Rivers and Coastal Waters: Better Measurement Finds More Pollution

For past debate topics on environmental issues, I have shown students data on the steady reductions in air, water, and land pollution across the United States. Pollution discharges into America’s rivers, lakes, streams, and coastal waters has been much reduced as billions of dollars was spent on new water treatment of municipal sewages and installation of less-polluting industrial processes as well as pollution-control equipment in factories.

Lake Washington, a large lake east of Seattle and now surrounded by cities and suburbs, was a murky mess in the 1950s, and closed to swimming. Now Lake Washington is a lot cleaner, even though population density around the lake is much higher (“Lake Washington: Fighting Pollution and Winning“)

[Studies by W. Thomas Edmonson and his students of Lake Washington] yielded startling data about the increase in blue-green algae in the water. The algae flourished in the polluted environment but died off quickly, washing up on Seattle’s beaches and creating an incredible stench that led the Seattle Post-Intellgencer to dub it “Lake Stinko” in the 1960s.

Claims that water quality has improved, as well as separate claims of increased pollution, depend upon measurement. The Pacific Research Institute’s 2011 Almanac of Environmental Trends (pdf) explains water quality measurement:

For two decades the chief source of national water quality assessment was the National Water Quality Inventory (NWQI), which every two years collected data from the 50 states that rated surface waters according to whether they were “swimmable” or “fishable.” (p. 133)

However, state measurement standards were inconsistent and aggregating this data gave unreliable results, so:

The EPA finally gave up on the NWQI, and it has launched the Wadeable Streams Assessment (WSA) in its place, describing it as “the first statistically defensible summary of the condition of the nation’s streams and small rivers.”  

The Environmental Protection Agency (EPA) and state agencies measured water quality levels in 1,300 streams small rivers and concluded:

For the nation as a whole, the first assessment finds 41.9 percent of river and stream miles to be in “poor” biological condition, 24.9 percent in “fair” condition, and 28.2 percent in “good” condition. …

Topping the list of river and stream pollution: “The leading contaminants of streams are nitrogen and phosphorus, found in the typical runoff from agricultural activity.” (p. 135).  Rivers and streams may not start out within the marine natural resources debate topic, but these waters flow downstream and into America’s coastal waters (though the Colorado river no longer does).

So… I’ve been telling students that America’s rivers, streams, lakes, and coastal waterways have been getting much less polluted since the 1960s, and this EPA survey appears to tell another story. Over 40% of river and stream miles, according to EPA, are “in ‘poor’ biological condition.”

Well, there’s pollution and there’s pollution. As societies grow wealthy, people take more interest in air and water quality, and can allocate funds for cleaner air and water. When families are struggling to feed their children and keep a roof over their heads, governments and companies are generally less willing to invest in modern pollution-control and sewage treatment equipment.

Though nitrogen and phosphorus levels from agricultural runoff pollute America’s rivers and streams, what is much less in these streams now is sewage. This report on Mississippi River Water Quality shows how dramatically sewage levers have dropped along the Mississippi over ten years after new sewage treatment plants came online. (chart on page 3)

Indur Goklany’s research in The Improving State of the World  provides a broader overview of environmental improvements around the world. The book’s full title is: The Improving State of the World Explains Why We’re Living Longer, Healthier, More Comfortable Lives on a Cleaner Planet.


Polluted water in the U.S. was a major cause of death until the early 1900s. Fish and shellfish die in today’s polluted rivers and streams. But it used to be children who died from water-related diseases, and they still die today in poor countries without adequate sewage-treatment.  Goklany writes:

During the 19th century, water-related diseases were rampant in the United States. Cumulatively, the death rate in 1900 due to typhoid and paratyphoid, various gastrointestinal diseases…, and all forms of dysentery was 1,860 per million. To put this in context, the annual crude death rate due to all causes was 8,650 per million in 1997. (p. 153).

Looking at how cleaner water in the U.S. reduced typhoid:

Mortality due to typhoid and paratyphoid dropped from 313 per million in 1900 to 76 in 1920 and 11 in 1940. By 1960, it was virtually eliminated.

Death in the U.S. from gastrointestinal diseases

declined from 1,427 per million in 1900 to 6 in 1970s… For all forms of dysentery, the death rate declined from 120 per million in 1900 to 3.3 in 1957 and 1.7 in 1998… 

Most students have no idea what these diseases are unless they have spent time outside tourist areas in poor countries.

So these are measures of dramatic improvement in water pollution levels across the U.S. over the last century. Still there is still room for more improvements.

The 2011 Almanac of Environmental Trends includes “A Primer on Hypoxia” on page 147 (partly show in image below). Agricultural runoff into rivers and then to America’s coastal areas makes life difficult or impossible for fish and shellfish by feeding bacteria in the water that consume oxygen. I discuss innovative ways to clean coastal waters in an earlier post “Cleaning Marine Ecosystems at the Dinner Table.”

Improved water quality measurement equipment has helped state and federal agencies gather far more empirical data on water pollution levels. This EPA news release, “EPA Finalizes California’s List of Polluted Rivers” reports:

Many more beaches, both inland and coastal, are on the 2010 list because bacteria reached unsafe levels for swimming. This increase is largely driven by a more extensive review of data collected by counties.

This finding, and all other “increases” in water pollution in the report are the result not of higher pollution levels, but of increased and improved measurement of pollution. The conclusion “More of California’s waterways are impaired than previously known…” is good news in the sense that with more and better data, attention can be better focused on dealing with the today’s causes of water pollution.