A Systematic Framework for the Design and Implementation of a Quality Management Practice: The Case of a Consulting Engineering Company

Company productivity and competitiveness in today's marketplace requires creative design, innovation, and the reduction of nonconformances, which require costly rework and can damage a firm's reputation with its customers and potential customers. Using the International Organisation of Standardization's (ISO) 9000 and 14000 series of standards, the authors of this article walk readers through the rigorous process of obtaining upper management buy‐in and sponsorship and engaging workers in a bottom‐up approach to establish the procedures necessary to perform world‐class engineering services.     

Comparison of Unsteady and Quasi‐Unsteady Flow Models in Simulating Sediment Transport in an Ephemeral Arizona Stream1

Hummel, Ryan, Jennifer G. Duan, and Shiyan Zhang, 2012. Comparison of Unsteady and Quasi‐Unsteady Flow Models in Simulating Sediment Transport in an Ephemeral Arizona Stream. Journal of the American Water Resources Association (JAWRA) 48(5): 987‐998. DOI: 10.1111/j.1752‐1688.2012.00663.x Abstract: Hydrodynamic and sediment transport models are useful engineering tools for predicting unsteady flood flow and sediment transport. Many models such as HEC‐RAS, HEC‐6, and IALLUVIAL apply quasi‐unsteady flow model, whereas others apply the unsteady flow model. It remains unknown if a quasi‐unsteady flow model is sufficiently accurate for simulating sediment transport in rapidly varied unsteady flood events, especially in ephemeral rivers in arid and semiarid regions. This study compared the quasi‐unsteady HEC‐RAS 4.1 model with one‐dimensional (1D) Finite Volume Method (FVM) based model in simulating flood flow and sediment transport in the Pantano Wash, a dryland river in the state of Arizona. The objective is to determine which sediment transport method is appropriate in predicting bed elevation changes in an ephemeral stream, Pantano Wash, and if an unsteady model is more accurate than a quasi‐unsteady flow model in predicting sediment transport. Results showed that the quasi‐unsteady HEC‐RAS model and the 1D FVM yielded similar results of bed degradation and aggradation for this dryland stream, although the FVM model predicted better flood hydrographs. Among the seven sediment transport formulas embedded in HEC‐RAS, Yang’s and Engelund‐Hansen’s equations gave the best matches with the field measurements for this particular case study.     

Impacts of organic carbon availability and recipient bacteria characteristics on the potential for TOL plasmid genetic bioaugmentation in soil slurries

The effectiveness of genetic bioaugmentation relies on efficient plasmid transfer between donor and recipient cells as well as the plasmid’s phenotype in the recipient cell. In the present study, the effects of varying organic carbon substrates, initial recipient-to-donor cell density ratios, and mixtures of known recipient bacterial strains on the conjugation and function of a TOL plasmid were tested in sterile soil slurry batch reactors. The presence of soil organic carbon was sufficient in ensuring TOL plasmid transconjugant occurrence (up to 2.1 ± 0.5%) for most recipient strains in soil slurry batch mating experiments. The addition of glucose had limited effects on transconjugant occurrence; however, glucose amendment increased the specific toluene degradation rates of some Enterobacteriaceae transconjugants in soil slurry. Initial cell density ratios and mixtures of recipient strains had smaller impacts on plasmid conjugation and resulting phenotype functionality. These observations suggest that genetic bioaugmentation may be improved by minimal altering of environmental conditions.     

Biosolids and distillery effluent amendment to Irish Miscanthus ×giganteus plantations: impacts on groundwater and soil

It is necessary to determine the risk of water pollution arising from amendment of organic by-products (OBs) to energy crops under Irish conditions. Therefore, the impact of landspreading two OBs on the quality of groundwater underlying plantations of Miscanthus X giganteus was assessed. Municipal biosolids and distillery effluent (DE) were spread annually (for 4 yr) on six 0.117-ha treatment plots at rates of 100, 50, and 0%. The 100% rate represented a maximum P load of 15 t ha(-1) as per Irish EPA regulation. Groundwater was sampled for 25 mo and tested for pH, electrical conductivity, NO(3)(-), orthophosphate (PO(4)(3-)), total soluble P, K(+), Cu, Cd, Cr, Pb, Ni, and Zn. Assessment of quality was based on comparison with Irish groundwater threshold values (GTVs). The study was limited to within-plot using a "well bottom" approach and did not investigate movement of groundwater plumes or vectors of percolation through the soil profile. Mean groundwater concentrations did not exceed GTVs during the sampling period for any species, with the exception of groundwater PO(4)(3-) in the 100% DE plot, which was almost double the GTV of 0.035 mg L(-1). There was no significant build-up of nutrients or heavy metals in groundwater (or soil) for any plot. Excessive PO(4)(3-) in the 100% DE plot groundwater is likely due to high background soil P, soil characteristics, and the occurrence of macropore/soil pore flow. These factors (particularly background soil P) should be assessed when determining suitable sites for land-spreading OBs.     

Appreciation, Use, and Management of Biodiversity and Ecosystem Services in California’s Working Landscapes

"Working landscapes" is the concept of fostering effective ecosystem stewardship and conservation through active human presence and management and integrating livestock, crop, and timber production with the provision of a broad range of ecosystem services at the landscape scale. Based on a statewide survey of private landowners of "working" forests and rangelands in California, we investigated whether owners who are engaged in commercial livestock or timber production appreciate and manage biodiversity and ecosystem services on their land in different ways than purely residential owners. Both specific uses and management practices, as well as underlying attitudes and motivations toward biodiversity and ecosystem services, were assessed. Correlation analysis showed one bundle of ecosystem goods and services (e.g., livestock, timber, crops, and housing) that is supported by some landowners at the community level. Another closely correlated bundle of biodiversity and ecosystem services includes recreation, hunting/fishing, wildlife habitat, and fire prevention. Producers were more likely to ally with the first bundle and residential owners with the second. The survey further confirmed that cultural ecosystem services and quality-of-life aspects are among the primary amenities that motivate forest and rangeland ownership regardless of ownership type. To live near natural beauty was the most important motive for both landowner groups. Producers were much more active in management for habitat improvement and other environmental goals than residential owners. As the number of production-oriented owners decreases, developing strategies for encouraging environment-positive management by all types of landowners is crucial.     

Water Quality and Plankton in the United States Nearshore Waters of Lake Huron

Our goal in the development of a nearshore monitoring method has been to evaluate and refine an in situ mapping approach to assess the nearshore waters across the Great Lakes. The report here for Lake Huron is part of a broader effort being conducted across all five Great Lakes. We conducted an intensive survey for the United States nearshore of Lake Huron along a continuous shoreline transect (523?km) from Port Huron, Michigan, to Detour Passage. A depth contour of 20?m was towed with a conductivity-temperature depth profiler, fluorometer, transmissometer, and laser optical plankton counter. Multiple cross-contour tows (10-30?m) on the cruise dates were used to characterize the variability across a broader range of the nearshore. The cross-contour tows were comparable with the alongshore contour indicating that the 20-m contour does a good job of representing the nearshore region (10-30?m). Strong correlations were observed between water quality and spatially associated watershed land use. A repeat tow separated by several weeks investigated temporal variability in spatial patterns within a summer season. Strong correlations were observed across each variable for the temporal repeat across broad- and fine-scale spatial dimensions. The survey results for Lake Huron nearshore are briefly compared with a similar nearshore survey in Lake Superior. The biomass concentrations of lower food web components of Lake Huron were notably approximately 54-59?% of those in Lake Superior. The towed instrumentation survey supported the recent view of a change in Lake Huron to an ultra-oligotrophic state, which has been uncharacteristic in recent history.     

Predicting emissions from oil and gas operations in the Uinta Basin,Utah

In this study, emissions of ozone precursors from oil and gas operations in Utah’s Uinta Basin are predicted (with uncertainty estimates) from 2015–2019 using a Monte-Carlo model of (a) drilling and production activity, and (b) emission factors. Cross-validation tests against actual drilling and production data from 2010–2014 show that the model can accurately predict both types of activities, returning median results that are within 5% of actual values for drilling, 0.1% for oil production, and 4% for gas production. A variety of one-time (drilling) and ongoing (oil and gas production) emission factors for greenhouse gases, methane, and volatile organic compounds (VOCs) are applied to the predicted oil and gas operations. Based on the range of emission factor values reported in the literature, emissions from well completions are the most significant source of emissions, followed by gas transmission and production. We estimate that the annual average VOC emissions rate for the oil and gas industry over the 2010–2015 time period was 44.2E+06 (mean) ± 12.8E+06 (standard deviation) kg VOCs per year (with all applicable emissions reductions). On the same basis, over the 2015–2019 period annual average VOC emissions from oil and gas operations are expected to drop 45% to 24.2E+06 ± 3.43E+06 kg VOCs per year, due to decreases in drilling activity and tighter emission standards.

Implications: This study improves upon previous methods for estimating emissions of ozone precursors from oil and gas operations in Utah’s Uinta Basin by tracking one-time and ongoing emission events on a well-by-well basis. The proposed method has proven highly accurate at predicting drilling and production activity and includes uncertainty estimates to describe the range of potential emissions inventory outcomes. If similar input data are available in other oil and gas producing regions, then the method developed here could be applied to those regions as well.     

Development of Models for Predicting the Distribution of Indoor Nitrogen Dioxide Concentrations

Extensive data on residential indoor and outdoor NO₂ levels have been collected in a limited number of U.S. locations. To date, researchers have analyzed these data sets individually, but have not analyzed them in the aggregate. Results have not, therefore, been suitable for application in a nationwide exposure assessment. This paper presents an analysis of indoor and outdoor NO₂ field measurements from five U.S. metropolitan areas for homes with gas-fueled ranges and discusses potential applications of the results. Using linear regression analysis, the relationship between indoor NO₂ and various predictor variables was explored. Results indicated that ambient NO2 levels alone explain an estimated 37 percent of the variability in indoor NO₂ levels, that the relationship between indoor and outdoor NO₂ concentrations differs significantly from summer to winter months, and that homes with range pilot lights have indoor levels approximately 7 ppb greater than homes without pilot lights. A logistic regression model which predicts the distribution of indoor NO₂ levels based on ambient NO₂ concentrations was developed. Estimation and testing of the logistic model indicated good model performance. The model is particularly useful for addressing policy-oriented questions that involve the concept of "acceptable" threshold levels for human exposure to NO₂.     

Measurement of Organic Acids,Aldehydes, and Ketones in Residential Environments and Their Relation to Ozone

Abstract

Ozone and several polar volatile organic compounds (VOCs) including organic acids and carbonyls (aldehydes and ketones) were measured over an approximately 24 hour period in four residences during the winter of 1993 and in nine residences during the summer of 1993. All residences were in the greater Boston, Massachusetts area. The relation of the polar VOCs to the ozone concentration was examined. Indoor carbonyl concentrations were similar between the summer and winter, with the total mean winter concentration being 31.7 ppb and the total mean summer concentration being 36.6 ppb. However, the average air exchange rate was 0.9 hr^?1 during the winter and 2.6 hr^?1 during the summer. Therefore, the estimated carbonyl emission rates were significantly higher during the summer. Indoor organic acid concentrations were about twice as high during the summer as during the winter. For formic acid, the indoor winter mean was 9.8 ppb, and the summer indoor mean was 17.8 ppb. For acetic acid, the indoor winter mean was 15.5 ppb, and the summer indoor mean was 28.7 ppb. The concentrations of the polar VOCs were found to be significantly correlated with one another. Also, the emission rates of the polar VOCs were found to be correlated with both the environmental variables such as temperature and relative humidity and the ozone removal rate; however, it was difficult to apportion the relative effects of the environmental variables and the ozone removal.     

Emissions of Trace Products of Incomplete Combustion from a Pilot-Scale Incinerator Secondary Combustion Chamber

Abstract

Experiments were performed on a 73 kW rotary kiln incinerator simulator equipped with a 73 kW secondary combustion chamber (SCC) to examine emissions of products of incomplete combustion (PICs) resulting from incineration of carbon tetrachloride (CC14) and dichloromethane (CH2C12). Species were measured using an on-line gas chromatograph (GC) system capable of measuring concentrations of eight species of volatile organic compounds (VOCs) in a near-realtime fashion. Samples were taken at several points within the SCC, to generate species profiles with respect to system residence time. For the experiments, the afterburner on the SCC was operated at conditions ranging from fuel-rich to fuellean, while the kiln was operated at a constant set of conditions. Results indicate that combustion of CH2C12 produces higher levels of measured PICs than combustion of CC14, particularly 1, 2 dichlorobenzene, and to a lesser extent, monochlorobenzene. Benzene emissions were predominantly affected by the afterburner air/fuel ratio regardless of whether or not a surrogate waste was being fed.