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DeForest D.K.,Windward | Gensemer R.W.,GEI Consultants | Van Genderen E.J.,ZINC Inc | Gorsuch J.W.,Copper Development Association Inc
Integrated Environmental Assessment and Management | Year: 2011

Copper (Cu) can impair olfaction in juvenile Pacific salmon (as well as other fishes), thus potentially inhibiting the ability of juveniles to avoid predators or to find food. Because Cu is commonly elevated in stormwater runoff in urban environments, storm events may result in elevated Cu concentrations in salmon-bearing streams. Accordingly, there is concern that existing Cu criteria, which were not derived using data for olfactory-related endpoints, maynot be adequately protective of juvenile salmon. However, a modification of the US Environmental Protection Agency (USEPA) biotic ligand model (BLM) for deriving site-specific Cu criteria was recently proposed, which accounted for the sensitivity of olfactory endpoints. The modification was based on olfactory inhibition in juvenile coho salmon (Oncorhynchus kisutch) exposed to Cu in various combinations of pH, hardness, alkalinity, and dissolved organic carbon (DOC) concentrations. We used that olfactory-based BLM to derive 20% inhibition concentrations (IC20) values for Cu for 133 stream locations in the western United States. The olfactory BLM-based IC20 values were compared to the existing hardness-based Cu criteria and the USEPA's BLM-based Cu criteria for these representative natural waters of the western United States. Of the 133 sampling locations, mean hardness-dependent acute and chronic Cu criteria were below the mean olfactory-based BLM IC20 value in 122 (92%) and 129 (97%) of the waters, respectively (i.e.,<20% olfactory impairment would have been predicted at the mean hardness-based Cu criteria concentrations).Waters characterized by a combination of high hardness and very low DOC were most likely to have hardness-based Cu criteria that were higher than the olfactory-based BLM IC20 values, because DOC strongly influences Cu bioavailability in the BLM. In all waters, the USEPA's current BLM-based criteria were below the mean olfactory-based BLM IC20 values, indicating that the USEPA's BLM-based criteria are protective of olfactory impairment in juvenile salmon. © 2011 SETAC. Source


Dela Cruz R.,Southern California Edison | Blevins B.,Southern California Edison | Karam C.,GEI Consultants
Association of State Dam Safety Officials, Dam Safety 2015 | Year: 2015

As dams across the United States are ageing, the risk of failure increases. Failures continue to happen due to natural and man-made events. When a failure occurs, it can be impossible to recover from. According to the Insurance Information Institute, up 40% of businesses affected by a natural or human-caused disaster never reopen. While there are programs at both Federal and State levels of government to help ensure the continuous safe operation of dams, it is important that a dam owner takes a holistic approach to Dam Safety Emergency Management and develop a program that will prevent and protect dams from all hazards that threaten them, as well as, ensure that the owner and community are fully able to respond to, and recover from, any incident that may occur. A comprehensive Dam Safety Emergency Management Program should include the five components of emergency preparedness as established by the Federal Emergency Management Association (FEMA). These components are prevention, protection, mitigation, response, and recovery. How much should be invested in an emergency program depends upon many factors such as regulatory requirements, business design, and how much risk a business is willing to tolerate. Since not all risk can be insured, an emergency program is a good way to manage those risks. One way to quickly buy down risk is to invest in improving a dam owner's Situational awareness. The U.S. Coast Guard defines situational awareness as "the ability to identify, process, and comprehend the critical elements of information about what is happening. More simply, it's knowing what is going on around you." Having improved situational awareness will reduce the time it makes to make a decision, improve the accuracy of that decision, and ensure that whatever strategies are being made before, during, or after an emergency event are made taking into account all the information at hand. Because of the importance of situational awareness when managing dams in remote locations across an expansive region, Southern California Edison (SCE) has developed on a pilot platform called a " Dam Information Management System" (DIMS), a web-based information sharing system that integrates available data from stakeholders and multiple emergency management partners to enable processing and displays of real-time disaster related data. DIMS will serve as a decision making tool to timely detect and evaluate emergency conditions for each dam to categorize the appropriate emergency response level. It leverages Geographic Information System (GIS) technology to allow visualization and analysis of relevant information to enable a more integrated operational approach during normal operations and emergency conditions. While the emphasis is primarily on emergency management, it also includes a document retrieval system that allows users to easily access the most up-to-date dam safety documents, inspection reports, and other activity related information for a specific dam. This paper aims to present to the dam safety community the: importance of situational awareness in emergency management, available situational awareness tools and resources from governmental and nongovernmental partners, and need for a collaborative partnership in sharing of information for effective situational awareness. Source


Blauvelt R.P.,GEI Consultants | Fullmer D.,EWMA LLC.
Journal of ASTM International | Year: 2011

Topography often is used as a quick and preliminary method to identify local and regional ground water flow patterns within the upper-most saturated interval. This approach usually is applied in designing shallow monitoring networks at properties or in areas where little to no site specific hydrogeologic data are available. Perhaps the most problematic application of this method is in due diligence. Critical business decisions regularly are made based on potential environmental impacts from surrounding parcels using topographic presumptions about upgradient or downgradient ground water flow directions. However, what most practitioners fail to realize is that topography is a reliable predictor of ground water flow only under a fairly narrow range of physiographic conditions. To assist in determining when topography should be used to evaluate ground water flow direction within the upper-most saturated interval, we have developed an evaluation matrix that allows the investigator, who may have only modest hydrogeologic training, to rapidly identify when topography can be appropriately and reliably used to determine shallow ground water flow directions. Limitations on the use of the matrix are provided as well as suggestions for obtaining site specific data that allow for a more definitive understanding of shallow ground water flow without the need for intrusive field work. Copyright © 2011 by ASTM International. Source


Finno R.J.,Northwestern University | Arboleda-Monsalve L.G.,California State University, Long Beach | Sarabia F.,GEI Consultants
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2015

Ground movements observed during foundation installation and basement construction of a residential 53-story RC tower are presented. The One Museum Park West building is located in Chicago, Illinois, and was developed using a combination of bottom-up methods, used for the construction of a central concrete core of the building, and top-down methods to build five levels of basements. The excavation extended 13-15 m below grade and was made through soft to medium-stiff clays. The building was supported by drilled shafts and a perimeter wall formed by secant piles that transitioned to tangent piles below the bottom of the cut. The system was laterally braced with RC floor slabs structurally connected to the secant pile walls and the RC core. Field performance data were collected by means of settlement points and inclinometers located close to the walls on two sides of the excavation. The construction sequence and attendant ground movements during each main activity are summarized. As much as 160 mm of settlement was recorded in the adjacent streets throughout construction. Wall and foundation installation accounted for approximately 35% of the total settlements during construction, whereas top-down construction of the basement resulted in approximately 40% of the total settlements. These data emphasize the importance of considering all construction activities when making predictions of ground movements adjacent to deep supported excavations. © 2014 American Society of Civil Engineers. Source


Liao Y.,Kleinfelder , Inc. | Meneses J.,GEI Consultants
NCEE 2014 - 10th U.S. National Conference on Earthquake Engineering: Frontiers of Earthquake Engineering | Year: 2014

This paper presents the results of a study on characterizing site amplification of ground motions during the 2010 Mw 7.2 El Mayor-Cucapah earthquake using horizontal-to-vertical (H/V) spectral ratio method. The H/V spectral ratio shows peaks at about 0.2, 0.5, and 0.9 seconds for 2012 International Building Code (IBC) Site Classes B, C and D, respectively. The H/V spectral ratio technique predicts mean Fa=1.3 and Fv=1.7 for Class D sites and mean Fa=1.1 and Fv=1.3 for Class C sites. The two site classes show slightly smaller short-period amplification factors but substantially greater mid-period amplification factors compared with 2012 IBC code values. Sites with shear wave velocity in the upper 30 m (Vs30) between 180 and 250 m/s show similar amplification factors as 2012 IBC code values. These findings indicate that current 2012 IBC code may generally overestimate site amplification for both Site Classes C and D. Source

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