People were shocked by the headlines: stories of swimmers — mainly young children — drowning after getting stuck in powerful pool drains. In response, legislators passed laws requiring public pools to use anti-entrapment pool drain covers, which they hoped would eliminate the problem.

But with swimming season upon us, you might want to think twice before jumping into that pool or hot tub. According to an investigative report conducted by The Chicago Tribune, you might not be as safe as you think. The newspaper’s reporters found the anti-entrapment drain covers failed stringent safety tests and received flawed evaluations.

The Tribune reported that the U.S. Consumer Product Commission had been receiving complaints for more than two years that some models weren’t working properly. But the agency didn’t launch an investigation until last July.

Even worse, the newspaper found the lab that certified most covers used incorrect testing procedures that didn’t accurately mimic the powerful suction found in a pool or spa.

To keep most pools sanitary, pumps move water through a filtering system that uses one or more drains. If a drain cover is missing or broken, or if someone covers the holes in a drain, it can act like a powerful vacuum with hundreds of pounds of force. Stories abound of children being disemboweled after sitting on a drain or drowning after getting their hair tangled.

There were ninety-four reported cases of entanglement between 1999 and 2009. In 2007, a federal law required all public pools and spas to install anti-entanglement drain covers.

Before you swear off public pools, take heart. Lawmakers responded immediately after reading the Tribune report. In fact, U.S. Senator Dick Durbin has already urged the Consumer Product Commission to take action.