Water quality monitoring in New Hanover County continues to show levels of a form of bacteria that indicates fecal contamination of several creeks and waterways.
Whether that bacteria is coming from human sources—faulty septic systems, aging sewer pipes, or some other source—remains to be determined, commissioners were told at their regular meeting Monday.
The latest results of an ongoing effort to monitor the quality of water in the county were presented to the board in an annual report, summarized in half an hour by county Planning Manager Shawn Ralston and Brad Rosov, a marine biologist with consulting firm Coastal Planning & Engineering of North Carolina.
Rosov said testing over the past 12 months has shown the presence of bacteria in several waterways, particularly at monitoring sites along Pages Creek, located in the northern part of the county; Motts Creek, in the southern part; and Smith Creek, in the west.
A particular type of bacteria—enterococci—indicates the source is a warm-blooded animal, Rosov said, and further testing showed a high likelihood of human-borne fecal contamination, though he noted the source of that contamination needs to be determined through additional testing.
“Monitoring for enterococci bacteria tells you that there is bacteria from the guts of a warm-blooded animal. It doesn’t tell you the source of it,” Rosov told the board. “Birds, avian sources; raccoons—there’s a lot of things that are out there utilizing the waterways besides just us.
“But it’s important to determine whether or not it’s coming from human sources, because—should it be coming from human sources—there’s more of a risk for pathogenic exchange between humans,” he said. “So it could become a human health risk if the source is coming from humans, i.e. through a leaky sewer or septic tank type of situation.”
Finding the source
To determine that, Rosov said the monitoring program reallocated funds to contract with Rachel Noble, a marine sciences professor at UNC-Chapel Hill, whom Rosov said is “world-renowned in what she does, which is looking for mechanisms and methods to understand where the bacteria load is coming from.”
Tests were conducted at four of the county’s most problematic sites, including a site in the septic-served Marquis Hills neighborhood, a site on Candlewood Drive in the Smith Creek watershed, and two sites in the area of Pages Creek. Measurements following six rain events produced a total of 24 samples, and of those, Noble found 21, or 88 percent, yielded strong results for at least two of three markers of human fecal contamination.
“So unfortunately she found, when she targeted to see whether or not humans were the source, sure enough it did come back the vast majority of the time,” Rosov told the board. “So we have seen an issue there with human contamination within those sites.”
While those sites revealed some of the highest levels of contamination, Ralston noted that many creeks and watersheds in the county are considered “impaired,” in that their designated use—be that fishing, recreation or biological use—has been deemed as not being met.
“Major causes of impairment here in our area are mostly from nonpoint source pollutions,” Ralston said, “so not from an actual pipe that is discharging into a water body, but from urban runoff or stormwater runoff, agricultural runoff, septic tank failures or marina contamination.”
Ralston noted the purpose of the monitoring program, started in 1993, has become twofold: to measure the overall health of a given watershed, and to address public health concerns.
“In the county, we have a lot of people that access the water, that get in the water and swim and fish and shellfish. So when we do see that there is a contamination issue, we want to be able to alert the public very quickly,” she said, noting the county has posted red signs at boat ramps and access points where contamination levels have caused concern.
“In the 1990s, we started to see the continued closure of our shellfish areas, and that brought about this community desire to try to improve our water qualities and to prevent the further degradation of water quality,” she said. “We realized within our government that water quality affected future growth potential, future development potential, fishing, recreational uses, as well as our tourism here. So it greatly affects our economy.”
While New Hanover monitors seven watersheds in the unincorporated part of the county, it also coordinates data with other monitoring programs conducted locally. The City of Wilmington monitors waterways within the city’s boundaries, Ralston also noted.
Next steps
Ralston said the county would take the results from this past year and conduct additional testing to determine potential remediation efforts. She noted the county continues to work with the Cape Fear Public Utility Authority on the septic-to-sewer projects planned for Marquis Hills and Heritage Park, and she said the authority would also start testing samples with high bacteria counts for any presence of ammonia—an indicator of sewage—to determine the sources of fecal contamination.
Related story: CFPUA joins county in committing funds for septic-to-sewer projects
“This is a good way for us to rule out whether the problem is actually coming from an active sewer issue,” Ralston emphasized—a point that Rosov reiterated.
“The bacteria has really been the take-home message here this year,” Rosov said. “With the follow-up study that we had with Dr. Rachel Noble, we were able to determine that there was human fecal contamination identified within some of these creeks which we monitored. We will be looking forward in the future to hopefully examine this just a bit further and take the next baby step to determine where this is all coming from.”
Commissioners thanked the presenters for the report, with Commissioner Jonathan Barfield emphasizing their points.
“I am concerned about the high levels of human waste in our waterways and our creeks. I know that shellfishing is a big thing here, whether it’s oysters or clams or crabs, and I think it’s important that we continue to monitor,” he said.
“I’m glad that you’re taking the next step to find out exactly what the source was, in terms of whether it was human or animal waste. Now we need to figure out exactly where it’s coming from,” he said, “and then also continue to educate the public—that these waters may not be safe for you to be in.
“The ocean is one thing,” Barfield said, “but when you’re in those creeks—I know a lot of our young folk like to jet-ski and fish and those kind of things in those areas—the worst thing that could happen is someone ingest a fish that’s been highly contaminated with human waste and get sick from that. So thank you for your efforts and keep on doing what you’re doing.”
Ralston noted the county maintains a page on its website that lists the program’s results and other water quality monitoring reports and statistics. That page can be accessed via this link.
Jonathan Spiers is a reporter for Port City Daily. He can be reached at (910) 772-6313 or [email protected]. On Twitter: @jrspiers
