In the case of hardwoods, after one generation of trees is harvested, another will grow from the old stumps, providing a renewable source of revenue for communities and industries for decades to come. Garner, which is in the troubled Neuse River watershed, and Edenton, which sits at the point of land where the Chowan River meets the Albemarle Sound, worked with Frederick to install systems after tests showed the towns' conventional treatment programs weren't in compliance with government standards. Everything's working fine now. The town may sell some of its 60-foot sycamores for timber this winter, he says. Operation of the system is simple.
Wastewater is held in a lagoon or tank until most solids in it settle out.
Then, it is chlorinated and sprayed on fields of trees through standard irrigation piping and sprayers. Tests of nutrient levels in surrounding soil, groundwater and surface water are performed at regular intervals to determine the system's effectiveness. The type of trees used varies according to the type of soil at each site. The systems likely would do well in most areas of the United States, Frederick says, but they may not be practical everywhere. In cold climates, the threat of frozen or burst water pipes might prevent spraying in winter, reducing the system's cost-effectiveness.