CONTAMINATED MUCK WON'T INTERFERE WITH PORT DREDGING, MASSPORT SAYS

CONTAMINATED MUCK WON'T INTERFERE WITH PORT DREDGING, MASSPORT SAYS

Plans to enlarge Boston harbor shipping channels will survive the recent discovery of toxic chemicals in material dredged from the harbor bottom, the Massachusetts Port Authority's maritime director said.

The discovery of the chemicals has delayed a separate dredging project, the digging of a trench for an under-harbor tunnel. But, "this doesn't change the way I would approach the maritime dredging project," said Anne Aylward, the Massport maritime director. Massport will hire a consultant this month to oversee a $500,000 program to test ship channel muck, and plan alternative disposal options.The top layer of the harbor's mud is saturated with toxic chemicals, including arsenic, cadmium, mercury and polychloriated biphenyls (PCBs), which the Army Corps of Engineers has ordered dumped on land instead of at sea.

Earlier analysis had shown the surface layer of harbor mud was badly polluted, said Sue Douglas, spokeswoman for the corps' New England Division.

"It appears the (tunnel) dredging began before the upland site was ready," Ms. Douglas said.

The corps is allowing construction of a plastic-lined holding pit on the edge of Logan International Airport near the harbor's edge, but that can not permanently store the polluted muck unless it is detoxified.

State officials were scrambling to determine if lime or some other substance can neutralize the pollutants in mud dredged thus far. That material is stored in five barges.

Some observers wonder what went wrong with the initial tunnel ditch digging in Anchorage 1, where smaller vessels drop anchor.

"You'd think they'd have had the whole thing checked out before they got started," said a harbor pilot, who noted that the ship channel dig-out will include Chelsea Creek, Boston's major petroleum storage area.

Ms. Aylward said Massport hopes to avert similar problems for the $26 million ship channel dredge project, due to start in late 1993. Massport hopes the availability of clean dredge material from under the bottom's surface will persuade environmental regulators the contaminated mud can be capped at sea.