, which have been shown to worsen kidney disease.

Over the past decade, researchers have documented the degradation of plastics and the release of chemicals from plastic polymers and additives in plastics and microplastics. A 2023 study found that pipe material and age can contribute to the release of microplastics in drinking water.

Biofilm – the layer of microorganisms that builds up on surfaces that come into contact with water – can also cause problems in pipes. A 2023 study showed how this biofilm can accumulate heavy metals such as lead, which can then be slowly released into the water over time. This buildup is a problem with any pipe. However, some studies have reported that the release of organic substances from polymer-based pipes can promote the growth of biofilms, and plastic materials can promote the buildup of pathogens in pipes. More studies are needed to assess whether biofilm in plastic pipes is a bigger problem.

Concerns about durability

Although PVC and other plastic pipe materials have a long lifespan, there are issues with durability.

A study of Dutch sewer systems, where plastic pipes have been used extensively since at least the 1970s, found warping, leaks and root growth. Some cities in the United States that installed plastic drinking water pipes have encountered similar problems.

Prescott, Arizona, began using PVC plastic pipe in the mid-1980s and noticed durability issues in the 1990s. In 2023, the mayor of Prescott announced a switch from PVC plastic to ductile iron, citing durability and leakage issues.

In Hamilton, Ohio, HDPE service lines and water mains began to fail prematurely after just 20 years, despite the estimated lifespan of HDPE being 80 years. The city is now switching to iron and copper.

Fire can melt plastic and release toxic chemicals

Plastic is also a fire hazard. Studies have shown that plastic pipes can melt at high temperatures and release harmful chemicals.

The fire that swept through Lahaina, Hawaii, in 2023 damaged plastic water pipes and contributed to a drop in water pressure when Maui firefighters needed it most. In the aftermath, residents were warned that plastic pipes could contaminate water supplies by leaching dangerous chemicals. Loss of pressure can create a kind of vacuum that sucks chemicals and bacteria into water systems.

Plastic can also release harmful chemicals when heated during fires. Water tests in California communities affected by wildfires in 2017 and 2018 found that water systems were contaminated with volatile organic compounds such as the carcinogenic benzene.

You might also like

Comments are closed.