According to a national report, the number of lead pipes in Missouri is the highest in the United States.

The Natural Resources Defense Council estimates that there are at least 330,000 lead pipes that carry tap water to homes and other buildings in Missouri—ranking sixth among all states in the country.

The environmental advocacy non-profit organization said that the total number may be underestimated given the challenges and lack of data to investigate the water supply system. However, the recent comprehensive reform of federal regulations will force utility companies to take a nationwide inventory of leaded water pipes in the next few years, thereby gaining a clearer understanding of decades-old public health problems.

Erik D. Olson, senior director of health strategy at NRDC, said that in Missouri and across the country, drinking water usually flows into homes through lead pipe service lines. He said that these narrow pipes are about the width of a garden hose and branch out from the water pipes, "basically the lead straws that enter your house."

Lead is more durable and flexible than iron, and is usually the material of choice for water pipes, especially in the early 1900s. Some cities, such as Chicago, went a step further and mandated the use of lead pipes in building codes.

Although the federal government banned the use of lead pipes more than 30 years ago, many water systems and utilities have not yet replaced them.

Federal law requires water companies, cities, and states to monitor lead and other pollutants in water. However, because many lead service lines are on private property, it is difficult to control the water quality of the taps-and homeowners usually have to bear the cost of replacing them.

"We often hear from the water supply company,'Well, it's safe when the water is in our system,'" Olsen said. "What they mean is that when it leaves the water treatment plant, it has no lead. But the reality is that lead will be absorbed in the narrower pipes from the water pipes on the street to your home."

Lead is a powerful toxin that has a wide-ranging, usually latent effect on human health. Even in small amounts, it can cause heart and kidney disease, fetal miscarriage, and premature delivery. In children, lead exposure can permanently damage the brain and nervous system and cause behavioral problems.

Many cities have adjusted the pH of the water or added special anti-corrosion chemicals to prevent lead from penetrating into the water. Olson said that changes in water chemistry or physical interference in the pipeline during construction will release lead in drinking water.

"As long as you bury that lead pipe in the ground, it is essentially a time bomb; it will disappear at some point," he said.

Track lead pipe state by state

For decades, the Environmental Protection Agency has not required cities or states to track the number of lead service lines. The recently revised regulations will require all water systems across the country to count lead pipes and share their data publicly—but not until 2024.

In order to estimate the current number of lead pipes in the United States, NRDC requires all 50 states and the District of Columbia to estimate.

Only 10 states, including Illinois, provided statewide lead pipe estimates. Illinois is the state with the largest number of lead pipes of any state in the United States, with more than 679,000. Another 782,000 pipes of unknown material may be lead, bringing the potential total statewide in Illinois to 1.4 million.

Missouri officials did not share any data with NRDC.

In an email, a representative of the Missouri Department of Natural Resources told NRDC that the department "never collected [lead service line] data statewide" but that it will start receiving lists from the water supply system in 2024 To maintain compliance with federal statutes.

This non-profit organization estimated the number of lead pipes in Missouri based on data from the 2016 Water Industry Survey. The total number is 330,000, ranking sixth in the United States. On a per capita basis, Missouri ranks fourth in the country with 5,362 lead pipes per 100,000 people.

The investigation report stated that there may be as many as 12 million lead pipes in use across the country.

Daniel Giammar, an environmental engineer at the University of Washington, studied water quality but was not involved in the study. He said the results were "approximately the same as previous estimates."

Giammar added that trying to catalog lead service pipelines can be very challenging because many of them were installed nearly a century ago.

"We are talking about buildings that are most likely to be completed in 1940 or even before 1930," he said. "Some places just don't have good records, or no one knows where they are."

But this situation will change in the next few years, as newly revised federal regulations come into effect, and water companies must report information about lead service lines.

Giammar said: "Utilities must know where their main service lines are, and they must have an easy-to-search way for customers to find the location of these lines in the entire system." "This will be huge. In three years, We will know more than we do now."

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