I. The Navigability Test

In 1870, the United States Supreme Court established the foundational test for determining whether a body of water falls under federal jurisdiction. In The Daniel Ball, 77 U.S. (10 Wall.) 557, the Court held that waters are navigable when they are “used, or are susceptible of being used, in their ordinary condition, as highways for commerce, over which trade and travel are or may be conducted in the customary modes of trade and travel on water.”¹

This test, which remains binding precedent after more than 150 years, contains three elements. First, the waterway must exist in an “ordinary condition”—that is, it must be a persistent, functioning hydrological system rather than an ephemeral or artificial one. Second, it must be capable of serving as a “highway for commerce.” Third, trade or travel must be, or must be capable of being, conducted upon it.

The test does not specify minimum width. It does not require that the waterway be open to public access. It does not require that the commerce be conducted by boat. It requires only that a body of water function, in its ordinary condition, as a highway for the movement of goods.

This is a factual test. It can be applied to any hydrological system. Including one that happens to be enclosed inside a human being.

II. The Hydrological System

The human circulatory system comprises approximately 60,000 miles of blood vessels, including arteries, veins, and capillaries.² For context, the entire United States inland waterway system—the rivers, canals, and intracoastal channels collectively regulated by the Army Corps of Engineers—totals approximately 25,000 miles.³

The human circulatory system is, by linear measure, 2.4 times larger than the federal waterway network.

This system is not ephemeral. It operates continuously from approximately the third week of embryonic development until death, a period that averages 78.8 years in the United States according to the CDC’s most recent National Vital Statistics Report.⁴ The Mississippi River, by comparison, has existed in its current course for approximately 70 million years. In operational uptime, the human circulatory system achieves a 100 percent duty cycle for its entire service life. No federal waterway matches this reliability.

The system maintains a consistent fluid medium. Human blood plasma contains approximately 0.9 percent sodium chloride by weight, making it a saline solution.⁵ For comparison, the Chesapeake Bay—one of the most heavily regulated navigable waterways in the United States—ranges from 0.05 percent salinity at its northern head to approximately 2.5 percent at its mouth.⁶ The bloodstream’s salinity falls squarely within the range of waters that federal agencies have asserted jurisdiction over for more than a century.

III. The Commerce Question

The Daniel Ball test hinges on whether the waterway serves as a “highway for commerce.” This requires examining what moves through the system, and whether that movement constitutes commerce in any legally cognizable sense.

The human heart pumps approximately 5 liters of blood per minute at rest, totaling roughly 7,571 liters—or approximately 2,000 gallons—per day.⁷ This fluid carries a cargo manifest that would be the envy of any port authority.

Red blood cells, numbering approximately 25 trillion in the average adult, transport oxygen from the lungs to every tissue in the body and return with carbon dioxide for export.⁸ This is, by any functional definition, a pickup-and-delivery logistics operation running on a continuous loop. The oxygen delivery rate at rest is approximately 250 milliliters per minute; during exercise it exceeds 3,000 milliliters per minute.⁹ The system scales on demand. FedEx does not.

Beyond oxygen, the bloodstream transports glucose, amino acids, fatty acids, vitamins, and minerals to downstream consumers. It carries hormones—insulin, cortisol, thyroxine, epinephrine—which function as regulatory signals between organs. It transports manufactured goods: albumin produced by the liver, antibodies manufactured by B-lymphocytes, clotting factors assembled from hepatic production lines.¹⁰

It also handles waste removal. Urea, creatinine, bilirubin, and metabolic byproducts are collected from production sites and transported to the kidneys and liver for processing and disposal.¹¹ This is the biological equivalent of a barge hauling industrial waste to a treatment facility—a function that, when performed on actual navigable waterways, triggers jurisdiction under the Clean Water Act.

The total economic value of the goods transported through the human bloodstream is difficult to quantify precisely, because the downstream consumers would die without them. But the pharmaceutical replacement cost offers a useful proxy. The wholesale cost of replacing the oxygen-carrying capacity of a single unit of packed red blood cells is approximately $225.¹² The body contains approximately 35 units’ worth. Insulin alone costs approximately $3,000 per year at U.S. retail pricing.¹³ Albumin replacement costs $150 to $300 per 25-gram unit; the body produces 12 to 25 grams daily.¹⁴

By the most conservative accounting, the bloodstream transports goods with an annual replacement value exceeding $500,000 per person. The Mississippi River handles approximately $130 billion in cargo annually across roughly 500 million short tons.¹⁵ Per mile of waterway, the human circulatory system moves cargo of comparable economic density.

IV. The Jurisdictional Expansion

The scope of federal jurisdiction over navigable waters has expanded dramatically since The Daniel Ball. The Clean Water Act of 1972, codified at 33 U.S.C. § 1362(7), defines “navigable waters” as “the waters of the United States, including the territorial seas.”¹⁶ The use of “the waters of the United States” was deliberately broader than the traditional navigability test. Legislative history confirms that Congress intended to “exercise its powers under the Commerce Clause” to the fullest constitutional extent.¹⁷

The Army Corps of Engineers subsequently interpreted this mandate expansively. Under 33 C.F.R. § 328.3, the Corps asserted jurisdiction over not only traditionally navigable waters, but also tributaries, adjacent wetlands, and “other waters” whose degradation could affect interstate commerce.¹⁸

In Rapanos v. United States, 547 U.S. 715 (2006), Justice Kennedy’s concurrence established the “significant nexus” test: waters fall under federal jurisdiction if they possess a “significant nexus” to traditionally navigable waters, meaning they “significantly affect the chemical, physical, and biological integrity” of downstream navigable waters.¹⁹

Even after the Supreme Court narrowed the scope in Sackett v. EPA, 598 U.S. ___ (2023), requiring a “continuous surface connection” to traditionally navigable waters, the core Daniel Ball navigability test remains untouched for waters that independently satisfy it.²⁰

The question, then, is not whether the circulatory system has a “nexus” to external navigable waters. The question is whether it independently satisfies the navigability test. As demonstrated in Section III, it does.

V. The Law Enforcement Gap

If the human bloodstream qualifies as a navigable waterway, it follows that federal agencies with jurisdiction over navigable waters have authority over the circulatory system. The implications are considerable.

The United States Coast Guard, established under 14 U.S.C. § 101, is charged with enforcing federal law on “the high seas and waters subject to the jurisdiction of the United States.”²¹ The Coast Guard’s mission includes search and rescue, law enforcement, environmental protection, and aids to navigation. The human circulatory system currently operates without a single navigational aid. There are no channel markers. There are no buoys. The red blood cells navigate 60,000 miles of vasculature using chemical gradients and laminar flow alone.

This is, by Coast Guard standards, a navigational catastrophe.

The system does maintain a security force. White blood cells, numbering between 4,500 and 11,000 per microliter of blood, patrol the circulatory system continuously.²² At an estimated total blood volume of 5 liters (5 million microliters), this represents a standing force of 22.5 billion to 55 billion active patrol units. By comparison, the U.S. Coast Guard employs approximately 42,000 active-duty personnel.²³ The bloodstream’s security contingent outnumbers the Coast Guard by a factor of approximately 535,000 to one.

And yet, this force operates entirely outside federal oversight. No white blood cell has ever received a commission. No neutrophil has been sworn in. The entire immune system functions as an unlicensed paramilitary organization conducting continuous operations within a federal waterway.

VI. The Pollution Problem

The Clean Water Act, 33 U.S.C. § 1311(a), prohibits the “discharge of any pollutant by any person” into navigable waters without a permit.²⁴ A “pollutant” is defined under § 1362(6) to include “chemical wastes, biological materials, heat, [and] industrial, municipal, and agricultural waste discharged into water.”²⁵

The liver discharges bilirubin, a chemical waste product of hemoglobin degradation, directly into the bloodstream at a rate of approximately 250 to 350 milligrams per day.²⁶ The kidneys discharge urea, creatinine, and uric acid. The adrenal glands discharge cortisol. The pancreas discharges insulin and glucagon. Every endocrine organ in the body is, under the literal text of the Clean Water Act, a point source discharging pollutants into a navigable waterway without a National Pollutant Discharge Elimination System (NPDES) permit.

The penalty for unpermitted discharge under § 1319(c) includes fines of up to $50,000 per day per violation.²⁷ An adult human body contains dozens of organs continuously discharging substances into the bloodstream. At a conservative estimate of 10 organs discharging daily, the per-person penalty exposure is $500,000 per day, or $182.5 million per year.

Across the 335 million residents of the United States, the aggregate unpermitted discharge liability is approximately $61 quadrillion per year. This exceeds the gross world product by a factor of roughly 600.

VII. The Navigation Improvement Mandate

Under 33 U.S.C. § 401, it is unlawful to “create any obstruction not affirmatively authorized by Congress, to the navigable capacity of any of the waters of the United States.”²⁸ This provision, part of the Rivers and Harbors Act of 1899, was enacted to prevent unauthorized construction of bridges, dams, and other structures that impede commercial navigation.

Atherosclerotic plaque, the arterial deposits that narrow blood vessels and restrict flow, is the leading cause of death in the United States. The Centers for Disease Control and Prevention reports that heart disease kills approximately 695,000 Americans per year.²⁹ Atherosclerosis is, functionally, the unauthorized construction of an obstruction in a navigable waterway. It reduces channel width, impedes the flow of commercial traffic, and ultimately causes system failure.

The Army Corps of Engineers spends approximately $6.5 billion annually on navigation infrastructure, including dredging operations to maintain channel depths on federal waterways.³⁰ The medical equivalent—coronary angioplasty, bypass surgery, stent placement—costs the U.S. healthcare system approximately $30 billion per year.³¹

If the bloodstream is a navigable waterway, then cardiovascular medicine is not healthcare. It is federally mandated channel maintenance.

VIII. The Constitutional Foundation

The federal government’s authority over navigable waters derives from the Commerce Clause, Article I, Section 8, Clause 3 of the Constitution, which grants Congress the power “to regulate Commerce with foreign Nations, and among the several States.”³²

The Supreme Court has held, repeatedly, that the Commerce Clause empowers Congress to regulate activities that “substantially affect” interstate commerce. In Gonzales v. Raich, 545 U.S. 1 (2005), the Court upheld federal regulation of locally grown marijuana on the grounds that the aggregate effect of local activity on the national market was sufficient to trigger Commerce Clause authority.³³

The human circulatory system transports substances that, in aggregate, drive the entirety of the national economy. Every worker who contributes to interstate commerce does so because their circulatory system delivered the oxygen, glucose, and hormones necessary for their brain and muscles to function. Disability from circulatory failure removes workers from the labor force; the American Heart Association estimates the annual cost of cardiovascular disease to the U.S. economy at $407.3 billion in direct medical costs and lost productivity.³⁴

Under the Raich aggregate-effects framework, the Commerce Clause interest in 335 million simultaneously operating circulatory systems is not merely substantial. It is total.

IX. Conclusion

The evidence is systematic and it is inescapable. The Daniel Ball navigability test requires a persistent hydrological system that functions as a highway for commerce. The human circulatory system is a 60,000-mile network of channels that moves 2,000 gallons of cargo daily, including oxygen, nutrients, manufactured proteins, regulatory hormones, and waste products with an aggregate annual replacement value exceeding $500,000 per person. It has operated continuously, without interruption, since the third week of embryonic development. It employs a security force that outnumbers the Coast Guard by a factor of half a million.

It satisfies every element of the navigability test. It satisfies every element of the Commerce Clause analysis. And it has been operating entirely outside federal jurisdiction since the passage of the Rivers and Harbors Act of 1899.

There are 335 million unregistered, uninspected, and unpermitted navigable waterways in the United States. They have names. They pay taxes. Some of them are reading this article, blissfully unaware that they are, under federal maritime law, infrastructure.

Ergo.