The Louisville area’s tap water meets all federal standards, according to the annual water quality report released today by Louisville Water Company. But ten percent of the homes tested showed elevated levels of lead.

These lead levels represent problems with the infrastructure–like lead pipes–and not problems with the city’s water source or treatment. And Louisville Water Company spokeswoman Kelley Dearing Smith said those results aren’t representative of the company’s whole system.

“When customers ask me, is lead a concern with drinking water? For the majority of our customers, absolutely not,” she said.

By law, the company only has to test homes where it’s suspected elevated lead levels might be a problem. This year, it tested 52 homes and five were above the government’s “action level” for lead.

Dearing Smith says when the company discovers elevated lead levels it replaces the service lines immediately. About five percent of the company’s service lines are made out of lead, and Louisville Water is working to phase them out by 2020.

But exposure to lead in drinking water at the levels discovered in those five homes can cause health problems. For babies and children, the Environmental Protection Agency warns that high lead levels can lead to delayed development, and possible deficits in attention span and learning abilities. In adults, it can increase blood pressure and could eventually cause kidney problems.