WASHINGTON – State and federal agencies hope to turn an environmental problem into a solution by combining poultry manure with harbor dredge to make a fertile soil substitute.
If the proposal works, it could make a positive out of two very large negatives for the state: Maryland produces as much at 400,000 tons of chicken manure a year and removes 5 million cubic yards of dredge from bay shipping channels.
U.S. Department of Agriculture researchers plan to begin analyzing dredge samples in December to see if poultry manure can replace the organic matter that, over time, is washed out of the dredged sediment.
Environmental and poultry officials both embraced the project, which is being backed by the Maryland Department of Environmental Services and the Maryland Port Authority.
After the state enacted fertilizer regulations this year that “could force poultry growers out of business,” news that manure could be used to turn dredge into soil was hailed by Bill Satterfield, executive director of the Delmarva Poultry Industry Inc.
“We welcome the Maryland Port Authority and the state of Maryland’s interest in working with poultry growers instead of against them,” Satterfield said. “We’re just encouraged that the state of Maryland is trying to do something to help poultry farmers.”
The Chesapeake Bay Foundation, which has fought to keep dredge out of the bay, also supported the project.
“It sounds like it could be an interesting alternative to the disposal options,” said Jenn Aiosa, a staff scientist with the foundation. “Our main goal is to keep it [dredge] out of the bay. We would be supportive of any solution.”
The port authority has been dumping the silt, soil and sand that it dredges from bay harbors and shipping channels on Hart-Miller Island near Baltimore. But the island has filled to capacity and the state must now find other ways to deal with the dredged material.
Patricia D. Millner, a microbiologist with the USDA, said the dredged material “can probably be treated to produce good soil substitutes.” But only if it’s what she called “good dredgings.”
“Bad dredgings, i.e., those contaminated with high concentrations of heavy metals, [toxic] PCBs and other recalcitrant materials will not be suitable starting materials for production of soil replacements,” said Millner, who heads the Soil Microbial Systems Laboratory in Beltsville.
High salt concentrations that cannot be sufficiently treated could also make dredged material unsuitable as a soil substitute.
Researchers will study ways to extract salt from the soil and reduce its acidity so it can be used on land, but metal will not be treated in this project, Millner said.
The research program is funded by a grant from Maryland Environmental Services and is expected to take about three years to complete.
“There is probably no single answer to Maryland’s poultry litter problem,” Millner said. “However, to the extent that is possible, it is the intent of the research team to incorporate as much of the litter as would be prudent and possible for the remediation of the dredge materials and the production of good soil.”