Sediment analysis- Galveston Bay

A study of selected heavy metals was carried out on sediments collected at 22 stations in Galveston and related Bays. Of the 3 metals listed in the EPA criteria for dredge spoil evaluation, only zinc exceeds the limits established for considering sediments polluted to the extent of creating dredge spoil disposal problems. The oxygen demand and related parameter measurements for the bay suggest that the sediment load reflects the level of these reported for the overlying water. For oil and grease, highest concentrations occur along the upper and west side of Galveston Bay, near Texas City and in portions of Trinity Bay located within or near existing oil and gas fields. Pesticide measurements on the surface sediments indicate persistent and detectable quantities of the benzene hexachlorides (a-BHC, B-BHC and lindane) within the bay, especially along the north and west sides of Galveston Bay. The heavy metal content of the Houston Ship Channel sediments reflects results of previous studies for other parameters in these sediments. Namely, the quality of sediments in the upper half of the channel (miles 10-24) is very poor and these sediments require special considerations in their disposal.