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Floodplain restoration as a means of stormwater management (SWM) can benefit communities and the environment but is uncommonly chosen due to limited familiarity in rural and urban planning. This study uses life cycle assessment and life cycle costing (LCC) to compare four SWM alternatives for a typical rural setting undergoing development. We evaluate a case study in Lancaster County, PA in the Chesapeake Bay Watershed which, through community stakeholder planning, undertook a novel SWM plan by restoring its historic floodplain. We evaluate the life cycle impact assessment (LCIA) metrics, global warming (GW), eutrophication and acidification and cost for each alternative over a 100‐year period of analysis including construction, maintenance, and end‐of‐life decommissioning. Assuming a 5% discount rate, and that soils do not require off‐site hauling due to contamination, the cost and LCIA metrics for floodplain restoration are not significantly higher than the more conventional surface basin alternative. Although LCC is highly sensitive to the transport of soil off‐site, more than doubling the costs for the underground stormwater infiltration basin (USIB) and increasing eightfold the cost for the floodplain restoration, contaminated soil removal is rarely needed on rural land. For USIB, LCIA metrics are sensitive to the choice of recycling versus incinerating plastic components, with recycling resulting in lower GW; and for the permeable pavement alternative, additional maintenance to extend its lifetime shows favorable cost and reduced GW. We conclude that in rural settings where soil is not contaminated, floodplain restoration offers environmental and social benefits for SWM that outweigh its costs. [ABSTRACT FROM AUTHOR]

Abstract: Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental “systems-level” decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required design life indicates that barrier replacement could increase its life cycle environmental impact above that of the cement barrier. [Copyright &y& Elsevier]

Low Impact Development (LID) is part of a new paradigm in urban water management that aims to decentralize water storage and movement functions within urban watersheds. LID strategies can restore ecosystem functions and reduce runoff loadings to municipal water pollution control facilities (WPCF). This research examines the avoided energy and greenhouse gas (GHG) emissions of select LID strategies using life cycle assessment (LCA) and a stochastic urban watershed model. We estimate annual energy savings and avoided GHG emissions of 7.3GJ and 0.4 metric tons, respectively, for a LID strategy implemented in a neighborhood in New York City. Annual savings are small compared to the energy and GHG intensity of the LID materials, resulting in slow environmental payback times. This preliminary analysis suggests that if implemented throughout an urban watershed, LID strategies may have important energy cost savings to WPCF, and can make progress towards reducing their carbon footprint. [Copyright &y& Elsevier]

Renewable and low carbon fuel standards being developed at federal and state levels require an estimation of the life cycle carbon intensity (LCCI) of candidate fuels that can substitute for gasoline, such as second generation bioethanol. Estimating the LCCI of such fuels with a high degree of confidence requires the use of probabilistic methods to account for known sources of uncertainty. We construct life cycle models for the bioconversion of agricultural residue (corn stover) and energy crops (switchgrass) and explicitly examine uncertainty using Monte Carlo simulation. Using statistical methods to identify significant model variables from public data sets and Aspen Plus chemical process models, we estimate stochastic life cycle greenhouse gas (GHG) emissions for the two feedstocks combined with two promising fuel conversion technologies. The approach can be generalized to other biofuel systems. Our results show potentially high and uncertain GHG emissions for switchgrass-ethanol due to uncertain CO2 flux from land use change and N2O flux from N fertilizer. However, corn stover-ethanol, with its low-in-magnitude, tight-in-spread LCCI distribution, shows considerable promise for reducing life cycle GHG emissions relative to gasoline and corn-ethanol. Coproducts are important for reducing the LCCI of all ethanol fuels we examine. [ABSTRACT FROM AUTHOR]

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• GHG impact and cost of alternative polymer materials compared for long-lived pipe assets. • LCA of recycled HDPE/nanoclay composite material compared with pristine polymer. • Pipe service life predictions from experiments integrated with stochastic LCA models. • Maintaining functional equivalency requires larger mass of polymer for recycled blends. • Bio-HDPE reduces costs and environmental impacts for long-lived pipe assets. High density polyethylene (HDPE) is a thermoplastic used in many engineering applications but one that imposes environmental burdens when produced and environmental costs at end-of-life (EOL). Replacing pristine HDPE with post-consumer recycled (PCR) HDPE or bio-based polymer (bio-HDPE) in long-lived goods could mitigate those impacts. We investigate cradle-to-gate and cradle-to-grave greenhouse gas (GHG) emissions and costs of four alternative resins, pristine HDPE, pristine/PCR HDPE, bio-HDPE and nanoclay-pristine/PCR HDPE composite, and their use in 100-year drainage pipe, respectively. We construct stochastic LCA models that combine service life prediction from experiments with parametric and scenario uncertainty modeling using Monte Carlo simulation and non-parametric bootstrapping. Results differ significantly on a resin versus pipe product basis owing to the functional unit requirement for meeting pipe service life, if governed by crystallinity and fracture energy, properties that call for greater quantities of material in recycled and nanoclay composite HDPE compared to pristine HDPE. The nanocomposite pipe has varying GHG emissions compared to all alternatives due to high mass requirement if assuming crystallinity and fracture energy govern failure, but this predicted mass may be reduced given that the nanoclay can prolong fracture time, which would reduce GHG emissions and pipe production cost. Despite a large GHG reduction relative to pristine HDPE, the bio-HDPE resin has the highest material production cost; however, considering life cycle costs, the incremental difference among all alternatives is small over a range of discount rates, rendering the bio-HDPE pipe a promising solution for addressing climate change in long-lived thermoplastic assets. [ABSTRACT FROM AUTHOR]

• Modelling and simulation of renewable diesel production from lignocellulose. • Cost analysis for renewable diesel production from biomass sorghum. • Preliminary evaluation of environmental metrics using LCA. Computer simulations are used to study the production of renewable diesel through the biochemical transformation of biomass sorghum Sorghum bicolor (L.) Moench] to free fatty acids using a genetically modified strain of Escherichia Coli. We evaluate select environmental and economic metrics using life cycle assessment (LCA) and techno-economic analysis (TEA). The biofuel supply chain includes feedstock production, handling, pretreatment and hydrolysis, fermentation to free fatty acids, saponification of the free fatty acids, wax production on an electrochemical synthesis reactor, and hydrocracking to convert the wax to renewable diesel. The TEA model developed uses experimental data from pretreatment to wax synthesis steps and literature for the conversion of wax to diesel. The TEA model is integrated into a life cycle inventory model to estimate life cycle greenhouse gas and non-renewable energy consumption. Considering both environmental and economic factors we find that the performance of this pathway to produce renewable diesel returns lower product yield, higher cost, and higher GHG and energy impacts compared to biomass-to-ethanol pathways, primarily due to poor process yields (mainly fermentation). This limitation in the metabolic pathway constrains the maximum yield potential of FFA and therefore renewable diesel and other potential co-products from biomass derived sugars. [ABSTRACT FROM AUTHOR]