Hurricane Matthew dropped so much water on Eastern North Carolina last fall that it washed typical pollution out of the state’s rivers, according to a post-storm report by state environmental regulators.

While it moved near the Eastern N.C. coast Oct. 8 and 9 of last year, Matthew dropped an average of 5 to 8 inches of rain on the state, with maximums reaching 17 inches during a 24-hour period. According to the report by the N.C. Division of Water Resources, the 5 to 8 inches represented 200 to 400 percent more than normal for the entire month of October.

“While many eastern North Carolina areas were inundated by floodwaters and incidents of spills, breaches or waste facility shutdowns were reported,” the study said, “the amount of water discharged into the river basins resulted in a diluting effect, which primarily resulted in lower than normal concentration of various pollutants.”

State regulators monitored water conditions at 30 sites in seven river basins across Eastern North Carolina, with the first tests coming in the days following the storm and the last as late as January. In nearly all cases, the report said, the storm did not result in lasting impacts to the state’s rivers.

Matthew Starr, the Upper Neuse riverkeeper for environmental group Sound Rivers, said the idea that so much water over a short period of time diluted pollutants should be concerning for routine conditions.

“It should be pretty eye opening to many people,” he said, “that without a storm, we have a real problem with water quality and the discharges that happen throughout industrial animal agriculture, the discharge that happens from wastewater treatment plants in floodplains.” 

Water quality testing

During the first phase of testing, in the days after the storm, for instance, a monitoring site on the Neuse River in Kinston showed elevated levels of fecal coliform, turbidity, pesticides and organic carbons. By the second phase of testing, which took place between mid-November and January 2017, the elevated levels of fecal coliform remained, but the pesticides and organic carbons were no longer elevated.

“While flooding created major widespread damage to property and infrastructure,” the report said, “results from extensive sampling in eastern North Carolina indicate the impact of these pollutants to surface waters appears to have been transient, lasting several weeks as water levels returned to normal and water temperatures dropped.”

Typically, the report said, testing that took place between Oct. 19 and 26 of last year indicated the water diluted pollutants.

About two weeks later, the same tests showed higher bacterial and nitrogen oxide concentrations, while sites upstream in the Neuse and Tar-Pamlico basins showed high bacterial concentration because of the Army Corps of Engineers’ decisions to hold back water at the B. Everett Jordan and Falls of the Neuse dams.

Testing in the same places several months later showed conditions similar to routine conditions, with fecal coliform remaining elevated at nine of the 30 sites.

The Division of Water Resources report also indicated that while wastewater, stored fuel and other pollutants were released into surface waters during the flooding, tests found little to no presence of pesticides, herbicides, fuel or semi-volatile organic compounds in the water after the storm.

Farm’s impacts

Sound Rivers has worked with representatives of the pork industry to find ways to restore funding for a voluntary conservation easement program that would be used to buy out some farms in flood plains. Earlier this month, the N.C. Pork Council’s board of directors unanimously voted to support re-establishing the program, which was started in 1999 and resulted in easements being placed on 42 farms.

Matthew’s impact on hog farms was significantly less than Floyd’s — 14 flooded lagoons compared to 55 and 2,800 swine killed compared to 21,474. Environmentalists and industry officials attributed much of that progress to the conservation easement program.

The N.C. Senate’s budget proposal did not include funding for the conservation easement program, but Starr said he is hopeful the House’s proposal would include some money for it.

Starr also questioned why the report did not address poultry farms across the state’s eastern region.

“One impact that you don’t see are any references to industrial poultry facilities,” Starr said, “and that is because DEQ doesn’t know where they are, which really hinders their ability to assess water quality.”