SLIDES: Energy Development Water Needs Assessment and Water Supply Alternatives and Analysis

Presenter: Benjamin Harding, Principal Engineer, AMEC Earth and Environmental 15 slide

Phosphorus Release from Bottom Sediments at Lake Wister, Oklahoma, Summer 2010

A previous reservoir model of Lake Wister, Oklahoma suggested that internal P sources were dominant, and that a watershed management plan need not be developed to address external sources. The objectives of this study were to collect intact sediment cores from three sites at Lake Wister and measure sediment O₂ demand (SOD) and soluble reactive P (SRP) release to the overlying water during lab incubations under quiescent conditions. The measured SOD rates were between 9.9 and 22.6 mg m⁻² hr⁻¹ on average across the three sites, where the shallow headwaters site had the least SOD. The SRP release rates were estimated to vary from less than zero to 3.30 mg m⁻² d⁻¹ on average across the sites, and release rates were greatest under anaerobic conditions in the cores collected from deep waters near the dam and water intake structure. These measured values were an order of magnitude less than used in the calibration of the previous reservoir model, suggesting that internal P cycling was likely not the dominant P source; thus, it might be premature to neglect external P sources to Lake Wister. A watershed‐based strategy that focuses on internal and external P sources is needed for this drinking water supply reservoir to improve overall water quality

MDP Optimal Control under Temporal Logic Constraints

In this paper, we develop a method to automatically generate a control policy for a dynamical system modeled as a Markov Decision Process (MDP). The control specification is given as a Linear Temporal Logic (LTL) formula over a set of propositions defined on the states of the MDP. We synthesize a control policy such that the MDP satisfies the given specification almost surely, if such a policy exists. In addition, we designate an "optimizing proposition" to be repeatedly satisfied, and we formulate a novel optimization criterion in terms of minimizing the expected cost in between satisfactions of this proposition. We propose a sufficient condition for a policy to be optimal, and develop a dynamic programming algorithm that synthesizes a policy that is optimal under some conditions, and sub-optimal otherwise. This problem is motivated by robotic applications requiring persistent tasks, such as environmental monitoring or data gathering, to be performed.Comment: Technical report accompanying the CDC2011 submissio

Russian Nuclear Submarines: U.S. Participation in the Arctic Military Environmental Cooperation Program Needs Better Justification

A letter report issued by the Government Accountability Office with an abstract that begins "Norway, Russia, the United Kingdom, and the United States participate in the Arctic Military Environmental Cooperation (AMEC) program, a multilateral effort that seeks to reduce the environmental impacts of Russia's military activities through technology development projects. AMEC has primarily focused on Russia's aging fleet of nuclear submarines. Section 324 of the National Defense Authorization Act for Fiscal Year 2004 required GAO to review AMEC, including its relationship to the Department of Defense's (DOD) Cooperative Threat Reduction (CTR) program. In accordance with the act, GAO (1) assessed the extent to which AMEC supports and complements the CTR program, (2) identified AMEC member countries' financial contributions to the program, (3) assessed AMEC's future program objectives, and (4) evaluated DOD's proposal to expand its technology development activities to Russia's Pacific region.

Defence and the Arctic : go with the floe?

Article published in the RUSI Journal, Volume 154, Issue 4 August 2009 , pages 82-86As the Arctic ice melts, the polar region is becoming increasingly exposed to the political tussles of resource exploitation. Accompanying the territorial disputes is the imminent militarisation of the international space by circumpolar states. The UK has a difficult decision to make: either include the Arctic in its future defence strategy or advocate a zone of peace in this valuable part of the world. it cannot do both

U.S. Geological Survey External Quality-Assurance Project Report for the National Atmospheric Deposition Program / National Trends Network and Mercury Deposition Network, 2011-12

The U.S. Geological Survey operated six distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program (NADP) / National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2011–2012. The field-audit program assessed the effects of onsite exposure, sample handling, and shipping on the chemistry of NTN samples; a system-blank program assessed the same effects for MDN. Two interlaboratory-comparison programs assessed the bias and variability of the chemical analysis data from the Central Analytical Laboratory and Mercury Analytical Laboratory (HAL). A blind-audit program was implemented for the MDN during 2011 to evaluate analytical bias in HAL total mercury concentration data. The co-located–sampler program was used to identify and quantify potential shifts in NADP data resulting from the replacement of original network instrumentation with new electronic recording rain gages and precipitation collectors that use optical precipitation sensors. The results indicate that NADP data continue to be of sufficient quality for the analysis of spatial distributions and time trends of chemical constituents in wet deposition across the United States. Co-located rain gage results indicate -3.7 to +6.5 percent bias in NADP precipitation-depth measurements. Co-located collector results suggest that the retrofit of the NADP networks with the new precipitation collectors could cause +10 to +36 percent shifts in NADP annual deposition values for ammonium, nitrate, and sulfate; -7.5 to +41 percent shifts for hydrogen-ion deposition; and larger shifts (-51 to +52 percent) for calcium, magnesium, sodium, potassium, and chloride. The prototype N-CON Systems bucket collector typically catches more precipitation than the NADP-approved Aerochem Metrics Model 301 collector.National Atmospheric Deposition Programpublished or submitted for publicationis peer reviewedOpe

Seismic Retrofit of Crane Valley Dam

Crane Valley Dam is located on the North Fork of Willow Creek in Madera County, California, and is owned by Pacific Gas & Electric Company (PG&E). The results of seismic stability analyses performed in 2005 and 2006 showed that the dam’s hydraulic fill embankments would experience large deformations during and after the earthquake shaking postulated for the site. To improve the seismic stability and performance of the dam, PG&E initiated the Crane Valley Dam Seismic Retrofit Project (Project), which includes placing new rockfill buttresses on the upstream and downstream slopes of the dam, constructing internal drainage improvements, reinforcing portions of the dam’s concrete core wall, and raising the dam crest. Project components were designed to meet seepage control and seismic stability criteria and to accommodate existing facilities, limited site access, seasonal reservoir operations, and environmentally sensitive areas within and adjacent to the Project site. Engineering analyses included static, seepage, and dynamic finite element analyses to evaluate the potential for liquefaction of hydraulic fill materials and post-earthquake stability of the retrofitted dam embankment. Construction of the Project began in Octobe