It’s become a familiar warning: Once again, romaine lettuce is off the shelves of grocery stores and (hopefully) absent from dinner tables after yet another E. coli outbreak.

Earlier this year, Americans experienced the largest E. coli outbreak the country has seen in the last decade, leaving hundreds sick and five dead after consuming the lettuce. No deaths have been reported in connection with the latest E. coli outbreak, though more than a dozen have been hospitalized.

With American crops heavily regulated thanks to legal measures like the Food Safety Modernization Act (FSMA), how do we still experience so many crises when it comes to this household staple green?

According to food critic and Atlantic editor Corby Kummer, the answer lies in the water where the lettuce is grown. When former President Obama signed FSMA into law in 2011, the law contained a clean water regulation that Congress never funded.

“It’s the clean water failure to have any kind of enforcement in place, and that probably caused this outbreak,” Kummer said. “Maybe Congress could get it together to say, 'Maybe we’d better start funding clean water regulations.'”

In a Nov. 1 statement, U.S. Food and Drug Administration (FDA) Commissioner Scott Gottlieb announced that the FDA, the Centers for Disease Control and Prevention and the Arizona Department of Agriculture launched an investigation into the outbreak. According to their assessment, which sampled irrigation canal water collected in the Yuma region, “the most likely way the romaine lettuce became contaminated was from the use of water from the irrigation canal, since the outbreak strain was not found in any of the other samples collected in the region.”

Despite the warnings, rumors swirled that President Donald Trump consumed the contaminated lettuce in his Thanksgiving meal, after Caesar salad made an appearance on the menu. In a statement, the White House dissuaded rumors, claiming that no romaine was served, but Kummer said he’s not so sure.

“Any idiot who would look directly at an eclipse when every warning said not to would of course put romaine in his salad,” Kummer said. “[Trump] would think it was a hoax: 'Food safety? Who cares?'”