Chantal de Fouquet has written a feature article in ES&T and says

The sample mean of data collected during critical pollution periods is a biased estimator of the annual mean. The bias can be corrected by weighting techniques, which take into account the measurement dates. The differences with standard calculations become important to characterize the temporal evolution when sampling changes with time. Sound statistical methods are therefore needed.

Using regular averaging techniques in these cases will most times overestimate the true mean.  The author recommends using kriging to supply the proper weights to the observations.  Practitioners should keep this in mind when compliance issues arise.  This is a feature article and is FREE.  Download it here. 

Thanks again to everyone who tuned in to the webinar.  For those of you who wanted more information.

• Here is a link to Microcomputer.com who sells the CANOCO software that I use for PCA.
• Here is a link to the Ordination Webpage at Oklahoma State University.  They have extensive information on ordination techniques and this is a good place to start for those who want to look under the hood and learn more.
• Here is a link to the website of Edward Tufte who is the author of “The Visual Display of Quantitative Information” along with several other books on how to present data.
• Finally here is a link to Eager Eyes, which is Robert Kosara’s place to reflect on the world of information visualization and visual communication of data.

One item that I did not cover in the webinar today that should have been included was that PCA maximizes the variance for the rotation of the original variable P space.  So the first PC axis accounts for the most variance in the model and the second PC axis the second most variance in the model.  If there are any questions please post them or email me.

Why do we use conceptual site models (CSMs) and what makes a good CSM?  Travis Shaw of the USACE, Seattle District says that the definition of a CSM is a method to describe what is known or can be inferred about a site for the purpose of making a descision. 

Conceptual Site Models synthesize what is known about a site and also aid in identifying attributes to monitor changes in those systems over time.  The type of model that is developed depends upon the management goals for the site but usually achieve the following:

• Store information and capture institutional knowledge.
• Provide users with predictive capabilities and scenario-building information.
• Identify priority targets, processes, stressors, and threats (actual or potential) affecting them.
• Help managers understand site dynamics, responses to stressors (natural and anthropogenic), and ranges of natural variability.
• Identify links between state/site components, drivers, stressors, system responses, and monitoring attributes.
• Facilitate evaluation of monitoring data.
• Provide a framework for interpreting monitoring results in an adaptive management context and for prioritizing actions.
• Document assumptions, knowledge, experience, and unknowns/information gaps.
• Be valuable tools for a variety of audiences.
• Help identify thresholds of condition that may be difficult or impossible to reverse.

Conceptual models do not need to be complex, and management-oriented conceptual models are routinely used to help direct management and monitoring activities.  Perhaps one of the most important aspects of a conceptual model is the ability to illustrate the relationship between an indicator parameter and the state of the site.  Most importantly these models can provide context for monitoring remedial activities.

Monica Z. Bruckner has a good primer on water isotopes and their uses.  Won’t take long to learn about this very useful tool.  Visit the webpage here.

James R. Rustad has published an article in ES&T titled “Peak Nothing: Recent Trends in Mineral Resource Production“  that states instead of reaching peak production of oil and other mined commodities that

Although many resources have exhibited logistic behavior in the past, many now show exponential or superexponential growth.

I can’t wait to read the feedback.  See his data and calculations here.

I was able to download for free the article “Field Evidence for Intrinsic Aerobic Chlorinated Ethene Cometabolism by Methanotrophs Expressing Soluble Methane Monooxygenase” published in Bioremediation Journal by Wymore and coauthors.  This is good paper that describes the use of Enzyme Activity Probes to document (yes I will say it again)  aerobic TCE and DCE cometabolism.  Enzyme activity probes are explained in the new ITRC Environmental Molecular Diagnostics Fact Sheets that I linked to a couple of posts ago.  Download the article here.

The journal Ground Water has published its 50th volume.  The journal was first published in 1963 and started with an editorial written by Bill Walton who was the journals first editor.  Below is an excerpt from the first editorial, that was also revisited in the first editorial of the 50th volume.

Water is a necessary commodity to mankind and ground water is the largest available source of fresh water. Ever increasing demands for water continue to accelerate the development of ground water. Inevitably when development increases new problems arise, and greater effort is required to solve problems associated with the exploitation of ground-water resources……. As a result scientific knowledge of ground water has expanded in recent decades. It is reasonable to presume that such knowledge will continue to grow at a rate commensurate with the increasing use of ground water.

The 50th volume editorial written by Franklin W. Schwartz the current Editor-in-Chief of Ground Water also states the objectives of the science are changing.

Another new reality is a push toward accountability in science. Harris (2002) and Feder (2011) emphasize that governments are becoming less interested in papers as an outcome, than in devising solutions to problems through technologies and patents. Science is viewed as a contributor to the creation of wealth, jobs, and economic growth. In a sense, such an emphasis will bring us full circle to themes represented by early papers in the journal.

I wonder if this means the journal will become more applied.  Time will tell.  All of the articles in this issue are free, I suppose as a celebration.  Read them here.

Neil S. Shifrin has an editorial article in the Winter edition of Remediation Journal.  In it he states that monitoring networks left over from plume delineation result in oversampling for remediation and long-term monitoring purposes.  He also writes that once the  plume boundaries are known and the dynamics of the system are understood (from several rounds of sampling) that one or a few selected wells will usually suffice for remediation purposes and protection of public health.

I agree that on the whole we over sample.  The money that could be saved by a more judicious approach to long-term monitoring could go a long way toward cleaning up more sites.  Managing sites by concentration is expensive and not necessarily protective.  A good middle ground is to use flux-based monitoring.  In a flux-based system if water and contaminant mass is not moving then the frequency of sampling should be low.  The main idea is to understand the movement of mass to a potential receptor.  In some states ground water no matter what it’s use or non use is the receptor, and in those cases we are back to the original ideas of Mr. Shifrin.  Read the article here.

Paul Anastas a Science Advisor to the U.S. EPA as well as the Agency’s Assistant Administrator for Research and Development has published a feature article in the journal Environmental Science and Technology detailing a new path for the agencies Research Enterprise.  Below is the Abstract from the article.

Environmental protection in the United States has reached a critical juncture. It has become clear that to address the complex and interrelated environmental challenges we face, we must augment our traditional approaches. The scientific community must build upon its deep understanding of risk assessment, risk management, and reductionism with tools, technologies, insights and approaches to pursue sustainability. The U.S. Environmental Protection Agency (EPA) has recognized this need for systemic change by implementing a new research paradigm called “The Path Forward.” This paper outlines the principles of the Path Forward and the actions taken since 2010 to align EPA’s research efforts with the goal of sustainability.

Some of the principles of this new paradigm include;

• Sustainability
• Systems Approach
• Integrated Trans-Disciplinary Research
• Empower Solutions
• Acting Catalytically
• Relevant, Responsive, Rapid Research
• Produce Impact
• Produce Innovation

One of the main points of the article is that the days of reductionist science (at least for EPA) appear to be numbered.  Well, our world is complex system of systems.  I’ve seen these efforts in the past at other agencies and new directions can provide space for science that can make a difference.  Read the article here.

SERDP and ESTCP conducted a workshop on Investment Strategies to Optimize Research and Demonstration Impacts in Support of DoD Restoration Goals (published in October 2011).  In that document they offer several key reasons to why sites fail or why goals are not met.  They included;

1. Unrealistic expectations
2. Technology performance uncertainties
3. Inadequate site characterization
4. Lack of adaptive site management
5. Reluctance of regulatory community to accept data from new tools or techniques

I would add the old line that the definition of insanity is doing the same thing again and again and expecting a different outcome.  Sometimes the regulatory framework is such that the ‘failed remedy’ is what is mandated.  This can be difficult, especially when the protection of human health and ecological receptors is at stake.  One of the reasons for this blog is to inform people about the new and advanced environmental tools that may help with these issues.  Download the whole report at the SERDP website.  You will need to put in the report name into the search bar and it will bring it up for download.