NEW ORLEANS -- Even before the water crisis in Flint, Michigan, there were calls for the Environmental Protection Agency to adopt tougher standards against lead in drinking water nationwide.
It's especially concerning in cities with aging infrastructure like New Orleans, where lead pipes installed in the early 1900s are still in service.
Rachael DePauw said she's done as much as she can to protect her daughters against the dangers of lead, repainting the walls of her 1930s home and trying not to track dirt inside.
But in 2014, tests showed her 3-year-old daughter Phoebe had three times the level of lead in her blood that's recommended by the Centers for Disease Control and Prevention.
"You can't count on basic infrastructure like water being safe. I mean what, it's just scary," DePauw told CBS News.
Water tests in DePauw's home confirmed the presence of lead: 8.5 parts per billion. That's still below the 15 parts per billion the EPA considers safe.
But scientists like Adrienne Katner from Louisiana State University question the numbers.
"There is no safe level of lead," Katner said. "The evidence is mounting that there are neurocognitive impacts on a child, behavioral impacts."
The most recent lead testing in New Orleans of the city's 137,000 water customers was in 2014. The state requires just 53 homes be tested, and only one was found unsafe.
But Katner said in her independent testing, out of 151 sites, so far she's found 12 with unsafe levels.
"We are doing everything we can with one of the most-extensive water quality labs in the South," Cedric Grant, executive director of the city's water board, told CBS News.
Grant said the water leaves the plants lead-free. But once it exits city pipes, it may travel through lead pipes to people's homes. After that, the water quality is left up to the homeowner.
"I am not responsible for what goes from the meter to them. I'm ready to assist, I'm ready to provide information," Grant said. "It's a customer responsibility at that point."
In New Orleans and other cities, corrosion control chemicals are added to the water to try to keep the lead out of homes. The EPA is considering a change that would make utilities share the burden with customers of replacing some of the nation's estimated 10 million lead service lines.