National Aquatic Resource Surveys: 

An Update January 2011

Working with state, tribal, and other federal agency partners, the U.S. Environmental Protection 

Agency (EPA) is conducting statistical surveys of the nation’s streams and rivers, lakes and 

reservoirs, coastal waters, and wetlands. 

Introduction 

• States, tribes, federal agencies and other 

organizations collect water quality data to 

respond to many Clean Water Act 

requirements. Because they use differing 

monitoring designs, indicators, and methods, 

EPA cannot combine their information to 

effectively answer questions about the 

quality of the nation’s waters or track 

changes over time. 

• EPA and its state, tribal, and federal 

partners are implementing a series of 

aquatic resource surveys to address this 

national information gap. 

These National Aquatic Resource Surveys (NARS) 

use randomized sampling designs, core indicators, 

and consistent monitoring methods and lab 

protocols to provide statistically-defensible 

assessments of water quality at the national scale. 

Additionally, the national surveys are helping build 

stronger monitoring programs across the country 

by fostering collaboration on new methods, new 

indicators and new water quality research. EPA 

plans to implement the surveys on a five year 

rotation. As the surveys repeat, we will be able to 

track changes over time and advance our 

understanding of important regional and national 

patterns in water quality. 

Streams and Rivers 

• A 2006 water quality survey, the Wadeable 

Streams Assessment, found that 28%

of the nation’s small streams support 

healthy biological communities, a key goal of 

the Clean Water Act.

• The survey reported that nutrients and 

excess sedimentation are at high levels in 

30% of the nation’s streams. Streams with 

high levels of these pollutants have twice the 

risk of degraded biological communities as 

streams with low levels. 

• Data from the next of these surveys — the 

2008-2009 National Rivers and Streams 

Assessment — are now being analyzed for 

release in 2012. 

The 2006 streams survey highlighted significant 

problems affecting streams and established a 

nationally 

consistent 

baseline against 

which we can 

track water 

quality changes 

in the future. 

In 2008 and 

2009, EPA, states, tribes and other partners 

sampled approximately 2,300 National Rivers and 

Streams Assessment (NRSA) sites. Data are now 

being validated and analyzed, and the final NRSA 

report is expected in 2012. The results from this 

survey will allow us to compare more recent water 

quality conditions in small streams with the 

findings of the 2006 Wadeable Streams 

Assessment. 

Lakes, Ponds and Reservoirs 

• A 2007 survey of the nation’s lakes, the 

National Lakes Assessment (NLA), found 

that 56% of our lakes are in good biological 

condition. 
• The survey reported that more than onethird of our lakes exhibit poor shoreline 

condition. Poor biological health is 3 times 

more likely in lakes with poor lakeshore 

habitat.

• The NLA found that nearly 20% of lakes 

have high levels of nutrients. Lakes with 

excess nutrients are 2.5 times more likely to 

have poor biological health.

• Microcystin — an algal toxin that can harm 

humans, pets and wildlife — was found to be 

present in about one-third of U.S. lakes. 

In 2007, EPA, states, tribes and other partners 

sampled over 1,150 lakes for the NLA. State, 

USGS and other national labs analyzed tens of 

thousands of samples. The NLA provides data on 

the extent of lakes that support healthy biological 

communities and information on recreational 

indicators of lake condition. EPA and our partners 

continue to analyze data from the NLA, including 

creating a lake macroinvertebrate index, 

conducting regional or state specific assessments, 

and finalizing the results of the pathogen data. 

A technical steering committee comprised of EPA, 

state, tribal, and various federal agencies is now 

planning the next NLA. The committee is 

reviewing the 2012 design and indicators, and will 

decide on final indicators by spring 2011. 

Coastal Waters 

• The National Coastal Condition Assessments 

(NCCA) are documenting slight 

improvements in the quality of coastal 

waters, in spite of increasing development. 

• The 2010 NCCA’s sampling season 

concluded in October with state and other 

partners collecting data at more than 1,300 

sites. 

• To address the oil spill in the Gulf of Mexico, 

additional analyses of oil-related 

constituents are being conducted at a 

number of sites in the Gulf. 

The National Coastal Condition Reports (NCCR) 

describe the ecological condition of the coastal 

waters of the United States based on five 

indicators: a water quality index, a sediment 

quality index, a benthic index, a coastal habitat 

index, and a fish tissue contaminants index. The 

most recent report released in December 2008, the 

NCCR III, reported that the overall condition of the 

nation's coastal waters is fair based on an 

aggregation of the five indicators and has improved 

slightly since the 1990s. 

In 2010, EPA, States, and other partners conducted 

sampling for the next NCCA. Field crews sampled 

over 1,300 marine and Great Lakes sites. State and 

contract labs across the country are analyzing and 

validating data for this survey. A final report is 

expected by December 2012. 

Wetlands 

• In 2011, EPA and the states will be 

conducting a groundbreaking survey of the 

condition of the nation’s wetlands, with a 

report planned for 2013. 

• Planning and research for this survey has 

already moved the science of wetlands 

monitoring forward and has re-engaged 

many states in this effort. 

EPA is collaborating with the U.S. Fish and 

Wildlife Service (FWS) to design the National 

Wetland Condition Assessment to ensure that it 

effectively complements the FWS Status and 

Trends reports, which focus on the distribution of 

wetlands rather than their condition. EPA, states 

and tribes are coordinating a number of regional 

pilot projects to test design approaches, field 

protocols, and indicators for use in the survey. 

Lessons learned from these pilot projects are 

informing the final preparations for field and lab 

manuals, quality assurance, and other aspects of the 

survey. 

To learn more about the National Aquatic Resource 

Surveys, visit www.epa.gov/aquaticsurveys

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