Environmental officials are monitoring algae bloom levels on Lake Hopatcong.

The blooms have returned, but are not as severe as last year when the lake was closed for most of the summer. Blooms are made of cyanobacteria.

Members of the Lake Hopatcong Foundation say that the blooms are likely to become more common in the future.

"We're holding our breath that it doesn't get worse. We saw the numbers all going one way, up, up, up. And all of a sudden, this last week they started coming down a bit,” says foundation chairman Marty Kane. “So, there is reason for some encouragement. But I don't think you can manage a lake in New Jersey these days and not be worried, not be nervous."

Officials say that while it is fine for people to swim in the lake, dogs should avoid the water for the time being.