Potential drinking water impacts from road salt storage facilities in Vermont’s Lake Champlain Basin

Use of deicing materials (road salt) in Vermont has increased in the past decades. Chemical constituents associated with deicing materials can potentially pose a risk to drinking water quality. While deicing materials applied to roads represent a distributed, ephemeral source of salts, deicing material storage facilities are a potential year-round source of materials that can impact drinking water wells. Prior to this project there was no existing spatial database of these facilities in Vermont’s Lake Champlain Basin. A database of deicing material storage facilities was created for this project, with the aim to make it publicly available in order to benefit numerous stakeholders, including the VT Department of Health, VT Department of Environmental Conservation, Vermont Agency of Natural Resources and the Vermont Open Geodata Portal, and Vermont Rural Water Association. This report (1) documents the locations and storage methods for municipal, as well as Vermont Agency of Transportation (VTrans) road salt and deicing material storage facilities in the Vermont portion of the Lake Champlain Basin and (2) analyzes these locations with respect to public and private drinking water wells. We also conducted an analysis to identify drinking water wells at parcels and schools hydrologically downgradient of the facilities and explored geospatial methods to evaluate whether these facilities pose a higher risk to vulnerable communities in the Lake Champlain Basin

Nutrient Leaching from Compost: Implications for Bioretention and Other Green Stormwater Infrastructure

This work is made available under the terms of the Creative Commons Attribution 4.0 International license,. Compost is often used as a soil amendment in gardens, agricultural fields, and other landscaped systems to alter soil biophysical characteristics and increase availability of valuable nutrients including nitrogen (N), phosphorus (P), and carbon (C). However, leaching of soluble nutrients from compost is of concern, particularly in wet settings, such as within green stormwater infrastructure, riparian areas, and floodplains. This research highlights the importance of saturation as an influencing factor on the nutrient leaching potential of different composts and compost-amended bioretention soils. Nutrient leaching potential was evaluated for five different compost types and two compost-amended bioretention soil mixes under increasing saturation durations, measured at 10 min, 1 day, 5 days, and 10 days of saturation. Results indicated significant increases in NH4+ concentrations in leachate for all composts and bioretention media from 10 min to 10 days. Over the same time period results showed decreases in NO3- concentrations in the leachate from all five composts, but an increase in NO3- concentration for one compost-amended bioretention media and no significant change in the other bioretention media. In response to increased saturation durations, PO43- concentrations in the leachate were found to significantly increase at each stage, from 10 min, to 1 day, to 5 days, to 10 days; overall there were higher PO43- concentrations in the leachate from the five composts than in the leachate from the two bioretention mixes

Now I See: Photovisualization to Support Agricultural Climate Adaptation

Published with license by Taylor & Francis Group, LLC. To remain viable, agricultural producers will need to adapt to changing climatic conditions in coming decades. Agricultural advisers play an important role in helping producers decide to adopt appropriate adaptation practices. Photovisualizations have the potential to complement currently utilized outreach and education strategies. This research uses a focus group approach to explore (1) whether photovisualizations can aid in decision-making about climate change adaptation, and (2) what characteristics of photovisualizations are most effective at conveying spatial aspects of adaptation practices. We found that photovisualizations generate rich discussions about ecological and economic effects as well as tradeoffs associated with climate adaptation practices. To have the greatest impact, photovisualizations should be used when producers are considering implementing high-cost or high-risk projects, when practices are likely to dramatically change the visual landscape, or when a practice is unfamiliar to a producer

Soil media CO\u3csub\u3e2\u3c/sub\u3e and N\u3csub\u3e2\u3c/sub\u3eO fluxes dynamics from sand-based roadside bioretention systems

Green stormwater infrastructure such as bioretention is commonly implemented in urban areas for stormwater quality improvements. Although bioretention systems\u27 soil media and vegetation have the potential to increase carbon (C) and nitrogen (N) storage for climate change mitigation, this storage potential has not been rigorously studied, and any analysis of it must consider the question of whether bioretention emits greenhouse gases to the atmosphere. We monitored eight roadside bioretention cells for CO2-C and N2O-N fluxes during two growing seasons (May through October) in Vermont, USA. C and N stocks in the soil media layers, microbes, and aboveground vegetation were also quantified to determine the overall C and N balance. Our bioretention cells contained three different treatments: plant species mix (high diversity versus low diversity), soil media (presence or absence of P-sorbent filter layer), and hydrologic (enhanced rainfall and runoff in some cells). CO2-C and N2O-N fluxes from all cells averaged 194 mg m-2 h-1 (range: 37 to 374 mg m-2 h-1) and 10 μg m-2 h-1 (range: -1100 to 330 μg m-2 h-1), respectively. There were no treatment-induced changes on gas fluxes. CO2-C fluxes were highly significantly correlated with soil temperature (R2 = 0.68, p \u3c 0.0001), while N2O-N fluxes were weakly correlated with temperature (R2 = 0.017, p = 0.04). Bioretention soil media contained the largest pool of total C and N (17122 g and 1236 g, respectively) when compared with vegetation and microbial pools. Microbial biomass C made up 14% (1936 g) of the total soil C in the upper 30 cm media layer. The total C and N sequestered by bioretention plants were 13,020 g and 320 g, respectively. After accounting for C and N losses via gas fluxes, the bioretention appeared to be a net sink for those nutrients. We also compared our bioretention gas fluxes to those from a variety of natural (i.e., grasslands and forests) and artificial (i.e., fertilized and irrigated or engineered) land-use types. We found bioretention fluxes to be in the mid-range among these land-use types, mostly likely due to organic matter (OM) influences on decomposition being similar to processes in natural systems

Effects of different soil media, vegetation, and hydrologic treatments on nutrient and sediment removal in roadside bioretention systems

Water quality performance of eight roadside bioretention cells in their third and fourth years of implementation were evaluated in Burlington, Vermont. Bioretention cells received varying treatments: (1) vegetation with high-diversity (7 species) and low-diversity plant mix (2 species); (2) proprietary SorbtiveMedia™ (SM) containing iron and aluminum oxide granules to enhance sorption capacity for phosphorus; and (3) enhanced rainfall and runoff (RR) to certain cells (including one with SM treatment) at three levels (15%, 20%, 60% more than their control counterparts), mimicking anticipated precipitation increases associated with climate change. A total of 121 storms across all cells were evaluated in 2015 and 2016 for total suspended solids (TSS), nitrate/nitrite-nitrogen (NOx), ortho-phosphorus (Ortho-P), total nitrogen (TN) and total phosphorus (TP). Heavy metals were also measured for a few storms, but in 2014 and 2015 only. Simultaneous measurements of flow rates and volumes allowed for evaluation of the cells’ hydraulic performances and estimation of pollutant load removal efficiencies and EMC reductions. Significant average reductions in effluent stormwater volumes (75%; range: 48–96%) and peak flows (91%; range: 86–96%) was reported, with 31% of the storms events (all less than 25.4 mm (1 in.), and one 39.4 mm (1.55 in.)) depth completely captured by bioretention cells. Influent TSS concentrations and event mean concentrations (EMCs) was mostly significantly reduced, and TSS loads were well retained by all bioretention cells (94%; range: 89–99%) irrespective of treatments, storm characteristics or seasonality. In contrast, nutrient removal was treatment-dependent, where the SM treatments consistently removed P concentrations, loads and EMCs, and sometimes N as well. The vegetation and RR treatments mostly exported nutrients to the effluent for those three metrics with varying significance. We attribute observed nutrient exports to the presence of excess compost in the soil media. Rainfall depth and peak inflow rate had consistently negative effects on all nutrient removal efficiencies from the bioretention cells likely by increasing pollutant mobilization. Seasonality followed by soil media presence, and antecedent dry period were other predictors significantly influencing removal efficiencies for some nutrient types. Results from the analysis will be useful to make bioretention designers aware of the hydrologic and other design factors that will be the most critical to the performance of the bioretention systems in response to interactive effects of climate change

Crowdsourced Delphis: Designing solutions to complex environmental problems with broad stakeholder participation

There is a well-established need for increased stakeholder participation in the generation of adaptive management approaches and specific solutions to complex environmental problems. However, integrating participant feedback into current science, research, and decision-making processes is challenging. This paper presents a novel approach that marries a rigorous Delphi method, borrowed from policy and organizational sciences, with contemporary “crowdsourcing” to address the complex problems of water pollution exacerbated by climate change in the Lake Champlain Basin. In an online Delphi forum that occurred over a six-week period during the Spring of 2014, fifty-three participants proposed and commented on adaptive solutions to address water quality in the context of climate change. In a follow up Multi-Stakeholder workshop, thirty-eight stakeholders participated in refining and synthesizing the results from the forum. To inform modeling and policy dialogue, the resulting list of interventions was analyzed by time horizon, domain, type of adaptation action, and priority level. The interventions suggested by stakeholders within the crowdsourcing forum have contributed to the current policy dialogue in Vermont including legislation to address phosphorus loading to Lake Champlain. This stakeholder approach strengthens traditional modeling scenario development to include solutions and priorities that have been collectively refined and vetted

Evaluation of nitrogen and phosphorus removal from a denitrifyingwoodchip bioreactor treatment system receiving silage bunker runoff

Leachate and storm-driven runoff from silage storage bunkers can degrade receiving water bodies if left untreated. This study evaluated a novel treatment system consisting of three treatment tanks with a moving-bed biofilm reactor and paired side-by-side denitrifying woodchip bioreactors for the ability to reduce influent nutrient mass loads. Flow-based samples were taken at four locations throughout the system, at the inflow to the first tank, outflow from the tanks prior to entering the woodchip bioreactors, and from the outflows of both bioreactors. Samples were analyzed for concentrations of nitrogen (N) and phosphorus (P) species. Inflow concentrations were reduced from the bioreactor outflows by an average of 35% for total N (TN) and 16% for total P (TP) concentrations on a storm event basis. The treatment system cumulatively removed 76% of the TN mass load, 71% of the nitrite + nitrate-N (NO2-+NO3--N) load, 26% of the TP mass load, and 19% of the soluble reactive P load, but was a source of ammonium-N, based on the monitoring of 16 storm events throughout 2019. While the system was effective, very low NO2-+NO3--N concentrations in the silage bunker runoff entered the bioreactors, which may have inhibited denitrification performance

Effects of skeletal streetscape design on perceived safety

It is important for planners and urban designers to understand how physical characteristics of urban streetscapes contribute to perceptions of them as safe, comfortable urban spaces. While urban design theory offers numerous suggestions for successful streetscapes there is meager empirical evidence of their effects. We suggest that this is largely due to precision and sample size limitations on audit-based physical design and human perception measurements. This paper overcomes these limitations by identifying a key set of streetscape skeleton design variables that can be efficiently measured using a GIS-based method. It then measures these variables on a large and diverse sample of streetscapes, and examines their relationship to crowdsourced perceived safety scores, a useful indicator of environmental comfort. Regression modeling indicates that factors related to streetscape enclosure have a substantial positive effect on perceived safety. These include street tree canopy, the number of buildings along a block, and the cross-sectional proportion-the ratio of building height to width across the street between building façades. Importantly, these streetscape-scale skeleton variables have greater effect than neighborhood-scale urban form and affluence measures that are commonly used to identify desirable urban environments. Planning practitioners can draw on our results to set priorities for urban forestry and design guidelines that shape the spatial proportions of streetscapes and their success as spaces that feel safe and comfortable for human users

From the household to watershed: A cross-scale analysis of residential intention to adopt green stormwater infrastructure

Improved stormwater management for the protection of water resources requires bottom-up stewardship from landowners, including adoption of Green Stormwater Infrastructure (GSI). We use a statewide survey of Vermont paired with a cross-scale and spatial analysis to evaluate the influence of interacting spatial, social, and physical factors on residential intention to adopt GSI across a complex social-ecological landscape. Specifically, we focus on how three GSI practices, (“rain garden (bio retention),” “infiltration trenches,” and “actively divert roof runoff to a rain barrel/lawn/garden instead of the street/sewer”) vary with barriers to adoption, and household attributes across stormwater contexts from the household to watershed scale. Private landowners, who may be motivated more by on-site and neighborhood stormwater problems, may gravitate toward practices like infiltration trenches compared with practices (e.g., rain gardens) perceived to serve stormwater function over larger areas. Diversion of roof runoff was found to be more likely to be a part of a larger assembly of green behaviors. Improved stormwater management outcomes at the watershed, town, neighborhood, and household levels depend on adaptive approaches and adjusting strategies along the rural-urban gradient, across the bio-physical landscape, and according to varying norms and institutional arrangements

Should I stay or should I go? Exit options within mixed systems of public and private health care finance

Mixed public–private finance is widespread in health care systems internationally. In one variant of mixed finance, some countries (e.g., Germany) allow eligible beneficiaries to fully exit from the public (social insurance) system and purchase private insurance. Using a controlled laboratory experiment, we empirically investigate the predictions of a political economy model of mixed systems of public and private finance with two types of exit: universal-exit, when all individuals can choose to exit the public system, and conditional-exit, when only individuals with an income at or above a threshold income level can choose to exit. We find that high-income individuals are less likely to exit under universal-exit than under conditional-exit, despite having the same incentive to exit in both treatments. Sensitivity treatments suggests that a number of factors may be at play in explaining this result, including learning effects, a priming effect and a framing effect, but that other-regarding preferences do not appear to be an important factor