BANGOR — This summer’s dry conditions are sparking worries of forest fires and water quality on some rivers.

Greg Stewart of the U.S. Geological Survey says stream flows for this time of year are below normal and groundwater levels in some parts of the state are also very low. Stewart tells the Bangor Daily News that levels are particularly low on the Piscataquis, prompting water quality concerns.

The Maine Forest Service’s Kent Nelson says vegetation on the forest floor is drier than 2002, when there was a severe drought. Nelson says there have been 473 grass fires through Monday, the biggest ones in Washington and Aroostook counties.

Many of those fires were caused by unattended campfires.