

Todd Sheppard


How does soil become a pollutant? And a plow a “point source” of pollution?

By Lewis Perdue

CWA Violation

On its face, the Clean Water Act (CWA) is very clear that a violation consists of:

  1. The discharge of,
  2. A pollutant into,
  3. Waters of the United States.

Permits and Exemptions Legalize Pollution

The CWA does legalize a regulated amount of pollution in two cases:

  2. If a farming exemption applies.

With no exemption, many ordinary farming practices can be prosecuted if a farmer does not have a permit which  can cost tens of thousands of dollars (Clean Water Act Permits: Expensive, time-consuming, uncertain).




  4. That any land that is part of the Waters of the United States (WOTUS) has not been filled, destroyed or converted to agriculture. WOTUS includes wetlands, but also shallow, seasonal and “ephemeral” stream beds and depressions that are dry except during rainy season.  <<LINK TO nexus anchor in nexus ARTICLE section>>

How does soil become a pollutant?

If a field, forest or other ag land fails to meet all the regulatory and legal standards listed above, then:


  • a plow becomes a point source of pollution and,
  • the soil in a field becomes dredged or fill material when the plow moves it. That soil then becomes a pollutant.


While  the terms “dredged or fill material” often have negative connotations to ordinary citizens, the term also applies to ordinary soil.


The CWA and associated regulations classify ordinary soil and rock as a pollutant when it is removed from its natural surroundings and placed elsewhere. If soil is moved — even a fraction of an inch — it is classified as “redeposited.”


And if that re-deposition happens within an area considered “Waters of the United States,” then it is illegal unless it has a permit or exemption.


A Federal District Court judge in Duarte v. U.S. Army Corps of Engineers, agreed with the U.S. Department of Justice (representing the Corps of Engineers) that, when a plow lifts soil from its undisturbed state, it converts that tilled soil into a pollutant:

“Plain dirt, once excavated from waters of the United States, could not be redeposited into those waters without causing harm to the environment.” Federal District Court decision in Duarte, page 29, line 7.

“In sum, soil is a pollutant. …  The equipment … caused the material, in this case soil, to move horizontally, creating furrows and ridges. … Further, when that newly plow-createddredged or fill material’ forms a furrow to either side of the plow, it has been redeposited’.” — Duarte, page 29, line 14.

Many lay people and farmers may find the reference to “Waters” somewhat confusing because the term, for regulatory purposes, can apply to land which is dry for most of the year. For more on that, see: Trying To Make Sense Out Of Clean Water Act Regulation.

How does a plow turn into a “point source” of pollution?

The judge in the Duarte, case illustrated how a plow becomes a “point source of pollution:”

The CWA defines the term ‘point source’ to mean, ‘[a]ny discernible, confined and discrete conveyance, including but not limited to any . . . conduit. . ., [or] container. . . from which pollutants are or may be discharged’.– Duarte, page 31, line 4

Under the broad statutory language, courts have found ‘bulldozers and backhoes’ to be ‘point sources’ under the CWA, because they collect and pile material that may eventually find its way into the waters of the United States…” Also, “…grader, tractor pulling discs, and a ripper are point sources. — Duarte, page 31, line 4

NOTE: The Duarte v Corps case is cited here even though its decision is not binding outside the Eastern District of California. However, it is the most recent one involving farm exemptions. In addition, the opinion cites and relies upon current and significant federal court cases including the U.S. Supreme Court and U.S. Courts of Appeal which are courts of precedent.

Articles in this series (so far)

Interesting and/or helpful links