C. Scott SmithSmith, C. Scott, Raul P. Lejano, Oladele Ogunseitan, and J. Aaron Hipp. 2007. Cost Effectiveness of Regulation-Compliant Filtration to Control Sediment and Metal Pollution in Urban Runoff. Environmental Science & Technology 41(21) 7451-7458. Abstract
Hipp, J. Aaron, Oladele Ogunseitan, Raul Lejano, and C. Scott Smith. 2006. Optimization of Stormwater Filtration at the Urban/Watershed Interface. Environmental Science & Technology 40 (15):4794-4801. Abstract
Lejano, Raul P., and C. Scott Smith. 2006. Incompatible Land Uses and the Topology of Cumulative Risk. Environmental Management 37 (2):230-246. Abstract
Boarnet, Marlon G., C. Scott Smith, and K. S. Nesamani. 2003. Comparing the Influence of Land Use on Nonwork Trip Generation and Vehicle Distance Traveled: An Analysis using Travel Diary Data. In Center for Activity Systems Analysis. Irvine, CA: Institute for Transportation Studies. Abstract
Smith, C. Scott. 2003. Modeling opportunity: Employment accessibility and the economic performance of metropolitan Phoenix neighborhoods. In Integrated Land Use and Environmental Models, edited by: S. Guhathakurta.
Bolin, B., A. Nelson, E. J. Hackett, K. D. Pijawka, C. Scott Smith, D. Sicotte, E. K. Sadalla and E. Matranga. 2002. The ecology of technological risk in a Sunbelt city. Environment and Planning A. Volume 34, (2), pages 317-339. Abstract
Morrison Institute for Public Policy. 2000. Hits and misses: Fast growth in metropolitan Phoenix. School of Public Affairs, College of Public Programs, Arizona State University, Tempe, AZ.
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Publications
Smith, C. Scott, Raul P. Lejano, Oladele Ogunseitan, and J. Aaron Hipp. 2007. Cost Effectiveness of Regulation-Compliant Filtration to Control Sediment and Metal Pollution in Urban Runoff. Environmental Science & Technology 41(21) 7451-7458.
Environmental pollution from cities is a major ecological problem attributed to contaminated runoff from nonpoint sources. The U.S. Environmental Protection Agency’s guidance on implementation of total maximum daily loads (TMDL) does not adequately cover methods to improve waters impaired by nonpoint sources. To comply with TMDLs, cities may install filters in curb inlets, or use other Best Management Practices (BMPs). We tested 10 different filters and found their effectiveness in retaining pollutants ranged from 0 to >90%, depending on combinations of pollutant types (metals, pathogens, and total suspended sediments (TSS)) and filter materials. Hence, the decision to deploy filters into curb inlets must consider land use patterns associated with specific categories of pollutants generated within cities. We developed a geographic information system (GIS)-enabled model for estimating and mitigating emissions of pollutants from urban regions into watersheds. The model uses land use categories and pollutant loadings to optimize strategic placement of filters to accommodate TMDLs. For example, in a city where the landuse pattern generates 4 106 kg of TSS, 55 kg of Cd, and 2 103 kg of Zn per year into 498 curb inlets that discharge into a sensitive watershed, the optimized placement of 137, 92, and 148 filters can achieve TMDL endpoints for each pollutant, respectively. We show further that 158 strategically placed filters effectively meet the requirements simultaneously for all three pollutants, a result at least 5 times more effective than random placement of filters.
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Hipp, J. Aaron, Oladele Ogunseitan, Raul Lejano, and C. Scott Smith. 2006. Optimization of Stormwater Filtration at the Urban/Watershed Interface. Environmental Science & Technology 40 (15):4794-4801.
The implementation of Total Maximum Daily Load (TMDL) to control urban runoff presents major structural and managerial challenges for cities. We developed a decision support system (DSS) for TMDL compliance at the city level to solve for a phased, least-cost strategy toward meeting four TMDLs using stormwater filtration. Based on a case-study city, we modeled wet weather flows and associated discharge of Total Suspended Sediment (TSS), cadmium, copper, and zinc to receiving waters by coupling U.S. EPA’s Storm Water Management Model (SWMM v. 5.0) with the geographic dataset of the urban drainage network. We linked a mixed integer linear programming algorithm to the watershed model for deriving cost-effective selection and placement of curb inlet filters to meet mass- and concentration-based TMDL requirements. The least cost solution for meeting the city’s TMDL waste load allocations for TSS (73.9% reduction), Cd (50.6% reduction), Cu (30.0% reduction), and Zn (55.7% reduction) would require 1071 filter inserts at a cost of $1.7 million. In contrast, random placement of 1071 filters or uniform placement of 1266 filters is effective only for TSS and would cost $4.0 million and $4.8 million, respectively. Our results demonstrate the increases in cost-effectiveness of using an optimization-based DSS for urban watershed management.
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Lejano, Raul P., and C. Scott Smith. 2006. Incompatible Land Uses and the Topology of Cumulative Risk. Environmental Management 37 (2):230-246.
The extensive literature on environmental justice has, by now, well defined the essential ingredients of cumulative risk, namely, incompatible land uses and vulnerability. Most problematic is the case when risk is produced by a large aggregation of small sources of air toxics. In this article, we test these notions in an area of Southern California, Southeast Los Angeles (SELA), which has come to be known as Asthmatown. Developing a rapid risk mapping protocol, we scan the neighborhood for small potential sources of air toxics and find, literally, hundreds of small point sources within a 2-mile radius, interspersed with residences. We also map the estimated cancer risks and noncancer hazard indices across the landscape. We find that, indeed, such large aggregations of even small, nondominant sources of air toxics can produce markedly elevated levels of risk. In this study, the risk profiles show additional cancer risks of up to 800 in a million and noncancer hazard indices of up to 200 in SELA due to the agglomeration of small point sources. This is significant (for example, estimates of the average regional point-source-related cancer risk range from 125 to 200 in a million). Most importantly, if we were to talk about the risk contour as if they were geological structures, we would observe not only a handful of distinct peaks, but a general ``mountain range'' running all throughout the study area, which underscores the ubiquity of risk in SELA. Just as cumulative risk has deeply embedded itself into the fabric of the place, so, too, must intervention seek to embed strategies into the institutions and practices of SELA. This has implications for advocacy, as seen in a recently initiated participatory action research project aimed at building health research capacities into the community in keeping with an ethic of care.
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Boarnet, Marlon G., C. Scott Smith, and K. S. Nesamani. 2003. Comparing the Influence of Land Use on Nonwork Trip Generation and Vehicle Distance Traveled: An Analysis using Travel Diary Data. In Center for Activity Systems Analysis. Irvine, CA: Institute for Transportation Studies.
This study uses two-day travel diary data to examine whether land use matters more for an individual’s total vehicle miles traveled (VMT). More specifi-cally, sociodemographic, land use, and street connectivity variables are used to estimate nonwork trip frequency and nonwork vehicle miles traveled via ordered probit and ordinary least-squares regression models. We compare standardized coecients of the models and conclude that: (1) the influence of land use variables is similar in both the trip generation and VMT regressions; and (2) income is the primary determinant of both trip frequency and VMT, but that land use exerts an influence that is on par with other sociodemographic characteristics after the primary role of income is considered.
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Bolin, B., A. Nelson, E. J. Hackett, K. D. Pijawka, C. Scott Smith, D. Sicotte, E. K. Sadalla and E. Matranga. 2002. The ecology of technological risk in a Sunbelt city. Environment and Planning A. Volume 34, (2), pages 317-339.
In this paper we examine the spatial distributions of four types of technological hazards in the Phoenix, Arizona, metropolitan area. The focus is on the locations of hazardous industrial and toxic waste sites in relation to the demographic composition of adjacent neighborhoods. Our interest is to determine whether hazardous sites, including industrial facilities in the EPA's Toxic Release Inventory, Large Quantity Generators of hazardous wastes, Treatment, Storage, and Disposal Facili-ties, and federally identified contamination sites, are disproportionately located in areas with lower income and minority residents. We examine patterns of environmental inequity in Phoenix, a sprawl-ing Sunbelt city with a growing post-Fordist industrial sector. First, using 1996 EPA data for four types of technological hazards, and 1995 Special Census data for Maricopa County, we employ a GIS to map the spatial distributions of hazardous sites and to analyze the demographic characteristics of census tracts with and without point-source hazards. A second methodology is used to produce a cumulative hazard density index for census tracts, based on the number of hazard zonesöone-mile-radius circles around each facilityöthat overlay each tract. Both methodologies disclose clear patterns of social inequities in the distribution of technological hazards. The cumulative hazard density index provides a spatially sensitive methodology that reveals the disproportionate distribution of risk burdens in urban census tracts. The findings point to a consistent pattern of environmental injustice by class and race across a range of technological hazards in the Phoenix metropolitan region.
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