Maintaining high-volume, low-pressure surface-coating regulatory compliance using the U.s. Environmental Protection Agency's data quality objectives process

To effectively reduce the environmental compliance costs associated with meeting specific requirements under the Aerospace Manufacturing and Rework Facility's National Emission Standard for Hazardous Air Pollutants rule, the U.S. Environmental Protection Agency's (EPA) Data Quality Objective (DQO) process has been proposed as a suitable framework for developing a scientifically defensible surface compliance monitoring program. By estimating the variability associated with the air cap pressure of high- volume, low-pressure (HVLP) surface-coating spray equipment, the number of monitoring samples necessary for an affected facility to claim compliance with a desired statistical confidence level was established. Using data taken from the pilot test facility, the DQO process indicated that the mean of at least 21 HVLP air cap pressure samples taken over the compliance period must be < or = 10 pounds per square inch (psig) gauge for the facility to claim regulatory compliance with 99.99% statistical confidence. Fewer compliance samples could be taken, but that decision would lead to a commensurate reduction in the compliance confidence level. Implementation of the DQO-based compliance sampling plan eliminates the need for an affected facility to sample all regulated HVLP surface-coating processes while still maintaining a high level of compliance assurance.     

Stream restoration and enhancement projects: is anyone monitoring?

Declines in salmon stocks and general watershed health in Washington State, USA, have led to an increase in stream restoration and enhancement projects initiated throughout the state. The increasing number of projects has also raised questions regarding the monitoring of these efforts. Project managers receiving hydraulic project approvals (HPAs) were surveyed to determine whether monitoring was taking place on their projects. About half the project managers surveyed reported the collection of baseline data and the use of biological, physical, chemical, or other water quality measures for their projects. Of those who reported collection of monitoring data, only 18% indicated that monitoring was required. Respondents were also asked to rank the importance of various project goals on a Likert scale. Project managers with projects focusing on “engineering” goals (e.g., roadbed stabilization) were less likely than other project managers to collect baseline monitoring data. Project managers with projects focusing on “restoration/ecological” or “fisheries” goals were more likely than other project managers to collect monitoring measures. Although monitoring appears to be taking place in slightly more than half of the projects surveyed, the nature of the data collected varies widely across projects, and in most cases the monitoring effort is voluntary. This suggests that project sponsors, funders, and managers must consider the issues involved in requiring appropriate monitoring, establishing standardized monitoring guidelines, the time frames in which to monitor, providing other incentives for conducting monitoring, and ensuring adequate funding for monitoring efforts.     

Benefits to poorly studied taxa of conservation of bird and mammal diversity on islands

Protected area delineation and conservation action are urgently needed on marine islands, but the potential biodiversity benefits of these activities can be difficult to assess due to lack of species diversity information for lesser known taxa. We used linear mixed effects modeling and simple spatial analyses to investigate whether conservation activities based on the diversity of well‐known insular taxa (birds and mammals) are likely to also capture the diversity of lesser known taxa (reptiles, amphibians, vascular land plants, ants, land snails, butterflies, and tenebrionid beetles). We assembled total, threatened, and endemic diversity data for both well‐known and lesser known taxa and combined these with physical island biogeography characteristics for 1190 islands from 109 archipelagos. Among physical island biogeography factors, island area was the best indicator of diversity of both well‐known and little‐known taxa. Among taxonomic factors, total mammal species richness was the best indicator of total diversity of lesser known taxa, and the combination of threatened mammal and threatened bird diversity was the best indicator of lesser known endemic richness. The results of other intertaxon diversity comparisons were highly variable, however. Based on our results, we suggest that protecting islands above a certain minimum threshold area may be the most efficient use of conservation resources. For example, using our island database, if the threshold were set at 10 km² and the smallest 10% of islands greater than this threshold were protected, 119 islands would be protected. The islands would range in size from 10 to 29 km² and would include 268 lesser known species endemic to a single island, along with 11 bird and mammal species endemic to a single island. Our results suggest that for islands of equivalent size, prioritization based on total or threatened bird and mammal diversity may also capture opportunities to protect lesser known species endemic to islands. Beneficios de los Taxa Poco Estudiados para la Conservación de la Diversidad de Aves y Mamíferos en Islas     

Optimization of sampling strategy to determine pathogen removal efficacy of activated sludge treatment plant

Environmental Science and Pollution Research - Large-scale wastewater schemes rely on multi-barrier approach for the production of safe and sustainable recycled water. In multi-barrier wastewater...     

Definition of an airworthiness certification framework for civil unmanned aircraft systems

The development of effective safety regulations for unmanned aircraft systems (UAS) is an issue of paramount concern for industry. The development of this framework is a prerequisite for greater UAS access to civil airspace and, subsequently, the continued growth of the UAS industry. The direct use of the existing conventionally piloted aircraft (CPA) airworthiness certification framework for the regulation of UAS has a number of limitations. The objective of this paper is to present one possible approach for the structuring of airworthiness regulations for civilian UAS. The proposed approach facilitates a more systematic, objective and justifiable method for managing the spectrum of risk associated with the diversity of UAS and their potential operations. A risk matrix is used to guide the development of an airworthiness certification matrix (ACM). The ACM provides a structured categorisation that facilitates the future tailoring of regulations proportionate to the levels of risk associated with the operation of the UAS. As a result, an objective and traceable link may be established between mandated regulations and the overarching objective for an equivalent level of safety to CPA. The ACM also facilitates the systematic consideration of a range of technical and operational mitigation strategies. For these reasons, the ACM is proposed as a suitable method for the structuring of an airworthiness certification framework for civil or commercially operated UAS (i.e., the UAS equivalent in function to the Part 21 regulations for civil CPA) and for the further structuring of requirements on the operation of UAS in un-segregated airspace.     

Cryptic herbivores mediate the strength and form of ungulate impacts on a long-lived savanna tree

Plant populations are regulated by a diverse array of herbivores that impose demographic filters throughout their life cycle. Few studies, however, simultaneously quantify the impacts of multiple herbivore guilds on the lifetime performance or population growth rate of plants. In African savannas, large ungulates (such as elephants) are widely regarded as important drivers of woody plant population dynamics, while the potential impacts of smaller, more cryptic herbivores (such as rodents) have largely been ignored. We combined a large-scale ungulate exclusion experiment with a five-year manipulation of rodent densities to quantify the impacts of three herbivore guilds (wild ungulates, domestic cattle, and rodents) on all life stages of a widespread savanna tree. We utilized demographic modeling to reveal the overall role of each guild in regulating tree population dynamics, and to elucidate the importance of different demographic hurdles in driving population growth under contrasting consumer communities. We found that wild ungulates dramatically reduced population growth, shifting the population trajectory from increase to decline, but that the mechanisms driving these effects were strongly mediated by rodents. The impact of wild ungulates on population growth was predominantly driven by their negative effect on tree reproduction when rodents were excluded, and on adult tree survival when rodents were present. By limiting seedling survival, rodents also reduced population growth; however, this effect was strongly dampened where wild ungulates were present. We suggest that these complex interactions between disparate consumer guilds can have important consequences for the population demography of long-lived species, and that the effects of a single consumer group are often likely to vary dramatically depending on the larger community in which interactions are embedded.     

Impacts of Land‐Cover Change on Suspended Sediment Transport in Two Agricultural Watersheds1

Schilling, Keith E., Thomas M. Isenhart, Jason A. Palmer, Calvin F. Wolter, and Jean Spooner, 2011. Impacts of Land‐Cover Change on Suspended Sediment Transport in Two Agricultural Watersheds. Journal of the American Water Resources Association (JAWRA) 47(4):672‐686. DOI: 10.1111/j.1752‐1688.2011.00533.x Abstract: Suspended sediment is a major water quality problem, yet few monitoring studies have been of sufficient scale and duration to assess the effectiveness of land‐use change or conservation practice implementation at a watershed scale. Daily discharge and suspended sediment export from two 5,000‐ha watersheds in central Iowa were monitored over a 10‐year period (water years 1996‐2005). In Walnut Creek watershed, a large portion of land was converted from row crop to native prairie, whereas in Squaw Creek land use remained predominantly row crop agriculture. Suspended sediment loads were similar in both watersheds, exhibiting flashy behavior typical of incised channels. Modeling suggested that expected total soil erosion in Walnut Creek should have been reduced 46% relative to Squaw Creek due to changes in land use, yet measured suspended sediment loads showed no significant differences. Stream mapping indicated that Walnut Creek had three times more eroding streambank lengths than did Squaw Creek suggesting that streambank erosion dominated sediment sources in Walnut Creek and sheet and rill sources dominated sediment sources in Squaw Creek. Our results demonstrate that an accounting of all sources of sediment erosion and delivery is needed to characterize sediment reductions in watershed projects combined with long‐term, intensive monitoring and modeling to account for possible lag times in the manifestation of the benefits of conservation practices on water quality.