Understanding stewardship behaviour: factors facilitating and constraining private water well stewardship

Regulatory frameworks to ensure municipal drinking water safety exist in most North American jurisdictions. However, similar protection is rarely provided to people reliant on water provided from private wells. In Canada, approximately 4 million people depend on privately owned, domestic wells for their drinking water. Numerous studies have shown that people who rely on private wells for their water supplies are at risk from nitrate and bacterial contamination. Given the fact that regulations relating to private wells tend to be weak or poorly enforced, actions taken by well owners to protect their own drinking water safety are extremely important. Drawing on one of the largest and most comprehensive surveys of private well owners ever conducted in Canada or elsewhere, this paper explores factors that influence well owner stewardship behaviour. Key behaviours examined included annual testing of well water and inspection of wells, measures to protect water quality, and proper decommissioning of unused wells. A geographically-stratified survey, sent to 4950 well owners in Ontario, Canada, resulted in an effective response rate of 34% (n = 1567). Logistic regression analyses revealed that motivations for well stewardship behaviours included reassurance, the perception of problems, and knowledge of the environment. Knowing how to perform stewardship behaviours was an important antecedent to action. Barriers to stewardship included complacency, inconvenience, ignorance, cost, and privacy concerns. To promote stewardship, local initiatives, better educational materials, and enforcement through real estate laws are all required. Ultimately, drinking water safety for people reliant on private wells is shown to be a responsibility shared by governments and private well owners.     

Inspiring England's urban fringes: multi-functionality and planning

The urban fringe has been described as 'planning's last frontier'; a zone of transition and interface between town and country where a broad variety of land uses and activities come together, and where development pressure is often intense. In this paper, we argue that the urban fringe possesses special characteristics, making it more than simply a transitional landscape. These characteristics centre on patterns of land use, biodiversity and leisure/development opportunity which are unique to the urban edge and to land extending away from built-up areas. The uniqueness, diversity and particular dynamics of the urban fringe demands a special brand of planning and management response. Therefore we suggest that the principle of 'multi-functionality' provides a framework for action, showing how diversity can be managed and supported. Through brief case studies, we demonstrate how functional interactions at the urban fringe might be promoted in the future.     

Comparison of selected non-exhaustive extraction techniques to assess PAH availability in dissimilar soils

Recently, it has become apparent that the use of total contaminant concentrations as a measure of potential contaminant exposure to plants or soil organisms is inappropriate and that bioavailability of contaminants is a better measure of potential exposure. In light of this, non-exhaustive extraction techniques are being investigated to assess their appropriateness in determining bioavailability. In this study, phenanthrene extractability using hydroxypropyl-beta-cyclodextrin (HPCD) and desorption kinetics using butan-1-ol (BuOH) were determined in three dissimilar spiked soils. The soils were extracted after 1 d, 40 d and 80 d of soil-compound contact time. The amount of phenanthrene extracted by HPCD was compared to the rapidly desorbed fraction removed by BuOH. Further experiments using the same soils and extraction methods to assess the relative extractability of phenanthrene, pyrene and benzo(a)pyrene were conducted. Overall, the extraction methods used in this study had different extraction efficiencies. Results suggest that as compound hydrophobicity increased, BuOH became a more exhaustive extractant with respect to HPCD, especially for soils with high clay and organic matter content. These results are important as they highlight differences between two contrasting non-exhaustive extraction techniques both of which have been suggested to be appropriate in the assessment of bioavailability.     

Influence of diesel concentration on the fate of phenanthrene in soil

The aim of this study was to investigate the influence of diesel on the loss and bioavailability of soil-associated [14C]phenanthrene with time. In addition, the temporal development of phenanthrene catabolic activity and the impact of co-contaminant mixtures on the soil microflora were also assessed. With respect to compound fate, the results suggested that competitive effects between dissimilar co-contaminants did influence [14C]phenanthrene loss. Where diesel was present at a concentration of 0, 20, 200 and 2000 mg kg(-1), increased phenanthrene loss was observed with increasing diesel concentrations. In the 20,000 mg kg(-1) diesel treatment, however, a significantly higher amount of the initial [14C]activity remained after 225 days. Furthermore, initial degradation of phenanthrene in this treatment was retarded as a result of repressed phenanthrene catabolic activity. These results were complemented by a 4-fold increase in total culturable bacterial cell numbers in the 20,000 mg kg(-1) treatment when compared with the 2000 mg kg(-1) after 225 days of incubation time.