At its heart, a major new U.S. EPA report that synthesizes more than 1,000 studies about connections among streams, wetlands, rivers and lakes comes down to what elementary school students are taught about the water cycle.
Streams flow into creeks that flow into rivers.
But the devil -- and most likely lawsuits and legislative wars -- is in the details as the Obama administration prepares a rule proposal aimed at clarifying what water resources fall under the regulatory jurisdiction of the Clean Water Act.
Nancy Stoner, EPA's acting assistant administrator for the water office, said in a blog post last week that the report -- which faces a review by a Scientific Advisory Board and a public comment period before it can be made final -- would "serve as a basis" for a rulemaking (E&ENews PM, Sept. 17).
The administration's goal is to free regulators and industry from a legal quagmire created by confusing Supreme Court rulings on the Clean Water Act in 2001 and 2006 (Greenwire, Feb. 7, 2011).
The high court struggled with a provision in the 1972 water law that gives EPA and the Army Corps of Engineers regulatory authority over "navigable waters." Federal regulators for years interpreted those words broadly and claimed jurisdiction over waters that ultimately connected to navigable waters. But the Supreme Court in 2001 blew a hole in that interpretation, striking down the corps' method of using migratory birds to connect isolated wetlands to a jurisdictional water body.
In 2006, the high court voted to further rein in regulators, but the justices split on how to define government jurisdiction. Justice Anthony Kennedy, who joined the majority in the decision, opted to write his own opinion that laid out a less stringent test than the majority's for determining the Clean Water Act's reach.
Under Kennedy's approach, a water body should be regulated under the Clean Water Act if it has a "significant nexus" to navigable waters. The nexus is to be determined based on the law's goal of restoring and maintaining "the chemical, physical and biological integrity of the Nation's Waters," he wrote.
The convoluted decision opened the door to competing interpretations, leaving stakeholders in limbo. Meanwhile, in the wake of guidance issued by the George W. Bush administration that greens say effectively rolled back federal protections on numerous small streams and wetlands, hundreds of enforcement cases were dropped (Greenwire, April 18, 2012).
'How are they going to draw lines'?
The EPA report released last week appears to lay the foundation for a broader interpretation of the Clean Water Act.
It concludes that streams -- regardless of their size or how frequently they flow -- affect downstream waters by trapping sediment, providing habitat for wildlife and absorbing nutrients that would otherwise degrade larger water bodies. It also concludes that wetlands and open waters in floodplains share similar connections with downstream waters.
On one of the most legally contested matters -- geographically isolated wetlands -- the report sidesteps general conclusions, saying such wetlands occur physically "along a gradient of hydrologic connectivity-isolation" ranging from "truly isolated depressional wetlands" to "those connected via intermittent or permanent surface flows." Kennedy envisioned that decisions about the connectivity of these types of wetlands may need to be made on a case-by-case basis and then be applied across similar classes of wetlands.
The scientific report notes, however, that isolation can enhance the ecological value of a wetland, allowing those areas to store extra water and sediment during storms that could have otherwise affected downstream waters.
"It's very hard to say that wetlands aren't connected," said Joy Zedler, a wetlands ecologist at the University of Wisconsin who chaired a 2001 National Academy of Sciences panel on wetland mitigation. "One could argue intellectually that all parts of all ecosystems are connected, so it's really a question of how much connection is enough connection for whatever purpose one is interested in."
That question -- how much of a connection is needed to meet the threshold for Kennedy's "significant nexus" -- will ultimately be decided by policymakers, not scientists. But Deidre Duncan, an attorney for the Waters Advocacy Coalition, an industry group, said she was disappointed the report didn't do more to quantify the value of various connections.
"EPA has really asked the wrong questions in this report," she said. "Everything is connected -- even land is connected and has value -- and so ... is it then up for them to regulate everything? How are they going to draw lines, and are they going to draw lines or are they just going to regulate everything?"
The 331-page report includes abundant data -- for instance, it reports the findings from a litany of studies about what percentage of pollutants have been shown to be captured and retained by various wetlands. But Duncan said assessment of these types of relative values should have been the focus of the report's conclusions.
The report also touches on an issue that became a hot button in a guidance proposed by the Obama administration in 2012 that was quietly withdrawn last week.
Environmentalists say Kennedy's "significant nexus" test allowed for the value of non-navigable waters to be considered not just individually, but collectively, or in "aggregation." For instance, filling in a single small stream may have little impact on the large river into which it flows. But dumping fill into several similar streams in the same watershed could have a significant, cumulative effect.
The report concurs with this aggregation principle, stating that "to understand the health, behavior, and sustainability of downstream waters, the effects of small water bodies in a watershed need to be considered in aggregate."
But Duncan said this approach is merely a way of "making things that may not be significant significant."
"Certainly when you put a bunch of small things together, whatever it is, it takes on a different form and becomes bigger," she said. "In some ways that's an acknowledgement that the individual stream or water body at issue may not be significant in its own right."
Aggregation could be key to establishing jurisdiction over areas of seemingly isolated wetlands like the Great Plains' prairie potholes -- shallow depressions formed as glaciers covering the region 10,000 years ago melted.
Small prairie potholes in a region that also has medium and large ones may not seem important on their own, said Zedler, the wetlands ecologist. But because the smaller potholes are the first to thaw in the spring, they are critical for providing food and habitat to waterfowl, she said.
Federal regulators have typically shied away from using birds to connect wetlands after the 2001 Supreme Court decision struck down the migratory bird rule. But Jan Goldman-Carter, wetlands and water resources counsel at the National Wildlife Federation, argued that the ruling doesn't prevent regulators from looking at birds' or amphibians' local movements across water bodies to prove a biological connection.
"There's a difference between migration and basing this on migratory habitat, as opposed to actual day-to-day survival," she said. "What we're talking about here in terms of the biological linkage is not a migration linkage, it's a survival linkage that's closely tied to that aquatic ecosystem."
But, she acknowledged, this assertion hasn't been tested in court, and since the 2008 guidance, agencies have largely avoided claiming jurisdiction over wetlands like prairie potholes that could be considered geographically isolated.
Supreme Court decision spurred scientists
Environmental groups are also urging the administration to take a regulatory approach that allows for a scientific learning curve.
Although wetlands science is a well-established field, it wasn't until the Supreme Court's Clean Water Act decision in 2001 that scientists really turned their eyes to connectivity.
Margaret Palmer, a University of Maryland professor and director of the National Socio-Environmental Synthesis Center, said that until then many scientists simply took connectivity for granted.
"When some of us saw that [decision], we thought, 'Gee, I guess we need to go out and get more of these distinct measurements and get data on this so that there aren't questions," she said. "The decision actually motivated work."
The field of connectivity is also burgeoning, she said, as increasing numbers of streams dry up for most of the year as a consequence of climate change and overextraction. But because of the multiple layers of peer review involved in the EPA study, a great deal of recent work is not included.
Jeanne Christie, executive director of the Association of State Wetland Managers, said the basics of connectivity are known and have remained consistent over time. But, she noted, "there are just huge areas that we know very little about."
For instance, she said, the importance of mycelium -- the threadlike vegetative part of a fungus -- to ecosystems is only beginning to be understood. In forests, scientists are finding critical connections between mycelium and plants' abilities to be productive, she said, and it's unclear how this might translate into aquatic systems.
"Many of our practices in land development and alteration of waterways could just tear that apart, and we're just starting to realize that that's important," she said.
Environmentalists contend it will be important for any new rule to have a mechanism for incorporating new scientific discoveries.
"If every time new science emerges -- some of which might be pivotal in terms of demonstrating connectivity -- you have to reincorporate it into a document like this and then go back and do a rulemaking; that wouldn't be a very good approach," said Scott Yaich, director of conservation operations for Ducks Unlimited.
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