Signs warning about water contamination were posted Monday along the San Dieguito River to the ocean in Del Mar because of a broken sewer line.
The line was accidentally broken by a construction crew near Via de La Valle and Valley Avenue in Solana Beach around 1:15 p.m. Monday, The San Diego Union-Tribune reported.
An estimated 8,000 gallons of sewage spilled into a storm drain and into the river for about an hour after the break, according to the newspaper.
Warning signs about the contamination were expected to remain until water samples confirm it is safe again for recreational use. It was not immediately clear how long that might be.