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Abrasion of tires on road surfaces leads to the formation of tire and road wear particles (TRWPs). Approximately 5.9 million tonnes/year of TRWPs are emitted globally, and 12–20% of emissions generated on roads are transmitted into surface waters, where they can release (i.e., leach) chemical compounds that adversely affect aquatic species. To better understand the ecological risk of TRWPs, an acute, probabilistic ecological risk assessment model was developed and applied. This was a screening-level, conceptual ecological risk assessment (ERA) based on secondary data from published scientific studies. The model was demonstrated using British Columbia (BC) Highway 97 (TRWP source) and Kalamalka Lake (receiving water) in Canada, considering two spatial scenarios with varied highway (HWY) lengths and lake volumes. TRWP-derived chemical leachates considered for ERA were aniline, anthracene (ANT), benzo(a)pyrene (B(a)P), fluoranthene (Fl), mercaptobenzothiazole (MBT), and zinc (Zn). An assumed 'total TRWP-derived leachate set' was also assessed, representing all compounds present in tire-derived leachate test solutions. The results indicated the risk to aquatic species in two spatial scenarios. In scenario 1, ecotoxicity risk was high from exposure to TRWP-derived zinc and the total TRWP-derived leachate set. Scenario 2 results indicated acute risk was high from all TRWP-derived chemicals examined, except MBT. This preliminary ecological risk screening provides an early signal that freshwater lakes adjacent to busy highways may be at risk from TRWP contamination, indicating a need for further research. This research is the first ERA of TRWPs in Canada, and the results and methodology provide a foundation for future research and solutions development. [Display omitted] • Tire and road wear particles (TRWPs) are a major source of micropolymer • Ecological risk assessment (ERA) was conducted to assess the risk of TRWPs. • Two scenarios were developed by considering lake spatial factors. • The risk quotients for both scenarios ranged from 4.3E-05 to 2.5E+02. • ERA results can assist in minimizing the impacts of TRWPs in surface waters. [ABSTRACT FROM AUTHOR]

• The urban densification is putting pressure on buried water infrastructure (BWI). • Sixty-two key performance indicators (PIs) were selected for the assessment. • A hybrid approach was adopted to aggregate the selected PIs. • An integrated level of service (ILOS) index was developed. • The ILOS index was applied to four municipalities within British Columbia, Canada. Buried water infrastructure (BWI) services (drinking water, wastewater, and stormwater) are vital for sustainable urban development, which can be impacted by increasing densification needs. This study aims to develop an integrated level of service (ILOS) index to evaluate the performance of BWI underneath the urban densification. Development of the ILOS index involved identifying and selecting key performance indicators (PIs) under the pre-defined criteria and objectives. Initially, eighty-four PIs were identified through comprehensive literature. These PIs were reduced to sixty-two, based on experts' judgment and feedback using three selection criteria and further grouped into a hierarchical structure. A hybrid approach of dynamic fuzzy cognitive maps and an ordered weighted average operator was adopted to aggregate PIs into the ILOS index using the bottom-up approach. The developed ILOS index was applied to four municipalities within British Columbia, Canada. The results show that all four municipalities need to significantly improve their BWI for sustainable growth and effective urban management. A sensitivity analysis was conducted to identify the most important PIs for the design of the ILOS index. Future research will be conducted to apply the proposed approach for better decision-making of growth scenarios, which will provide early warning changes in urban densification. [ABSTRACT FROM AUTHOR]

Urban densification has dominated the land uses and land covers which may jeopardize the quality of life and sustainable development. Moreover, urban densification process exerts stress on buried water infrastructure (BWI) performance. In this study, the need of predicting the change in urban densification and its subsequent impacts on BWI performance over time has drawn attention to conduct a temporal analysis. A hybrid approach was used to select the significant control performance indicators (CPIs) and conduct a temporal analysis. Eight scenarios were generated using the Canadian Council of the Ministers of the Environment Water Quality Index approach to address the change in drinking water quality. The proposed approach was implemented in a municipality of British Columbia, Canada, as a case study. The results showed a 40 % decrease in the BWI performance due to the urban areas have rapidly grown both in population and built-up areas over three decades. Furthermore, an ideal situation was assumed to show that the targeted service level (i.e., 0.5) can be achieved with 3 % to 5 % improvement in every five years of service level. These findings will assist the decision makers to understand the linkage between CPIs to maintain and achieve the required BWI performance. • Urban growth patterns and their impacts on buried water infrastructure (BWI) • Significant control performance indicators were selected using empirical models. • A hybrid approach coupled with water quality index is used for temporal analysis. • The proposed approach was applied to a municipality of British Columbia, Canada. • Over time, 40 % decrease was observed in BWI performance due to densification. [ABSTRACT FROM AUTHOR]

Sustainable built environment has been of interest to many stakeholders in the recent years. However, life cycle economic performance as one of the key dimensions of sustainability has not been sufficiently investigated for buildings constructed using off-site construction methods such as modular construction. This research has proposed a framework to benchmark the life cycle economic sustainability of single-family modular homes. First, suitable economic performance criteria were selected and suitable measurable economic performance indicators were developed under each criterion. A performance level function was established for each indicator by which all indicators can be calculated and presented by a normalized performance level that enables combining quantitative and qualitative indicators. Subsequently, a multi-criteria decision analysis-based methodology was employed to develop a set of economic sustainability indices at the criteria level and also at the overall economic sustainability performance level. To compare and contrast the developed indices of a given modular building with the performance of similar conventional buildings, suitable performance benchmarks scales were established using the data of the historical economic performances of conventional homes. To examine the application of the proposed framework, two case study modular homes in British Columbia, Canada were analyzed. The results showed that both benchmarking homes performed 'Excellent' with respect to the overall economic sustainability. However, improvements are required to enhance the economic performance with respect to a number of criteria. The proposed framework can assist the construction decision makers, developers, and contractors with making informed decisions on the selection of the construction method. Furthermore, it can be used to address the underperforming areas over the life cycle of a modular building, even if the decision on the construction method has already been made. [ABSTRACT FROM AUTHOR]

• A cradle-to-gate LCA is performed to investigate the environmental impacts due to construction of modular and conventional buildings. • An AHP-based framework is proposed to develop the environmental indices for the material production, construction, and cradle-to-gate phases. • The environmental impacts of construction of three conventional and modular homes in the Okanagan, British Columbia, Canada, are benchmarked. • A basis to create a benchmarking database for environmental performance of modular and conventional construction methods is provided. Traditional on-site and modular off-site methods are the main construction methods in the residential building sector. Regardless of different advantages and disadvantages offered by each of these two construction methods, the overall environmental trade-offs between them are still unclear. This paper applies a cradle-to-gate life cycle assessment (LCA) to benchmark the environmental performance of conventional and modular construction methods. To this end, three single-family buildings (one conventional and two modular) designed and constructed in the Okanagan, British Columbia, Canada, were used as representatives of typical houses built by on-site and off-site methods in the region. The required data such as raw materials, material and workforce transportation, and energy resources was collected from the corresponding homebuilders through a questionnaire survey. Then, the environmental impact measures such as global warming potential were calculated through LCA analyses. Subsequently, the calculated impact measures along with their importance weights were incorporated into an analytic hierarchy process (AHP) based framework to develop a set of environmental impact indices for the material production phase, the construction phase, and summation of these phases (i.e., cradle-to-gate). Furthermore, a sensitivity analysis was performed to eliminate the human subjectivity involved in AHP. Eventually, individual impact measures and also the developed impact indices were compared and contrasted between the benchmarking buildings. The analyses revealed that construction of the first modular building resulted less environmental impacts than the other two buildings. Nevertheless, the lowest environmental performance was due to the second modular building. This disclosed that none of the modular and conventional construction methods is the absolute option for environmentally friendly construction. However, implementation of strategies such as optimal designs and decrease in material and worker transportation of both modular and conventional building projects and increase in annual production of modular manufacturing centers can reduce the material and energy consumption and the subsequent environmental impacts. This paper also provides a basis to create a benchmarking database by adding future LCA studies for new modular and conventional building projects. [ABSTRACT FROM AUTHOR]

• Building-level hybrid RE systems support net-zero development goals and climate change mitigation. • Energy planning is multi-dimensional, and is affected by uncertainties. • A life cycle thinking based fuzzy decision support model is presented for identifying optimal hybrid building energy mix. • A combinatorial multi-objective optimisation was adopted considering the most viable RE technologies in the local market. • Solar PV and geothermal heating are the optimal residential energy choices for BC, under the selected case study scenario. The increasing concerns about the environmental and economic impacts of conventional centralised energy generation and fossil fuel usage have prompted an interest in renewable-based decentralised energy systems. Implementing such systems at building level can facilitate the development of net-zero energy buildings. Energy system planning is a multi-faceted problem that involves technical, economic, environmental, and social dimensions, and affects multiple stakeholders at different levels. A multi-objective optimisation approach is needed to identify the optimal energy choices at building level, while paying attention to stakeholder priorities and other constraints. The objective of this study is to develop a model to identify the optimal mix of renewable energy (RE) while also accounting for uncertainties, which can be integrated at building level with life cycle thinking. A framework was proposed for planning an optimised hybrid RE system at building level to support the net-zero development goals. The optimisation model was developed considering the objectives of minimising energy system cost, maximising operational cost savings, minimising the life cycle environmental impacts, and maximising the RE fraction. A combinatorial optimisation approach was adopted to reflect the practical engineering aspects of energy planning problems based on technologies available in the market. The developed framework was demonstrated through a case study conducted for an average multi-unit residential buildings (MURB) located in British Columbia, Canada. The results indicated that under the defined stakeholder priorities and constraints, ground source heat pumps and solar photovoltaics (PV) are the optimal energy choices for MURB, and the optimal energy system combination supplied 44% of the building's energy demand through RE. The findings will inform and guide community developers and other stakeholders with an interest in residential buildings, on the most suitable clean energy options for their building project during the pre-project planning stage. [ABSTRACT FROM AUTHOR]

• An integrated chemical hazard screening and indexing system was developed. • The existing chemical hazard screening and indexing approaches were discussed. • More than half of the assessed chemicals were screened into high hazard groups. • Individual hazard indexing systems could generate underestimated hazard results. Various chemicals used in hydraulic fracturing have raised environmental and human health (EHH) concerns regarding water resources contamination, leading to the transition towards the use of chemicals with minimum EHH hazards. Chemical hazard screening and indexing approaches have been used to measure the chemical hazard of hydraulic fracturing, and each approach is associated with inherent advantages and limitations. In this study, the two chemical hazard assessment approaches were discussed, and an integrated chemical hazard screening and indexing system was developed to combine the strengths of the two approaches. The integrated system was applied to assess the EHH hazards of representative hydraulic fracturing chemicals used in British Columbia, Canada. The hazard screening results showed that more than half of the ingredients and additives were classified into high hazard groups. Moreover, the integrated system generated more critical hazard assessment results than two hazard indexing systems, revealing that using the individual hazard indexing approach could result in underestimated EHH hazards for chemicals. The integrated system can significantly improve the data confidence levels of hazard assessment results compared to a previously developed indexing system. The integrated system can also help formulate fracturing fluids with low EHH hazards by identifying ingredients of high hazard concerns. [ABSTRACT FROM AUTHOR]

The ever-increasing anthropogenic greenhouse gas (GHG) emissions worldwide make it quite challenging to meet country-specific Nationally Determined Contributions (NDC) targets. Therefore, it is evident that the existing emissions abatement measures need to be taken a step further. Internationally Transferred Mitigation Outcomes (ITMOs) are allowed in Article 6.2 of the Paris Agreement as a cooperative approach to achieving NDC goals. There is a potential to create ITMOs between Canada and China by replacing coal use in China with British Columbia (BC)'s liquefied natural gas (LNG) supply. Replacing coal with LNG in energy generation applications is a promising approach to mitigate emissions. With global and national pressures to reduce emissions, China has created a market for LNG imports to cater to its rising natural gas (NG) consumption due to the coal-to-gas source switching strategy. However, the terms under Article 6.2 requires generated ITMOs to ensure environmental integrity, support sustainable development goals, and have a robust accounting system. Therefore, the current study aims to quantify the life cycle environmental outcomes of generating ITMOs by exporting LNG from BC to Chinese end-users while integrating uncertainties and to provide policy recommendations in adherence with the requirements of Article 6.2. Different LNG export scenarios were generated in the study and environmental impacts of each scenario were assessed and compared using a life cycle assessment (LCA) framework developed by the authors. Sensitivity and uncertainty analyses were conducted to understand the impacts created by the data uncertainties in the final result. By replacing conventional coal with NG, approximately 40–45% and 26%–32% emissions reductions can be obtainable for Chinese textile and chemical industries, respectively. The highest emissions reduction of approximately 60% was observed when coal is replaced with NG for district heating. The life cycle emissions (LCE) quantification framework provided in the study provides stakeholders with a systematic approach to determine the total GHG emissions and emissions reduction potential of different LNG export scenarios. [ABSTRACT FROM AUTHOR]

• Energy planning needs multi-objective decision making and uncertainty integration. • The most suitable planning methods needs to be identified for optimal outcomes. • The optimization models lead to similar results but different computational times. • When cost and impact uncertainty increases, suitability of renewables decreases. • Robust optimization technique has high potential when planning under uncertainty. Distributed energy systems renewable energy are one solution to the environmental and economic concerns of energy use. While energy planning and optimization have been conducted mainly as a mathematical exercise, practical approaches that incorporate the engineering realities and uncertainties are limited. Decision makers find challenges in community energy planning due to the lack of expertise, planning tools, and information. While a multitude of models and tools are currently available, there are no means of identifying the most appropriate or accurate methods, especially considering uncertainty. The main objective of this study is to compare and identify the strengths and limitations of various mathematical modelling techniques used in energy planning for grid connected renewable energy systems. As a case study demonstration, different multi-objective optimization techniques with and without uncertainty consideration (i.e. robust optimization, linear optimization, Taguchi Orthogonal Array method, and Monte Carlo simulation) were applied on a selected neighborhood in British Columbia. The optimization outcomes and the time and effort for evaluation were compared for the different methods. The findings indicate that robust optimization can be used to develop an uncertainty-based decision model. It significantly reduces evaluation time compared to the other methods. Although the presence of uncertainties can change the optimal configuration of a planned energy system, the assessment method itself does not significantly impact the outcomes. The findings of this study will enable the energy planners and researchers to compare different multi-objective optimization techniques, and to select the best for planning renewable energy projects, especially during the pre-project planning stage. [ABSTRACT FROM AUTHOR]

• Life cycle impacts of thermal desorption treatments of drill cuttings were assessed. • Thermomechanical cuttings cleaner generated the lowest impacts using hydropower. • Rotary drum dryer generated the lowest impacts in onsite drill cutting treatment. • Thermal desorption process contributed 80–90 % of the total impacts of systems. • Regression models were developed to help estimate impacts of different treatments. The life cycle impacts of treatment of typical oil-based drill cuttings (OBDCs) using three low-temperature thermal desorption (LTTD)-based systems, including thermomechanical cuttings cleaner (TCC), screw-type dryer (STD), and rotary drum dryer (RDD), were explored with a case study in British Columbia, Canada. Two energy supply scenarios, including diesel generator-based onsite (scenario i) and hydropower-based offsite (scenario ii) treatments, were considered in the assessment. The results show that RDD generated the lowest life cycle impacts in terms of damages to human health, ecosystems, and resources in scenario i. TCC-scenario ii generated the lowest impacts among all assessed cases, suggesting that using renewable energy can greatly reduce the impacts of LTTD-based OBDCs treatment. Also, net environmental benefits could be achieved considering the reuse of recovered oil, and the highest net environmental benefits were obtained in TCC-scenario ii. The process contribution analysis found that thermal desorption process accounted for 80–95 % of impacts in almost all impact categories. Energy consumption contours and linear regression models were also developed to help drilling waste managers estimate the life cycle impacts of using hydropower-driven TCC to treat OBDCs with different water and oil contents. [ABSTRACT FROM AUTHOR]

The building sector accounts for 40% of the energy use and one-third of the greenhouse gas (GHG) emissions globally. Buildings deteriorate with age, which leads to a decrease in their energy performance. Therefore, it is significant to improve the energy performance of aging building block although it is challenging. The two main decision paths for municipalities are renovation and reconstruction. This study investigated the above options for the older housing stock in a densely populated urban centre in British Columbia, Canada. A scenario-based analysis approach was taken to evaluate the life cycle GHG emissions of six different renovation and reconstruction scenarios. The total life cycle emissions were calculated for each scenario including the embodied and operational emission, and the emissions from building construction and maintenance. A BIM-LCA combined approach was used to assess the embodied GHG emissions with the SimaPro software. HOT2000 software was used to model the operational GHG emissions. The results show that in the reconstruction scenarios, around 40% of the emissions are from the material manufacturing stage. The embodied emissions generated from the reconstruction scenarios are 5–6 times higher than the renovation scenarios. The life cycle GHG emissions of the existing house can be reduced by applying renovations, with the emissions saving gradually increasing with the level of retrofitting. The passive house reconstruction scenario delivers the greatest benefit in terms of life cycle emissions reduction compared to all other scenarios. In terms of the GHG emission intensity per unit area, the newly-built houses in scenarios 5 and 6 also have lower life cycle GHG emission per square meter than the renovated existing houses in scenario 1–4 after 15 and 10 years to breakeven respectively. Based on this, it can be concluded that when considering the older existing building stock, a careful weighing of options must take place before making the decision on replacing them with new construction. However, it is also important to consider the economic and social aspects before making decisions to renovate or replace existing houses. The study outcomes will support city planners and urban development planners to make decisions on BC aging building stock development, especially in high population density neighbourhoods. • Renovation/replacement decision of aging building stock should consider lifecycle impacts. • A scenario-based approach was taken to assess overall GHG emissions of each decision for residential buildings. • Operational GHG emissions reduce with the extent of renovation while increase in embodied emissions. • The life cycle emissions of moderate to extensive renovations have similar outputs as the code-constructed new buildings. • Replacing older houses with new passive construction can significantly reduce life cycle emissions. [ABSTRACT FROM AUTHOR]

Recent studies have shown that Canada will not achieve its 2030 emission reduction targets outlined in the Paris Agreement. Canadian energy decision makers are now at a crossroad between making sound fiscal decisions and ramping up efforts to meet emission reduction commitments. Approximately 195,000 people are living in off-grid Canadian communities, with most of these communities relying on fossil-fuel based energy generation. Hybrid renewable energy systems provide a novel solution to address the high costs of off-grid energy and Canada's emission reduction targets. To address the competing stakeholder priorities in off-grid energy planning (e.g., economic, environmental, and system performance), the authors of this paper employed a generalizable combinatorial-based alternative ranking method. Alternative energy technology combinations were simulated to calculate key performance indicator values. The framework allows decision makers to identify the most feasible energy system based on their priorities. A case study was performed with the developed framework for a small off-grid community in British Columbia, Canada. The results show that feasibility of energy system configurations vary greatly based on differing decision-making priorities. The case study also confirmed that hybrid renewable energy systems have better environmental performance compared to their fossil fuel counter parts, but at a significantly higher cost. The study further confirms that the balance between environmental and economic performance of off-grid energy systems can be improved through proper component sizing, management practices, and the integration of energy storage. • Life cycle impacts need to be considered in off-grid hybrid renewable energy systems planning. • Hybrid renewable energy systems incur lower environmental impacts at higher costs. • Combining fossil fuel generators and battery banks reduces emissions at a lower cost. • Decision makers' priorities has a high impact in the ranking of energy system configurations. • The developed method accounts for different priorities in energy system feasibility assessment. [ABSTRACT FROM AUTHOR]