The Black River originates in SampsonCounty with the confluence of the Great Coharin and Six Forks Creeks. It runs in a southeasterly direction for approximately 60 miles before joining the Cape Fear about 15 miles northwest of WilmingtonNorth Carolina.
In the upper reaches of the Black River, swine facilities are heavily concentrated next to the wetlands, streams and creeks that feed it. Like other rivers that flow directly to the ocean, pollutants discharged into the Black River along the way are delivered downstream to the ocean. The Black river is also more dramatically sloped. This promotes a more rapid flow of water and pollutants downstream.
Many of North Carolina's rivers receiving swine pollution, like the Neuse and Tar-Pamlico, are not so fortunate. These, often slow moving rivers, discharge into the Albemarle-Pamlico Sound where their pollution discharges stagnate and cause serious water quality problems.
The Black River is listed as an Outstanding Resource, indicating high water quality. The swine industry often points to this as proof that swine facilities do not pollute surface waters. Can this be explained? It can and the answer lies in the geography. Where the swine facilities are located in the Black River watershed their pollution impacts are clearly visible. Scientists taking water samples have found that the tributaries in the Black River headwatersare loaded with macrophytes and have low levels of dissolved oxygen. Our aerial flights and photographs show that in the upper region of the Black River, many of the wetlands, streams and creeks are heavily matted with excessive vegetative growth, a clear sign of nutrient (fertilizer) pollution. Moreover, the Black River remains unpolluted by other sources. The swine facilities are the only major source of these nutrients. Locals report that the vegetative growth began to appear after the swine industry set up their operations. It is also reported that the River's 80 year old white cypress trees are now dying and fishing near where the swine facilities are located is in decline. North Carolina scientists are also sampling the ditches that drain the swine facilities at the headwaters of the Black River. Their data on phosphorus from soil samples reflects excessively high levels of contamination—some well above the state’s “stop phosphorus application” guideline level.
In an article published in the Fayetteville Observer on December 17, 2003, three well known and respected scientists from North Carolina, Drs Mike Mallin, Larry Cahoon and Bill Showers, were quoted on the issue of swine facilities and their impacts on the Black River. Their remarks are as follows:
"Showers is a researcher at N.C. State University who has concluded that hog waste is seeping into groundwater and ending up in the Black River. He has been able to isolate an isotope of nitrogen common only to animal waste and follow its path.
In one study, he used monitoring wells to study groundwater under two hog farms separated by a stream that enters Stewart's Creek, which flows into the Black River. The farm fields had been receiving hog waste for at least 20 years, but no artificial fertilizer for at least 10.
Showers found that nitrate concentrations from hog waste increased 1.5 times to 10 times downstream from the farms.
''To say they are not exporting nitrogen is hydrologically impossible,'' Showers said. ''The question is how much exporting, and I don't think we have a really good handle on that at all.''
''We certainly are going to see a change. Whether we will be in real trouble remains to be seen,'' Showers said. ''It is going to take several decades before we realize the full impact of that (hog) industry on the environment.''
The Black River is in good shape now partly because it's fed by deep underground aquifers, Showers said. Mallin added that the stream moves fast enough to flush nutrients out.
Larry Cahoon, a researcher at UNC-Wilmington, thinks the effect of nutrients is already being felt. Cahoon said he has seen dense aquatic weeds in the tributaries of the Black River, an indication of excessive nutrients.
''Where do the nutrients come from that support the weeds in those creeks?'' Cahoon asked. ''One can argue that row-crop agriculture has been there all along and that commercial fertilizers are getting into these creeks. That must certainly be true.
But it is simply irrational to claim that hog waste spread on the ground is not getting into these creeks if fertilizer spread on the ground is getting in.'' All things considered, the Black River is coping with swine pollution better than most other public waters in eastern North Carolina. But this is not because the swine industry is not polluting it. Rather, it is because the Black River is protected by a filtration system of extensive wetlands and vegetative buffers along its course, including the upper region where most of the swine facilities are located. These wetlands and buffers purify the water of nitrogen fertilizer through a process know as denitrification. The Black River also benefits from another even more significant factor. During periods of low flow, as pollutants from swine operations move down river, they are massively diluted by a significant groundwater discharge from an extremely old and pure underground aquifer. At that point, pollutants that the wetlands and buffers were unable to remove are dilluted by a heavy volume of unpolluted water.
But for the Black River and all the other rivers in eastern North Carolina, time is running out. Technologies to replace the industry's polluting lagoons and sprayfields are both available and affordable. All that is lacking in North Carolina is the legislative will to make it happen.