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Nutrients

Overview

Plants and animals need nutrients to survive. But when too many nutrients enter rivers, streams and the Chesapeake Bay, they fuel the growth of algae blooms and create conditions that are harmful for fish, shellfish and other underwater life. In fact, excess nutrients are the main cause of the Bay’s poor health.

How do excess nutrients enter the Chesapeake Bay?

While nutrients are a natural part of the Chesapeake Bay ecosystem, nutrients have never been so abundant in the environment. Before humans built roads, homes and farm fields, most nutrients were trapped and absorbed by forest and wetland plants. As these habitats were removed to accommodate a growing population, nutrient pollution to the Bay increased.

Almost all people and industries in the watershed—and even some outside of the watershed—send nutrients into the Bay and its tributaries. Nitrogen and phosphorous are the two nutrients of concern in the area. In general, these nutrients reach the Bay from three sources: wastewater treatment plants; urban, suburban and agricultural runoff; and air pollution.

  • There are hundreds of wastewater treatment plants in the watershed. In 2005, watershed jurisdictions put a new permit process in place to limit the amount of nutrients these plants could send into rivers and streams. Computer simulations of pollution controls put in place between 2009 and 2013 indicate that nitrogen loads to the Bay from wastewater treatment plants and combined sewer overflows have declined 54 percent since 1985, while phosphorous loads from the same sources have declined 72 percent.
  • Nutrients that run off of the land and into the water through urban, suburban and agricultural runoff come from a range of sources, including lawn fertilizers, septic systems and livestock manure.
  • Air pollution emitted by cars and trucks, industries, gas-powered lawn tools and other sources contributes about one-third of the total nitrogen load entering Chesapeake waterways. This air pollution can come from any location within the Bay’s “airshed,” which measures about 570,000 square miles and stretches to Canada, Ohio and South Carolina.

Nutrients can also come from natural sources, like soil, plant material and wild animal waste.

Why are excess nutrients a problem for the Chesapeake Bay?

Excess nutrients fuel the growth of harmful algae blooms, which:

  • Block sunlight from reaching underwater grasses
  • During decomposition, create “dead zones” that rob the water of oxygen and suffocate marine lif

Take Action 

For Chesapeake Bay restoration to be a success, we all must do our part. Our everyday actions can have a big impact on the Bay. By making simple changes in our lives, each one of us can take part in restoring the Bay and its rivers for future generations to enjoy.

To lower nutrient pollution in the Bay watershed, consider reducing the amount of pollution that can run off your property: install a green roof, rain garden or rain barrel to capture and absorb rainfall; use porous surfaces like gravel or pavers in place of asphalt or concrete; and redirect home downspouts onto grass or gravel rather than paved driveways or sidewalks. If you have a lawn to take care of, use fertilizers properly: do not use more than needed, and do not apply to dormant lawns or frozen ground. You can also reduce air pollution by walking, biking or taking public transportation, or using electric or manual lawn mowers and yard tools instead of gas-powered machines.

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Chesapeake Bay News


Nitrogen Loads and River Flow to the Bay

Approximately 248 million pounds of nitrogen reached the Bay during the 2013 water year, which is below the 1990-2013 average load of 338 million pounds. The 2013 load is 26 million pounds less than the 2012 load. 

Annual average river flow to the Bay during the 2013 water year was 49.1 billion gallons per day (BGD), which is below the 1990-2013 mean flow of 53.4 BGD. The 2013 flow is 2.6 BGD less than the 2012 flow.


Phosphorus Loads and River Flow to the Bay

Approximately 14.4 million pounds of phosphorus reached the Bay during the 2013 water year, which is below the 1990-2013 average load of 21.1 million pounds. The 2013 load is 0.1 million pounds higher than the 2012 load.

Annual average river flow to the Bay during the 2013 water year was 49.1 billion gallons per day (BGD), which is below the 1990-2013 mean flow of 53.4 BGD. The 2013 flow is 2.6 BGD less than the 2012 flow.

 

Reducing Nitrogen Pollution

Computer simulations of pollution controls implemented between July 2009 and June 2013, calibrated using monitoring data, indicate that nitrogen loads to the Bay would have decreased 20.28 million pounds to 262.38 million*.




Reducing Phosphorus Pollution

Computer simulations of pollution controls implemented between July 2009 and June 2013, calibrated using monitoring data, indicate that phosphorus loads to the Bay would have decreased 2.04 million pounds to 17.19 million*.




Bay 101: Algae Blooms



April 03, 2012

What is an algae bloom and how does it form? Charlie Poukish from the Maryland Department of the Environment explains what fuels algae blooms and how they can spell trouble for underwater life.

Bay 101: Fish Kills



June 15, 2012

Decomposing algae blooms can suck oxygen out of the water, suffocating marine life and causing fish kills. In this follow-up to Bay 101: Algae Blooms, Charlie Poukish from the Maryland Department of the Environment documents a fish kill and explains how actions on land can affect life in the water.

Produced by Steve Droter
Music: “A Moment of Jazz” by Ancelin

Bay 101: Water Clarity



July 13, 2011

Clear water is critical to underwater life. Bay grasses need sunlight to grow, and fish need sunlight to see. But what factors cause water clarity to fluctuate? Adam Davis from the Chesapeake Research Consortium explains, and uses a secchi disc to measure water clarity in Spa Creek.

Produced by Matt Rath
Music: “A Moment of Jazz” by Ancelin

From the Field: Monitoring water quality in the Chesapeake Bay



September 07, 2012

Scientists from Maryland Department of Natural Resources and University of Maryland’s Chesapeake Biological Laboratory show us key methods for tracking nutrient levels and determining the health of the Chesapeake Bay.
Closed Captions: http://www.youtube.com/watch?v=U1prV3zpeZA

Produced by Steve Droter
Music: “Room with a View” by Jahzzar


Publications

Estimates of County-Level Nitrogen and Phosphorus Date for Use in Modeling Pollutant Reduction

Publication date: June 01, 2009 | Type of document: Report | Download: Electronic Version

This report documents the calculations and procedures for the preparation of the input data to the Watershed Model - HSPF Phase 5. These calculations are used for creating the calibration data as well as scenario data. They form the basis…

2011 Milestones to Reduce Nitrogen and Phosphorus

Publication date: May 12, 2009 | Type of document: Report | Download: Electronic Version

2011 Milestones to Reduce Nitrogen and Phosphorus

NPDES Permitting Approach for Discharges of Nutrients in the Chesapeake Bay Watershed

Publication date: December 29, 2004 | Type of document: Report | Download: Electronic Version

In accordance with the requirements of the Clean Water Act (CWA) and the goals of the Chesapeake 2000 agreement, this paper describes an approach that the US Environmental Protection Agency Regions II and III (EPA) and Chesapeake Bay…

Setting and Allocating the Chesapeake Bay Basin Nutrient and Sediment Loads: The Collaborative Process, Technical Tools and Innovative Approaches

Publication date: December 01, 2003 | Type of document: Report | Download: Electronic Version

The Chesapeake 2000 agreement has been guiding Maryland, Pennsylvania, Virginia and the District of Columbia, the Chesapeake Bay Commission and the U.S. Environmental Protection Agency (EPA) in their combined efforts to restore and protect…

Economic Analyses of Nutrients and Sediment Reduction Actions To Restore Chesapeake Bay Water Quality

Publication date: June 01, 2003 | Type of document: Report | Download: Electronic Version

In developing revised water quality standards for the Chesapeake Bay and its Tidal tributaries, states may conduct use attainability analyses. This document provides economic analyses performed by the CBP related controls to meet revised…

Recommendations for Coordinating Phosphorus Based Nutrient Management Policies in the Chesapeake Bay Region

Publication date: September 01, 2002 | Type of document: Report

Phosphorus plays a major role in nonpoint source pollution. It has become evident that agriculture is experiencing over-application of phosphorus, which has resulted in phosphorus enriched soils in certain locations. The Agricultural…

Benchmarks for Nitrogen, Phosphorus, Chlorophyll and Suspended Sediments in Chesapeake Bay

Publication date: April 10, 2002 | Type of document: Report

One of the Tidal monitoring and Analysis Workgroup's primary responsibilities is assessing and reporting the status and trends of nutrients and other parameters monitored within the scope of the Chesapeake Bay Program water quality and…

Effects of Atmospheric Nitrogen Deposition on Algal Assemblages in Chesapeake Bay

Publication date: August 01, 2001 | Type of document: Report

The report describes results from five sampling periods and examine the effects of atmospheric nitrogen deposition on changes in algal biomass, as well as major algal classes.

The Phosphorus Detergent Ban

Publication date: June 19, 2000 | Type of document: Report | Download: Electronic Version

The phosphorus detergent ban was implemented in the Bay signatory jurisdictions in the mid to late eighties. After the ban's implementation, it became clear that the ban resulted in a significant reduction of discharge in phosphorus from…

Status Yields and Trends of Nutrients and Sediment and Methods of Analysis for the Nontidal Data-Collection Programs, Chesapeake Bay Basin

Publication date: December 31, 1997 | Type of document: Report | Download: Electronic Version

This is a report on the status yields and trends of nutrients and sediment and methods of analysis for the nontidal data-collection programs in the Chesapeake Bay Basin

Nitrogen Oxides: Impact on Public Health and the Environment

Publication date: January 01, 1997 | Type of document: Report

This report examines the cost effectiveness of control options which reduce nitrate deposition to the Chesapeake watershed and the tidal Bay. The object of the analysis is to determine the sources of atmospheric nitrate deposited to the…

Atmospheric Nitrogen Deposition Loadings to the Chesapeake Bay: An Initial Analysis of the Cost Effectiveness of Control Options

Publication date: November 01, 1996 | Type of document: Report

Eutrophication -- low dissolved oxygen -- caused by excess nutrients, is the most significant water quality problem facing the Bay. The Chesapeake Bay Program jurisdictions have committed to reduce nitrogen and phosphorus pollution reaching…

Managing Nutrients to Prevent Pollution

Publication date: September 01, 1996 | Type of document: Report | Download: Electronic Version

Nine action recommendations derived from a 1996 nutrient conference are addressed.

Airsheds and Watersheds - The Role of Atmospheric Nitrogen Deposition

Publication date: October 11, 1995 | Type of document: Report

This report summarizes the workshop proceedings which focused on atmospheric nitrogen compounds. Scientists in key policy and regulatory officials explored mechanisms by which air and water pollution control programs worked together to…

The advantages of Measures of Particulate Carbon, Nitrogen and Phosphorous by Direct Analysis.

Publication date: June 01, 1993 | Type of document: Report | Download: Electronic Version

This document is intended to address the inconsistency between parts of the CBP in the sampling and analytical methodology for the determination of particulate concentrations, and offer alternative sampling and analytical procedures to be…

DRAFT- Nitrogen Outputs from Forested Watersheds in the Chesapeake Bay Drainage Basin

Publication date: January 01, 1993 | Type of document: Report | Download: Electronic Version

This report focuses on the identified need of the Chesapeake bay Program to better simulate nitrogen outputs from the forested portions of the Bay drainage and a short-term desire to the US EPA to be able to build off of the existing HSPF…

Trends in Nitrogen in the Chesapeake Bay, 1984-1990

Publication date: June 01, 1992 | Type of document: Report

The primary purpose of this analysis is to determine whether selected lateral and mid-Bay stations in the Chesapeake Bay mainstem have the same overall levels of certain water quality parameters.
 

Adjusting Helix Kjeldahl Nitrogen Results: Maryland Chesapeake Bay Mainstem Water Quality Monitoring Program

Publication date: February 01, 1992 | Type of document: Report

In this report, a comparison data set with helix and block results for the same samples was analyzed to estimate the magnitude of the low bias of the helix method compared to the block method.

Biological Nitrogen and Phosphorus Removal in Oxidation Ditches and High Nitrate Recycle Systems

Publication date: August 01, 1990 | Type of document: Report | Download: Electronic Version

As part of the Chesapeake Bay Agreement to which the State of Maryland is a signatory, several plants in Maryland will be required to reduce the nitrogen and phosphorus levels in their affluent. To examine the feasibility of biological…

Nitrogen and Phosphorous Determinations in Estuarine Waters: A Comparison of Methods Used in Chesapeake Bay Monitoring.

Publication date: August 01, 1987 | Type of document: Report | Download: Electronic Version

This study was performed to compare standard EPA techniques for determining nitrogen and phosphorus concentrations in natural waters with oceanographic techniques typically employed by estuarine and marine scientists.




Maps




From Around the Web

Bay FAQs

  • Where do nutrients come from?
  • Why do scientists monitor phytoplankton?
  • What causes poor water clarity?

 

Bay Terms

  • Airshed
  • Algae bloom
  • Dead zone
  • Nitrogen
  • Nutrients
  • Phosphorus
  • Wastewater

 

Bay-Friendly Tips

  • Test Your Soil
  • Test your soil to determine how much fertilizer your lawn needs (if any at all) and the best time to apply it.
  • Reduce Emissions
  • When possible, walk, bike or take public transportation to reduce vehicle emissions that can pollute our air and water.
  • Reduce Emissions
  • Avoid letting your car idle. Idling for even 10 seconds can waste fuel, damage your engine and pollute our air and water.
  • Don’t Overapply Fertilizer
  • Use only the amount of lawn fertilizer you need. Twice the product won't make your lawn twice as green!
  • Reduce Polluted Runoff
  • Wash your car on grass or gravel rather than pavement so soapy, grimy wash water won't run off your property.
  • Pick Up Pet Waste
  • Pick up after your pet. Pet waste contains nutrients and bacteria that can wash into local waterways if left on the ground.
  • Fertilize in the Fall
  • If you need to fertilize your lawn, do it in the fall. Spring rains wash fertilizer off lawns and into local waters.

 

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