Miles of defunct, lead-covered telephone cables have long sat abandoned beneath the cerulean waters of Lake Tahoe. Now, after years of legal back-and-forth, the cables have been removed.

Scuba divers discovered the cables on the lake’s sandy, silty bottom in 2012. The cables consist of copper wires surrounded by a layer of lead sheathing. They were laid in Lake Tahoe decades ago—possibly as early as the 1920s—while telephone service was expanding across the United States. As technology advanced, telecom companies installed newer cables, but they left the old ones in place.

Over time, the Lake Tahoe cables suffered damage from boat anchors and debris. Health and environmental activists and residents grew concerned that the torn cables were leaching lead into the lake, which is a popular swimming destination and provides drinking water for some nearby households.

The cables’ origins are a little murky, but they are believed to have been originally installed by Bell Systems, which was later acquired by AT&T, as the San Francisco Chronicle’s Gregory Thomas reported in August. In 2021, the nonprofit California Sportfishing Protection Alliance filed a civil lawsuit against AT&T over the cables.

A 2023 Wall Street Journal investigation subsequently found abandoned, lead-covered telecommunications cables across the nation. The publication hired an environmental consulting firm to take soil and water samples from areas near the cables. Testing near the cables in Lake Tahoe showed lead levels that, in one sample, were 2,533 times higher than those recommended by the U.S. Environmental Protection Agency (EPA), according to the Wall Street Journal.

AT&T disputed the claims that the cables had contaminated Lake Tahoe, and it commissioned its own lead tests that concluded the cables were “safe and pose no threat to public health nor the environment,” per its website. But the telecommunications company agreed to remove the cables anyway.