Toxics Release Inventory (TRI) Program

2012 TRI National Analysis: Large Aquatic Ecosystems - Introduction

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Water pollution, surface runoff, contaminated sediment, toxic discharges, and air emissions can affect the environmental quality of the land, water, and living resources within an aquatic ecosystem. Persistent toxic pollutants can be especially problematic in aquatic ecosystems because pollutants can accumulate in sediments and may bioaccumulate in the tissues of fish and other wildlife at the top of the food chain to concentrations many times higher than in the water or air, causing environmental health problems for humans and wildlife.

A watershed is the land area that drains to a common waterway. Rivers, lakes, estuaries, wetlands, streams, and oceans are catch basins for the land adjacent to them. Ground water aquifers are replenished based on water flowing down through the land area above them. These important water resources are sensitive to chemicals and other pollutants released within or transferred across their boundaries.

This section of the National Analysis focuses on large aquatic ecosystems (LAEs) which are comprised of multiple small watersheds and water resources within a large geographic area. The Large Aquatic Ecosystems Council was created by the U.S. Environmental Protection Agency in 2008 to focus on protecting and restoring the health of critical aquatic ecosystems. Currently there are 10 LAEs in this program. Click on any of the 10 LAEs featured on the map below to see an analysis of toxic chemical releases in each LAE.

Large Aquatic Ecosystems (LAEs) in EPA’s LAE Program


View Larger Map, Click on any one of the Large Aquatic Ecosystems in the map to see detailed information.

Each LAE profile includes information on:

  • The top TRI reporting industry sectors based on quantity of toxic chemicals desposed of or otherwise released;
  • Trends in the disposal or other releases from 2003 to 2012; and
  • The top chemicals disposed of or otherwise released to the air, water, land, and off-site transfers.

For consistency in presenting year to year trends, only the years 2003 and later are shown. (Prior to 2003, some industry sectors and chemicals were added to the TRI reporting requirements. Also note that reporting was required for 16 new chemicals in 2011 and one new chemical in 2012, and data for these 17 chemicals have not been included in the trend charts.)

The total quantity of toxic chemicals managed as wastes varies greatly among the LAEs along with the types and sizes of industrial facilities. How facilities dispose of or release toxic chemicals within the LAEs - whether to the land, air, or water - also varies greatly among the LAEs, as shown below.

TRI Disposal or Other Releases by Large Aquatic Ecosystem, 2012
Total Disposal or Other Releases by Large Aquatic Ecosystem per Square Mile, 2012
Note: This page was published in February of 2014 and uses the TRI National Analysis dataset made public in TRI Explorer in November of 2013.