What's in the Water? Archives | Coastal Review

Coastal Research: Would You Swim Here?

Jennifer Allen — Thu, 09 Jan 2020 05:00:01 +0000

A semester-long research project by University of North Carolina students looked at how contaminants get into Town Creek and how long they persist. Photo: Mark Hibbs

University of North Carolina undergraduates at coastal campuses spent the fall semester undertaking projects to answer pressing environmental questions, making their capstone presentations in December. This is the second of two reports stemming from presentations on water quality. Read the first report.

MOREHEAD CITY – There was a definite “no” from one of the 15 undergraduates who spent the fall studying Town Creek’s water quality when asked if they’d swim in the Beaufort estuary for a half an hour.

The University of North Carolina Chapel Hill student told the audience during the December presentation of their findings at UNC-Institute of Marine Sciences that while she did get in the water when they began the research project to collect oysters, she was very careful not to put her head underwater, and doesn’t know if she would do that now after the testing. “I wouldn’t, personally,” she added.

“As long as you’re not ingesting the water, then perhaps. If you’re not drinking it or you don’t have any open wounds, then for a half an hour, I would consider swimming in Town Creek,” said her classmate, while another student added that if you do go swimming, you should make sure you disinfect any cuts after getting out of the water.

A part of the UNC Institute for the Environment’s Field Site program, the students set out at the beginning of last semester as their capstone project to figure out how contaminants get into Town Creek, which is surrounded by the two new bridges leading into town, two marinas and the county airport, and what happens once the contaminants are in the water. Professors Johanna Rosman and Nathan Hall were the program instructors.

Student Hayley Russo began the presentation of “An Integrated Assessment of Water Quality in Town Creek, an Estuary in Beaufort, North Carolina” by explaining that Beaufort, the client for the research project, plans to develop and improve existing sewer and stormwater infrastructure.

“So, a detailed assessment of the water quality in Town Creek will provide them with a baseline dataset that encompasses the overall potential contaminants within Town Creek, as well as the existing state of the system,” she said.

The students found that water flushes out of the system too rapidly for nutrient loading to cause eutrophication and harmful algal blooms. Fecal indicator bacteria are present and exceed state-regulated standards at some stormwater locations. Vibrio bacteria are highest near stormwater outfalls. And oysters and marshes do not have sufficient time to remove nutrients and microbes because of the quick flushing time.

Hall told Coastal Review Online following the presentation that, under the direction of Beaufort Mayor Rett Newton and Town Manager John Day, the town was very interested in learning more about the factors that affect fecal pollution and nutrient pollution in Town Creek.

Nathan Hall

“The team hopes to provide the Town of Beaufort a baseline data set of water quality measurements and an improved understanding of the sources and fate of pollutants in Town Creek,” Hall said. “This information will be critical for assessing, predicting, and managing changes in water quality, positive or negative, associated with expected future increases in development pressure but also planned improvements to waste/stormwater infrastructure.”

Newton said after the presentation that the town appreciates the collaboration with UNC-IMS as the effort continues to clean up town waterways.

“We know there are some challenges in Town Creek. This capstone research effort was professional, thoughtful, thorough and will help us find and mitigate or eliminate the sources of contaminants. We will continue to look for opportunities to work with the spectacular marine science capabilities in Carteret County to improve our community and the surrounding areas,” he said.

Day explained that the next step is underway for the town.

“We are currently working with USDA Rural Development on a funding package for utility improvements in the $15 million range,” he said, referring to the U.S. Department of Agriculture program. “The information from the UNC-IMS water quality analysis will assist us in prioritizing the improvement projects, and, very importantly, help us qualify for grant funding by illustrating the need to mitigate water quality issues through sewer line improvements.”

Hall explained that previous capstone projects at the institute included investigating the role of living shorelines in stabilizing property loss due to erosion, effects of marine debris on coastal ecosystems, potential for wind energy development along the North Carolina coast, impacts of marinas on water quality, ecosystem services of oyster reefs, and factors influencing water quality in highly developed canal systems in Pine Knoll Shores and Atlantic Beach.

“This year’s project on the factors influencing water quality in Town Creek in Beaufort was modeled around the latter two studies, which had successfully provided useful information to Pine Knoll Shores and Atlantic Beach regarding water quality of their canal systems,” he said.

Sources of pollution are identified on this map of Town Creek and Beaufort. Source: UNC

About the project

Hall told Coastal Review Online that the goal for the students with the project was to assess the current water quality in Town Creek and to learn about the factors and processes that affect it.

Primarily, they were interested in nutrient pollution that can cause eutrophication, or an excess of nutrients, and pollution by microbes that can cause illness, he said.

The students split into groups to address different aspects of the problem.

“One group mapped potential sources of nutrients and fecal contamination within the watershed, and conducted a survey of Beaufort residents and businesses to learn how Town Creek is used — boating, fishing, swimming, etc. — and what water quality issues are seen as most important,” Hall explained.

Two groups of students collected water samples throughout Town Creek, including near marinas and stormwater outfalls, which are potential sites where pollutants could enter the body of water, Hall continued. “The students then analyzed the samples at IMS to determine the concentrations of bacteria species indicative of fecal pollution, nutrients (fertilizers) that can stimulate algal growth, and different types of microscopic algae in the water.”

A third group used GPS-equipped sampling devices called drifters to measure how fast or slow pollutants in the creek are flushed by the tides and two other groups looked at Town Creek’s marshes and oyster beds to estimate the ability of these habitats to remove algae and nutrients from the creek, he said.

“The students combined results from these project components to assess the main sources of pollutants to Town Creek, and the extent to which they are removed from the system by tidal flushing and filtration by marshes and oyster reefs,” Hall explained.

Shown are the UNC-Chapel Hill undergraduates who spent the fall studying Beaufort water quality. Photo: UNC IMS

The findings

The students presented their findings Dec. 6 to an audience of about two dozen in a second-floor meeting room on the Morehead City campus.

Russo explained early in the presentation that the students determined that within a 1-mile radius of Town Creek, the potential contamination sources include 16 dockage sources, 44 stormwater sources, seven wastewater sources and five housing subdivision sources. Additionally, there are four areas of concerns, with three located adjacent to the public access site next to Town Creek Marina. Seven sampling stations were used to check the data.

After assessing potential contamination sources for Town Creek, the students worked to find where the pollutants go once they enter the water. Students, to better understand circulation in the system, calculated the flushing time, or how long it takes for all of the creek’s water to be completely refreshed with new water, and residence time, or how long it takes for a specific section of water to leave the system. They determined that contaminants are flushed out between 25 to 52 hours, overall. The residence time was calculated to be about four hours or less.

Contaminants near the back of the embayment are likely to remain in the system longer but overall, the students found that Town Creek is a well-flushed system.

Student Rebecca Williams explained that a group looked at samples from Town Creek and Gallants Channel, which feeds Town Creek, and found that chlorophyll a, an indicator of the algae growing in water, and nutrient concentrations were low in Town Creek compared to North Carolina standards and likely flushed out before they can accumulate. The students also concluded that the system is not experiencing algal bloom.

Overall, stormwater drains showed consistently higher nutrient concentrations than other site types, which suggests that stormwater outflows are a source of nutrient input into the system, Williams continued. The significantly lower nutrient concentrations in the channel sites suggests that nutrients and chlorophyll a are being flushed out of the system at a fast flushing time.

The students looked at the impact of rainfall events on nutrient concentrates in stormwater outflow sites. Although rainfall increased nutrient concentrations in Town Creek, it is not reflected in the channelsites due to the fast residence time .

The fecal indicator bacteria, or FIB, such as E.coli and enterococcus, which are not naturally occurring in estuarine systems, serve as a proxy for pathogens like norovirus, salmonella and hepatitis a, which can be very expensive to monitor and quantify, Williams said.

The high FIB concentrations are potentially entering Town Creek by way of the stormwater outfall pipes, as well as possible other nonpoint sources of pollution and are influenced by tide fluctuations, Williams added. The naturally occurring vibrio populations behave similarly to FIB but are not entering through pipes.

Eric Von Amsberg explained that the group that looked at how marshes and oysters can change the concentrations of nutrients estimated that the marsh grass removal rate of nitrogen is about 20 days and phosphorus is around 90 days. The group calculated that the best estimate for clearance time is 6.6 days for oysters, significantly longer than the flushing time of about two days.

In Von Amsberg’s summary of the findings, he explained that due to the short flushing and residence time, water leaves the system very quickly. Nutrient concentrations, fecal indicator bacteria and vibrio are high nearest stormwater outfalls while chlorophyll a concentrations were low.

FIB, which are not native to the estuary, exists in high concentrations around stormwater outfalls, and because they do not exist in nature, the input of that is likely due to stormwater, he continued.

The high natural concentration of Vibrio near stormwater outfalls could be due to the addition of nutrients as well as other qualities of the water like the stagnation of water near stormwater drains.

“Because the flushing time is one to two days and a lot of these marsh and oyster processes take a number of days, they do not have sufficient time or coverage to effectively filter the water in Town Creek, however if the areas of marsh and oyster reef were expanded, it may make a more significant impact on water quality,” he said.

FIB are present at some stormwater locations, where they often exceed state-regulated standards. Stormwater might be the largest area to look at in the future, as well as Vibrio concentration near stormwater outfalls. “And as mentioned earlier, oysters and marshes do not have sufficient time to remove nutrients and microbes due to flushing, however if the areas were larger, they might make a significant impact,” he added.

Hall told Coastal Review Online that as instructors, “We hope that the team has gained an appreciation for how different parts of natural ecosystems are connected, how people pollute but also value and protect ecosystems, and how working as a team can simultaneously be challenging and rewarding.”

Coastal Research: One Town’s Septic Risks

Catherine Kozak — Wed, 08 Jan 2020 05:00:48 +0000

Aerial View of Nags Head. Photo: CSI

University of North Carolina undergraduates at coastal campuses spent the fall semester undertaking projects to answer pressing environmental questions, making their capstone presentations in December. This is the first of two reports stemming from presentations on water quality.

WANCHESE — It’s an unsavory subject no one likes to talk about, but student researchers with the University of North Carolina Chapel Hill have shown why coastal residents need to be talking a lot more about septic tanks.

“It’s a literal out-of-sight, out-of-mind kind of thing,” Nags Head Mayor Ben Cahoon said about the systems. “It’s just one of those things that works until it doesn’t.”

In a presentation in December at the Coastal Studies Institute, 12 participants in a semester-long program tested and analyzed climate change impacts on underground septic in Nags Head. The data indicated that, absent remediation, higher groundwater levels and increased flooding eventually could make the systems ineffective and polluting.

“It’s hard to know how changes in the environment will impact coastal populations and infrastructure, like wastewater treatment systems,” said student narrator Peter Marcou in “Flushed: A Potty Talk Podcast,” an informative and surprisingly entertaining three-part podcast highlighting the research findings. “This means we don’t know what these communities will look like in a few decades. But we can begin to look at the systems that are already changing, map them out and try to prepare for the future.”

Cahoon, who made his observation in the podcast about the general lack of awareness of septic, agreed that few understand how the systems work — or why they don’t.

Conducted by the Outer Banks Field Site program through the UNC Institute for the Environment, the Nags Head project is in the second year of a three-year study. It’s the first time the field site capstone project has been planned for longer than two years.

Last year, students analyzed historical water quality data compiled by the town and compared it to samples collected from three surface-water drainage ditches, two groundwater wells and one ocean outfall pipe, according to the 2018 capstone report. Tests looked at levels of nutrients and bacteria and whether caffeine was present. Although there was a “high variability” in the data, the report said, it suggested that storms increase interactions between septic leachate and surface water reservoirs. In addition, it said, contamination spikes found at certain sites were likely caused by a point-source pollutant such as animal waste or a leaking septic tank.

“The overall trend in the data is that (the) water level has increased over time,” the report said, although the data set was too short to definitively attribute the cause, “… we expect sea level rise will continue to increase the water level of this coastal town, further shrinking the separation between groundwater and septic drainfields, thereby posing increasing risks to water quality.”

But as a resort town with the Roanoke Sound on its western border and the Atlantic Ocean on its eastern edge, Nags Head has long been an active steward of its recreational water quality. In a recent presentation to the town, former Mayor Bob Muller said that the town recognized as far back as 1982 that proper wastewater processing was important to its economic and environmental health. About 20 years later, a proactive program, now known as the Todd D. Krafft Septic Health Initiative, was created by Krafft, who died in September. Lauded as one of the most visionary and innovative municipal programs of its kind in the state, the initiative offers free inspections and low-interest loans to encourage property owners to maintain functional septic systems.

Muller, who was then serving as the mayor, said that Krafft understood the value of septic maintenance before most people thought about it.

“Failing systems meant declining water quality,” Muller said in his comments to the town board at its Dec. 4, 2019, meeting, “and declining water quality meant a declining Nags Head.”

Since the program began, he said, about 4,500 septic systems have been inspected and more than 1,200 repaired, many with the help of a loan.

“That is an amazing record,” Muller said. The board subsequently passed a resolution renaming the initiative in Krafft’s honor.

In addition to its water quality and septic work, Nags Head, which has a year-round population that swells to 40,000 in the summer, was interesting as a research target for the UNC field site program because of its efforts to address the impacts of climate change with an ongoing engineered stormwater management project. The town is also one of the few communities in the state that has participated in North Carolina Sea Grant’s community sea level rise vulnerability study.

“The town has been a really wonderful partner to work with,” said Linda D’Anna, field site faculty member at the Coastal Studies Institute. “They’ve been really great about sharing information and providing feedback without inserting themselves. I think they’ve been finding the results interesting.”

D’Anna said she was skeptical when the proposal was first made to study septic wastewater systems for three semesters — “I was like, ‘Really?’” she recalled — but she has since gained appreciation for the systems’ critical role in human and environmental health. At the same time, she said she has witnessed a growing awareness among the general public about the impacts of flooding and rising seas on the operation of their septic tanks.

D’Anna added that it was “wonderful” watching the students, who were mostly juniors and seniors studying environmental studies or sciences, as they tackled a topic they initially knew little about, grew in confidence as they learned more and saw results in their data collection.

“It’s great that they kind of take ownership, and they’ve created something,” D’Anna said.

The third year’s final semester of septic study has yet to be nailed down, but D’Anna said she expected that the 2020 students will build on the work of the previous years.

According to the U.S. Environmental Protection Agency, more than a third of homes in the Southeast use septic systems. In North Carolina, about 48% of properties depend on septic systems, which total more than 2 million statewide. On the Outer Banks, where sewer treatment plants are widely associated with overdevelopment as well as high costs, most properties are hooked up to septic. In Nags Head, about 80% of wastewater systems are some version of a septic tank and a drainfield with gravel-filled trenches.

Simply put, the waste products are flushed into the tank; the solids settle and are biologically broken down, the effluent flows through drainage pipes into the soil, where it is “cleaned” by filtering through the sandy soil. The tank and drain field are sized to the number of occupants of the home, and the system must be permitted by the state health department. Beyond those standards, there is no requirement to maintain the tanks. Problems occur when the tank needs to be cleaned, or when the soil is oversaturated by flooding or overuse — say, by 25 young people stuffed into a 10-occupant house in the summer — causing the wastewater or sometimes solids to bubble up to the surface.

But bad things can happen under the surface, too.

In the 2019 semester, the students’ capstone report, “People, Water, and Septic: A Coastal Case Study,” showed that half of Gallery Row’s sub-watershed were susceptibile, mostly in areas between the highways, to mingling of groundwater and wastewater during the sampling period between Sept. 21 and Oct. 29. Overall, data indicate that low-lying, flat areas that are more vulnerable to flooding are more likely to be contaminated.

But there were also encouraging signs. The places where groundwater levels were lowered in Nags Head’s stormwater management project appeared to have fared better in maintaining water quality. By making more room for floodwater in the ground, it also created an unanticipated side bonus of a larger area of unsaturated soil for wastewater to filter through.

“Just like all research, it opened up more questions than answers,” said Cahoon, the town’s mayor, in an interview. “But there’s potential . . . to create more separation between septic systems and ground water and improve the performance.”

Cahoon, who along with some other town officials attended the students’ presentation in support of their work, said that their research makes clearer the relationship between stormwater and wastewater, and how management of them often overlaps. It is also obvious that the effects of climate change, including rising seas pushing up groundwater levels, more intense storms and rain events, more erosion and more frequent sound tide and ocean overwash, will result in more flooding and challenge drainage.

“We were really excited to have the students looking at this issue,” he said. In the process, they encouraged a closer look at what’s going on in the ground the septic tanks sit in and confirmed that the water table is only going to get higher. “They’ve scratched the surface.”

Assistant Town Manager Andy Garman said that the town will soon start work on an update to its 2005 decentralized wastewater management plan. The scope of the plan is not yet finalized, he said, but it will include water quality monitoring. The draft plan, expected to be submitted to the board of commissioners in about two months, will encompass findings from a draft state report from 2015 that detailed periodic pollution from ocean outfalls caused by stormwater. For unknown reasons, the state report was never finalized.

Of the state’s 10 ocean outfalls, which are owned by the state Department of Transportation, eight are in Nags Head and one is in Kill Devil Hills.

“It’s paramount that we incorporate any information that came out of that study,” Garman said.

The Outer Banks Field Site students also interviewed town residents and found that many had noted the increased problem with flooding, although they attributed it to increased development and more impermeable surfaces as much as deluges from more frequent and severe storms. But the interviews also found that most property owners, despite their view of clean water as essential to their quality of the life and the tourism economy, do not see a risk of septic contamination of surface and ground waters. That observation led the students to suggest that the town should do more outreach, so visitors and residents understand better the hazards of wastewater pollution.

Cahoon said that Nags Head will continue to seek solutions to protect wastewater infrastructure and water quality. In addition to lowering the water table, options could include, perhaps, a small “package” system that treats a section of a neighborhood where septic is no longer feasible.

“It’s going to be an incremental process,” he said. In the near term, Cahoon said the town will be seeking to line up grants and more vigorously promote the septic initiative to maintain the existing systems.

But he insisted a large, expensive municipal treatment plant in Nags Head is not in the cards.

“I can’t imagine a scenario where we would have bacteria in the water coming from a few locations, and the answer to that is a town wide wastewater system,” he said.

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