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Quan Q.,Xian University of Technology | Dong L.,Xian University of Technology | Li J.K.,Xian University of Technology | Shen B.,Xian University of Technology | Jin C.X.,Environmental Consulting and Technology Inc.
Nature Environment and Pollution Technology | Year: 2014

To achieve more reasonable and effective treatment of urban stormwater, researchers proposed the Low Impact Development (LID) method, which is regarded as a sustainable solution. Studies have shown that the bio-retention system was effective in tackling urban runoff problems and was one of the most commonly used LID. In hydrologic modeling, DRAINMOD has a new application in bio-retention simulation. A model named Hydrologic Performance Tool (HyPer Tool) is proposed based on the output of DRAINMOD simulations on various bio-retention designs. This paper utilized HyPer Tool to simulate the bio-retention system in the urban road runoff in Xi'an, China with different rainfall conditions and characteristics. Meanwhile, this paper discussed and analysed the dynamic changes of pollutants and impurities during bio-retention system runoff purification in the four typical designs of HyPer Tool bio-retention ponds so as to provide an objective evaluation on bio-retention - an urban rainfall-flood management approach.

Parker J.,Environmental Consulting and Technology Inc. | Dawson M.,Sand Creek Consultants Inc. | Montle S.,Center for Community Progress
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2012

Chevy in the Hole, once the industrial heartbeat of Flint, MI, and the automotive industry, now consists of 130 acres of blighted urban riverfront surrounded by universities, schools, neighborhoods, and hospitals. The City of Flint is using a repertoire of mechanisms by which trees and vegetation can better environmental quality of soils and groundwater, commonly referred to as phytotechnologies, to build a foundation of reuse that cuts costs, recycles wastes, creates green space, protects the environment, and connects the community to this historical site. The basis for this specific project is to utilize trees as both a vehicle for bettering the overall environmental quality of a contaminated, underutilized urban riverfront Brownfield site and a foundation for a green habitat corridor connecting two major universities and stimulate redevelopment in the local neighborhoods. This is an abstract of a paper presented at the 106th AWMA Annual Conference and Exhibition (Chicago, IL 6/25-28/2013).

Kumar A.,Drexel University | Adak P.,Environmental Consulting and Technology Inc. | Gurian P.L.,Drexel University | Lockwood J.R.,RAND Corporation
Journal of Exposure Science and Environmental Epidemiology | Year: 2010

Although approximately 35 million people in the US obtain drinking water from domestic wells, few studies have investigated the risk of arsenic exposure from this source. In this paper arsenic concentrations were modeled for public and domestic wells using a dataset from the US Geological Survey (USGS). Excess lifetime and annual risks for lung and bladder cancer were calculated based on the carcinogenic potency and average arsenic concentrations in public and domestic water supplies. Monte Carlo uncertainty analysis was used to estimate the degree of confidence in these estimations. Results indicated that domestic well users accounted for 12% of the US population, but 23% of overall arsenic exposure from drinking water. Assuming that the new and more restrictive arsenic maximum contaminant limit (MCL) is implemented for public water supplies, it is anticipated that the proportion of people experiencing excess annual fatalities from drinking water from domestic wells will increase to 29% unless corresponding efforts are made to reduce exposures among domestic well users. Differences between public and domestic wells were not consistent across the nation. Public wells tend to tap deeper aquifers than domestic wells, and as a result local arsenic-depth trends can contribute to differences between public and domestic wells. Domestic wells and public wells in the western US have the highest arsenic levels with excess fatality risks estimated to be in the range of 1 per 9300 to 1 per 6600 in these regions. Uncertainty distributions of excess fatalities were developed and resultant uncertainties were propagated in arsenic exposure and potency factor. Uncertainty in the carcinogenic potency of arsenic was the dominant source of uncertainty in most regions, but for domestic wells in the New England and Southeast regions uncertainty in arsenic exposure was dominant, indicating that additional data on arsenic concentrations in these areas would substantially improve regional risk estimates. © 2010 Nature Publishing Group All rights reserved.

Zhang J.,Capital Normal University | Said A.,Environmental Consulting and Technology Inc. | Ross M.,University of South Florida
Journal of Irrigation and Drainage Engineering | Year: 2010

Hydrologic model calibration is always a challenging and tedious process especially for the calibration of complex models, which includes continuous hydrograph models, requires sophisticated calibration methods. The Hydrologic Simulation Program-FORTRAN (HSPF) is one of the popular and powerful time variable hydrologic models. However, in order to improve the assessment of hydrologic activities in shallow ground water settings, the model needs to be reliably calibrated for ground water contribution. Little guidance is provided in the literature concerning the manner of this contribution. In fact, the most common calibration of HSPF uses subjective parameter fitting and focuses on the attainment of statistical goodness of fit of runoff fluxes and water levels, ignoring ground water components. The goal of this research is using a different approach to calibrate HSPF with observed water table records. In this study, HSPF is applied on a small area in west-central Florida and calibrated by comparing active ground water storage to well elevation records in range land and forested land covers. The Nash-Sutcliffe efficiency and correlation coefficient computed using observed and simulated daily flows are 0.91 and 0.96 at Peace River, respectively, also with good fair results for other stations in the model domain. The study shows that improved calibration of the model can be achieved if active ground water storage and well records are compared for timing and magnitude of fluctuations. © 2010 ASCE.

Zeng J.,South Florida Water Management District | Zhang L.,South Florida Water Management District | Deaton L.,South Florida Water Management District | Damisse E.,South Florida Water Management District | And 2 more authors.
World Environmental and Water Resources Congress 2011: Bearing Knowledge for Sustainability - Proceedings of the 2011 World Environmental and Water Resources Congress | Year: 2011

Lack of field flow measurements is an obstacle to flow rating at structures, especially for complex hydraulic structures, specifically when they experience extremely high or low flow conditions. This paper investigates the feasibility of using the Computational Fluid Dynamic (CFD) simulated flow data for spillway and culvert rating where the field-measured flow data is inadequate or unavailable. Compared to field-measured flow, the CFD-computed flow data has proven to be accurate and reliable for both ogee spillways and box culverts flow rating. This paper also presents an example of applying CFD-computed discharge data to improve rating for a complex hydraulic structure without field flow measurements. This study demonstrates that CFD simulations are able to offer cost-effective supplement to the field measurements for flow rating at the prototype spillway, culvert and complex hydraulic structure. © 2011 ASCE.

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