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News Article | May 8, 2017

PASADENA, Calif.--(BUSINESS WIRE)--Tetra Tech (NASDAQ: TTEK) announced today that Coffey, a Tetra Tech Company, has been selected by the Australian Defence Infrastructure Panel (DIP) to provide essential infrastructure support and advisory consulting services to the Australian Department of Defence over a five-year period. Coffey also served on the previous Panel, which ran from 2010 to 2017. The DIP was established in 2004 by the Australian Department of Defence to streamline access to high quality infrastructure-related professional services by awarding a select group of leading consulting and engineering firms the ability to perform critical infrastructure improvement work for the Australian government. Under the previous DIP, Coffey supported the development of improved air, water, and land infrastructure in Australia, including management of a $1.1 billion New Air Combat Capability Infrastructure project from initial study through construction. Under the new panel, Coffey will leverage the broader Tetra Tech platform to provide a wide range of infrastructure support and project management services ranging from initial site and capacity investigations to design reviews, site selection, and cost planning functions. “We are very pleased that Coffey has been selected as one of the leading engineering firms to provide services to the Defence Infrastructure Panel,” said Dan Batrack, Tetra Tech’s Chairman and CEO. “This award comes at a critical time in infrastructure development in Australia. With the support of Tetra Tech’s industry-leading infrastructure platform, Coffey can provide best-in-class engineering services to the Australian Department of Defence.” Tetra Tech is a leading, global provider of consulting and engineering services. We are differentiated by Leading with Science to provide innovative technical solutions to our clients. We support global commercial and government clients focused on water, environment, infrastructure, resource management, energy, and international development. With 16,000 associates worldwide, Tetra Tech provides clear solutions to complex problems. For more information about Tetra Tech, please visit, follow us on Twitter (@TetraTech), or like us on Facebook. Any statements made in this release that are not based on historical fact are forward-looking statements. Any forward-looking statements made in this release represent management’s best judgment as to what may occur in the future. However, Tetra Tech’s actual outcome and results are not guaranteed and are subject to certain risks, uncertainties and assumptions ("Future Factors"), and may differ materially from what is expressed. For a description of Future Factors that could cause actual results to differ materially from such forward-looking statements, see the discussion under the section "Risk Factors" included in the Company’s Form 10-K and 10-Q filings with the Securities and Exchange Commission.

Elias E.,New Mexico State University | Rodriguez H.,TetraTech Inc. | Srivastava P.,Auburn University | Dougherty M.,Auburn University | And 2 more authors.
Forests | Year: 2016

We used coupled watershed and reservoir models to evaluate the impacts of deforestation and l Niño Southern Oscillation (ENSO) phase on drinking water quality. Source water total organic carbon (TOC) is especially important due to the potential for production of carcinogenic disinfection byproducts (DBPs). The Environmental Fluid Dynamics Code (EFDC) reservoir model is used to evaluate the difference between daily pre- and post- urbanization nutrients and TOC concentration. Post-disturbance (future) reservoir total nitrogen (TN), total phosphorus (TP), TOC and chlorophyll-a concentrations were found to be higher than pre-urbanization (base) concentrations (p < 0.05). Predicted future median TOC concentration was 1.1 mg· L-1 (41% higher than base TOC concentration) at the source water intake. Simulations show that prior to urbanization, additional water treatment was necessary on 47% of the days between May and October. However, following simulated urbanization, additional drinking water treatment might be continuously necessary between May and October. One of six ENSO indices is weakly negatively correlated with the measured reservoir TOC indicating there may be higher TOC concentrations in times of lower streamflow (La Niña). There is a positive significant correlation between simulated TN and TP concentrations with ENSO suggesting higher concentrations during El Niño. © 2016 by the authors.

PubMed | TetraTech Inc., University of Thessaly and Chatham University
Type: | Journal: Physiology & behavior | Year: 2016

Previous reports indicate that regular, but not excessive, exercise can moderate the response to anxiety and alter the immune response, therefore we hypothesized that college student athletes who were actively participating on an NCAA Division III athletics team (in-season) would have lower levels of anxiety and higher salivary IgA levels than similar college athletes who were in their off-season. NCAA Division III athletes participate in athletics at a level of intensity that is more moderate compared to other NCAA divisions. Alterations in the microbiome have been associated with alterations in psychosocial well-being and with exercise. Therefore, we also proposed that the oral microbiota would be different in in-season versus off-season athletes.In this pilot study, nineteen female students participating on a NCAA Division III athletic team (hockey=in-season; soccer=off-season) were compared for level of fitness (modified Balke test of VOThe proportion of subjects reporting severe anxiety on an anxiety scale (GAD-7) were significantly greater in the off-season group compared to the in-season group (p=0.047, Chi-squared test). In-season athletes had significantly higher salivary IgA/total protein levels than off-season athletes (one-sided Students t-test; p=0.03). Cortisol levels were not significantly different in the two groups. The total culturable bacteria counts were higher among in-season athletes (p=0.0455, Wilcoxon Rank Sum test), as measured by CFUs on blood agar plates, an estimate of total culturable bacteria, including pathogenic and non-pathogenic bacteria. In contrast, there was a decrease in the growth of bacteria from the oral cavity of the in-season athletes, when the growth of bacteria on mitis salivarius agar (primarily oral streptococcus) was measured (p=0.0006, Wilcoxon Rank Sum test). There was a negative correlation (Spearman Rank correlation coefficient=-0.651, p=0.0018 one-sided) between high IgA levels and the growth of bacteria on mitis salivarius agar in the combined group of in-season and off-season athletes, suggesting a protective response of high IgA levels to the typical oral pathogenic bacteria. Anxiety levels (GAD-7) in the in-season group were positively correlated with growth of oral bacteria on blood agar (Spearman Rank correlation coefficient of 0.622 for in-season, p value=0.033 one-sided) and mitis salivarius agar (Spearman Rank correlation coefficient=0.671 for in-season, p value=0.021 one-sided), and negatively correlated in off-season athletes on blood agar (-0.689 for off-season, p value=0.028 one-sided), supporting the hypothesis that the microbiota are distinct in in-season and off-season athletes and may be associated with anxiety levels.These findings are supportive of the hypothesis that participation in college level athletics has a positive effect on student-athlete health, specifically enhanced protective oral immunity, reduced anxiety, and alterations in oral microbial populations.

Livermore J.A.,University of Iowa | Jin Y.O.,University of Iowa | Arnseth R.W.,TetraTech Inc. | Lepuil M.,TetraTech Inc. | Mattes T.E.,University of Iowa
Environmental Science and Technology | Year: 2013

Biostimulation of groundwater microbial communities (e.g., with carbon sources) is a common approach to achieving in situ bioremediation of organic pollutants (e.g., explosives). We monitored a field-scale approach to remediate the explosive RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) in an aquifer near the Iowa Army Ammunition Plant in Middletown, IA. The purpose of the study was to gain insight into the effect of biostimulation on the microbial community. Biostimulation with acetate led to the onset of RDX reduction at the site, which was most apparent in monitoring well MW309. Based on previous laboratory experiments, we hypothesized that RDX degradation and metabolite production would correspond to enrichment of one or more Fe(III)-reducing bacterial species. Community DNA from MW309 was analyzed with 454 pyrosequencing and terminal restriction fragment length polymorphism. Production of RDX metabolites corresponded to a microbial community shift from primarily Fe(III)-reducing Betaproteobacteria to a community dominated by Fe(III)-reducing Deltaproteobacteria (Geobacteraceae in particular) and Bacteroidetes taxa. This data provides a firsthand field-scale microbial ecology context to in situ RDX bioremediation using modern sequencing techniques that will inform future biostimulation applications. © 2013 American Chemical Society.

News Article | December 27, 2016

VANCOUVER, British Columbia, Dec. 27, 2016 (GLOBE NEWSWIRE) -- Panoro Minerals Ltd. (TSXV:PML) (Lima:PML) (Frankfurt:PZM) ("Panoro", the "Company") is pleased to announce the appointment of Mr. Ronald A. Hall to the Board of Directors of the Company.  Mr. Hall holds a BSc. in Metallurgy from Cardiff University in the UK and has over 40 years’ experience in the management, operation, evaluation and design of mining projects globally.  Over his career he has worked and lived in the UK, South Africa, Botswana, Canada, Australia, China and elsewhere where he has advanced mining projects from early stages through feasibility and into development and operation.  From 2004 to 2011, Mr. Hall lead the growth of Wardrop Engineering’s mining business in Vancouver, B.C. and internationally, including the establishment of offices in the UK, China, Chile, Brazil, Hong Kong and Australia, prior to the acquisition of Wardrop by TetraTech Inc. Mr. Hall is currently an independent director of Chinalco Mining Corporation International (CMCI), a publicly listed company on the Hong Kong stock exchange, which operates the Toromocho Copper project in Peru. The Company has granted options to purchase 600,000 shares exercisable at a price of $0.20 per share to Mr. Hall pursuant to the Company's stock option plan. “We are delighted that Ron has joined our Board. His broad and relevant experience will be of great benefit as we move forward in the development and increased valuation of our flagship projects,” stated William Boden, Chairman of the Company. Panoro Minerals is a uniquely positioned Peru focused copper exploration and development company. The Company is advancing a significant project portfolio in the strategic Andahuaylas-Yauri belt in south central Peru, including its advanced stage Cotabambas Copper-Gold-Silver-Molybdenum and Antilla Copper-Molybdenum Projects.  The Company is well financed to expand, enhance and advance its projects in the region where infrastructure such as railway, roads, ports, water supply, power generation and transmission are readily available and expanding quickly.  The region boasts the recent investment of over $US 15 billion into the construction or expansion of four large open pit copper mines. Since 2007, the Company has completed over 70,000 m of exploration drilling at these two key projects leading to substantial increases in the mineral resource base for each, as summarized in the table below. Preliminary Economic Assessments (PEA) have been completed for both the Cotabambas and Antilla Projects, the key results are summarized below. The PEAs are considered preliminary in nature and include Inferred Mineral Resources that are considered too speculative to have the economic considerations applied that would enable classification as Mineral Reserves. There is no certainty that the conclusions within the updated PEA will be realized. Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. Luis Vela, a Qualified Person under National Instrument 43-101, has reviewed and approved the scientific and technical information in this press release. On behalf of the Board of Panoro Minerals Ltd. William Boden, CPA, CA Chairman of the Board of Directors CAUTION REGARDING FORWARD LOOKING STATEMENTS: Information and statements contained in this news release that are not historical facts are “forward-looking information” within the meaning of applicable Canadian securities legislation and involve risks and uncertainties. Forward-looking statements are subject to a variety of known and unknown risks, uncertainties and other factors which could cause actual events or results to differ materially from those expressed or implied by the forward-looking statements, including, without limitation: This list is not exhaustive of the factors that may affect the forward-looking information and statements contained in this news release.  Should one or more of these risks and uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described in the forward‑looking information.  The forward‑looking information contained in this news release is based on beliefs, expectations and opinions as of the date of this news release.  For the reasons set forth above, readers are cautioned not to place undue reliance on forward-looking information.  Panoro does not undertake to update any forward-looking information and statements included herein, except in accordance with applicable securities laws. Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Spiller D.E.,Colorado School of Mines | Norgren C.A.,TetraTech Inc.
Mineral Processing and Extractive Metallurgy: 100 Years of Innovation | Year: 2014

The separation and upgrading of heavy mineral sands is accomplished by a combination of wet and dry processing. The wet side comprises liberation by scrubbing, size classification, and various techniques of gravity separation to produce a bulk (total) heavy mineral concentrate. The dry side, treating size classified total heavy mineral concentrate, principally involves the use of magnetic and electrostatic separation to produce marketable concentrates of rutile, ilmenite, zircon, monazite, and other heavy minerals. These various separating unit operations were invented, developed and/or adopted as the result of issues experienced at the operational level but ultimately driven by market forces.

Alfaro M.C.,University of Manitoba | Pathak Y.P.,TetraTech Company
Geotechnical Testing Journal | Year: 2012

This paper reports results from bench-scale plane-strain laboratory tests conducted in order to investigate the behavior of geogrid-reinforced silt specimens during freezing and thawing cycles. Soil-geogrid interaction was analyzed through comparison of the soil and geogrid strains. Vertical and lateral pressures were applied to the specimens to simulate anisotropic loading conditions in the field. Reinforced and unreinforced specimens were subjected to cycles of freezing (-25°C) and thawing (+23°C) temperatures inside a walk-in temperature-controlled environmental chamber. Measured geogrid strains at the end of 12 freezing-thawing cycles were on the order of 0.57 %. An additional strain of this magnitude in the reinforcement due to the freezing-thawing cycles would have only minimal effect on working strain levels in the design, which range from 1 % to 2 %. However, the strains induced by freezing and thawing can approach working design strains as the number of cycles increases. This could have significant long-term implications if accumulated strains were to overstrain the geogrid. The soil deformations were observed to be mostly horizontal. This pattern of deformations during the freezing and thawing of silt could result in shallow sliding at the face of slopes and embankments. The soil strains were higher than the geogrid strains, indicating relative movements between soil and reinforcement, mostly during thawing. Copyright © 2012 by ASTM International.

Nekouee N.,TetraTech Inc | Mahajan R.,TetraTech Inc | Hamrick J.,EATON Inc | Rodriguez H.,TetraTech Inc
World Environmental and Water Resources Congress 2013: Showcasing the Future - Proceedings of the 2013 Congress | Year: 2013

Hydraulic study of a selective withdrawal relief gate is presented. A comparison study between a computational fluid dynamics model, Flow3D, and a 3D hydrodynamic model, EFDC, has been performed. Flow3D is applied to simulate behavior of the flow by using limited compressible flow approximations and RNG turbulence model. EFDC is used to analyze the flow through the inlet using a shallow water solver configured equivalent to 2D Reynolds-Average Navier-Stokes (RANS) equations in vertical plane and Mellor-Yamada Turbulence Closure Scheme. Pressure heads and vertical opening velocity results from both models are compared. Computational fluid dynamic models provide us great insight to determine the hydraulic behavior and flow properties in these complex geometries. © 2013 American Society of Civil Engineers.

Van Gaalen J.F.,University of South Florida | Kruse S.,University of South Florida | Lafrenz W.B.,Tetratech Inc. | Burroughs S.M.,The University of Tampa
GroundWater | Year: 2013

A rise in water table in response to a rainfall event is a complex function of permeability, specific yield, antecedent soil-water conditions, water table level, evapotranspiration, vegetation, lateral groundwater flow, and rainfall volume and intensity. Predictions of water table response, however, commonly assume a linear relationship between response and rainfall based on cumulative analysis of water level and rainfall logs. By identifying individual rainfall events and responses, we examine how the response/rainfall ratio varies as a function of antecedent water table level (stage) and rainfall event size. For wells in wetlands and uplands in central Florida, incorporating stage and event size improves forecasting of water table rise by more than 30%, based on 10 years of data. At the 11 sites studied, the water table is generally least responsive to rainfall at smallest and largest rainfall event sizes and at lower stages. At most sites the minimum amount of rainfall required to induce a rise in water table is fairly uniform when the water table is within 50 to 100 cm of land surface. Below this depth, the minimum typically gradually increases with depth. These observations can be qualitatively explained by unsaturated zone flow processes. Overall, response/rainfall ratios are higher in wetlands and lower in uplands, presumably reflecting lower specific yields and greater lateral influx in wetland sites. Pronounced depth variations in rainfall/response ratios appear to correlate with soil layer boundaries, where corroborating data are available. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

Deverel S.J.,Hydrofocus Inc | Lucero C.E.,Hydrofocus Inc | Bachand S.,Tetratech Inc
San Francisco Estuary and Watershed Science | Year: 2015

We used available data to estimate changes in land use and wet, non-farmable, and marginally farmable (WNMF) areas in the Delta from 1984 to 2012, and developed a conceptual model for processes that affect the changes observed. We analyzed aerial photography, groundwater levels, land-surface elevation data, well and boring logs, and surface water elevations. We used estimates for sea level rise and future subsidence to assess future vulnerability for the development of WNMF areas. The cumulative WNMF area increased linearly about 10-fold, from about 274 hectares (ha) in 1984 to about 2,800 ha in 2012. Moreover, several islands have experienced land use changes associated with reduced ability to drain the land. These have occurred primarily in the western and central Delta where organic soils have thinned; there are thin underlying mud deposits, and drainage ditches have not been maintained. Subsidence is the key process that will contribute to future increased likelihood of WNMF areas by reducing the thickness of organic soils and increasing hydraulic gradients onto the islands. To a lesser extent, sea level rise will also contribute to increased seepage onto islands by increasing groundwater levels in the aquifer under the organic soil and tidal mud, and increasing the hydraulic gradient onto islands from adjacent channels. WNMF develop from increased seepage under levees, which is caused by changing flow paths as organic soil thickness has decreased. This process is exacerbated by thin tidal mud deposits. Based primarily on projected reduced organic soil thickness and land-surface elevations, we delineated an additional area of about 3,450 ha that will be vulnerable to reduced arability and increased wetness by 2050.

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