If You Care about the Climate Crisis, Here's What You Need to Know about Maryland's Clean Water Act Permit for Agricultural Pollution

David Flores

Nov. 15, 2019

David Flores co-authored this post with Kathy Phillips, the Assateague Coastkeeper, an on-the-water advocate who patrols and protects the Maryland and northern Virginia Eastern Shore coastal bays and stands up to polluters.

Last month, former CPR policy analyst Evan Isaacson wrote in this space about Maryland's proposal to revise and reissue its Clean Water Act pollution permit for concentrated animal feeding operations (CAFOs). He made a convincing case that those who love the Bay need to advocate for effective and enforceable CAFO regulations.

Traditionally, air pollution permits have been and will continue to be a critical component of climate policy in the United States, controlling emissions of greenhouse gas pollutants. But strong water pollution standards, including permits, are also a vital tool in addressing climate change because they are so important to state efforts to adapt.

Maryland's CAFO permit is what's described as a "general permit" because it's a single permit that will cover many hundreds of individual pollution sources – in this case, CAFOs. And because this one will be issued in 2020, and because it's a five-year permit, this is the permit that will address CAFO emissions until 2025, by which time the state is required to meet the pollution-reduction requirements of the Chesapeake Bay TMDL, the last, best hope for cleaning up the Bay. If the CAFO permit fails to achieve the pollution reductions it needs to, the problem won't get fixed in time to make a difference on the TMDL front.

As it happens, it's not until late 2021 that the state is required to develop a plan to address the impact of additional pollution loads attributable to the climate crisis. And those loads are significant. Last year, Bay scientists estimated that Maryland will need to address a substantial increase in such pollution because of climate change, including pollution related to more frequent and more intense rainfall, along with increases resulting from warmer air and water temperatures. Bay Program modelers project that Maryland will need to deal with an additional 2.2 million pounds of nitrogen per year by 2025 and another 100,000 pounds of phosphorus.

Clearly then, Maryland's new CAFO permit should account for the impacts of climate change. CAFOs are particularly vulnerable to flooding, one of the chief impacts of climate change, particularly on Maryland's Eastern Shore, the heart of the state's CAFO industry. Stronger hurricanes are more frequently following a path into the mid-Atlantic, bringing storm surge to the CAFOs' doorstep. River flooding, sunny-day flooding, and storm surge all have the potential to flood extensive portions of Maryland's industrial agricultural sector.


All dots indicate the location of facilities that have obtained coverage under Maryland's Clean Water Act CAFO discharge permit. Red dots indicate CAFOs at the highest risk of flooding due to high tidal conditions and/or storm surge from Category 1 and 2 hurricanes. Orange dots indicate CAFOs at medium risk of flooding due to designation of 100-year flood zones. Yellow dots indicate CAFOs at a lower risk of flooding due to designation of 500-year flood zones and/or storm surge from Category 3 and 4 hurricanes. Black dots are CAFOs that are not likely exposed to present risks of flooding, but many could soon flood as sea levels continue to rise. Blue shaded areas are those regions that are at risk of flooding form a hurricane or from high tides, according to data from NOAA or those regions that are within a FEMA-designated flood zone. Dark blue shaded areas indicate regions where multiple types of flood risks are projected and correspond with greater potential exposure.

When waters rise, ditches dug into farm fields can also funnel floodwaters directly to agricultural facilities, including CAFOs, accelerating the loss of farm acreage to saltwater intrusion, and carrying great quantities of animal waste and the carcasses of drowned chickens and turkeys downstream, a phenomenon observed recently during Hurricane Florence at a number of chicken CAFOs in North Carolina. In addition, floodwaters will likely carry a potent cocktail of pollution from farm fields – pesticides, fertilizers (much of it animal waste from CAFOs), and more – straight into the Chesapeake.


A flooded chicken CAFO in North Carolina releases pollution into floodwaters following Hurricane Florence. Photo credit: Rick Dover, Waterkeeper Alliance.

A straightforward way that state regulators could factor climate change into their CAFO planning would be to reject permit applications for new CAFO facilities located in areas that are likely to flood from present-day risks of flooding, such as storm surge or 100-year flood zones. Those areas are going to be increasingly likely to flood, as the impacts of climate change unfold over the next several years. Similarly, for existing permit-holders, permit writers could require enhanced pollution prevention planning and pollution control measures, including, for example, flood prevention practices like berms, constructed wetlands, ditch removal, and stronger and higher pond walls.

This isn't one of those problems that's years off. Frequent and intense rainfall is already having a big impact the Chesapeake Bay, seemingly washing away much of the gains we have made in reducing nutrient and sediment pollution through Bay restoration policies. The total amount of pollution scoured from the landscape and washed into creeks, rivers, and the Bay after just a few of these extreme rainfalls comprises a significant percentage of all pollution entering the Bay in a single year.


Agricultural ditches on the Eastern Shore of Maryland can act as vectors or conduits for coastal flooding. The red dots on the map indicate CAFO locations.

The increased intensity of precipitation, which has been attributed to climate change, contributes to flooding as well as the incidence and severity of stormwater pollution. Increasingly intense rainfall events have the potential to dislodge and wash away more pollution through ground saturation and soil erosion. Stormwater control structures, such as detention ponds, could receive more polluted stormwater at even higher volumes. As a result, stormwater controls could fail or require more frequent maintenance. For example, infill of sediment into stormwater detention ponds reduces their capacity and effectiveness.

Of course, nutrients and sediment aren't the only pollutants unearthed after heavy rains. Toxic floodwaters that form when low-lying industrial sites are inundated can create a substantial public health threat to surrounding communities, from the clusters of industrial sites around Baltimore to the dozens of CAFOs on the Eastern Shore in flood zones and areas particularly exposed to hurricanes and sea level rise. With the phrase "hundred-year storm" seeming to lose all meaning these days, it would be irrational not to modernize the CAFO permit and ensure these facilities – and the surrounding communities and waterways – are protected from today's climate impacts.


A chicken CAFO in Berlin, Maryland, near the Pocomoke River is flooded after four inches of rainfall within 24 hours during the summer of 2018. Photo credit: Assateague Coastal Trust/Tim Preziosi

Clean Water Act permits, like this CAFO permit, are not regulatory instruments primarily designed for controlling air emissions. However, as Maryland regulators have acknowledged in the past, thoughtfully designed stormwater management, including basic housekeeping practices, have the potential to produce co-benefits, among them, reducing greenhouse gas emissions, particulate matter, and other air pollution.

Nitrous oxide is a highly persistent greenhouse gas that is 300 times more potent than carbon dioxide. Nearly three-quarters of the nitrous oxide emitted in the United States is attributed to the agricultural sector, believed largely to come from manure, and indeed, emissions are increasing along with the expansion of industrial animal agriculture nationwide. When manure is stockpiled in large quantities, promoting anaerobic conditions, nitrous oxide is produced and emitted, along with the potent greenhouse gas methane. One recent study of manure over-applications to farm fields found that nitrous oxide emissions increased exponentially with each additional unit of manure applied.

Bay regulators have been historically concerned with air emissions of nitrogen-based chemicals like ammonia because a third of nitrogen pollution to the Bay occurs through deposition of pollutants. (See U.S. EPA, Chesapeake Bay Total Maximum Daily Load for Nitrogen, Phosphorus and Sediment, Appendix L, page L-2 (Dec. 29, 2010)). While some forms of nitrogen-based emissions have declined, ammonia emissions, like nitrous oxide, have increased along with the expansion of industrial agriculture and the quantity of animal manure produced. In a recent study, the Environmental Integrity Project estimated that a typical Eastern Shore CAFO – producing some 500,000 chickens annually – could produce up to 24 tons of ammonia per year, nearly double the previous estimate by EPA Bay regulators. Researchers attribute this higher estimate, in part, to such management practices as high-frequency reuse of bedding materials and to warmer climate conditions. While ammonia's contributions to climate change may be minimal compared to methane or carbon dioxide, it is a potent public health threat, especially for vulnerable communities adjacent and downwind of CAFOs and other industrial agriculture facilities.

Like the Bay cleanup, the stakes for addressing the unavoidable impacts of the climate crisis and the worsening harms that we can still avert have never been higher. Maryland permit writers have an opportunity to move the needle by adopting both climate adaptation and mitigation reforms in the next CAFO permit, to ensure that the permit reflects current, changed climate conditions and responds to the substantial impact of this industry on the Bay, our climate, and surrounding communities.

If you want to help the Chesapeake Bay and protect Marylanders from the harms of climate change, now is the time. You can submit public comments to the Maryland Department of the Environment online. Let the agency know you want a better Clean Water Act permit for CAFOs in Maryland.

Evan Isaacson, a former CPR policy analyst, contributed to this post.

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