Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Elevated Nitrogen and Phosphorus Still Widespread in Much of the Nation’s Streams and Groundwater

28.09.2010
Elevated concentrations of nitrogen and phosphorus, nutrients that can negatively impact aquatic ecosystems and human health, have remained the same or increased in many streams and aquifers across the Nation since the early 1990’s, according to a new national study by the U.S. Geological Survey.

“This USGS report provides the most comprehensive national-scale assessment to date of nitrogen and phosphorus in our streams and groundwater,” said Marcia McNutt, USGS Director. “For years we have known that these same nutrients in high concentrations have resulted in ‘dead zones’ when they reach our estuaries, such as during the spring at the mouth of the Mississippi, and now we have improved science-based explanations of when, where, and how elevated concentrations reach our streams and aquifers and affect aquatic life and the quality of our drinking water.”

“Despite major Federal, State and local efforts and expenditures to control sources and movement of nutrients within our Nation’s watersheds, national-scale progress was not evident in this assessment, which is based on thousands of measurements and hundreds of studies across the country from the 1990’s and early 2000’s,” said Matthew C. Larsen, USGS Associate Director for Water.

According to the U.S. Environmental Protection Agency, nutrient pollution has consistently ranked as one of the top three causes of degradation in U.S. streams and rivers for decades.

USGS findings show that widespread concentrations of nitrogen and phosphorus remain two to ten times greater than levels recommended by the EPA to protect aquatic life. Most often, these elevated levels were found in agricultural and urban streams. These findings show that continued reductions in nutrient sources and implementation of land-management strategies for reducing nutrient delivery to streams are needed to meet EPA recommended levels in most regions.

Nutrients occur naturally in water and are needed for plant growth and productive aquatic ecosystems; however, in high concentrations nutrients often result in the growth of large amounts of algae and other nuisance plants in streams, lakes and estuaries. The decay of these plants and algae can cause areas of low dissolved oxygen, known as hypoxic, or “dead,” zones that stress or kill aquatic life. Some forms of algae release toxins that can result in health concerns.

The study also found that nitrate is a continuing human-health concern in many shallow aquifers across the Nation that are sources of drinking water. In agricultural areas, more than one in five shallow, private wells contained nitrate at levels above the EPA drinking water standard. The quality and safety of water from private wells—which are a source of drinking water for about 40 million people—are not regulated by the Federal Safe Drinking Water Act and are the responsibility of the homeowner.

Because nitrate can persist in groundwater for years and even decades, nitrate concentrations are likely to increase in aquifers used for public drinking-water supplies during at least the next decade, as shallow groundwater with high nutrient concentrations moves downward into deeper aquifers.

“Strategies designed to reduce nutrient inputs on the land will improve the quality of water in near-surface parts of aquifers; however, decades may pass before quality improves in deeper parts of the aquifer, which serve as major sources for public-supply wells,” said Neil Dubrovsky, USGS hydrologist and lead scientist on this study. “Unfortunately, similar time delays for improvements are expected for streams that receive substantial inputs of groundwater”

A variety of sources can contribute nutrients to surface and groundwater, such as wastewater and industrial discharges, fertilizer and manure applications to agricultural land, runoff from urban areas, and atmospheric sources. USGS findings show that nutrient sources and resulting concentrations vary across the Nation. For example, concentrations of nitrogen generally are highest in agricultural streams in the Northeast, Midwest, and the Northwest, which have some of the most intense applications of fertilizer and manure in the Nation.

Differences in concentrations across the Nation also are due to natural features and human activities. For example, concentrations of nitrogen in streams draining parts of the agricultural Midwest are increased by contributions from artificial subsurface tile drains that are used to promote rapid dewatering of poorly drained soils. Conversely, concentrations of nitrate in streams draining parts of the Southeast appear to dissipate faster as a result of enhanced natural removal processes in soils and streams.

“This nationwide assessment of sources and natural and human factors that control how nutrients enter our streams and groundwater helps decision-makers anticipate where watersheds are most vulnerable to contamination and set priorities and management actions in different geographic regions of the country,” said Dubrovsky.

For more than 125 years, the USGS has served as the Nation’s water monitoring agency, including flow and (or) quality in selected streams and rivers across the U.S. USGS continues to work closely with the EPA, U.S. Department of Agriculture, the States, and local watersheds to assure that USGS monitoring and assessments provide useful information for managing nutrients throughout the Nation.

Water-quality data from more than 1,300 locations, much of it in real-time, is available through USGS Water Quality Watch. Additional information about surface water, groundwater and water quality is available at National Water Information System Web Interface. You can also receive instant, customized updates about water conditions by subscribing to WaterAlert, a new service from the USGS.

Kara Capelli | EurekAlert!
Further information:
http://www.usgs.gov

More articles from Ecology, The Environment and Conservation:

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>