Air sparging involves injecting oxygen into the contaminated groundwater. The presence of oxygen helps to remove semi-volatile aromatic hydrocarbon contaminants in the groundwater by expiditing biodegradation and volatilization. As oxygen passes through the groundwater, contaminants are carried from the saturated zone to the unsaturated zone and eventually exit as vapors. The benefit of this in-situ process is that remediation occurs in the soil, instead of stripping and cleaning the contaminants at another location.

Air sparging is essential, as it increases the rate of decomposition by microorganisms. As oxygen levels rise, the microbe’s ability to break down contaminants increases. The increased biodegradation ultimately translates into a faster remediation process.

The air sparging interval was set at two minutes during cleanup. Pure oxygen was injected into the soil, carrying contaminants to 16 different purging wells.

The YSI 600XL was vital in screening this process. Three sondes, each able to monitor conductivity, salinity, and dissolved oxygen, were placed downwell to monitor the remediation process’ success.

With the help of the 600XLs, the firm was able to ensure oxygen was spreading throughout the remediation zone and better understand how the procedure was affecting the groundwater’s quality. Since oxygen consumption directly correlates with contaminant levels, the data also helped the firm verify how much contamination was in certain areas.

The 600XL was chosen because of its unique ability to measure dissolved oxygen to levels as high as 50 mg/L without requiring sample movement. This was ideal, as the firm anticipated extremely high levels of oxygen. An additional YSI sonde with a flow cell was used to verify data accuracy.

The YSI sondes have been reliable, accurate, and easy to use, according to representatives from the firm. The YSI 600XL has enabled it to complete the project efficiently while ensuring complete ground and water remediation will occur.

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These lakes remain frozen for as many as 10 months of the year due to the extreme cold and deep snowpack that develops. Because of the severe climate, these lakes respond strongly to outside pressure.

They are sensitive indicators — sentinels — of both local and larger scale environmental changes. For example, while visitors to the region may remark about the pristine beauty of the lakes, research has demonstrated that nitrogen deposition from cities throughout the western U.S. has been falling on the mountains in snow and rain, slowly enriching the lakes with nitrogen.

This gradual nitrogen increase has stimulated greater algae growth and altered the underwater ecosystems in many ways. In nearby Red Lodge, Mont., records of snowfall date back many decades, highlighting dramatic changes the region has experienced. Since 1970, average annual snowfall has decreased from about 250 inches to about 100 inches per year. Such dramatic changes, common throughout the western U.S., affect everything from the prevalence of wildfires to the transparency of the lakes.

Scientists from Miami University of Ohio and the University of Maine are conducting research on a series of alpine and subalpine lakes throughout the Beartooth Mountains. Alpine lakes, lying above the tree line, are often cold and clear.

In order to understand these sensitive ecosystems better, researchers from Miami deployed a data buoy this summer in Heart Lake, a remote alpine lake with an elevation of 10,350 feet located just inside Montana. Heart Lake lies in a small granitic watershed; steep walls shelter water that is deeper than 100 feet.

Despite its beauty, Heart Lake is unusual by alpine lake standards. While most lakes in the region are low in both dissolved organic carbon (DOC) and chlorophyll (an indicator of algal biomass), Heart Lake has unusually high chlorophyll, often as high as 15-20 µg/L. In contrast, the average chlorophyll concentration of many lakes in the region is about 1.5 µg/L. The high concentration in Heart Lake is more commonly found in Midwest agricultural reservoirs than Montana cold mountain lakes.

Challenging terrain, lack of roads, and thin air meant researchers had to think creatively in order to study Heart Lake. The remoteness of the lake meant all equipment had to be carried in backpacks. Additionally, since the deployment was in a National Forest, the buoy needed to have a low profile.

Working with Fondriest Environmental, graduate students at Miami designed a mobile buoy that was modular and lightweight. For example, anchors were fashioned from sleeping bag stuff sacks filled with shoreline rocks, instead of the more traditional 70-pound pyramid weights. The final buoy weight was 35 pounds (not including sensors). When scientists first visited Heart Lake in early July, several inches of ice remained. Warm summer temperatures, however, quickly melted the ice, and the buoy was deployed. Scientists visited the lake weekly throughout the rest of the summer, collecting manual samples, changing data logger batteries, and calibrating sensors.

Connected to the buoy was a YSI sonde with temperature, conductivity, dissolved oxygen, chlorophyll, and turbidity probe units. Also suspended beneath the buoy was a Turner CDOM sensor (with Zebra-Tech wiper), a Biospherical radiometer sensors measuring transparency to both UV and PAR at two depths, and a temperature string to help understand the lake’s thermal structure. Finally, a topside-mounted Vaisala weather station measured air temperature, wind speed, wind direction, relative humidity, barometric pressure, and rainfall. Sensors were powered and run by a NexSens SDL500 submersible data logger.

The data show that Heart lake changes rapidly once the ice cover melts. For example, the chlorophyll concentration, as estimated from the YSI probe, climbed rapidly from less than 5 µg/L to more than 11 µg/L within a week. It then quickly settled back down to a long period of about 2 µg/L until the buoy was removed in late August.

This suggests that the high chlorophyll concentration may be stimulated by nutrients in the watershed that enter the lake during snowmelt. Other data analyses are still being conducted, but these initial results suggest that alpine lakes exhibit clear signals of broader landscape phenomenon. This sentinel quality makes alpine lakes an ideal (and beautiful) place to study environmental processes and changes.

— Kevin Rose is a PhD candidate in the Department of Zoology at Miami University working with Dr. Craig Williamson. Kevin’s research focuses on understanding optical indicators of allochthony and carbon cycling in aquatic ecosystems.

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The team includes personnel from Wayne State University, the Great Lakes Environmental Center, and the U.S. Army Corps of Engineers. The researchers are using bathymetric survey data and collecting sediment cores to assess river morphology.

The survey is part of the team’s larger effort to estimate the rate of sediment deposition behind the network of dams in the Great Lakes watershed that are tributary to federal harbors, where reservoir sediment problems are an issue.

There are more than 100 federal harbors or federally maintained navigation channels in the Great Lakes, through which almost all of the precipitation falling in the Great Lakes Basin eventually passes. This results in a massive accumulation of sediment and contaminants. The U.S. Army Corps of Engineers spends approximately $40 million removing 2-4 million cubic yards of sediment from these channels annually.

Findings will be compared to historical data to establish predicted future rates of sediment accumulation, as well as remaining storage capacity. The team has collected bathymetry and sediment cores at five locations and plans to study a total of 10 to 15 sites over a three-year period.

“We hope to obtain historical bathymetry for all sites so that we can compare it to the new bathymetry to assist in the estimation of sedimentation rates,” said Adam Lacey, a civil and environmental engineering student at Wayne State. “We are also trying to use sites with USGS sediment gages just upstream of the reservoir. This will allow us to develop sediment rating curves for the sites.”

The research sites are intended to be representative of the overall conditions in the watershed. Selecting the appropriate locations, the researchers noted, is critical to ensuring the resulting findings can be applied to the watershed more generally. Most sites will be agricultural basins. A handful of forested and urbanized areas, however, will be used for comparison.

Dr. Mark Baskaran, geology professor at Wayne State, is in the process of dating the sediment cores to determine sedimentation rates in different areas of the reservoirs.

Additionally, to gather the needed bathymetric data, the team utilized a boat-towable SonTek RiverSurveyor M9 rented from Fondriest Environmental. The acoustic Doppler profiling unit emits ultrasonic acoustic bursts of known frequency to measure bathymetric data as well as information about river discharge.

A 500 kHz vertical beam allows for depth measurement as deep as 80 meters. Additionally, a real-time kinematic (or differential) GPS system records position data within ±3 cm accuracy, allowing bathymetry GIS data.

Bluetooth connectivity provides a wireless link from the M9 to a laptop or smart phone. Bathymetric, GPS, and velocity data is then transmitted and displayed graphically in real time.

“The M9 worked great and was very easy to use,” Lacey said. “The software, RiverSurveyor Live, is very user friendly, and it was easy to export into MATLAB and Excel before it was uploaded into ArcGIS.” Lacey said the graphs generated by RiverSurveyor Live were also useful to the study, both in the field and for post processing.

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Many of them ascend the mountain while riding the Manitou and Pikes Peak Cog Railway, which takes patrons from Manitou Springs to the mountaintop year-round as long as weather permits.

Weather is closely monitored along the railway and at the summit to ensure train operation is safe. Wind gusts can exceed 100 mph at such high altitudes, and a sustained blast could pose a danger to the trains and their passengers.

In order to better assess weather conditions, Manitou and Pikes Peak Cog Railway general manager Spencer Wren had a NexSens weatherVIC weather monitoring system from Fondriest Environmental installed. The system is easy to set up and includes all components necessary for logging weather data directly to a Windows-based computer.

The weatherVIC system includes a Vaisala WXT520 multi-parameter weather sensor, pre-wired 100 foot sensor cable, AC power supply, and NexSens weatherVIC software. After a few simple steps, the station begins logging real-time weather data.

With the help of this highly accurate automatic weather station, officials can temporarily suspend train operation if gusts exceed a certain wind speed or other conditions indicate travel is unsafe.

Image Credit: http://www.flickr.com/photos/salim/175590434/

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An international team of researchers has traveled to Ross Island to study colonies of Adélie penguins. They are investigating the penguins’ foraging habits and how they are coping with climate change.

With rich existing data sets, these penguin colonies provide a unique opportunity for understanding climate change’s impact. There has been extensive field research on penguin colonies here, as well as a 45,000 year-old record of bones and egg shells sealed within frozen deposits.

Researchers are using several advanced technologies to monitor the birds, including computerized weigh bridges, satellite telemetry, GPS, and microchips that identify individual penguins.

The research team is also using Vaisala WXT520 multi-parameter weather sensors from Fondriest Environmental to monitor weather conditions closely in the area around the penguin colonies.

The WXT520 is a compact weather measurement device with no moving parts that simultaneously measures wind speed and direction, liquid precipitation, barometric pressure, temperature, and relative humidity.

With this combination of data, scientists are able to examine how penguin populations are influenced by food sources, habitat, competition, and climate. The information they learn on this remote arctic island could provide valuable insight into how climate change will eventually affect life elsewhere on the planet.

To learn more about the research project, visit http://penguinscience.com.

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In order to protect this esteemed natural resource, the member-supported, non-profit Lake Sunapee Protective Association carefully monitors the lake’s water quality. The LSPA was founded in 1898 and is New Hampshire’s oldest environmental association.

The organization has been testing water quality in Lake Sunapee since 1950. A few years ago, a real-time water quality and weather data buoy was deployed in the lake to assist with monitoring efforts.

Data is wirelessly transmitted from the buoy every ten minutes, and it is part of the Global Lake Ecological Observatory Network, or GLEON.

Instruments on the buoy measure air temperature, wind speed and direction, humidity, photosynthetically active radiation, dissolved oxygen, and temperature.

Temperature is measured every 2-3 meters down through the water column to provide a comprehensive lake temperature profile. The LSPA, however, recently needed to replace the buoy’s temperature sensor string. Officials were impressed with the rugged hardware construction of NexSens T-Node water temperature sensors and chose them as the replacement.

Each T-Node includes a completely sealed, extremely precise temperature measurement system with top and bottom waterproof connectors. The T-Nodes have a range of 0-50 ºC and an accuracy of +/-0.1 °C for high-precision measurements. T-Nodes can withstand underwater deployments as deep as 100 meters.

The T-Nodes connect with underwater cabling to build a string of measurement sensors that are suspended vertically in the water column. (T-Nodes can also be strung horizontally along the seabed.)

The LSPA’s data logging equipment needed an SDI-12 output interface to read the temperature profile data, so a NexSens SDL submersible data logger was utilized as an SDI-12 output controller.

Unlike many data loggers, the NexSens SDL can also function in a slave mode, allowing it to output data in SDI-12 or Modbus format to third-party data loggers. With the SDL in place, temperature data from the T-Nodes can be read by the buoy’s Campbell Scientific data logger and transmitted wirelessly along with other environmental data to a remote computer.

Image Credit: http://en.wikipedia.org/wiki/File:LSPA_GLEON.jpg

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Recognizing that weather is the driving force behind most wildfires, researchers and first responders in San Diego utilize a sophisticated network of weather monitoring stations to detect potential wildfire conditions.

The High Performance Wireless Research and Education Network, a National Science Foundation-funded project, provides the communication backbone for many of these weather stations. The network is being developed by researchers at the University of California, San Diego, led by Hans-Werner Braun.

The non-commercial, high-performance, wide-area, wireless network connects university campuses as well as a number of difficult to reach areas in remote environments. The network is formed using Internet routers on mountaintops, interconnected via wireless links. In addition to first responder activities, it is used for collaborative cyber infrastructure on research and education.

Fondriest Environmental has supplied Vaisala WXT520 multi-parameter weather sensors to provide real-time measurement data at the monitoring sites. Two new sensors will soon be added to this weather network. These solid-state sensors were initially chosen several years ago to replace cup and vane anemometers, which had suffered mechanical failures. The WXT520 was selected because it is a near-comprehensive and compact weather measurement device with direct digital output.

The weather data transmitted from remote locations allow officials to make decisions before a wildfire actually ignites. Additionally, the monitoring stations are equipped with video cameras that provide a live image feed.

If humidity drops below a certain pre-determined limit, and wind direction and speed meet certain parameters as well, real-time alerts are sent to appropriate parties. Mobilization of firefighting resources — from aircraft to fire crews — can then begin in response to the calculated fire risk.

Data from these weather stations are used significantly by local agencies, and it is also forwarded to the National Oceanic and Atmospheric Administration and National Weather Service. This real-time data is publicly available at http://hpwren.ucsd.edu/Sensors/

Image Credit: http://hpwren.ucsd.edu/news/20080927/

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Drilling for natural gas in the Marcellus shale formation poses a significant threat to the river basin. The shale’s sedimentary rock holds sizable natural gas reserves, and a recent boom in drilling has heightened the danger to local water quality.

The Susquehanna River Basin Commission has been working to establish a comprehensive network of real-time monitoring stations in small streams and rivers throughout the basin. A monitoring system for the Susquehanna River itself is already in place, but the more expansive network was called for to better assess the impact of the drilling.

NexSens Technology has provided the data logging and remote telemetry systems used in the network. Each water quality station includes a NexSens data logger equipped with either cellular or Iridium satellite telemetry.

Monitoring sites are planned for locations where drilling in the shale is most active, as well as other locations with no drilling to serve as control data. Many of the new stations will be used for the New York portion of the project and as part of a partnership developing between SRBC and the Pennsylvania Department of Conservation and Natural Resources.

The water quality data collected includes water temperature, level, pH, conductivity, dissolved oxygen, and turbidity measurements. It may be viewed by officials, scientists, and the public to keep tabs on their local rivers and streams for threats of natural gas pollution as well as any other irregularities in the water.

For more information on the remote monitoring network, visit the Susquehanna River Basin Commission’s website.

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The real-time data, among many other benefits, forms an early warning system for coastal water pollution near Cleveland drinking plant intakes, thus ensuring the quality of tap water for the roughly 1.5 million residents of the city.

NOAA’s Real-time Environmental Coastal Observations Network project is a response to the critical need for a regional coastal observing system. The ReCon project aims to create a national network of low-cost coastal buoys capable of making water quality measurements throughout the water column. This whole-water-column data is transmitted using high-bandwidth wireless Ethernet communication networking standards. ReCon is benefiting a wide range of constituents by providing data to the public and educational institutions through a Web interface.

The NexSens temperature strings that will be utilized by the NOAA data buoys consist of connectorized digital smart sensor nodes, or T-Nodes. The T-Nodes are connected with underwater cabling to build a string of measurement sensors that are suspended vertically in the water column. (T-Nodes can also be strung horizontally along the seabed.)

The temperature strings allow for measurements throughout the water column instead of at a single point. Some information on surface temperature in the Great Lakes can already be gathered from satellite surface temperature maps and from other buoys with single-point temperature sensors, but they do not provide information on the critical thermal structure of the lake.

Each T-Node includes a completely sealed, extremely precise temperature measurement system with top and bottom waterproof connectors. The T-Nodes have a range of 0-50 ºC and an accuracy of +/-0.1 °C for high-precision measurements. T-Nodes can withstand underwater deployments as deep as 100 meters.

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The Great Lakes Ocean Research Priorities Plan, formed by a collaboration of U.S. Geological Survey researchers from the Water Science Centers and Great Lakes Science Center, aims to refine the techniques and science used to asses recreational water quality in the interest of providing managers with better data with which to make beach closure decisions and protect the public from illness. A network of Great Lakes buoys will help gather real-time data for the study.

Current practices for monitoring beach water quality rely on culturing fecal-indicator bacteria, a process that can take 18-24 hours, meaning the results often come too late to protect beachgoers. Moreover, according to the USGS, “sources of fecal contamination in recreational waters are often unknown and/or of nonpoint origins.”

The relations between coastal processes (sediment transport and storage, ground-water/surface-water interactions, wave actions, seiches, etc.) and bacteria concentrations have not been comprehensively studied in the Great Lakes. Development of methods that discriminate between human and animal nonpoint-source fecal contamination are needed to help identify risks associated with contaminated recreational waters. Finally, recreational waters are seldom monitored for pathogens, which often have different transport and survival properties than the fecal-indicator bacteria used to indicate their presence.

USGS researchers are trying to get a better sense of how hydrologic properties influence these pathogens and their transport patterns. Aiding in the research is a real-time monitoring network that includes nearshore NexSens MB-300 buoys with SDL500 submersible data loggers and cellular telemetry packages. Absolute level transducers are suspended beneath the buoys to measure information on wave energy.

With a fast enough sampling rate, these level transducers are capable of monitoring data about wave frequency and height. The sensor is mounted at a fixed location underwater and calculates the height of the water column above it. As a wave crest passes by, water column height increases; when troughs approach, it decreases. The resulting record of sea surface elevations can be used to calculate wave energy data.

The wave measurements will be combined with other real-time data, such as turbidity, as well as on-shore photosynthetically active radiation (PAR) and precipitation. This data will be analyzed along with routine water quality sampling at a number of beach sites.

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