Environmental Survey of the Distribution and Metal Contents of Pteris vittata in Arsenic–Lead–Mercury-Contaminated Gold Mining Areas along the Bone River in Gorontalo Province, Indonesia

In this paper, we report ecological and environmental investigations on Pteris vittata in the As–Pb–Hg-polluted Bone River area, Gorontalo Province, Indonesia. The density distribution of P. vittata decreases from around the artisanal and small-scale gold mining (ASGM) site to the lower reaches of the Bone River, and it is rarely found near Gorontalo City. The maximum concentrations of As, Hg, and Pb recorded in the soil samples were 401, 36, and 159 mg kg−1, respectively, with their maximum concentrations in P. vittata recorded as 17,700, 5.2, and 39 mg kg−1, respectively. Around the ASGM sites, the concentrations of As, Pb, and Hg in P. vittata were highest in the study area. These data suggest that P. vittata, a hyperaccumulator of As, may be useful as a bioindicator for assessing environmental pollution by Pb and Hg.

The Assumption of Zero Leakage from Permanently Abandoned Wells on the Norwegian Continental Shelf

Quality data is essential for calculations of expected leakage in wells post Permanent Plug and Abandonment (PP&A). Such data may come from surveys studying hydrocarbon leakage to the marine environment. However, recent literature suggests that current regulatory practices for environmental surveys are suboptimal, giving reason to question the assumption that wells have experienced zero leakage from the deep reservoir post PP&A on the Norwegian Continental Shelf (NCS). We investigate whether such an assumption is credible. The credibility of the assumption of zero leakages is investigated through a review of literature addressing the integrity of wells post PP&A on the NCS, with particular emphasis on a 2021 report from the Norwegian Environmental Agency (NEA). Based on the review, the strength of knowledge supporting the assumption that no wells on the NCS have experienced leakages from their deep reservoirs is discussed. The implications of the uncertainty associated with the assumption of zero leakage on the NCS, the rationale for collecting more relevant data, and how these data may be obtained is also discussed in brief. The NEA report details the current regulatory practice for environmental surveys on the NCS. This regulatory practice, as it is described in the NEA report, give limited support to a zero leakage assumption. Norwegian regulations require two environmental surveys post Cessation of Production (CoP). These surveys may however occur in the period between CoP and PP&A, and the closest test stations are generally located 250 meters from the wells. Environmental surveys carried out that far from the well, and possibly prior to PP&A, influence data quality. We argue that the environmental survey data claiming zero leakage, lack sufficient evidence. Thus, based on the reviewed literature outlining the current environmental survey practice, although PP&A well design on the NCS should build on sound principles, we are not able to conclude on the assumption of zero leakage. The interest in risk-based PP&A approaches is increasing globally, and risk-based approaches rely on credible leakage calculations. The failure rates used in these leakage calculations should be based on quality data. The NEA report and other literature indicate that the quality of post PP&A leakage data on the NCS is questionable, and in some cases the data are non-existent. The paper includes suggestions on how to improve the regulatory practice related to environmental surveys.

U.S. Federal Aviation Administration Neighborhood Environmental Survey: Study Motivation and Results

As part of the agency's broader noise research program, the Federal Aviation Administration (FAA) has undertaken a multi-year research effort to quantify the impacts of aircraft noise exposure on communities around commercial service airports in the United States (U.S.). The overall goal of the study was to produce an updated and nationally representative civil aircraft dose-response curve; providing the relationship between annoyance and aircraft noise exposure around U.S. airport communities. To meet this goal, the FAA sponsored a research team to help design and conduct a national survey, known as the Neighborhood Environmental Survey (NES). By assessing the results of the NES through both internal review and input from public comment, the FAA seeks to better inform its noise research priorities and noise policies. This paper will outline the FAA's motivation to conduct the NES as well as how its findings will help inform ongoing work to address aircraft noise concerns. Additional information describing the noise methodology and survey methodology are provided in companion papers.

U.S. Federal Aviation Administration Neighborhood Environmental Survey: Noise Methodology

As part of the agency's broader noise research program, the Federal Aviation Administration (FAA) has undertaken a multi-year research effort to quantify the impacts of aircraft noise exposure on communities around commercial service airports in the United States (U.S.). The overall goal of the study was to produce an updated and nationally representative civil aircraft dose-response curve; providing the relationship between annoyance and aircraft noise exposure around U.S. airport communities. To meet this goal, the FAA sponsored a research team to help design and conduct a national survey, known as the Neighborhood Environmental Survey (NES). A multi-stage and statistically rigorous process was used to select a representative sample of US airports, including a balanced sampling frame that included six factors: geographic distribution, temperature, day-night split, operational tempo, fleet mis, and population density. The research team computed Day-Night Average Sound Levels (DNL) for the 20 airports in two waves: first for survey respondent selection, and then for pairing with respondent locations to create the dose response curve. Analysis of the responses and the associated DNL was used to generate dose-response curves for each individual airport and a national dose-response curve showing the percent "Highly Annoyed" for a given noise level. The National dose-response curve created from the mail questionnaire shows considerably more people are highly annoyed by aircraft noise at a given noise exposure level compared to historical FICON data. This paper presents the airport selection and noise modeling process used to support the creation of the National dose-response curve. Additional information describing the motivation to conduct the NES and how its findings will help inform ongoing work to address aircraft noise concerns; and the survey methodology are provided in companion papers.