Palm Beach divers monitoring a “beach re-nourishment” project for Ocean Ridge beaches recorded levels of turbidity far higher than legal limits. Using state-of-the-art equipment, Ed Tichenor, Director of the Palm Beach County Reef Rescue, recorded turbidity levels approaching 200 Nephelometric Turbidity Units (NTUs), when the permit conditions state that turbidity levels must not exceed 29 NTUs.

Independent scientists have proven that levels of turbidity lower than 29 NTUs can kill corals or retard their growth. The dredging is taking place in close proximity to extensive coral reefs in 65 feet of water, and Tichenor says the turbidity plume has migrated into the inlet and over the grassflats in Lake Worth Lagoon.

According to Tichenor, a retired environmental consultant with decades’ worth of monitoring experience, the consultant hired by the county to perform turbidity monitoring was taking samples in the clear water--uptide and upwind of the plumes. So, Palm Beach Reef Rescue assembled their own data and reported the excessive turbidity to Palm Beach County’s Department of Environmental Resource Management and the Florida Department of Environmental Protection. Those agencies called

a temporary halt to the dredging.

“Last Sunday, several dive boat operators and divers reported ‘horrendous’ turbidity. It is up to us, the local diving community, to be the watchdogs and make sure our valuable reefs are protected. The governmental regulatory agencies appear to actually do their jobs when they know someone is looking over their shoulder,” Tichenor emphasized.

For five of the last six days, pumping of the sediment has been curtailed because of excessive turbidity conditions. But, divers are concerned about the night-time dredging operations that have occurred since the agencies intervened. Twelve hours after a nighttime round of dredging, Tichenor recorded turbidity levels as high as 40 NTU’s.

“The shift to nighttime pumping suggests that the timing is designed to circumvent turbidity permit excursion detection rather than a modification of operations to come into compliance with the turbidity requirement,” wrote Tichenor, in a letter to Dan Bates, who heads up the County’s beach management program.

The use of poor-quality sediments has raised questions about the sustainability of “beach nourishment.” High levels of fine sediments and decaying carbonate sediments have caused high turbidity levels for months in the nearshore environment, even years after the completion of other beach dredging projects. The 2001 Juno Beach project is just one of a number of examples. 

FS