Supreme Court Decides That The Clean Water Act Regulates Some Discharges To Groundwater, But Isn’t Clear About Which

The federal Clean Water Act applies to point-source discharges to surface waters; it does not regulate the addition of pollutants to groundwater.  But what about discharges that travel through groundwater to surface waters?  The U.S. Supreme Court has now decided that the Clean Water Act regulates those discharges through groundwater that are the “functional equivalent” of a direct point-source discharge to surface waters.  What that phrase means in practice remains to be seen, although history may provide some help.  In recognition of the vagueness of its standard, the Supreme Court has invited EPA to issue clarifying regulations. 

The facts in County of Maui v. Hawaii Wildlife Fund were unusual.  The county pumps 4 million gallons per day of treated municipal wastewater into groundwater through four 200-feet-deep wells.  The pump site is about a half mile from the ocean.  An EPA-led study added dye to the wastewater, found that after 84 days the dye started to emerge from submarine seeps into the ocean, and concluded that 64% of the dye added to two of the four wells would eventually enter the ocean.  Although EPA and the State of Hawaii had concluded that the Clean Water Act did not apply (EPA apparently intended to regulate the discharge using the underground-injection provisions of the Safe Drinking Water Act), the wildlife fund filed a citizen suit and argued that the county was discharging without an NPDES permit in violation of the Clean Water Act.  The district court apparently concluded that the wastewater traveled from the pump site to the ocean through a lava tube—which could have been compared to a pipe—but unhelpfully wrote that the groundwater itself was a “conduit” and a “confined and discrete conveyance” (which is the key concept in the Clean Water Act’s definition of a point source).  The district court concluded that the discharge was “functionally” to the ocean, and that an NPDES permit was required. 

The county appealed to the Ninth Circuit, which affirmed but enunciated a different legal standard:  A discharge to groundwater needs an NPDES permit, it said, when pollutants in surface waters are “fairly traceable” to a discharge to groundwater. 

The Supreme Court, by a vote of 6-3, rejected this “fairly traceable” standard.  The Supreme Court also rejected the arguments made by both parties.  The county had argued that no discharge to groundwater is regulated under the Clean Water Act; the wildlife fund had argued that a “proximate cause” standard should apply. 

The Supreme Court looked for a “middle ground”.  It concluded that a permit should be required when “a pipe ends a few feet from navigable waters and the pipe emits pollutants that travel those few feet through groundwater”.  It also concluded that the Clean Water Act did not apply to “the 100-year migration of pollutants through 250 miles of groundwater to a river.”  The Court did not seem to recognize that 250 miles is an awfully long distance for groundwater to travel before it surfaces, even though the Court cited a more realistic case in which the discharge would take 60-420 years to travel one to four miles through groundwater before it surfaced. 

The Court settled on what might be called a walk-like-a-duck test (or conveys-like-a-pipeline test):  “Whether pollutants that arrive at navigable waters after traveling through groundwater are ‘from’ a point source depends on how similar to (or different from) the particular discharge is to a direct discharge.”  The Court recognized that this standard did not “clearly explain how to deal with middle instances”, and its list of seven “potentially relevant factors” is a muddle:  “(1) transit time, (2) distance traveled, (3) the nature of the material through which the pollutant travels, (4) the extent to which the pollutant is diluted or chemically changed as it travels, (5) the amount of pollutant entering the navigable waters relative to the amount of the pollutant that leaves the point source, (6) the manner by or area in which the pollutant enters the navigable waters, (7) the degree to which the pollution (at that point) has maintained its specific identity.” 

Missing from this list is a common-sense test that the district court applied:  Does the groundwater contribute more than a de-minimus amount of the pollutant to surface waters?  Because shallow groundwater moves very slowly though many soils, the flow of pollutant-containing groundwater into surface water can be very limited.  If the amount of groundwater-derived pollutant in the surface water is small compared to the pollutant loading from other sources, no one is likely to notice, and there is no good reason to call for Clean Water Act regulation of the source of that groundwater-carried pollutant.  So, for example, there may very well be plumes of TCE-contaminated groundwater that are flowing into San Francisco Bay.  But the small amount of TCE added to the bay each day, compared to the huge amounts of water in the bay and the huge amounts of flow, mixing, inflow from tributary rivers, and exchange with the ocean, makes any addition likely to be trivial.  In practice, this de-minimus test may prove more important than any of the others. 

Also missing from the Supreme Court’s consideration is a key Clean Water Act concept:  that a discharge occurs only when a pollutant is added to a “water of the United States” (although the word “discharge” is loosely used to refer to any release of pollutants to the environment).  In the TCE-plume example, the discharge occurs when the TCE molecules enter San Francisco Bay.  But those TCE molecules may have leaked into groundwater in the 1960s, and they may have come from underground tanks owned by entities that no longer exist.  If that TCE plume looks enough like a pipeline, will courts import a concept from CERCLA (and from Clean Water Act regulation of stormwater) and hold the current landowner liable as the discharger? 

The Supreme Court was comforted by the idea that this issue has not been much of a problem over the nearly 50 years since the Clean Water Act was enacted in 1972.  It may become more of a problem in the future, however, since virtually any attorney-fee-hungry group can file suit against countless entities that add pollutants to groundwater in ways—for example, though ponds that are not sealed—they never imagined would need a permit.  By choosing such a vague “functional equivalent” standard, the Supreme Court has encouraged more citizen suits. 

Perhaps state agencies will issue general permits that provide protection against citizen suits.  No doubt EPA will eventually issue guidance and perhaps regulation.  In the meantime, however, the regulated community is more at risk than it ever imagined itself to be.

Lawrence Bazel
Briscoe Ivester & Bazel LLP
155 Sansome Street, 7th Floor
San Francisco, CA 94104
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