sealcoat-runoff-to-stream in Fredericksburg Texas_courtesy USGS

Runoff from a sealcoated parking lot in Fredericksburg, Texas stains the gutter black as it flows to a nearby creek. Coal-tar-based sealcoat is commonly applied in Central Texas. Photo courtesy of the U.S. Geological Survey. — Runoff from a seal-coated parking lot in Fredericksburg, Texas stains the gutter black as it flows to a nearby creek. Coal-tar-based sealcoat is commonly applied in Central Texas. Photo courtesy of the U.S. Geological Survey.

Runoff from a sealcoated parking lot in Fredericksburg, Texas stains the gutter black as it flows to a nearby creek. Coal-tar-based sealcoat is commonly applied in Central Texas. Photo courtesy of the U.S. Geological Survey.