Environmental advocates are calling on state officials to notify the public about past tests showing high levels of E. coli in Folsom Lake and Lake Natoma, two of the region’s most popular areas for open water swimming and boating.

But officials responsible for recreational use on the lakes say the test results cited are too old, while the agency that conducted the tests says it has no responsibility for public notices.

The Central Valley Regional Water Quality Control Board in December concluded that the amount of E. coli in the lower American River had exceeded the federal threshold for safe recreational use. The test results didn’t become public until The Sacramento Bee reported them in late August.

The findings were based on water samples taken from 2007 to 2014. Some tests showed E. coli concentrations in Lake Natoma were eight times the level considered safe for recreational use by the U.S. Environmental Protection Agency.

A board report earlier this year found elevated E. coli levels in the lower American River in 2015 and 2016, but did not include samples from Lake Natoma and Folsom Lake, where tens of thousands of people swim, boat and fish every year. The board has limited funds for testing and wanted to focus on areas where higher levels had been found in the past, said Adam Laputz, assistant executive officer at the board. The highest concentrations have been near downtown Sacramento.