Occurrence and concentrations of traditional and emerging contaminants in onsite wastewater systems and water supply wells in eastern North Carolina, USA.

Onsite wastewater treatment systems (OWTSs) and private wells are commonly used in Eastern North Carolina, USA. Water from private wells is not required to be tested after the initial startup, and thus persons using these wells may experience negative health outcomes if their water is contaminated with waste-related pollutants including bacteria, nitrate or synthetic chemicals such as hexafluoropropylne oxide dimer acid and its ammonium salt (GenX). Water samples from 18 sites with OWTSs and groundwater wells were collected for nitrate, Escherichia coli (E. coli), total coliform, and GenX concentration analyses. Results showed that none of the 18 water supplies were positive for E. coli, nitrate concentrations were all below the maximum contaminant level of 10 mg L-1, and one well had 1 MPN 100 mL-1 of total coliform. However, GenX was detected in wastewater collected from all 18 septic tanks and 22% of the water supplies tested had concentrations that exceeded the health advisory levels for GenX. Water supplies with low concentrations of traditionally tested for pollutants (nitrate, E. coli) may still pose health risks due to elevated concentrations of emerging contaminants like GenX and thus more comprehensive and routine water testing is suggested for this and similar persistent compounds.

Wastewater based epidemiology as a surveillance tool during the current COVID-19 pandemic on a college campus (East Carolina University) and its accuracy in predicting SARS-CoV-2 outbreaks in dormitories.

The COVID-19 outbreak led governmental officials to close many businesses and schools, including colleges and universities. Thus, the ability to resume normal campus operation required adoption of safety measures to monitor and respond to COVID-19. The objective of this study was to determine the efficacy of wastewater-based epidemiology as a surveillance method in monitoring COVID-19 on a college campus. The use of wastewater monitoring as part of a surveillance program to control COVID-19 outbreaks at East Carolina University was evaluated. During the Spring and Fall 2021 semesters, wastewater samples (N = 830) were collected every Monday, Wednesday, and Friday from the sewer pipes exiting the dormitories on campus. Samples were analyzed for SARS-CoV-2 and viral quantification was determined using qRT-PCR. During the Spring 2021 semester, there was a significant difference in SARS-CoV-2 virus copies in wastewater when comparing dorms with the highest number student cases of COVID-19 and those with the lowest number of student cases, (p = 0.002). Additionally, during the Fall 2021 semester it was observed that when weekly virus concentrations exceeded 20 copies per ml, there were new confirmed COVID-19 cases 85% of the time during the following week. Increases in wastewater viral concentration spurred COVID-19 swab testing for students residing in dormitories, aiding university officials in effectively applying COVID testing policies. This study showed wastewater-based epidemiology can be a cost-effective surveillance tool to guide other surveilling methods (e.g., contact tracing, nasal/salvia testing, etc.) to identify and isolate afflicted individuals to reduce the spread of pathogens and potential outbreaks within a community.

Retrospective spatiotemporal analysis of malaria cases reported between 2000 and 2020 in North Carolina, USA.

BACKGROUND: There are 1,000-2,000 cases of malaria diagnosed in the United States annually and most are imported. METHODS: Malaria cases reported between 2000 and 2020 in North Carolina (NC) were analyzed (NC Department of Health and Human Services, Division of Public Health). Differences in numbers of NC malaria cases were further analyzed by year, month, county, gender, age, and country of origin. RESULTS: Most cases originated from travelers visiting Africa and returning to NC (i.e., Mecklenburg [N = 162 cases], Wake [N = 153], Guilford [N = 103], Durham [N = 74], and Cumberland [N = 41] Counties). Per capita analysis (i.e., per 100,000 population) was used to correct for differences in NC county population sizes and Durham (N = 22.8), Guilford (N = 19.0), Onslow (N = 14.7), Mecklenburg (N = 14.5), Wake (N = 13.5), Orange (N = 12.8) and Cumberland (N = 12.2) Counties showed the highest cases. Malaria was more prevalent among males (N = 532) relative to females (N = 245), and this difference was statistically significant. CONCLUSIONS: Travelers visiting malaria-endemic regions should be educated on malaria prevention measures (e.g., chemoprophylaxis, mosquito repellent). These measures should be readily available to travelers. The malaria registry in NC should be improved by requiring additional data related to imported malaria cases.

High-frequency assessment of air and water quality at a concentration animal feeding operation during wastewater application to spray fields.

Air and water quality at a concentrated animal feeding operation (CAFO) in Eastern North Carolina that uses a covered lagoon and anaerobic digester was evaluated for 2 weeks in August 2020. Real-time PM2.5 mass concentrations were determined using a reference ADR-1500 nephelometer and high-frequency measurements of dissolved inorganic nitrogen (DIN) were evaluated using autonomously logging sensors. Air and water quality parameters were assessed before, during and after wastewater from the lagoon was irrigated onto adjacent spray fields. Reference measurements were conducted alongside a HOBO weather station to collect real-time wind speed and direction, temperature, and humidity measurements. PM2.5 concentrations varied between 0 and 159 µg/m3 with an average concentration of 11 µg/m3, below EPA standard for secondary aerosols of 15 µg/m3. Higher PM2.5 concentrations were observed when wind originated from swine barns but not from covered lagoons. Water quality data showed that DIN concentrations downgradient from the CAFO were elevated relative to upstream concentrations. A groundwater seep that drains a spray field contained the highest average DIN concentration (31.0 ± 12.8 mg L-1), which was 25 times greater than upstream DIN concentrations (1.2 ± 0.8 mg L-1). Average DIN concentration at the downstream station was lower than the seep concentration (8.6 ± 16.2 mg L-1), but approximately 8 times greater than upstream. Air quality data show that the lagoon cover was effective at mitigating air quality degradation, whereas DIN concentrations in water were similar to previous studies on CAFOs using open lagoons. In addition, air and water quality parameters were significantly (p < 0.001) higher after irrigation, indicating possible influence due to ammonia and nitrate elevation. Additional research is needed to compare high-frequency data collected from swine CAFOs using capped and uncapped lagoon systems to better understand spatiotemporal air and water quality trends of this practice.

Phosphate treatment by onsite wastewater systems in nutrient-sensitive watersheds of North Carolina's Piedmont.

The goal of this study was to gain a better understanding of the PO4-P treatment efficiency of onsite wastewater systems (OWS) installed in nutrient-sensitive watersheds of the North Carolina Piedmont. Four OWS including two conventional and two single-pass sand filter (SF) systems were evaluated at sites with clay-rich soils. Piezometers were installed near all of the OWS, and down-gradient from the conventional OWS for groundwater collection and characterization. Septic tanks, groundwater, SF effluent, and surface waters were sampled each season during 2015 (five times) and analyzed for PO4-P and Cl concentrations and for various environmental parameters. The conventional and SF OWS reduced PO4-P concentrations by an average of 99% and 90%, respectively, before discharge to surface waters. Mass-load reductions of PO4-P were also greater for the conventional OWS (mean 95%), relative to SF (83%) systems. The effluents discharged by SF OWS were influencing surface water quality. Additional treatment of the effluent from single-pass SF with reactive media is suggested, along with monitoring of the final effluent for PO4-P concentrations. This research provides important information that is absent from the published literature concerning PO4-P contributions to water resources from OWS in clay soils.

Groundwater and stream E. coli concentrations in coastal plain watersheds served by onsite wastewater and a municipal sewer treatment system.

The goal of this study was to determine if onsite wastewater treatment systems (OWS) were influencing groundwater and surface water Escherichia coli concentrations in a coastal plain watershed. Piezometers for groundwater monitoring were installed at four residences served by OWS and five residences served by a municipal wastewater treatment system (MWS). The residences were located in two different, but nearby (<3 km), watersheds. Effluent from the four septic tanks, groundwater from piezometers, and the streams draining the OWS and MWS watersheds were sampled on five dates between September 2011 and May 2012. Groundwater E. coli concentrations and specific conductivity were elevated within the flow path of the OWS and near the stream, relative to other groundwater sampling locations in the two watersheds. Groundwater discharge in the OWS watershed could be a contributor of E. coli to the stream because E. coli concentrations in groundwater at the stream bank and in the stream were similar. Stream E. coli concentrations were higher for the OWS in relation to MWS watersheds on each sampling date. Water quality could be improved by ensuring OWS are installed and operated to maintain adequate separation distances to water resources.