PHA Meets Dredging Schedule and Reduces Ecological Liability

The Port of Houston is a 25-mile-long complex of diversified public and private cargo and passenger handing facilities connected to the Gulf of Mexico by the Houston Ship Channel. The Port of Houston Authority (PHA) owns and operates the public facilities along the Ship Channel and is the Channel’s official sponsor.

PHA conducted a sediment characterization to evaluate possible environmental impacts of its planned dredging of accumulated sediments between the channel edge and the loading docks. Sediment samples were collected from four locations and were found to contain polynuclear aromatic hydrocarbon (PAH) concentrations higher than those observed during previous sampling events.  As a result, potential ecological concerns over the dredging activities and disposal methods for the dredged material were identified.

Further evaluation of the laboratory data indicated that the PAH results were most likely biased high due to matrix interferences from other organic constituents such as petroleum hydrocarbons.  Based on these findings, PHA decided to have confirmation sediment samples collected and used additional analytical sample preparation methods to reduce the effects of the interferences and obtain more representative data.  WESTON provided the oversight of the confirmatory sediment-sampling program.

The confirmatory sampling results indicated that PAHs were actually considerably lower than the initial sampling results and were within regulatory guidelines. The confirmatory sampling results also compared favorably to the historical results and the ecological screening criteria, and were acknowledged to be more representative of sediment conditions in the Houston Ship Channel.

As a result of WESTON’s work, no special  handling or disposal of dredged materials was required, allowing the dredging program to continue as scheduled.