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Carlsbad, CA, United States

Goldenhersh L.E.,Enviance
Pollution Engineering | Year: 2010

The EPA has introduced greenhouse gas (GHG) reporting rule in the US with the objective to reduce emissions, which ensures the growth in the environmental consulting industry. Safe management of GHGs requires a centralized software system that operationalizes the cost-effective air emissions management practices such as sound data collection and validation protocols, facility-based task management and trend management. The software employed to comply with the GHG reporting rule ensures the accurate differentiation between SF6 and CO2. The senior management while complying with the GHG reporting rule focus on the cost, complexity and schedule for installation of a system in order to meet the requirements of the rule. The environmental engineering expertise in a company needs to identify the sources of GHG in the industrial process and define appropriate data collection, data validation, task management and reporting protocols for the efficient tracking of the GHGs. Source

Xue X.,Oak Ridge Institute for Science and Education | Hawkins T.R.,U.S. Environmental Protection Agency | Hawkins T.R.,Enviance | Ingwersen W.W.,U.S. Environmental Protection Agency | Smith R.L.,U.S. Environmental Protection Agency
International Journal of Life Cycle Assessment | Year: 2015

Purpose: This study demonstrates an approach to assess human health and ecotoxicity impacts of pesticide use by including multiple environmental pathways and various exposure routes using the case of corn grown for bio-based fuel or chemical production in US Midwestern states. Methods: Multiple tools including an environmental emission model (PestLCI), an impact analysis tool (USEtox), and additional databases were utilized to estimate the state-specific pesticide releases and their associated spatially explicit toxicity in Midwest states. Results and discussion: On average, chlorpyrifos and acetochlor exhibit the highest human toxicity potential (HTP) and the highest ecotoxicity potential (ETP) impact scores, respectively. The different ranking orders of pesticides for human health and ecosystem toxicity suggest that there are tradeoffs between these two impact categories. While the air pathway can account for 10–97 % of HTP, the water pathway is the dominating contributor for ETP for most of the pesticides. Moreover, while chlorpyrifos, fipronil, 2,4-d-2-ethylhexyl ester, simazine, and glufosinate–ammonium together account for more than 80 % of HTP per kilogram harvested corn, acetochlor is the dominating contributor in ETP due to its high ecotoxicity characterization factor and high application rates for corn. In addition, the spatial variation analysis shows that South Dakota and Missouri are the states that have the highest HTP (per kg corn), while Kansas exhibits the highest ETP (per kg corn) among Midwest states. Conclusions: HTP and ETP exhibit large variations across various pesticides, US states, and application times. While chemical properties and toxicity characteristics can result in up to five orders of magnitude of variation in HTP and ETP, the rest of the parameters (such as application times, soil properties, and climate conditions) can affect the results by up to two orders of magnitude. © 2015, Springer-Verlag (outside the USA). Source

Vineyard D.,U.S. Environmental Protection Agency | Ingwersen W.W.,U.S. Environmental Protection Agency | Hawkins T.R.,Enviance | Xue X.,U.S. Environmental Protection Agency | And 2 more authors.
Journal of the American Water Resources Association | Year: 2015

Green infrastructure (GI) is quickly gaining ground as a less costly, greener alternative to traditional methods of stormwater management. One popular form of GI is the use of rain gardens to capture and treat stormwater. We used life cycle assessment (LCA) to compare environmental impacts of residential rain gardens constructed in the Shepherd's Creek watershed of Cincinnati, Ohio to those from a typical detain and treat system. LCA is an internationally standardized framework for analyzing the potential environmental performance of a product or service by including all stages in its life cycle, including material extraction, manufacturing, use, and disposal. Complementary to the life cycle environmental impact assessment, the life cycle costing approach was adopted to compare the equivalent annual costs of each of these systems. These analyses were supplemented by modeling alternative scenarios to capture the variability in implementing a GI strategy. Our LCA models suggest rain garden costs and impacts are determined by labor requirement; the traditional alternative's impacts are determined largely by the efficiency of wastewater treatment, while costs are determined by the expense of tunnel construction. Gardens were found to be the favorable option, both financially (~42% cost reduction) and environmentally (62-98% impact reduction). Wastewater utilities may find significant life cycle cost and environmental impact reductions in implementing a rain garden plan. © 2015 American Water Resources Association. Source

Xue X.,Albany State University | Hawkins T.R.,Enviance | Schoen M.E.,Soller Environmental LLC | Garland J.,U.S. Environmental Protection Agency | Ashbolt N.J.,University of Alberta
Water (Switzerland) | Year: 2016

Abstract: Managing the water-energy-nutrient nexus for the built environment requires, in part, a full system analysis of energy consumption, global warming and eutrophication potentials of municipal water services. As an example, we evaluated the life cycle energy use, greenhouse gas (GHG) emissions and aqueous nutrient releases of the whole anthropogenic municipal water cycle starting from raw water extraction to wastewater treatment and reuse/discharge for five municipal water and wastewater systems. The assessed options included conventional centralized services and four alternative options following the principles of source-separation and water fit-for-purpose. The comparative life cycle assessment identified that centralized drinking water supply coupled with blackwater energy recovery and on-site greywater treatment and reuse was the most energyand carbon-efficient water service system evaluated, while the conventional (drinking water and sewerage) centralized system ranked as the most energy- and carbon-intensive system. The electricity generated from blackwater and food residuals co-digestion was estimated to offset at least 40% of life cycle energy consumption for water/waste services. The dry composting toilet option demonstrated the lowest life cycle eutrophication potential. The nutrients in wastewater effluent are the dominating contributors for the eutrophication potential for the assessed system configurations. Among the parameters for which variability and sensitivity were evaluated, the carbon intensity of the local electricity grid and the efficiency of electricity production by the co-digestion with the energy recovery process were the most important for determining the relative global warming potential results. © 2016 by the authors. Source

Lee S.-J.,University of Michigan-Flint | Hawkins T.R.,Enviance | Ingwersen W.W.,EPA | Young D.M.,Chemical Safety for Sustainability
Journal of Industrial Ecology | Year: 2015

Ecological footprint (EF) is a metric that estimates human consumption of biological resources and products, along with generation of waste greenhouse gas (GHG) emissions in terms of appropriated productive land. There is an opportunity to better characterize land occupation and effects on the carbon cycle in life cycle assessment (LCA) models using EF concepts. Both LCA and EF may benefit from the merging of approaches commonly used separately by practitioners of these two methods. However, few studies have compared or integrated EF with LCA. The focus of this research was to explore methods for improving the characterization of land occupation within LCA by considering the EF method, either as a complementary tool or impact assessment method. Biofuels provide an interesting subject for application of EF in the LCA context because two of the most important issues surrounding biofuels are land occupation (changes, availability, and so on) and GHG balances, two of the impacts that EF is able to capture. We apply EF to existing fuel LCA land occupation and emissions data and project EF for future scenarios for U.S. transportation fuels. We find that LCA studies can benefit from lessons learned in EF about appropriately modeling productive land occupation and facilitating clear communication of meaningful results, but find limitations to the EF in the LCA context that demand refinement and recommend that EF always be used along with other indicators and metrics in product-level assessments. © 2015, Yale University. Source

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