The field of environmental law often involves tangential explorations of scientific concepts. Lately, one scientific term – hydrologic connectivity – seems to keep finding its way into much of my work. As for many others, this principle of hydrology became familiar to me thanks to its place at the center of one of the biggest fights in the history of environmental law, spilling onto the front pages and into the public consciousness.
Over the last several decades, a pair of Supreme Court opinions resulted in complete confusion over where federal jurisdiction under the Clean Water Act begins and ends – that is, over which waterways it protects. The Obama EPA spent years examining the best available science to develop a rule to bring clarity and certainty and draw jurisdictional boundaries roughly where they existed before the high court got involved. The new rule drew the ire of conservative activists and resource extraction industries, while the subsequent repeal of the rule by the Trump administration has resulted in widespread condemnation by environmental advocates and, in particular, administrative law scholars.
What is interesting about this saga is that it is rooted in the issue of federal jurisdiction, not necessarily pollution reduction. But hydrologic connectivity is increasingly becoming a relevant environmental law and policy issue for advocates and courts for a variety of reasons. And I would suggest that the law needs to quickly catch up with the science if we want to modernize protection of our nation’s waters.
Courts Are Slowly Learning Hydrology
A basic rule of thumb is that the Clean Water Act regulates pollution in navigable surface waters but not groundwater (though many states regulate groundwater under state law). The decades-long jurisdictional fight described above is all about whether or not a stream, wetland, or isolated body of water deserves federal protection. And the answer, proposed by most reasonable minds, is that the boundaries of federal jurisdiction should be based on whether or not the affected body of water has a close or significant hydrologic connection, or nexus, to a clearly jurisdictional waterway.
This is how the topic of hydrologic connectivity came to be a hot topic in environmental law. The connections between waterways is the obvious and critical factor for determining whether a body of water is protected by federal environmental laws from disturbance. As it turns out, hydrologic connectivity is also becoming similarly essential for understanding whether or not pollution – flowing underground – can be considered illegal under the Clean Water Act.
A string of cases over the last year in federal district courts has found that, yes indeed, a short and direct flow of pollution through groundwater from a federally regulated Clean Water Act facility to a federally regulated waterbody can be considered a regulated conduit of "point source" pollution. No federal appeals court has yet upheld this theory, and there are many doubts about whether any will. After all, it is generally understood that the Clean Water Act pertains only to surface water.
So how can it be that a growing number of district courts have found that a groundwater conduit can give rise to a Clean Water Act claim? Where should the law draw the line between what is a jurisdictional underground conduit of pollution and what is a non-jurisdictional claim over groundwater?
If an enormous unlined pond is leaking hundreds of pounds of toxic chemicals every day into a major navigable river 10 feet away, it would seem hard to find fault with a court’s reasoning that the owner of that leaky waste storage site is directly violating the Clean Water Act by discharging those chemicals into a clearly jurisdictional waterway. Move that pond a mile away and it might be a completely different story – and outcome in court.
There’s An App for … Hydrologic Connectivity?
This is where a greater understanding of the dynamics of hydrologic connectivity comes into play. Recently, Inside EPA reported that an environmental consultant has urged EPA to solve the present jurisdictional spat involving repeal of the Clean Water Rule (or the Waters of the United States (WOTUS) rule) by developing a software tool grounded in the science of hydrologic connectivity.
There is an allure to developing a scientifically sound and publicly available tool that would provide the certainty and clarity that developers, land owners, and the public need. Of course, the scientific parameters and software algorithms used to build such a tool will likely be subject to much the same criticism and controversy that befell the Clean Water Rule, which merely tried to provide that same certainty and clarity. Nevertheless, a tool like this could not only go a long way toward resolving (and possibly intensifying) the current jurisdictional fight, but it might also be a helpful aide to courts, litigators, regulators, advocates, and environmental compliance officers and consultants.
Here in the Chesapeake region, a hydrologic connectivity tool, or at least a much wider recognition of the importance of groundwater dynamics, would be valuable for several reasons.
First, we are already blessed with the contributions of dozens of scientists and modelers who contribute to the Chesapeake Bay Program partnership. Thanks to their efforts, we can determine things like how much nitrogen pollution is generated from converting forest to suburban sprawl, how much sediment is transported from a first-order stream to the main stem of the Bay, or how much nitrogen from a coal plant hundreds of miles away will reach Chesapeake tidal waters. The Bay Program has even developed a tool that allows local planners and project developers to evaluate the impacts of a development in a particular location. In other words, we already have a platform or foundation of science and modelling on which to apply this new connectivity tool, making the Bay region a perfect place for a trial run.
Second, we know that so much of the pollution that causes algal blooms and dead zones in the Bay is transported there via groundwater. Advocates in this region are aware of the role that nonpoint source (“runoff”) pollution plays in harming water quality. Agricultural sources of nutrient pollution such as animal manure and excessive applications of chemical fertilizer, along with polluted urban runoff from the vast expanses of pavement in our growing metropolitan areas, are well understood to be the chief culprits of the Bay’s woes.
But what is less well understood are the mechanisms of transport – the hydrologic connections – of these pollutants from source to Bay. Dissolved nitrates and phosphorus course through groundwater over months, years, or even decades, harming local communities before reaching the Bay and its tributaries, where it stimulates the formation of the famous dead zones.
This legacy of our more polluted past is something that Bay Program scientists have attempted to grapple with and will continue to confound management efforts from state and local officials. For now, it is understood that soil and groundwater characteristics and the proximity to rivers and tidal portions of the Chesapeake Bay mean that pollution in some locations has a much worse impact on water quality than in other places. Because of this, state and local officials would be well advised to steer additional resources toward (and development away from) some areas.
New Tools Are Needed to Modernize Our Efforts to Regulate Water Pollution
When a company or other entity seeks to open a new facility, state permit writers immediately go to work with the facility’s engineers to understand how much pollution will be discharged to the nearest waters and what that means for that waterbody and any pollution budget established for it. But when a developer or local government proposes a massive new land development project with the potential for an even greater impact on water quality, state agencies don't perform this same exercise at the permitting stage to determine that project’s impact on water quality.
We need new tools that allow regulators, permitting authorities, developers, and concerned citizens to examine the suitability of a proposed project based on the known surface features and the less understood hydrologic connections between where runoff from the site infiltrates into the ground and the nearest surface water (or drinking water well).
For example, a proposed confined animal feeding operation located above a high water table with groundwater saturated by nitrates and immediately adjacent to tidal waters could have an enormous detrimental impact on the nearest waters (and public health) if not mitigated with additional restrictions in the permit. Similarly, the conversion of hundreds of acres of contiguous forest surrounding a stream for the construction of a sprawling suburban subdivision served by septic systems could ruin for decades the biological integrity of an otherwise healthy watershed.
These are just a few particularly problematic examples among hundreds of developments built in Maryland last year, as shown in the map below. The data and tools to track and identify particularly harmful developments are readily available for regulators that choose to use them (they were certainly available to this advocate). And if we want to protect our waters, it is essential for permit writers, regulators, and communities to have this information about the potential impact of a permitted project before a permit is approved.
But even if our state agencies utilized all of the currently available information to make more informed permitting decisions based on the known location of surface features, what is still missing is an understanding of the impact from any runoff generated by a new development (and not captured by forests and wetlands cleared by that development). This is why a hydrologic connectivity tool or even just a greater understanding of localized groundwater dynamics or the location of unmapped streams could go a long way to modernizing our protection of the Chesapeake Bay.