S pills, Leaks and Runoff Approximately 46 million gallons of oil that comes to the Eastern Seaboard comes through the Delaware Estuary by tanker and barge every day. As the demand for oil has increased, so has the size of the vessels that carry it. Modern tankers are more than ten times larger than they were in the 1940's. Most large spills in the Delaware Estuary happen north of Wilmington, DE as a result of groundings. Approximately 219,000 gallons of oil is spilled into the Delaware estuary annually.
Oil spills tend to make the news because of the large volume of oil that spills at one time.
Fifty percent is from used motor and industrial oil that was dumped on the ground or down drains and washed from the watershed by runoff and rivers. The health of our estuaries, rivers, lakes, and aquifers depends in part on how we landscape and maintain the areas surrounding our residential, commercial, and industrial buildings. Algae blooms that appear in our lakes and ponds are typically caused by water that contains high concentrations of nitrogen and phosphorus. When algae blooms appear, aquatic plants die since there is not enough oxygen in the water to sustain them. Fish kills may also result.