Some examples of oil and grease loadings to Galveston Bay are leaks from automobile crankcases, illegal dumping into storm sewers, motorboats, oil spills, and discharge from oil production platforms in the bay. Oil and grease is a generic term for material which actually contains numerous and variable chemical compounds, some of which are typically toxic. Priority Pollutants Priority Pollutants refer to a list of 126 specific pollutants that includes heavy metals and specific organic chemicals. These 126 pollutants were assigned a high priority for development of water quality criteria and effluent limitation guidelines because they are frequently found in wastewater. Many of the heavy metals, pesticides, and other chemicals listed below are on the priority pollutant list.
Heavy metals are elements from a variety of natural and human sources.
High levels of mercury, copper, and cadmium have been proven to cause serious environmental and human health problems in some bays around the world. Some of the sources listed above, such as lead in gasoline and heavy metals in some paints, are now being phased out by environmental regulations issued in the past ten years. Pesticides Pesticides comprise a large class of compounds of concern in Galveston Bay. Typical pesticides and herbicides include DDT, Aldrin, Chlordane, Endosulfan, Endrin, Heptachlor, and Diazinon. Besides toxicity, persistence in the environment is a key concern.