A former U.S. Postal Service mail carrier pleaded guilty Wednesday to dumping 15,000 pieces of undelivered mail in the sewer in northeast D.C.

USPS learned of mail in a catch basin at the intersection of Douglas Street and Anacostia Avenue last May and found 74 pieces of mail, according to the D.C. U.S. attorney's office. The next day, postal investigators removed a manhole cover near the catch basin and found 17 large trash bags full of mail.

Undeliverable because of sewer contamination, the mail was soaked and clumped together, and it shredded as it was picked up, prosecutors said.

Christopher Newton, 22, quit when a supervisor asked about the mail found in the sewer along his route.

In his guilty plea for obstructing mail, Newton confessed he was the only person responsible for dumping the mail, according to prosecutors.

Newton faces a maximum of six months in prison and a possible fine. He's due to be sentenced Sept. 6.