Background:Evidence suggests that the 44.5 million U.S. residents drawing their drinking water from private wells face higher risks of waterborne contaminant exposure than those served by regulated community water supplies. Among U.S. states, North Carolina (N.C.) has the second-largest population relying on private wells, making it a useful microcosm to study challenges to maintaining private-well water quality.Objectives:This paper summarizes recommendations from a two-day summit to identify options to improve drinking-water quality for N.C. residents served by private wells.Methods:The Research Triangle Environmental Health Collaborative invited 111 participants with knowledge of private-well water challenges to attend the Summit. Participants worked in small groups that focused on specific aspects and reconvened in plenary sessions to formulate consensus recommendations.Discussion:Summit participants highlighted four main barriers to ensuring safe water for residents currently relying on private wells: (1) a database of private well locations is unavailable; (2) racial disparities have perpetuated reliance on private wells in some urbanized areas; (3) many private-well users lack information or resources to monitor and maintain their wells; and (4) private-well support programs are fragmented and lack sufficient resources. The Summit produced 10 consensus recommendations for ways to overcome these barriers.Conclusions:The Summit recommendations, if undertaken, could improve the health of North Carolinians facing elevated risks of exposure to waterborne contaminants because of their reliance on inadequately monitored and maintained private wells. Because many of the challenges in N.C. are common nationwide, these recommendations could serve as models for other states. https://doi.org/10.1289/EHP890

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Previous evidence has identified potential racial disparities in access to community water and sewer service in peri-urban areas adjacent to North Carolina municipalities. We performed the first quantitative, multi-county analysis of these disparities. Using publicly available data, we identified areas bordering municipalities and lacking community water and/or sewer service in 75 North Carolina counties. Logistic regression was performed to evaluate the relationship between race and access to service in peri-urban areas, controlling for population density, median home value, urban status, and percent white in the adjacent municipality. In the peri-urban areas analyzed, 67% of the population lacked community sewer service, and 33% lacked community water service. In areas other than those with no black residents, odds of having community water service (p<0.01) or at least one of the two services (p<0.05) were highest for census blocks with a small proportion of black residents and lowest in 100% black census blocks, though this trend did not hold for access to community sewer service alone. For example, odds of community water service were 85% higher in areas that were greater than 0% but less than 22% black than in 100% black areas (p<0.001). Peri-urban census blocks without black populations had the lowest odds of community water service, community sewer service, and at least one of the two services, but this difference was only statistically significant for sewer. Peri-urban areas lacking service with no black residents were wealthier than 100% black areas and areas with any percent black greater than 0%. Findings suggest two unserved groups of differing racial and socioeconomic status: (1) lower-income black populations potentially excluded from municipal services during the era of legal racial segregation and (2) higher-income non-black populations. Findings also suggest greater racial disparities in community water than community sewer services statewide.

The migration of chlorinated volatile organic compounds from groundwater to indoor air-known as vapor intrusion-can be an important exposure pathway at hazardous waste sites. Because sampling indoor air at every potentially affected home is often logistically infeasible, screening tools are needed to help identify at-risk homes. Currently, the U.S. Environmental Protection Agency (EPA) uses a simple screening approach that employs a generic vapor "attenuation factor," the ratio of the indoor air pollutant concentration to the pollutant concentration in the soil gas directly above the groundwater table. At every potentially affected home above contaminated groundwater, the EPA assumes the vapor attenuation factor is less than 1/1000--that is, that the indoor air concentration will not exceed 1/1000 times the soil-gas concentration immediately above groundwater. This paper reports on a screening-level model that improves on the EPA approach by considering environmental, contaminant, and household characteristics. The model is based on an analysis of the EPA's vapor intrusion database, which contains almost 2,400 indoor air and corresponding subsurface concentration samples collected in 15 states. We use the site data to develop a multilevel regression model for predicting the vapor attenuation factor. We find that the attenuation factor varies significantly with soil type, depth to groundwater, season, household foundation type, and contaminant molecular weight. The resulting model decreases the rate of false negatives compared to EPA's screening approach.

During an outbreak of Ebola virus disease (EVD), hospitals' connections to municipal wastewater systems may provide a path for patient waste bearing infectious viral particles to pass from the hospital into the wastewater treatment system, potentially posing risks to sewer and wastewater workers. To quantify these risks, we developed a Bayesian belief network model incorporating data on virus behavior and survival along with structural characteristics of hospitals and wastewater treatment systems. We applied the model to assess risks under several different scenarios of workers' exposure to wastewater for a wastewater system typical of a mid-sized U.S. city. The model calculates a median daily risk of developing EVD of approximately 6.1×10 (90% confidence interval: 1.0×10 to 5.4×10 ; mean 1.8×10 ) when no prior exposure conditions are specified. Under a worst-case scenario in which a worker stationed in the sewer adjacent to the hospital accidentally ingests several drops (0.35 mL) of wastewater, median risk is 5.8×10 (90% CI: 8.8×10 to 9.5×10 ; mean 3.2×10 ) . Disinfection of patient waste with peracetic acid for 15 minutes prior to flushing decreases the estimated median risk to 3.8×10 (90% CI: 4.1×10 to 8.6×10 ; mean 2.9×10 ). The results suggest that requiring hospitals to disinfect EVD patient waste prior to flushing may be advisable. The modeling framework can provide insight into managing patient waste during future outbreaks of highly virulent infectious pathogens.