Runoff can also carry bacteria from failing septic systems far from the shore into streams that empty into bays near beaches. Boating Wastes Improperly handled boating wastes can pose a health and aesthetic threat to bathing beaches. Elevated concentrations of fecal coliform have been found in areas with high boating density. Many areas lack sufficient pump-out facilities, and compliance with the law appears to be poor in many areas. Oil Spills Oil spilled during tanker accidents, pipeline breaks, and refinery accidents can foul beaches.
Many oils evaporate quickly, creating unsafe fumes.
Other oils form globules that can float for days and wash onto beaches for weeks after a spill. In addition to the catastrophic oil spills, there are small oil spills every time it rains. Over the course of a year, urban runoff from a city of 5 million can contain as much oil and grease as a large tanker spill. Normal ship operations also frequently cause small oil spills. Waterfowl Several municipalities listed waterfowl as the cause of a beach closing or advisory.