Dr. Michael T. Coe (http://www.whrc.org/about/cvs/mtcoe.html)
April 12, noon, Johnson House

"Feedbacks between deforestation, climate, and hydrology in the Amazon"

Abstract

Deforestation in the Amazon causes important changes in the energy and water balance by changing how incoming precipitation and radiation are partitioned among sensible and latent heat fluxes. Pasturelands and croplands (e.g. soybeans and corn) generally have a higher albedo and decreased water demand, evapotranspiration, and atmospheric turbulence compared to the forests they replace. These differences in the water and energy balance work at a variety of time and space scales and the combined influences on regional hydrology are complex. Observations from micro (2) to meso (100s km²) and large (10,000 km²) spatial scales in the Amazon clearly show that deforestation reduces evapotranspiration and increases soil moisture and stream flow. These changes result from the reduced leaf area index, altered phenology, decreased root density and depth, and total water demand of the pasture and crops compared to the native vegetation. Global and meso-scale climate model studies indicate that once deforestation occurs on a very large scale (> several 100,000s km²), atmospheric feedbacks may reduce regional precipitation. Replacing forest with higher albedo, less water-demanding crops and pastures leads to reduced net surface radiation, decreased moisture convergence over the basin, decreased water recycling, and reduced precipitation. The south-southeastern Amazon region has been most affected by these changes because of the combination of large-scale historical deforestation and its geographic position in a climatological and ecological transition zone. Given the current distribution of protected lands in south-southeastern Amazon, mitigation of future ecological impacts of externally and regionally driven climate changes will depend heavily on leveraging existing policy mechanisms to strengthen the protection of forests on private lands.

A copy of the Announcement is available at https://niwr.net/competitive_grants/RFP

Suggested citation:

Barlow, P.M., and Leake, S.A., 2012, Streamflow depletion by wells—Understanding and managing the effects of groundwater pumping on streamflow: U.S. Geological Survey Circular 1376, 84 p. (Also available at http://pubs.usgs.gov/circ/1376/. )

October 2012 (volume 7 - issue 9)

Contributed by Rebekah Perkins, Graduate Research Assistant, Biosystems and Bioproducts Engineering, University of Minnesota (Advisors: Bruce N. Wilson and John S. Gulliver)

Funded by Minnesota Department of Transportation (Dwayne Stenlund, Technical Liaison)

Stormwater runoff from construction sites (Figure 1) is a substantial source of non-point source pollution. This runoff contains eroded sediment from the exposed, barren ground that is often transported to nearby water bodies causing water quality impairment, degrading their biotic communities and filling up the water body with sediment. To mitigate these negative impacts, it is important to determine the amount of eroded sediment in runoff. The quickest and most cost effective method of doing so is to measure the turbidity of the runoff. Turbidity is an optical property of water associated with the light scattering properties of the particles suspended in water. This measurement can be used as a surrogate to determine the actual concentration of sediment in construction site runoff. If addition, high turbidity can be the primary pollutant for visibility in the water body, etc.

Figure 1: Runoff off of a local Twin Cities construction site. (Photo: Brad Hanson)

The United States Environmental Protection Agency (USEPA) is working toward setting a turbidity limit for construction and demolition sites. Suitable guidelines are needed for contractors to be able to accurately and cost-effectively monitor the turbidity of the runoff from their construction sites. Research is being conducted at the University of Minnesota evaluating construction site turbidity both in the field and laboratory. An important goal of this research is to develop protocol for turbidity monitoring that is easily understandable, repeatable and adaptable to a majority of construction sites. The research is also being done to gain insight into the factors that affect turbidity in construction site runoff. Both of these activities will be useful in establishing a reasonable turbidity standard limit for Minnesota.

Sampling of turbidity on a highly mobile construction site is a challenge. We discovered that a new measurement apparatus was needed that can be put into place without generating scour and can facilitate the turbidity instrumentation, yet can be moved easily and placed in a new location when needed. The development and features of this apparatus will be described in a later issue of UPDATES.

While our field work has provided knowledge about the benefits and shortcomings of the current monitoring techniques, we also quickly realized that our ability to attain insight into the factors affecting turbidity field work was limited due to the unpredictable site conditions and limited quality of field data. We thus incorporated a laboratory experiment that allowed for a controlled setting and a repeatable process for many different soils. The laboratory experiment relied on the acquisition of 14 soils from all over Minnesota. Synthetic runoff was created using a rainfall simulator (Figure 2) that rained on the soil for 30 minutes at an intensity corresponding to the peak intensity of a 2 year, 24 hour storm. The runoff from these soils was collected and thoroughly examined so that trends in turbidity with soil characteristics can be determined and used to develop a predictive relationship between them.

Figure 2: Laboratory apparatus including rainfall simulator, soil box, and collection basin. (Photo taken by Rebekah Perkins)

During the 30 minute rainfall, 50 mL samples of runoff were collected every 5 minutes and analyzed to understand how turbidity and concentration change over time during a rainfall. Each sample was then diluted, and concentration and turbidity values were recorded for each dilution to create time dependent concentration vs. turbidity curves, such as seen in Figure 3. After performing a regression analysis with different possible functions, it was seen that a power fit best represents the data.

Figure 3: Example of dilution curves. Regression equations are reported under the legend for each time sample.

From the regression equations in Figure 3, it is seen that the exponent values are close, but the constants before the exponent are different. The variation in this constant indicates that the relationship between turbidity and concentration varies with time. However, similar exponents suggest that these differences can largely be represented by properly selecting the constant before the exponent.

All of the dilution curves for the 14 soils and several replicates are plotted in Figure 4. The soils followed a pattern from left to right: the most silty soil, OV S, has the largest exponent on the left side of Figure 3. Moving to the right, the soil’s sand content increases and the silt content decreases.

Figure 4: Dilution curves for all 14 soils plotted together.

Figure 4 shows the dramatic difference among soils in the relationship between turbidity and suspended sediment concentration. For a given sediment concentration, the turbidity can clearly vary greatly depending on the type of soil. For some soils, only a few grams of soil per liter will skyrocket turbidity well over 1000 NTU, the highest readable turbidity value for many field meters. This trend as well as many soil characteristics will be considered in an analysis of the data.
Laboratory data are more useful if they are representative of runoff on construction sites. Similarities between laboratory and field data were evaluated by comparing results obtained at a construction site with those gathered in the laboratory for the same soil. Results for these conditions are shown in Figure 5. Three field samples collected at different times for the same runoff event and twelve 50 mL samples from the laboratory experiment are shown in this figure. The average exponent value for the field and laboratory samples is 1.38 and 1.39 respectively. The constant before the exponent values for the field samples are larger than those of the laboratory data. The runoff from the site flows over a considerable distance. Over this distance, the deposition of larger particles is likely, resulting in a finer distribution of sediment in the field sample. Larger constants before the exponent for finer distributions of sediment are consistent with observed trends in Figure 4.

Figure 5: Field samples 3, 12, and 20 and laboratory dilution curves from two replicates of AHS, soil from the same location, plotted together.

A more rigorous analysis of laboratory data is currently being conducted. From the analysis of the 50 mL samples, we are investigating relationships between turbidity and concentration for the power function defined as:

Turbidity = α*(Concentration)^β

where α and β will be determined based on data analysis and soil characteristics.

Our next steps include a detailed regression analysis to understand how parameters of α and β change with runoff samples and soil characteristics. An understanding of the α and β values will be useful in extending the laboratory work to conditions at construction sites. These steps are necessary to predict the effectiveness of sedimentation ponds and other practices in reducing turbidity from construction sites. The results will also be useful in establishing turbidity standards for Minnesota.

References

• Ankcorn, P. D. “Clarifying Turbidity – The Potential and Limitations of Turbidity as a Surrogate for Water-Quality Monitoring.” Proceedings of the 2003 Georgia Water Resources Conference, Athens, GA, 23-24 April 2003.
• Jastram, J. D. , Zipper, C. E., Zelazny, L. W., and Hyer, K. E. “Increasing Precision of Turbidity-Based Suspended Sediment Concentration and Load Estimates.” J. Environ. Qual., 39, 1306-1326. 2009.
• Hach. “Determining the Relationship Between Turbidity and Total Suspended Solids”. Analytical Procedures. Method 8366.
• Patil, S. S., Barfield, B. J., and Wilber, G. G. “Turbidity Modeling Based on the Concentration of Total Suspended Solids for Stormwater Runoff from Construction and Development Sites.” World Environmental and Water Resources Congress 2011. Palm Springs, CA, 22-26 May, 2011.

Office of Water Quality Water-Quality Information Note 2012.08

Subject:  New Water-Quality Portal Provides Access to Over 150 million Water-Quality Data Records

The U.S. Geological Survey (USGS) and U.S. Environmental Protection Agency (USEPA) have launched a new Water Quality Portal for discovery and acquisition of water-quality data. Technological advances and continuing collaboration over the past 10 years have made it possible to bring together discrete chemical, physical, and microbiological data from USGS’s National Water Information System Web Interface (NWISWeb) and USEPA’s modern Storage and Retrieval Data Warehouse (STORET) into one common Portal. Improved access to water-quality information, such as provided by the Portal, can lead to better informed water-quality management and policy decisions at all levels.

The Portal provides a single, user-friendly web interface showing where water-quality information is available from federal, state, tribal and other partners. It greatly reduces time and effort required to discover, evaluate, acquire, compile, and format discrete water-quality data and information. The Portal is unique in that it provides scientists, policy-makers, and the public with a single web interface to query data stored in the modern STORET and NWISWeb systems. The Portal utilizes the common nomenclature known as the Water Quality Exchange (WQX) to output data from NWISWeb and STORET and provide it in a consistent format. 

Data can be identified and acquired based on state, county, watershed, site(s) and by authoritative data source. Downloaded data can be served in comma-separated, tab-separated, MS Excel, Keyhole Markup Language (KML) and Extensible Markup Language (XML) file formats.  Future enhancements planned for the Portal in the near term include a data mapper to further simplify data discovery and acquisition.

For USGS users, the new Portal enhances the ability to readily acquire STORET information. This new Portal provides improved access to a wider range of water-quality data beyond NWISWeb for development of projects and proposals for water-quality monitoring, assessment, research, synthesis, and models. The Portal enables the aggregation of data from multiple sources and at multiple scales that in the past were relatively more difficult and time consuming to discover, acquire, and format for analysis. This new Portal is the culmination of many years of collaborative work between USGS and USEPA.  Initial water-quality web services were released by both agencies in 2008 (http://www.usgs.gov/newsroom/article.asp?ID=2046) as a first step in a long-term data sharing collaboration. These initial web services provided data in a common format which allowed users to merge datasets after retrieval from each agency database. While web service calls developed using the older USGS “Mini Portal” interface (http://qwwebservices.usgs.gov/portal.html) continue to be supported, we encourage users to update software and scripts to reflect the updated URLs from the USGS/USEPA Water Quality Portal (http://www.waterqualitydata.us/portal.html).

The Portal is a cooperative service sponsored by the USGS, the USEPA, and the National Water Quality Monitoring Council (NWQMC). The NWQMC provides a forum to improve the Nation's water quality through partnerships that foster increased understanding and stewardship of our water resources. The Portal is supported, in part, through funding from the USGS’ National Monitoring Network for Coastal Waters and their Tributaries and the USEPA Office of Water. The new Water-Quality Portal can be accessed at http://www.waterqualitydata.us/.

For additional information on using or contributing data to the Portal, contact Nate Booth (nlbooth@usgs.gov). For programmatic and general information contact Mike Yurewicz (mcyurewi@usgs.gov ).

WaQI Notes are archived on the Office of Water Quality web site, http://water.usgs.gov/usgs/owq/WaQI/index.html

Signed,

The Office of Water Quality
September 7, 2012

Having only left to attend college and university in Montreal, Steiche now co-owns a café in neighbouring Bedford, and repeatedly mentions how beautiful his hometown and the Missisquoi Bay region are.

But the 34-year-old new father said he won’t allow his son to experience the same happiness that is being on the water, at least not anytime soon.

The bay, which is part of Lake Champlain, was overrun Thursday by blue-green algae.

Cyanobacteria, its scientific name, is naturally present in Quebec’s lakes and rivers in low concentrations, according to the environment ministry’s website.

But if the conditions are right, the algae multiplies and forms a bloom, what it’s called when it’s visible to the naked eye. And this year, the conditions were more than right.

The algae feed off of phosphorous, an element that can come from natural sources, but is also found in manure, compost, fertilizer, septic systems and waste water that has not been properly treated.

The Missisquoi Bay region was one of many affected by last year’s flooding. The flood waters introduced many of the ingredients needed to create a phosphorus surplus into the lake water.

The algae also thrives in warm temperatures and under UV rays.

Add low water levels and the natural shallowness of the bay, which means the sun can easily warm not only the water, but the soil beneath it as well, and conditions were rife this summer for the formation of blooms.

The phenomenon occurs every year in the Missisquoi Bay. What was abnormal is the extent of the problem.

Doug Shaver has lived in Philipsburg since 1980, but his family has been living in the area for generations.

He said the water was so murky Friday it seemed as though the bay was filled with blue and green paint. A white foam was also visible in the water.

The abundance of algae means there’s less oxygen in the water, which in turn kills the fish.

“You could take a stick of dynamite and throw it in the lake and watch the fish come up to the surface. It would be the same effect,” Shaver said.

He estimated that anywhere between 3,000 to 4,000 dead fish are piled up on the shore.

Mayor Réal Pelletier has lived along the shoreline for 20 years, and said he’s never seen a sight quite like the scene on the lake now.

He says at least two kilometres of shoreline is covered with rotting fish.

Pelletier said he contacted the environment ministry and the natural resources and fauna ministry to alert them of the problem. Though employees of the environment ministry came to test the water, both ministries told him they could not help clean up the fish.

They did suggest the municipality undertake the cleanup operation. But when neither agency could guarantee workers wouldn’t be harmed in the efforts, he decided against it.

Representatives from both ministries were unavailable Saturday to explain their policies when a town reports a case of blue-green algae of this scope.

Shaver explained the area’s residents are used to the bacteria’s annual appearance and the unpleasant but tolerable smell that comes along with it. But this year, it was something else entirely.

Steiche described the stench as a mix of rotting fish, “hot algae smell,” and pig manure. Pelletier likened it to a septic tank.

The smell was so vile that residents were forced to close their windows in order to escape it.

Philipsburg has also been under a boil water advisory since the beginning of last week, but Pelletier said he was told by the public safety ministry it was not related to the algae problem.

When the temperature cooled off and the wind picked up Friday night into Saturday, the blooms began to disappear and the water soon cleared up.

Though the bay is no longer murky, the reason why the blooms flourished with such fervour is still a mystery.

Theories abound, but no one knows for sure which and to what extent the common factors contributed to the sequence of events that unfolded Thursday into Friday.

“I’m waiting for the results from the (environment ministry), Pelletier said. “I hope they’re going to do more tests and find where it comes from, because I know the water is really low this year, but it can’t be only that.”

Read more: http://www.montrealgazette.com/technology/Blue+green+algae+kills+thousands+fish+Missisquoi+with+video/7112246/story.html#ixzz24lSjMcL4

The spiny waterflea, an aquatic invasive zooplankton native to Eurasia, has been confirmed in the Champlain Canal and the Glens Falls Feeder Canal. This marks the first known occurrence of spiny waterflea in the Lake Champlain Basin. Analysis of the samples collected by SUNY Plattsburgh working with the NYSDEC also suggests that fishhook waterflea, another invasive species, may be present in the two systems. 

A small number of spiny waterfleas, which compete with other zooplankton for food and foul anglers’ downriggers and fishing lines, were discovered during routine monitoring efforts, established to detect the presence of new invasive species.  This discovery is a reminder of the critical need to address the issue of the Champlain Canal as a potential vector for additional introductions between Lake Champlain and the Hudson River.

Experts from agencies in New York, Vermont, and Quebec were alerted to this new invasion, understanding that the introduction of a new aquatic invasive species (AIS) affects the entire watershed.  Dave Tilton, U.S. Fish and Wildlife Lake Champlain manager and Chairman of the Rapid Response Task Force, said “Biologists from state and federal agencies around Lake Champlain are currently working to determine whether feasible methods exist to prevent the spread of spiny waterflea to the Lake through the canal. This new threat illustrates how important it is to find the means to implement the Army Corps of Engineers' authority, granted by Congress, to complete a feasibility study and develop a barrier to invasive species in the Canal.”

Spiny waterfleas were identified in water samples taken north of Lock 9 in the Champlain Canal and in the western end of the Glens Falls Feeder Canal as part of the Lake Champlain Long-term Water Quality and Biological Monitoring Project, a joint effort by NYSDEC, Vermont Department of Environmental Conservation, and with funding from the Lake Champlain Basin Program. Sample identification was confirmed at the Lake Champlain Research Institute at SUNY Plattsburgh.

"The discovery of spiny waterflea in the Champlain Canal is a reminder that there are many other aquatic invasive species that may move between the Hudson and Champlain Watersheds through the canal," said Kathy Moser, New York State Department of Environmental Conservation Assistant Commissioner for Natural Resources.  "Individuals must take steps to ensure that their boats, fishing equipment and other recreational gear, are not transporting aquatic invasive species. We also need to redouble our efforts to prevent other aquatic invasive species

from moving through the Champlain Canal."

The New York State Canal Corporation is responsible for operation of the extensive canal system throughout NY, and they have a strong track record of working cooperatively with NYSDEC and the Lake Champlain Basin Program to address aquatic invasive species spread prevention in the Champlain Canal. The Canal Corporation has formally requested that the U.S. Army Corps of Engineers (USACE) initiate the Champlain Canal dispersal barrier feasibility study to determine how to best prevent the spread of aquatic invasive species.

“With the cooperation of the LCBP and the NYSCC, the Army Corps of Engineers may perform a study on the feasibility of a dispersal barrier for the Lake Champlain Canal under several existing authorities,” said Jenifer Thalhauser, Project Manager for the Corps of Engineers. “We are currently working together to identify the best approach to initiate this study.

Vermont Senator Patrick recently secured $200K for the Lake Champlain Basin Program to assist with a Champlain Canal Feasibility Study with the USACE. The study, a cooperative effort between USACE, NYSCC, and LCBP will investigate all possible options to reduce the spread of future AIS that might travel back and forth along the Champlain Canal.

“We urge all recreational users to take precautions to reduce the spread of invasive species,” said Meg Modley from the Lake Champlain Basin Program. “As is often the case with new introductions of aquatic invasive species, there are no practical means to eradicate spiny waterfleas, so limiting their spread is the only way to prevent their impacts on native aquatic communities.” Microscopic life stages of invasive species are not always visible to the naked eye. Therefore, never transport water from one lake to another.

It is very important that boaters, anglers and other recreational enthusiasts take precautions to avoid transporting this and other invasive species, particularly after leaving waters known to have an aquatic invasive species. Inspect and clean recreational equipment and boats, dry the equipment before using it on another water body and disinfect equipment when drying is not a possibility.

For further information, contact Meg Modley at LCBP (802) 372-3213.

-additional background information-

Native to Eurasia, the spiny waterflea arrived in the Great Lakes via transoceanic ships. It feeds on tiny crustaceans and other zooplankton that are food for fish and other native aquatic organisms, putting them in direct competition for this important food source. In warmer water temperatures they can hatch, grow to maturity, and lay eggs in as little as two weeks. Contrarily, "resting" eggs of spiny waterfleas can remain dormant for long periods of time prior to hatching. The tail spines of the spiny waterflea hook on fishing lines and foul fishing gear.

Spiny waterfleas were previously confirmed in Great Sacandaga Lake in 2008, and subsequently in Peck Lake, Stewarts Bridge Reservoir and Sacandaga Lake. Most of these waters flow into the Hudson River which is a source of water for the Glens Falls Feeder Canal which, in turn, feeds the Champlain Canal.

INSPECT & CLEAN your boat and boating equipment (anchor, lines, paddles, lifejackets, etc), trailer, tow vehicle hitch area, fishing gear (downriggers, line, reels, nets, etc), and recreational equipment (skis, tubes, towlines, etc) and remove all mud, plants and other organisms that might be clinging to them. Drain bilges, live wells, bait buckets, and lower units.

DRY your fishing and boating equipment before using it on another body of water. Drying is the most effective "disinfection" mechanism and is least likely to damage sensitive equipment and clothing. All fishing and boating equipment, clothing and other gear should be dried completely before moving to another body of water. This may take a week or more depending upon the type of equipment, where it is stored and weather conditions. A basic rule of thumb is to allow at least 48 hours for drying most non-porous fishing and boating gear at relative humidity levels of 70% or less.

DISINFECT your fishing and boating equipment if it cannot be dried before its use in another body of water. Disinfection recommendations vary depending on the type of equipment and organism of concern. Be particularly aware of bilge areas, livewells and baitwells in boats. These areas are difficult to dry and can harbor invasive species.

See the NYS DEC website for more information on aquatic invasive species and how you can stop their spread: http://www.dec.ny.gov/animals/48221.html

USGS Spiny Waterflea Fact Sheet: http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=162

There is no additional fee to attend this workshop, but advance sign-up is required. Please email ASDSO and ask to have your name added to the participant list. The objective of this workshop is to present the working principles of the DSS-WISE model, discuss the characteristics of the DSS-WISE "Lite" implementation, and give workshop participants hands-on experience with using the software tools. 

This special version of the DSS-WISE software -called DSS-WISE "Lite"-is now available for performing first-tier dam-break simulation and mapping automatically using a simple, graphical user interface connected to the Dams Sector Analysis Tool (DSAT). DSAT is a Web-based platform that provides secure access to multiple analytical modules and applications. One of the important features of DSAT is its geospatial viewer, which allows users to automatically set up a dam-break flood simulation using DSS-WISE Lite. See the Specialty Workshops page of the Dam Safety 12 website for agenda details to be posted soon. 

 Ground-water quality conditions in 230 wells and 35 springs in the Valley and Ridge Physiographic Province indicated that bedrock type and land use were dominant factors influencing groundwater quality. Wells and springs in carbonate-rock aquifers in the Valley and Ridge are much more likely to have anthropogenic contaminants than wells in siliciclastic-rock aquifers because of a combination of aquifer susceptibility and the land-use practices preferentially located on the land overlying these aquifers. The most powerful single predictor of elevated groundwater contaminant levels in the Valley and Ridge aquifers is rock type, as shown by higher likelihoods of elevated nutrients, pesticides, volatile organic compounds, and bacteria counts in carbonate-rock aquifers and of elevated radon and dissolved mineral concentrations in siliciclastic-rock aquifers.

· Trace elements and radon in groundwater across the United States – (USGS Report) Learn about other NAWQA trace element studies.

About 20% of untreated water samples from over 5,000 public, private, and monitoring wells across the nation contain concentrations of at least one trace element, such as arsenic, manganese, and uranium, at levels of potential health concern. Long-term exposure to arsenic can lead to several types of cancer, and high levels of uranium can cause kidney disease. In doses similar to some of those found in this study, manganese can adversely affect child intellectual function and, in large doses, acts as a neurotoxin, causing symptoms similar to those experienced by sufferers of Parkinson’s disease. Most trace elements, including arsenic, manganese, and uranium, get into the water through the natural process of rock weathering. In public wells these contaminants are regulated by the U.S. Environmental Protection Agency and are removed from the water before people drink it. However, trace elements could be present in water from private wells at levels that are considered to pose a risk to human health, because they aren’t subject to regulations.

· Subsurface transport of orthophosphate in five agricultural watersheds, USA – Access the featured article in the October 2011 issue of the Journal of Hydrology.

Phosphorus transport in groundwater was assessed at five agricultural watersheds in California, Indiana, Nebraska, Maryland, and Washington. Under conditions where phosphorus is either not entirely taken up by plant tissue or where soil chemistry does not favor either precipitation or sorption, sub-surface transport can result in elevated concentrations in groundwater or loadings to receiving streams. Iron oxides had an effect on phosphorus movement and concentrations at all locations, and groundwater chemistry, especially pH, exerted a major control on the amount of phosphorus adsorbed.

·  Simulation of decay of atrazine and metabolites in adapted and nonadapted soils – Access the featured article in the June 2011 issue of the Environmental Toxicology and Chemistry journal.

Decay of a common herbicide, atrazine, and its metabolites observed in unsaturated soils adapted to previous atrazine applications and in soils with no history of atrazine applications was simulated using a branched serial first-order decay model. Results from application of the model indicated that atrazine and its 3 primary metabolites are less persistent in adapted soils than in nonadapted soils and that hydroxyatrazine was the dominant primary metabolite in most of the soils tested. These can reduce the uncertainty in predicting the fate and transport of pesticides and their metabolites and thus support improved agricultural management schemes for reducing threats to the environment.

Streams

·  Organic compounds assessed in Chattahoochee River water used for public supply near Atlanta, Georgia, 2004-05 –  (USGS Fact Sheet)  Learn about other NAWQA source water-quality assessments.

Thirty-three of 266 organic compounds were commonly detected in source water and 27 were commonly detected in finished water from the Chattahoochee River, which is the main water-supply source for the Atlanta metropolitan area.  Eighteen of 33 organic compounds in source water also were commonly detected in finished water and often at similar low-level concentrations. Detected compounds included 11 pesticides and degradates and 4 personal care and domestic-use products. Many of the compounds detected most commonly in water from the Chattahoochee River were among the most commonly detected in ambient stream water and groundwater across the Nation.

·  Environmental factors that influence the location of crop agriculture in the conterminous United States – (USGS Report)
High-resolution geospatial data identifying the range of environmental conditions that influence the location of agricultural lands in the conterminous U.S. are described.

· Tillage Practices in the conterminous United States, 1989-2004 – Access the USGS (USGS Data Series)  
Methods used to aggregate county-level tillage practices (conservation tillage, reduced tillage, and intensive tillage) to the 8 digit hydrologic unit watershed are documented for the conterminous U.S.

·  Nitrate in the Mississippi River and its tributaries, 1980 to 2008: Are we making progress –

Access the featured article in the August 2011 issue of the Environmental Science and Technology journal. Learn about other NAWQA nutrient assessments.

Little consistent progress in reducing riverine nitrate has occurred since 1980 and flow-normalized concentration and flux are increasing in some areas of the Mississippi River basin based on results of the Weighted Regression on Time, Discharge, and Season (WRTDS) statistical method. Flow-normalized nitrate concentration and flux increased between 9 and 76% at four sites on the Mississippi River and a tributary site on the Missouri River, but changed very little at tributary sites on the Ohio, Iowa, and Illinois Rivers. Increases in flow-normalized concentration and flux at the Mississippi River at Clinton and Missouri River at Hermann were more than three times larger than at any other site. At most sites, concentrations increased more at low and moderate streamflows than at high streamflows, suggesting that increasing groundwater concentrations are having an effect on river concentrations.

·  Suspended Sediment/Sand Concentrations and Loads in the Mississippi River Basin, 1940-2009 – (USGS Data Series)

Annual total suspended-sediment and suspended-sand loads are presented at 48 sites within the Mississippi River Basin for water years 1940 through 2009.

·  SPARROW modeling to understand water-quality conditions in major regions of the United States: A featured collection introduction – The Featured Collection of the August 2011 issue of the Journal of American Water Resources Association focuses on the application of SPARROW (SPAtially Referenced Regressions On Watershed attributes) models. The regional SPARROW models simulate long-term mean annual stream nutrient loads as a function of a wide range of known sources and climatic (precipitation, temperature), landscape (e.g., soils, geology), and aquatic factors affecting nutrient fate and transport. The Featured Collection includes articles on descriptions and a synthesis of the 6 regional modeling studies of stream nutrients and 1 regional model of dissolved solids, methods used to compile the key geospatial datasets used in the models, an overview of the digital stream networks in the models, and a web-based decision support system that provides access to the regional SPARROW models. Learn more about the regional SPARROW models: Fact Sheet, Briefing Video, Regional SPARROW models.

·  Factors affecting stream nutrient loads:  A synthesis of regional SPARROW model results for the continental United States– (article)

·  A web-based decision support system for assessing regional water-quality conditions and management actions – (article) (Decision Support System)

Regional SPARROW models
·  Northeastern and Mid-Atlantic regions  – (article )

·  Southeastern United States – (article)

·  Laurentian Great Lakes – (article)

·  Missouri River Basin  – (article, fact sheet)

·  South-Central United States – (article)

·  Southwestern United States – accumulation of dissolved solids – (article)

·  Pacific Northwest – (article 2011)


       Supporting Articles
·  Digital hydrologic networks supporting applications related to spatially referenced regression modeling – (article)

·  Nutrient loadings to streams from municipal and industrial effluent –  (article)

·  A multi-agency nutrient dataset used to estimate loads, improve monitoring design, and calibrate regional nutrient SPARROW models – (article)

·  The regionalization of national-scale SPARROW models for stream nutrients – (article)