Like people, plants need nutrients, but too much of a good thing can be a problem. Nutrients, such as nitrogen and phosphorus, occur naturally, but most of the nutrients in our waterways come from human activities and sources—fertilizers, wastewater, automobile exhaust, animal waste. The USGS investigates the source, transport, and fate of nutrients and their impacts on the world around us.
Featured: Nutrient yields in the Mississippi/Atchafalaya River Basin

A new USGS study estimates total nitrogen (N) and total phosphorus (P) yields from catchments throughout the Mississippi/Atchafalaya River Basin, which drains about 41% of the conterminous U.S. Results could assist nutrient reduction strategies.
BACKGROUND
Nutrients are essential for plant growth, but the overabundance of nutrients in water can have many harmful health and environmental effects. An overabundance of nutrients—primarily nitrogen and phosphorus—in water starts a process called eutrophication. Algae feed on the nutrients, growing, spreading, and turning the water green. Algae blooms can smell bad, block sunlight, and even release toxins in some cases. When the algae die, they are decomposed by bacteria—this process consumes the oxygen dissolved in the water and needed by fish and other aquatic life to "breathe". If enough oxygen is removed, the water can become hypoxic, where there is not enough oxygen to sustain life, creating a "dead zone".
WHAT ARE NUTRIENTS?
Nutrients are chemical elements found in the food that plants and animals need to grow and survive. Although there are many kinds of nutrients, two of the most important and abundant are nitrogen and phosphorus. Nitrogen and phosphorus occur in a variety of forms, or species, and the species present can change as they move between the air, water, and soil.
- AMMONIA (NH3) and AMMONIUM (NH4+) are among the primary forms of nitrogen in natural waters. Ammonia can be toxic to fish. It is also soluble in water and relatively unstable in most environments. Ammonia is easily transformed into nitrate (NO3-) in waters that contain sufficient dissolved oxygen or into nitrogen gas in waters that have no dissolved oxygen.
- NITRATE (NO3-) is another primary form of nitrogen in lakes and streams. Nitrate is verysoluble in water and is stable over a wide range of environmental conditions. It is readily transported in groundwater and streams. An excessive amount of nitrate in drinking water can cause health problems.
- PHOSPHATES (containing PO43−) are the most common form of phosphorus in natural waters. Phosphates are only moderately soluble and, compared to nitrate, are not very mobile in soils and groundwater. Phosphates tend to remain attached to soil particles, but erosion can transport considerable amounts of phosphate to streams and lakes.
Learn more about nutrients in our Nation's surface water and groundwater.
USGS Circular 1350
WHAT HAPPENS WHEN THERE ARE EXCESSIVE NUTRIENTS?
Eutrophication is a natural process that results from accumulation of nutrients in lakes or other bodies of water. Algae that feed on nutrients grow into unsightly scum on the water surface, decreasing recreational value and clogging water-intake pipes. Decaying mats of dead algae can produce foul tastes and odors in the water; their decay by bacteria consumes dissolved oxygen from the water, sometimes causing fish kills. Human activities can accelerate eutrophication by increasing the rate at which nutrients enter the water. Algal growth is usually limited by the available supply of either phosphate or nitrate, and we say that a water body is nitrogen limited if the ratio of nitrogen species to phosphorus species (N:P) is low, or is phosphorus limited if N:P is high.
Harmful algal blooms (HABs) are can be caused by many different types of algae in freshwater ecosystems, and can be triggered by nutrient enrichment. The most frequent and severe blooms typically are caused by cyanobacteria, the only known freshwater algae with the potential for production of toxins potent enough to harm human health. CyanoHABs can threaten human and aquatic ecosystem health. Economic damages related to cyanoHABs include the loss of recreational revenue, decreased property values, and increased drinking-water treatment costs.
RELATED USGS RESEARCH
The USGS works extensively across the country on a variety of aspects related to nutrients and eutrophication. Explore the related projects tab for some examples or click the links below.
- Agriculture and the Quality of the Nation's Waters
- Regional Stream Quality Assessments
- SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
- Harmful Algal Blooms
- Effects of Nutrient Enrichment on Stream Ecosystems
- Nutrient Loading for the Mississippi River and Subbasins
- Water-Quality Benchmarks, Including Nutrient Criteria
ADDITIONAL RESOURCES
U.S. Environmental Protection Agency
Natural Resources Conservation Service
Nutrients can come from many areas, but mostly they are associated with runoff from agricultural applications. Here are a few studies that relate to nutrients.
Agriculture and the Quality of the Nation's Waters
SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
NWQP Research on Harmful Algal Blooms (HABs)
Groundwater/Surface-Water Interaction
Agricultural Contaminants
Water-Quality Benchmarks for Contaminants
Regional Stream Quality Assessment (RSQA)
Phosphorus and Water
Nitrogen and Water
Biological Response to Nutrients
Excess Nutrients
Below are data or web applications related to USGS research on nutrients.
Data and model archive for multiple linear regression models for prediction of weighted cyanotoxin mixture concentrations and microcystin concentrations at three recurring bloom sites in Kabetogama Lake in Minnesota
Input and results from a boosted regression tree (BRT) model relating base flow nitrate concentrations in the Chesapeake Bay watershed to catchment characteristics (1970-2013)
Datasets and metadata for estimates of nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology
County-Level Estimates of Nitrogen and Phosphorus from Commercial Fertilizer for the Conterminous United States, 1987-2012
Water Quality and Hydrologic Data (2011-13) for Freshwater Science Paper titled, "Patterns of Diel Variation in Nitrate Concentrations in the Potomac River"
Follow the links below to USGS publications on nutrients and the quality of our nation's waters.
Understanding the influence of nutrients on stream ecosystems in agricultural landscapes
Nitrogen and phosphorus sources and delivery from the Mississippi/Atchafalaya River Basin: An update using 2012 SPARROW models
Factors affecting nitrate concentrations in stream base flow
Nitrate in streams during winter low‐flow conditions as an indicator of legacy nitrate
Cyanotoxin occurrence in large rivers of the United States
Cyanotoxins occur in rivers worldwide but are understudied in lotic ecosystems relative to lakes and reservoirs. Eleven large river sites located throughout the United States were sampled during June–September 2017 to determine the occurrence of cyanobacteria with known cyanotoxin-producing strains, cyanotoxin synthetase genes, and cyanotoxins. Chlorophyll-a concentrations spanned the range from o
Network controls on mean and variance of nitrate loads from the Mississippi River to the Gulf of Mexico
Using age tracers and decadal sampling to discern trends in nitrate, arsenic and uranium in groundwater beneath irrigated cropland
Response of nitrogen loading to the Chesapeake Bay to source reduction and land use change scenarios: A SPARROW‐informed analysis
Variable impacts of contemporary versus legacy agricultural phosphorus on US river water quality
Phosphorus and nitrogen transport in the binational Great Lakes Basin estimated using SPARROW watershed models
Drinking water quality in the glacial aquifer system, northern USA
Monitoring the Riverine Pulse: Applying high-frequency nitrate data to advance integrative understanding of biogeochemical and hydrological processes
Point-source nutrient loads to streams of the conterminous United States, 2012
Below are data or web applications related to USGS research on nutrients.
There are numerous software packages scientists use to investigate water quality and pollution transport. Here are a few examples of applications USGS uses.
RSPARROW
RSPARROW, now available on the USGS GitLab repository, provides the first open-source version of the USGS SPARROW water-quality model
SPARROW modeling: Estimating contaminant transport
SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources.
See what is newsworthy concerning water-quality in the Nation's lakes and rivers.
What's In Your Stream? Get Online to Find Out!
A new update to an online interactive tool for learning about pesticides, nutrients, and overall stream health in major regions of the U.S. is available from the U.S. Geological Survey’s Regional Stream Quality Assessment.
- Overview
Like people, plants need nutrients, but too much of a good thing can be a problem. Nutrients, such as nitrogen and phosphorus, occur naturally, but most of the nutrients in our waterways come from human activities and sources—fertilizers, wastewater, automobile exhaust, animal waste. The USGS investigates the source, transport, and fate of nutrients and their impacts on the world around us.
Featured: Nutrient yields in the Mississippi/Atchafalaya River BasinA new USGS study estimates total nitrogen (N) and total phosphorus (P) yields from catchments throughout the Mississippi/Atchafalaya River Basin, which drains about 41% of the conterminous U.S. Results could assist nutrient reduction strategies.
BACKGROUND
Nutrients are essential for plant growth, but the overabundance of nutrients in water can have many harmful health and environmental effects. An overabundance of nutrients—primarily nitrogen and phosphorus—in water starts a process called eutrophication. Algae feed on the nutrients, growing, spreading, and turning the water green. Algae blooms can smell bad, block sunlight, and even release toxins in some cases. When the algae die, they are decomposed by bacteria—this process consumes the oxygen dissolved in the water and needed by fish and other aquatic life to "breathe". If enough oxygen is removed, the water can become hypoxic, where there is not enough oxygen to sustain life, creating a "dead zone".
A scientist collects water-quality sample to better understand the role of nutrients in the overabundance of duckweed and algae. Too much nitrogen and phosphorus in water can lead to an overgrowth of free-floating plants such as duckweed and filamentous algae, resulting in dense layers of scum on the surface of the water. This can damage aquatic plants, fish, and other lake organisms by depriving them of the oxygen and sunlight they need to survive. (Credit: James Fischer) WHAT ARE NUTRIENTS?
Nutrients are chemical elements found in the food that plants and animals need to grow and survive. Although there are many kinds of nutrients, two of the most important and abundant are nitrogen and phosphorus. Nitrogen and phosphorus occur in a variety of forms, or species, and the species present can change as they move between the air, water, and soil.
- AMMONIA (NH3) and AMMONIUM (NH4+) are among the primary forms of nitrogen in natural waters. Ammonia can be toxic to fish. It is also soluble in water and relatively unstable in most environments. Ammonia is easily transformed into nitrate (NO3-) in waters that contain sufficient dissolved oxygen or into nitrogen gas in waters that have no dissolved oxygen.
- NITRATE (NO3-) is another primary form of nitrogen in lakes and streams. Nitrate is verysoluble in water and is stable over a wide range of environmental conditions. It is readily transported in groundwater and streams. An excessive amount of nitrate in drinking water can cause health problems.
- PHOSPHATES (containing PO43−) are the most common form of phosphorus in natural waters. Phosphates are only moderately soluble and, compared to nitrate, are not very mobile in soils and groundwater. Phosphates tend to remain attached to soil particles, but erosion can transport considerable amounts of phosphate to streams and lakes.
Learn more about nutrients in our Nation's surface water and groundwater.
USGS Circular 1350WHAT HAPPENS WHEN THERE ARE EXCESSIVE NUTRIENTS?
Eutrophication is a natural process that results from accumulation of nutrients in lakes or other bodies of water. Algae that feed on nutrients grow into unsightly scum on the water surface, decreasing recreational value and clogging water-intake pipes. Decaying mats of dead algae can produce foul tastes and odors in the water; their decay by bacteria consumes dissolved oxygen from the water, sometimes causing fish kills. Human activities can accelerate eutrophication by increasing the rate at which nutrients enter the water. Algal growth is usually limited by the available supply of either phosphate or nitrate, and we say that a water body is nitrogen limited if the ratio of nitrogen species to phosphorus species (N:P) is low, or is phosphorus limited if N:P is high.
Harmful algal blooms (HABs) are can be caused by many different types of algae in freshwater ecosystems, and can be triggered by nutrient enrichment. The most frequent and severe blooms typically are caused by cyanobacteria, the only known freshwater algae with the potential for production of toxins potent enough to harm human health. CyanoHABs can threaten human and aquatic ecosystem health. Economic damages related to cyanoHABs include the loss of recreational revenue, decreased property values, and increased drinking-water treatment costs.
Harmful algal blooms turn water in Milford Lake, Kansas, emerald green. (Credit: Jennifer Graham, USGS) RELATED USGS RESEARCH
The USGS works extensively across the country on a variety of aspects related to nutrients and eutrophication. Explore the related projects tab for some examples or click the links below.
- Agriculture and the Quality of the Nation's Waters
- Regional Stream Quality Assessments
- SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
- Harmful Algal Blooms
- Effects of Nutrient Enrichment on Stream Ecosystems
- Nutrient Loading for the Mississippi River and Subbasins
- Water-Quality Benchmarks, Including Nutrient Criteria
ADDITIONAL RESOURCES
U.S. Environmental Protection Agency
Natural Resources Conservation Service
- Science
Nutrients can come from many areas, but mostly they are associated with runoff from agricultural applications. Here are a few studies that relate to nutrients.
Agriculture and the Quality of the Nation's Waters
Intensive studies by the USGS National Water-Quality Assessment (NAWQA) Project in agricultural areas provide insight into how agricultural activities have altered the natural flow of water and the way that agricultural chemicals enter streams and aquifers, and in particular how nutrients affect algal and invertebrate communities in agricultural streams.SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources. Interactive, online SPARROW mapping tools allow for easy access to explore relations between human activities, natural processes, and...NWQP Research on Harmful Algal Blooms (HABs)
Harmful algal blooms (HABs) are caused by a complex set of physical, chemical, biological, hydrological, and meteorological conditions. Many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duration, and toxicity of HABs.Groundwater/Surface-Water Interaction
Water and the chemicals it contains are constantly being exchanged between the land surface and the subsurface. Surface water seeps into the ground and recharges the underlying aquifer—groundwater discharges to the surface and supplies the stream with baseflow. USGS Integrated Watershed Studies assess these exchanges and their effect on surface-water and groundwater quality and quantity.Agricultural Contaminants
About 40 percent of the land in the United States is used for agriculture, and agriculture supplies a major part of the our food, feed, and fiber needs. Agricultural chemicals move into and through every component of the hydrologic system, including air, soil, soil water, streams, wetlands, and groundwater.Water-Quality Benchmarks for Contaminants
How does the water quality measure up? It all depends on what the water will be used for and what contaminants are of interest. Water-quality benchmarks are designed to protect drinking water, recreation, aquatic life, and wildlife. Here you’ll find links to some of the most widely used sets of water, sediment, and fish tissue benchmarks and general guidance about their interpretation.Regional Stream Quality Assessment (RSQA)
The goals of the Regional Stream Quality Assessment (RSQA) are to characterize multiple water-quality factors that are stressors to aquatic life (contaminants, nutrients, sediment, and streamflow alteration) and to develop a better understanding of the relation of these stressors to ecological conditions in streams throughout the region.Phosphorus and Water
Nutrients, such as nitrogen and phosphorus, are essential for plant and animal growth and nourishment, but the overabundance of certain nutrients in water can cause a number of adverse health and ecological effects.Nitrogen and Water
Nutrients, such as nitrogen and phosphorus, are essential for plant and animal growth and nourishment, but the overabundance of certain nutrients in water can cause several adverse health and ecological effects.Biological Response to Nutrients
Eutrophication, or excess nutrients in streams, is typically one of the top reasons that a stream is listed as impaired on the 303(d) list as part of the Clean Water Act.Excess Nutrients
USGS scientists have gained a better understanding of the nutrient supply and how nutrients affect habitat quality, algal productivity, and food-web dynamics in the Bay-Delta. - Data
Below are data or web applications related to USGS research on nutrients.
Data and model archive for multiple linear regression models for prediction of weighted cyanotoxin mixture concentrations and microcystin concentrations at three recurring bloom sites in Kabetogama Lake in Minnesota
Multiple linear regression models were developed using data collected in 2016 and 2017 from three recurring bloom sites in Kabetogama Lake in northern Minnesota. These models were developed to predict concentrations of cyanotoxins (anatoxin-a, microcystin, and saxitoxin) that occur within the blooms. Virtual Beach software (version 3.0.6) was used to develop four models: two cyanotoxin mixture (MIInput and results from a boosted regression tree (BRT) model relating base flow nitrate concentrations in the Chesapeake Bay watershed to catchment characteristics (1970-2013)
This data release contains a boosted regression tree (BRT) model (written in the R programming language), and the input and output data from that model that were used to relate base flow nitrate concentrations in the Chesapeake Bay watershed to catchment characteristics. The input data consists of two types of information: 1) surface water nitrate concentrations collected by the USGS and partnerinDatasets and metadata for estimates of nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology
This USGS data release contains datasets, metadata, and figures associated with estimating nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology. There are three shapefiles with associated metadata and figures representing the shapefiles: Catchments_GWcontribN.shp: NHDPlus catchment estimates of groundwater contribution of nitraCounty-Level Estimates of Nitrogen and Phosphorus from Commercial Fertilizer for the Conterminous United States, 1987-2012
This data set contains county-level estimates of nitrogen and phosphorus from fertilizer, for both farm and nonfarm uses, for the conterminous United States, for 1987 through 2012. State-level farm and nonfarm nitrogen and phosphorus were derived from the Association of American Plant Food Control Officials (AAPFCO) commercial fertilizer sales data. State estimates were then allocated to the countWater Quality and Hydrologic Data (2011-13) for Freshwater Science Paper titled, "Patterns of Diel Variation in Nitrate Concentrations in the Potomac River"
This data set includes nitrate concentration, water temperature, and discharge collected every 15 minutes during Dec. 2011 - Nov. 2013 from the USGS gage at the Potomac River near Wash, DC, Little Falls Pump Sta (01646500). Additional data includes day length, and photosynthetically active radiation from USDA research station in Beltsville, MD. Several calculations derived from these data are incl - Multimedia
- Publications
Follow the links below to USGS publications on nutrients and the quality of our nation's waters.
Understanding the influence of nutrients on stream ecosystems in agricultural landscapes
Sustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and long-term economic,AuthorsMark D. Munn, Jeffrey W. Frey, Anthony J. Tesoriero, Robert W. Black, John H. Duff, Kathy Lee, Terry R. Maret, Christopher A. Mebane, Ian R. Waite, Ronald B. ZeltFilter Total Items: 54Nitrogen and phosphorus sources and delivery from the Mississippi/Atchafalaya River Basin: An update using 2012 SPARROW models
Nitrogen (N) and phosphorus (P) inputs throughout the Mississippi/Atchafalaya River Basin (MARB) have been linked to the Gulf of Mexico hypoxia and water‐quality problems throughout the MARB. To describe N and P loading throughout the MARB, SPAtially Referenced Regression On Watershed attributes (SPARROW) models were previously developed based on nutrient inputs and management similar to 1992 andAuthorsDale M. Robertson, David A. SaadFactors affecting nitrate concentrations in stream base flow
Elevated nitrogen concentrations in streams and rivers in the Chesapeake Bay watershed have adversely affected the ecosystem health of the bay. Much of this nitrogen is derived as nitrate from groundwater that discharges to streams as base flow. In this study, boosted regression trees (BRTs) were used to relate nitrate concentrations in base flow (n = 156) to explanatory variables describing nitroAuthorsSusan Wherry, Anthony J. Tesoriero, Silvia TerziottiNitrate in streams during winter low‐flow conditions as an indicator of legacy nitrate
Winter low‐flow (LF) conditions in streams provide a potential opportunity to evaluate the importance of legacy nitrate in catchments due to the dominance of slow‐flow transport pathways and lowered biotic activity. In this study, the concentration, flux, and trend of nitrate in streams during winter low‐flow conditions were analyzed at 320 sites in the conterminous United States. LF flow‐normalizAuthorsHenry M. Johnson, Edward G. StetsCyanotoxin occurrence in large rivers of the United States
Cyanotoxins occur in rivers worldwide but are understudied in lotic ecosystems relative to lakes and reservoirs. Eleven large river sites located throughout the United States were sampled during June–September 2017 to determine the occurrence of cyanobacteria with known cyanotoxin-producing strains, cyanotoxin synthetase genes, and cyanotoxins. Chlorophyll-a concentrations spanned the range from o
AuthorsJennifer L. Graham, Neil Dubrovsky, Guy Foster, Lindsey R. King, Keith Loftin, Barry Rosen, Erin StelzerNetwork controls on mean and variance of nitrate loads from the Mississippi River to the Gulf of Mexico
Excessive nitrate loading to the Gulf of Mexico (GoM) has caused widespread hypoxia over many decades. Despite recent reductions in nitrate loads observed at local scales, decreases in nitrate loading from the MRB to the GoM have been small (1.58 % during 2002-2012) with a low level of analytical confidence in this trend. This work seeks to determine the reasons why local-scale improvements have nAuthorsJohn T. Crawford, Edward G. Stets, Lori A. SpragueUsing age tracers and decadal sampling to discern trends in nitrate, arsenic and uranium in groundwater beneath irrigated cropland
Repeat sampling and age tracers were used to examine trends in nitrate, arsenic and uranium concentrations in groundwater beneath irrigated cropland. Much higher nitrate concentrations in shallow modern groundwater were observed at both the Columbia Plateau and High Plains sites (median values of 10.2 and 15.4 mg/L as N, respectively) than in groundwater that recharged prior to the onset of intensAuthorsAnthony J. Tesoriero, Karen R. Burow, Lonna Frans, Jonathan V. Haynes, Christopher M. Hobza, Bruce D. Lindsey, John E. SolderResponse of nitrogen loading to the Chesapeake Bay to source reduction and land use change scenarios: A SPARROW‐informed analysis
In response to concerns regarding the health of streams and receiving waters, the United States Environmental Protection Agency established a total maximum daily load for nitrogen in the Chesapeake Bay watershed for which practices must be in place by 2025 resulting in an expected 25% reduction in load from 2009 levels. The response of total nitrogen (TN) loads delivered to the Bay to nine sourceAuthorsMatthew P. Miller, Paul D. Capel, Ana M. Garcia, Scott W. AtorVariable impacts of contemporary versus legacy agricultural phosphorus on US river water quality
Phosphorus (P) fertilizer has contributed to the eutrophication of freshwater ecosystems. Watershed-based conservation programs aiming to reduce external P loading to surface waters have not resulted in significant water-quality improvements. One factor that can help explain the lack of water-quality response is remobilization of accumulated legacy (historical) P within the terrestrial-aquatic conAuthorsSarah M. Stackpoole, Edward G. Stets, Lori A. SpraguePhosphorus and nitrogen transport in the binational Great Lakes Basin estimated using SPARROW watershed models
Eutrophication problems in the Great Lakes are caused by excessive nutrient inputs (primarily phosphorus, P, and nitrogen, N) from various sources throughout its basin. In developing protection and restoration plans, it is important to know where and from what sources the nutrients originate. As part of a binational effort, Midcontinent SPARROW (SPAtially Referenced Regression On Watershed attribuAuthorsDale M. Robertson, David A. Saad, Glenn A. Benoy, Ivana Vouk, Gregory E. Schwarz, Michael T LaittaDrinking water quality in the glacial aquifer system, northern USA
Groundwater supplies 50% of drinking water worldwide, but compromised water quality from anthropogenic and geogenic contaminants can limit usage of groundwater as a drinking water source. Groundwater quality in the glacial aquifer system, USA (GLAC), is presented in the context of a hydrogeologic framework that divides the study area into 17 hydrogeologic terranes. Results are reported at aquifer-AuthorsMelinda L. Erickson, Richard M. Yager, Leon J. Kauffman, John T. WilsonMonitoring the Riverine Pulse: Applying high-frequency nitrate data to advance integrative understanding of biogeochemical and hydrological processes
Widespread deployment of sensors that measure river nitrate (NO3-) concentrations has led to many recent publications in water resources journals including review papers focused on data quality assurance, improved load calculations, and better nutrient management. The principal objective of this paper is to review and synthesize studies of high-frequency NO3- data that have aimed to improve undersAuthorsDouglas A. Burns, Brian A. Pellerin, Matthew P. Miller, Paul Capel, Anthony J. Tesoriero, Jonathan M. DuncanPoint-source nutrient loads to streams of the conterminous United States, 2012
Total nitrogen and phosphorous loads were estimated for 5,430 major point-source facilities (all types) and 11,537 minor wastewater treatment facilities discharging to streams in the conterminous United States during 2012. Facilities classified as a major discharger are typically a facility that discharges greater than one million gallons of water per day however some industrial facilities are claAuthorsKenneth D. Skinner, Molly A. Maupin - Web Tools
Below are data or web applications related to USGS research on nutrients.
- Software
There are numerous software packages scientists use to investigate water quality and pollution transport. Here are a few examples of applications USGS uses.
RSPARROW
RSPARROW, now available on the USGS GitLab repository, provides the first open-source version of the USGS SPARROW water-quality model
SPARROW modeling: Estimating contaminant transport
SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources.
- News
See what is newsworthy concerning water-quality in the Nation's lakes and rivers.
What's In Your Stream? Get Online to Find Out!
A new update to an online interactive tool for learning about pesticides, nutrients, and overall stream health in major regions of the U.S. is available from the U.S. Geological Survey’s Regional Stream Quality Assessment.