Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Algorithm provides early warning system for tracking groundwater contamination

14.08.2018

Berkeley Lab researchers devise system to monitor contaminant plumes

Groundwater contamination is increasingly recognized as a widespread environmental problem. The most important course of action often involves long-term monitoring. But what is the most cost-effective way to monitor when the contaminant plumes are large, complex, and long-term, or an unexpected event such as a storm could cause sudden changes in contaminant levels that may be missed by periodic sampling?


An aerial view of cleanup efforts at the Savannah River Site.

Credit: Savannah River Site

Scientists at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and Savannah River National Laboratory have developed a low-cost method for real-time monitoring of pollutants using commonly available sensors. Their study, "In Situ Monitoring of Groundwater Contamination Using the Kalman Filter," was published recently in the journal, Environmental Science & Technology.

"Conventional methods of monitoring involve taking water samples every year or every quarter and analyzing them in the lab," said Haruko Wainwright, a Berkeley Lab researcher who led the study. "If there are anomalies or an extreme event, you could miss the changes that might increase contaminant concentrations or potential health risk. Our methodology allows continuous monitoring in situ using proxy measurements, so we can track plume movement in real time."

"Analysis of the autonomous in situ data can be rapidly analyzed remotely using machine learning methods," she added. "It can act as an early warning system - we can detect sudden changes in contaminant levels. These changes may indicate a need for more or less intervention in terms of the remediation strategy, ideally leading to improved as well as more cost-effective cleanup."

Environmental monitoring has become more important in recent years as remediation methods have been shifting away from intensive groundwater treatment and soil removal. "Intensive cleanup has a lot of negative environmental impacts, including air pollution, large energy-water use, and waste production," Wainwright said. "So experts have started thinking about a paradigm shift from this very intensive remediation to a more sustainable remediation, or 'green remediation,' so we don't just think at the contaminant level but we think about the net environmental impact."

However, long-term monitoring could be costly over time for large contaminations. What's more, current long-term monitoring strategies do not consider how abrupt or gradual changes in weather, such as heavy rain events, might influence plume behaviors. This aspect is particularly important when considering persistent plumes, such as those associated with metal or radionuclide contamination.

The new approach starts with sensors to track water quality variables that have been determined to be reliable indicators of contaminant levels. For the purposes of this study, the researchers tracked levels of tritium and uranium-238 in the groundwater at the Savannah River Site, a former nuclear weapons production site in South Carolina managed by the DOE.

For this site, they measured the acidity (or pH) levels and specific conductance (a measure of electrical conductance); these variables were determined to be reliable indicators for tritium and uranium-238 concentrations. The data from the multiple sensors were then fed into a Kalman filter to estimate contaminant concentrations. A Kalman filter is not a physical filter but rather a mathematical algorithm that can integrate mixed time-series data to make estimates. It is commonly used in various fields, such as traffic prediction and remote sensing.

Using historical data from the Savannah River Site, the researchers found that their technique provided reliable information about plume behavior over the last 20 years, indicating that the new approach holds significant promise as a long-term monitoring strategy for rapidly assessing a contaminant's plume stability. Another advantage over conventional approaches is that it can reduce the frequency of manual groundwater sampling and lab analysis, and thus reduce the monitoring cost.

Wainwright, who is an expert in groundwater contamination and environmental data analytics, said this methodology can be used for both surface and underground water. It can also potentially be used to track other metals, radionuclides, and organic compounds commonly found in groundwater, such as arsenic, chromium, and fuels.

"There are so many different types of sensors available now, and sensor networking and rapid statistical analysis is straightforward," she said. "We can put together all types of in situ sensors and estimate the target contaminant concentration using this framework for data integration in real-time."

She added: "Improved monitoring techniques are essential to protect public health and the ecology. People feel safe if it's properly monitored. Our technique is a way to monitor such sustainable remediation - effectively and cheaply."

###

The study was funded by DOE's Office of Environmental Management and Office of Science. The other co-authors of the study are Franziska Schmidt of UC Berkeley, Boris Faybishenko of Berkeley Lab, Miles Denham of Panoramic Environmental Consulting, and Carol Eddy-Dilek of Savannah River National Laboratory. The advances build upon concepts developed through the Office of Science's Watershed Scientific Focus Area project.

Lawrence Berkeley National Laboratory addresses the world's most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab's scientific expertise has been recognized with 13 Nobel Prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy's Office of Science. For more, visit http://www.lbl.gov.

DOE's Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Media Contact

Julie Chao
jhchao@lbl.gov
510-486-6491

 @BerkeleyLab

http://www.lbl.gov 

Julie Chao | EurekAlert!
Further information:
https://newscenter.lbl.gov/2018/08/13/algorithm-provides-early-warning-system-for-tracking-groundwater-contamination/
http://dx.doi.org/10.1021/acs.est.8b00017

More articles from Earth Sciences:

nachricht Hundreds of bubble streams link biology, seismology off Washington's coast
22.03.2019 | University of Washington

nachricht Atmospheric scientists reveal the effect of sea-ice loss on Arctic warming
11.03.2019 | Institute of Atmospheric Physics, Chinese Academy of Sciences

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>