Green Bay Wisconsin Waterfront News & Great Lakes News (Page 1,823)

The study highlights a new and important finding: Controllable well construction choices, not just location and depth, influence arsenic concentrations in drinking water.

“Chronic exposure to high levels of naturally occurring arsenic through drinking water can cause certain cancers, skin abnormalities and other adverse human health effects,” said Melinda Erickson, a USGS research hydrologist and the lead author of the study. “Results from this study can help improve arsenic concentration predictions and help identify safer groundwater supply options in similar aquifers throughout the U.S. and globally.”

The glacial aquifers of Minnesota used for domestic wells commonly have elevated arsenic concentrations. The new study found that short well screen lengths of four or five feet, which are typical, were associated with higher probabilities of elevated arsenic concentrations. At the time of well drilling, choosing to place a well screen farther beneath the overlying confining unit, also called an aquitard, and/or using a longer-length screen would lower, though not eliminate, the risk of having high arsenic concentrations in the well water. 

USGS scientists created arsenic hazard maps for regions in northwestern and central Minnesota, and used a sophisticated statistical model to determine which environmental and man-made variables influence arsenic concentrations. They found that natural aquifer characteristics, such as position on the landscape and soil chemistry, were among the most influential for predicting elevated arsenic levels.

Public water supplies are regulated by the U.S. Environmental Protection Agency, but maintenance, testing and treatment of private water supplies are the responsibility of the homeowner. The EPA’s maximum arsenic level allowed for public water supplies is 10 micrograms of arsenic per liter of water. In Minnesota, arsenic concentrations exceed 10 micrograms of arsenic per liter in about 11 percent of newly constructed private wells, and arsenic is detectable in about 50 percent of wells. The Minnesota Department of Health recommends that well owners with detectable arsenic treat their drinking water.

Glacial and other sand and gravel aquifers similar to those in Minnesota exist across the northern U.S. and in places like southeastern Asia. Results from the study can help improve arsenic concentration prediction methods and groundwater infrastructure far beyond Minnesota.

This research was funded by the Minnesota Department of Health through the Minnesota Clean Water Fund and the USGS. The new study is published in the journal Water Resources Research. For more information about USGS water studies in Minnesota, visit the USGS Water Resources of Minnesota website.

This illustration compares the construction characteristics of two water wells. Note that the distance from the top of the well screen to the confining unit, or aquitard, is much shorter for the well on the right, as is the length of the screen in the underlying aquifer unit. Placing a well screen farther beneath the confining unit and/or using a longer-length screen, as shown for the well on the left, can decrease the likelihood of elevated arsenic concentrations in domestic well water. 

Credit: Modified from Figure 1 in Erickson & Barnes, 2005, reprinted with permission.

Original Article

USGS.gov

USGS.gov

https://www.usgs.gov/news/design-private-wells-can-lead-safer-drinking-water-minnesota

USGS.gov

Beginning in early November and lasting for several months, a low-level helicopter will begin flying over parts of seven states in the Mississippi Alluvial Plain, or MAP, to acquire a more robust picture of aquifers in the area.

This high-resolution, airborne geophysical survey, coordinated by U.S. Geological Survey scientists in partnership with local agencies, will provide critical data for the evaluation and management of groundwater resources in the region. This survey represents the second phase of the study as initial flights and data acquisition over the MAP started in February using the same helicopter system.

The helicopter and geophysical instrumentation is expected to arrive in Greenwood, Mississippi, on or around October 31. After arrival, setup and testing will occur, so the helicopter and device it tows beneath will be visible as soon as November 2-4. Once testing is completed, daily production flights in the region will begin, with flights operating out of Greenwood for approximately two weeks.

CGG RESOLVE helicopter system in Greenwood, Mississippi. The USGS is working with CGG and other partners to gather geophysical information related to the Mississippi Alluvial Plain. The helicopter will be deployed in several smaller focus areas of interest where a series of high-resolution survey grids will be acquired.

(Credit: Burke Minsley, USGS. Public domain.)

CGG Airborne of Ontario, Canada, under contract to the USGS, will make the daytime, low-level flights over more than 20 million acres within the MAP, including a buffer around the entire area. Experienced pilots who are specially trained and approved for low-level flying will operate the aircraft. All flights are coordinated with the Federal Aviation Administration to ensure accordance with U.S. law.

The MAP is one of the most productive agricultural regions in the nation and depends on groundwater for irrigation. It constitutes the third largest area of irrigated cropland in the U.S., consisting of approximately 29,000 square miles, or 19 million acres, and includes parts of Missouri, Tennessee, Arkansas, Mississippi, Louisiana, Kentucky and Illinois.

"This survey will allow the USGS to develop a high-resolution, three-dimensional representation of the groundwater resources for one the most important irrigated agricultural regions in the U.S.," said project lead and USGS scientist Wade H. Kress.

Instruments on the helicopter will collect information about the geology in shallow aquifers of the region. When the data analysis is complete, resulting state-of-the-art maps will help USGS researchers understand the aquifer system that supports groundwater resources at depths up to about 300 feet underground.

This survey will be flown along mainly east-west lines at about 200 feet above the ground. The helicopter will have an attached electromagnetic instrument housed in a cylinder called a bird that is towed about 100 feet beneath the aircraft.

The helicopter will also carry scientific instruments including a magnetometer and a gamma-ray spectrometer. None of the instruments pose a health risk to people or animals.

The survey is being conducted by the USGS Water Availability and Use Program as part of the Mississippi Alluvial Plain Regional Water Availability Study.  More information about this project can be found online.

Map of Mississippi Alluvial Plain airborne geophysical flight plan. Black lines indicate planned flight paths for an upcoming low-level helicopter survey that will occur over several months. Flights are scheduled to begin in the first week of November, 2018, based out of Greenwood, Mississippi. Online map and status updates can be found at http://arcg.is/01nraa.

(Public domain.)

Original Article

USGS.gov

USGS.gov

https://www.usgs.gov/news/seeking-water-above-low-level-helicopter-fly-above-mississippi-alluvial-plain

USGS.gov

During this string of intense storms, more than 100 USGS scientists and technicians were mobilized across the affected regions to keep the USGS’s streamgage network operational, perform on-site measurements of flooded rivers, install storm-tide and wave sensors prior to the nor’easter, and measure high-water marks as flood waters receded.

A second nor’easter was affecting areas from Virginia to Maine on March 7, and was expected to bring heavy snow to some areas already impacted by the nor’easter that hit the area March 2-3.

In the coming days and weeks, USGS specialists will continue to monitor streamgages, make on-site measurements of river discharge to determine how much water is flowing, and provide data to aid the response in the Midwest and Mississippi watershed. The data from the USGS’ nationwide streamgage network provides vital information to the U.S. Army Corps of Engineers, the National Weather Service, and other state and local agencies, enabling them to make river forecasts, operate flood control structures, and make important emergency management decisions. Besides aiding first responders and other emergency managers during the flooding, USGS streamgage data and flood science is used in the aftermath of floods and coastal storms to make decisions for long-term recovery.

Meanwhile, in the Northeast, coastal communities are just beginning to recover from the first nor’easter. Its intense winds and storm surge caused coastal erosion and tidal flooding in some states, leading to several deaths and leaving almost a million people without power. USGS crews will continue to document coastal flooding in the affected areas by analyzing the data gathered by the storm-tide and wave sensors deployed before the storm, and by flagging and surveying high-water marks, which will indicate to scientists how high the flood waters reached.

As some states struck by the severe weather begin to return to normal, others are dealing with continued flooding and the dangers that come with it. Here’s a look at some ongoing field work the USGS has been involved with over the past few weeks.  

Arkansas, Louisiana, Mississippi, and Tennessee

David Crum, USGS hydrologic technician, prepares for a discharge measurement on the Mississippi River near Memphis, Tennessee February 27, 2018.  Photo by Jerry Garrett, USGS. (Public domain.)

From the upper Midwest to southern Mississippi, as much as 15 inches of rain fell during the past two weeks, causing major flooding in parts of Michigan, Indiana, Illinois, Kentucky, Arkansas, Texas, and Tennessee. In some parts of Arkansas, Tennessee, Mississippi, and Louisiana, as much as 10 inches of rain fell in a five-day period — equal to two months of rain in just a few days. Though recent drought meant that flooding wasn’t as extreme as it could have been, streams exceeded moderate to major flood levels in portions of these four states.

During the flooding, the states recorded numerous peaks of record, or measurements that were the highest ever recorded at those specific streamgages. Visit the Lower Mississippi Gulf Water Science Center website for current conditions of rivers and streams in the Lower Mississippi Gulf region.

Indiana

Beginning February 19, parts of Indiana saw up to seven inches of rain across northern portions of the state. This rain, which fell onto snow-covered frozen ground, increased runoff and caused flooding.

Communities along the Ohio River in the southern portion of the state, such as Evansville and New Albany, were affected. So were parts of South Bend, Elkhart, Goshen, and some smaller towns on the St. Joseph, Kankakee, Iroquois, and Tippecanoe rivers.

Twelve people from the Indianapolis office responded. During the flooding, Indiana saw six peaks of record. Visit the USGS website for current conditions of Indiana’s rivers and streams.

Michigan

On February 22, 2018, USGS hydrologic technician Thomas Morgan took a period of record discharge measurement on the St. Joseph River at Niles, MI. The measurement — of 23,200 cubic feet per second — is the highest ever made at this site, which has been in operation since 1931. Photo by Nathan Prokopec, USGS. (Public domain.)

In Michigan, heavy rain, melting snowpack, and frozen ground combined to create textbook conditions for flooding. Hundreds of homes and businesses in flood-prone areas of the Grand, Kalamazoo, and St. Joseph river watersheds were affected. Though high water has largely subsided, some waterways are still overflowing their banks.

More than 20 crews were deployed in Michigan to take streamflow and water-level measurements and the state recorded seven peaks of record. For up-to-date information on rivers and streams in Michigan, visit the USGS website.

Kentucky

USGS measures discharge at the Ohio River at Olmsted Lock and Dam. USGS photo. (Public domain.)

Heavy rainfall in late February across the upper portion of the watershed caused moderate to major flooding along the middle and lower Ohio River. At the request of the U.S. Army Corps of Engineers, researchers used a boat to make special discharge measurements at various locations downstream of Barkley and Kentucky lakes. The Corps had not released a volume of water this large from those reservoirs since 2010, and wanted to verify the amount to be released. Along the Ohio River, USGS crews collected the highest discharge measurements ever taken at three different gauges. Special water quality samples were also collected for the National Water Quality Program on the lower Ohio River at two locations. Thirteen people from the USGS offices in Murray and Louisville responded over the course of 10 days.

Ohio

As with other states, flooding in Ohio was caused by rain and snowpack thaw. While the state was spared more severe rainfall, the combination of an inch or two of rain daily on top of already saturated ground made for flooding.

The flooding in Ohio has now subsided but during the event, more than 10 crews in Ohio measured high flows in Ohio. Visit the USGS website for current conditions of rivers and streams in the state of Ohio.

The Northeastern states

On Friday, March 2, a powerful nor’easter struck the Mid-Atlantic and New England states for the second time this winter, similar to a storm that caused record-breaking flooding in parts of the region in January. With strong winds and high waves, a major nor’easter can lead to flooding equivalent to or greater than a hurricane’s effect.  

Sal Amador, a USGS hydrologic technician, flags a high-water mark on a utility pole in Boston, Massachusetts. Photo by Christopher Bruet, USGS. (Public domain.)

USGS field crews deployed over 50 storm-tide and wave sensors from Maine to Delaware the day before the March 2 storm made landfall. The sensors are part of a relatively new USGS mobile network of instruments, designed for rapid deployment in the path of an oncoming storm, called the Surge, Wave, and Tide Hydrodynamics Network, or SWaTH Network. They continuously measure wave height and tide levels and provide information on the timing, duration, and extent of storm-tide flooding. Data are collected four times per second, providing a detailed picture of the storm.

Scientists went back to recover the sensors on March 5 and 6, as soon as it was safe to do so after the storm. All data from the sensors will be available via the USGS Flood Event Viewer later this week, and over the coming weeks USGS scientists will closely analyze the information.  

USGS research teams also spread out along the coast from Maine to Connecticut starting on March 4, to document the storm-tide flooding by flagging and surveying high-water marks, which are debris and dirt lines that reveal how high the flood waters reached. The teams’ first priority was to visit locations where high-water marks were found after a record-breaking blizzard that struck the region in 1978, and high-water mark locations from the January 2018 nor’easter, so the effects of those three significant storms can be carefully compared. Time was of the essence, since the winter storm of March 7 could wipe away the high-water marks.

The information gathered from the sensors and high-water marks will help officials understand coastal storms, prepare for their impacts, and ultimately build more resilient communities. Real-world data on a variety of storms and tracks allow for more precise and informed forecasts for future scenarios.

In southeast New York, USGS’ network of permanent real-time tide gauges recorded high water levels that persisted through six full cycles of high and low tides before gradually receding, with minor to moderate flooding recorded at 16 different gauges. Water levels reached major flood heights at one location, the Hudson Bay at Freeport, New York. That state’s crews were also out in the field collecting high-water marks and retrieving storm-tide and wave sensors soon after the high waters receded, and information about the New York coastal flooding is also available on the  USGS Flood Event Viewer.

Looking Toward the Future

Though flooding in the affected states has largely subsided, the USGS will continue to monitor stream conditions and use data collected to prepare for future disasters. For up-to-date info on conditions in your area visit the USGS WaterWatch website. Sign up for high-water alerts at the USGS WaterAlert website.

The USGS Coastal Change Hazards Portal provides forecasts on the potential for beach erosion, overwash and inundation during hurricanes and other severe coastal storms.

Real-time, six-hour forecasts of storm-induced total water levels and potential coastal changes can be found through the USGS Total Water Level Viewer.

The USGS also operates a network of permanent tide gauges that provide real-time information through the National Water Information System. These gauges supplement NOAA's long-term network of gauges.

Original Article

USGS.gov

USGS.gov

https://www.usgs.gov/news/usgs-flood-experts-respond-high-water-central-northeastern-us

USGS.gov

U.S. Geological Survey scientists will conduct a high-resolution airborne survey to study the geology under a region of the central Upper Peninsula, Michigan, until as late as July, 2018. The data will help USGS researchers improve their understanding of geology, including buried rock types and faults, in the region.

As part of this research, a low-flying airplane under contract to the USGS through EON Geosciences will be used. The aircraft will be operated by experienced pilots who are specially trained and approved for low-level flying. All flights are coordinated with the Federal Aviation Administration to ensure accordance with United States law.

“This study will help the USGS and partnered scientists understand the region’s fundamental geology and tectonic history in much greater detail than is currently known,” said USGS scientist Benjamin Drenth, a Denver-based researcher leading the survey.

The airplane will carry instruments to measure variations in the earth's magnetic field. Because different rock types vary in content of magnetic minerals, the resulting maps allow visualization of the geologic structure below the surface. The instruments carried on the aircraft only make passive measurements, and thus pose no health risk to humans or animals.

This survey will be flown in a grid pattern. North-south lines will be flown approximately 500 feet apart at elevations from 250-1000 feet above the ground, and one mile apart in an east-west direction. All survey flights will occur during daylight hours.

Original Article

USGS.gov

USGS.gov

https://www.usgs.gov/news/media-advisory-low-flying-airplane-study-geology-central-upper-peninsula-michigan

USGS.gov

In 2014-2016, the USGS and partners sampled study wells in northeast, northwest and central Minnesota—areas that commonly have elevated arsenic concentrations in well water—and examined the effects of various water-sampling methods for each of the wells. The researchers found that arsenic levels were most reliable when they were filtered, collected from household plumbing instead of from the drill rig pump or collected several months after well construction and installation.

“Improving the reliability of arsenic tests can help protect the health of people who drink well water in Minnesota by ensuring that residents receive the best possible information about the quality of their water,” said Melinda Erickson, a USGS hydrologist and the lead author of the study.

Chronic exposure to high levels of naturally occurring arsenic through drinking water is a human health hazard that can cause certain cancers, skin abnormalities and other adverse health effects. Minnesota state code requires that all new potable drinking wells be tested for arsenic. However, the code does not specify how to best collect samples for testing, and test results can vary depending on which sampling methods are used.

Particles and fine sediments within well water samples can result in inconsistent arsenic concentration measurements. The new study found that reducing the amount of sediments in water samples used for testing can improve the precision and consistency of arsenic measurements for private wells.

“Establishing guidance for drillers that includes specific sampling protocols for the filtration of water samples and/or collection of samples from household plumbing would improve the reliability of information provided to well owners because those samples have less undesirable sediment,” Erickson said.

Public water supplies are regulated by the U.S. EPA, but maintenance, testing and treatment of private water supplies are the sole responsibility of the homeowner. The maximum arsenic level allowed for public water supplies is 10 micrograms of arsenic per liter. In Minnesota, arsenic concentrations exceed 10 micrograms of arsenic per liter in about 11 percent of newly constructed private wells, and in certain counties, more than 35 percent of tested wells exceed the benchmark. 

The USGS partnered with the Minnesota Department of Health on the new study, which is published in the journal Groundwater. The research was funded by the State of Minnesota Clean Water Fund through the Minnesota Department of Health and the USGS Cooperative Matching Fund. The work was also supported by the National Science Foundation Graduate Research Fellowship Program and an internship provided through the Graduate Research Internship Program.

Original Article

USGS.gov

USGS.gov

https://www.usgs.gov/news/not-all-arsenic-tests-are-created-equal

USGS.gov

As part of the monitoring program, USGS scientists collected samples and used state-of-the-art sensors to gather water-quality data for 30 major Great Lakes tributaries during 2011 through 2013. Using sophisticated scientific models to analyze the data, scientists were able to more accurately estimate the amounts, or loads, of sediment and nutrients entering the Great Lakes from tributaries than by using traditional techniques. The program is highlighted in a new USGS publication.

“The approach we developed as part of the USGS water monitoring program provides an enhanced understanding of short-term variability and long-term changes in the quality of water from tributaries,” said Dale Robertson, a USGS scientist and the lead author of the report. “Understanding inputs from these rivers is important because they can affect the environmental health of the Great Lakes.”

Scientists collected and processed water-quality information from tributaries located in a wide range of land-use settings. Water-quality information included water flow; concentrations of total phosphorus, total nitrogen and suspended sediment; and data from sensors, such as turbidity.

“Taken together, the water-quality and input information from these rivers provide a broader and more accurate picture of how water from tributaries influences the environmental health of the Great Lakes, which are a multi-billion dollar per year resource,” Robertson said.

Due to the new methodology, the annual load estimates resulting from this water-quality monitoring effort may be different from previously released estimates by the USGS and other entities, according to Jon Hortness, the USGS Great Lakes Program Coordinator. 

The USGS Great Lakes tributary monitoring program can help evaluate the overall effects of Great Lakes Restoration Initiative management efforts.

The USGS monitoring program, its new scientific modeling approach and its water-quality estimates for 2011­ through 2013 are published in the Journal of Great Lakes Research.

For more information about USGS water studies in the Great Lakes and Midwest, please visit the USGS Upper Midwest Water Science Center or the USGS Great Lakes Restoration Initiative websites.

Original Article

USGS.gov

USGS.gov

https://www.usgs.gov/news/water-quality-monitoring-program-aids-restoration-great-lakes

USGS.gov