Reducing the amount of nitrogen and phosphorus entering the Bay has been the cornerstone of the Bay Program’s efforts to clean up the Chesapeake since 1987. As the Executive Council prepares to lay out the need for additional action, here — in question and answer form — is a recap of where the cleanup effort has been, and where it is headed.
How did nutrients get to be a problem?
It’s largely the fault of munitions built up for World War I and modern industrialization. For centuries, the amount of nitrogen available for use was relatively stable; animal waste was the main source of fertilizer. But during World War I, the Germans needed to increase their supply of nitrate, which is needed to make munitions explode. So they learned to tap an inexhaustible source: the atmosphere.
Nitrogen in the atmosphere is a stable gas which typically is not available for use by most plants. In the decades after the war, technology developed by the Germans was used to produce huge amounts of cheap, chemical fertilizers that were used in agriculture in increasing amounts. At the same time, industrialization led to the increased burning of fossil fuels, which release large amounts of long-stored nitrogen when burned.
Worldwide, it’s estimated that today there is about twice as much nitrogen in the environment than a century ago. In the Bay watershed, with its large human population and plenty of agricultural land, cars and power plants, there is anywhere from six to eight times as much nitrogen today than in the past.
Likewise, the amount of phosphorus has increased over historic levels. As with nitrogen, the amount of phosphorus on the landscape was once stable. But phosphorus is a mineral that can be mined from the ground, which has increased the amount available not only for fertilizers, but other purposes such as cleaning agents in detergents. (Although phosphates are banned in laundry detergents within most of the watershed, they are found in other cleaners such as dish soap and dishwasher detergent.)
Why are nutrients a problem?
Excess nutrients overfertilize the Bay, causing increased algae growth. Sometimes a single algae species becomes so dense that it forms a “bloom” which can actually change the color of the water. When algae cloud the water, they prevent underwater grass beds from getting the sunlight they need to survive. As a result, the grass beds — which provide food and habitat for crabs, waterfowl and a host of fish species — occupy only a fraction of their historic range in the Bay.
When the algae die, they sink and are decomposed by bacteria in a process that rapidly uses up oxygen needed by fish and other water dwellers to survive. This is especially a problem in deep areas where oxygen can’t be replenished from the air. In the summer, a third or more of the Bay’s volume is typically rendered a “dead zone” because of oxygen depletion. Oxygen depletion caused by algae die-offs is also a problem in many shallow areas and tidal streams, although usually for shorter periods of time.
Blooms create added problems. Most zooplankton — an algae predator which in turn is an important food for fish and other species — require a mix of algae species to thrive. Frequent single species blooms can actually limit zooplankton production, reducing the amount of food available in the food chain leading to fish and crabs.
Further, some of those blooms can consist of harmful species that kill predators or, in some cases, affect human health. Lacking enough predators such as zooplankton to control the algae, the excess is eaten by oxygen-consuming bacteria. The Chesapeake is the most bacteria-enriched estuary known to exist in the United States. Some bacteria species that thrive in the Bay can affect the health of both humans and fish.
Nitrogen tends to fuel algae blooms in saltier portions of the Bay, while phosphorus is the main problem in low salinity and fresh water areas.
Aren’t nutrients a good thing for plants and animals?
Yes. If it were not for nutrients, nothing would grow in the Bay. But the Bay has far more nutrients than it can handle. Compounding the problem is the Chesapeake and its watershed have lost much of their ability to absorb nutrients. The Bay was once filled with oysters that helped to filter excess algae from water. But today, oysters are at only about 1 percent of their historic levels because of disease and overharvesting. Menhaden, a filter-feeding fish, is also near historic lows in the Bay. In the watershed, the loss of nutrient-absorbing forests and wetlands also adds to the problem.
If we reduce nutrients, will all of the Bay’s nutrient problems go away?
No. Nutrients are the most fundamental water quality issue for the Bay, but controlling nitrogen and phosphorus only sets the stage for the return of a healthy Chesapeake Bay. The recovery will also require major efforts to restore habitats, such as oyster reefs and underwater grass beds, and improved fisheries management to prevent the overfishing of critical species that are either commercially or ecologically valuable in the Bay.
Where do nutrients entering the Bay come from?
Agricultural runoff is the leading source, accounting for about two-fifths of both the nitrogen and phosphorus entering from the watershed. Discharges from wastewater treatment plants are also a major source, followed by runoff from urban and suburban areas. Air pollution is also a big factor for nitrogen, with the combustion of fossil fuels and ammonia escaping livestock operations accounting for somewhere between a quarter and a third of the total.
Are nutrients a problem just in the Bay?
Absolutely not. A recent National Academy of Sciences report concluded that nutrient-related problems are “the greatest pollution threat faced by the coastal marine environment,” contributing to huge oxygen-depleted dead zones, harmful algae blooms, the loss of coral reefs and other problems. Because pollution control programs, in general, have not focused on nutrient issues, most coastal areas have continued to degrade in recent decades. Other coastal areas around the world face similar problems.
Who is responsible for fixing the Bay’s problem?
In 1983, the federal government and the states of Maryland, Virginia and Pennsylvania and the District of Columbia joined forces to create the Chesapeake Bay Program, a cooperative partnership aimed at cleaning up the Bay and restoring its “living resources.” In the past two years, New York, Delaware and West Virginia have signed an agreement pledging to control nutrients in their parts of the Bay watershed.
What has it done to address nutrients?
In 1987, the Bay Program’s top policy body, the Executive Council, signed an agreement committing to a 40 percent reduction of nutrients by the year 2000. The Executive Council includes the governors of the three states, the mayor of the District of Columbia, the administrator of the EPA, and the chairman of the Chesapeake Bay Commission (which represents the legislatures of the three states).
40 percent! Wasn’t that a lot?
Not as much as one might think. The 1987 Bay Agreement called for “at least a 40 percent reduction” in nitrogen and phosphorus entering the Bay by 2000. But the next year, officials modified the goal, by saying it applied only to “controllable” sources. Nutrients from the air, from “headwater states” of New York, West Virginia and Delaware, from septic systems and a variety of other sources were considered “uncontrollable.” In reality, the “40 percent” goal was equal only to a 22 percent cut in nitrogen; the phosphorus goal, meanwhile, amounted to a 37 percent reduction.
Was the goal met?
No. Baywide, computer models that track nutrient control actions estimate nitrogen loads were reduced 53 million pounds, 24 million pounds short of the goal. Phosphorus was reduced 8 million pounds, missing the goal by 2.3 million pounds. (The starting point, or “baseline,” from which the reductions are measured is 1985, when it is estimated that 338 million pounds of nitrogen, and 27.1 million pounds of phosphorus entered the Bay.)
Is the Bay getting better?
Not yet. Although there are year-to-year fluctuations (wet years send more runoff — and nutrients — into the Bay than dry years), there has been no Baywide trend over the past decade for key water quality indicators such as dissolved oxygen and acreage of underwater grasses. But in some places where nutrient reductions have been made, such as small rivers on Maryland’s Western Shore and parts of the Potomac River, there have been encouraging rebounds for underwater grass beds. But other places have seen little improvement, and a few areas have gotten worse.
Why are water quality improvements taking so long?
While computer models show reductions, actual water monitoring data have shown few changes in nutrient levels except for areas where wastewater treatment plants have a big influence. In part, that’s because many of the nutrients, especially nitrogen, enter streams through groundwater. That’s a journey that can take years to complete, so the impact of nutrient control actions can take years to show up. Also, some nutrient control activities, such as planting streamside forest buffers, can take years to become fully effective at reducing nutrient runoff. Further, many techniques used to reduce nutrient runoff are relatively new, and it’s possible that some nutrient reduction actions are not as effective as thought.
Will We Need More Nutrient Reductions?
Yes. As early as 1992, Bay scientists were publicly suggesting that further substantial nutrient reductions would be needed to significantly improve Chesapeake water quality. At about the same time, the Bay Program’s own computer models were showing that the “40 percent controllable” nutrient reduction would result in only modest water quality improvements if attained.
By the late 1990s, it was clear that the old goal was far too modest to mend a Bay overwhelmed by six to eight times its natural nutrient load. In 1997, the Executive Council directed the Bay Program to begin planning nutrient reduction efforts that would go beyond the 2000 goal to improve habitat conditions for the Bay’s living resources.
What happened with the directive?
To a large degree, it was overtaken by events. During the 1990s, suits by environmental groups across the nation began forcing the EPA and the states to carry out long-overlooked requirements of the Clean Water Act that called for states to monitor all waterbodies and list, every two years, all waterways that failed to meet water quality standards. Those “impaired” waterbodies are placed on the EPA’s so-called “dirty waters” list and are required to have a Total Maximum Daily Load, or TMDL.
Simply put, a TMDL is a calculation of the total load of pollutants a waterbody can receive and still attain the water quality standard along with a “margin of safety.” A TMDL identifies all sources that contribute to the impairment, whether located in the segment with the problem or farther upstream, and allocates reductions from those sources so water quality standards can be achieved. In 1999, the EPA added parts of the Bay and its tidal tributaries to Virginia’s dirty waters list. In a settlement stemming from a lawsuit against the EPA, a court-approved schedule was set requiring Virginia to develop a TMDL for the Bay by 2011. About the same time, Maryland listed its portions of the Bay as “impaired” because excess nutrients kept them from meeting water quality standards.
What’s so awful about a TMDL?
It depends on your perspective. Many environmental groups believe that TMDLs are an important tool to force the cleanup of about 20,000 waterways that still fail to meet water quality standards 30 years after the Clean Water Act was passed. Many state and federal officials worry, especially in an area as large as the 64,000-square-mile Bay watershed, that it would be difficult to enforce regulatory elements of a TMDL without numerous court challenges. As a result, the Chesapeake 2000 agreement approved by the Executive Council called for eliminating water quality impairments by 2010, a year before a TMDL would be required under the consent decree.
Why is the Bay “impaired”?
Mainly for dissolved oxygen. When written decades ago, state officials established a one-size-fits-all water quality standard for the Bay which essentially calls for a dissolved oxygen standard of 5 milligrams of oxygen per liter of water to support aquatic life.
Does the Bay have to be cleaned up to meet its dissolved oxygen standard?
Unfortunately, it’s not so simple. Most scientists generally agree that deep areas of the Bay never had 5 milligrams of oxygen per liter of water, even when Capt. John Smith explored it nearly 400 years ago. Although human actions have made the situation worse, the Bay’s poor ability to mix water means that even under “natural” conditions, many deep areas would have low levels of dissolved oxygen.
Do the standards have to be changed?
Yes and no. The EPA and the states are working to develop a suite of new standards. In some cases, such as in deep water, the standards will call for lesser amounts of dissolved oxygen (but more than is commonly found today). In other places, such as juvenile fish spawning areas, dissolved oxygen standards will be higher.
In addition, the Bay Program is developing new standards for water clarity aimed at allowing underwater grasses to rebound, as well as new standards aimed at limiting concentrations of chlorophyll a (a measure of algae). The goal is to develop a suite of new standards that are directly tied to the conditions that fish, shellfish, underwater grasses and other resources need to thrive.
How do they know what resources need? Do they talk to fish?
No, Dr. Doolittle doesn’t live around the Bay. Nonetheless, the Chesapeake is the best-studied estuary (an area where salt and fresh water mix) in the nation. Scientists know how much dissolved oxygen different fish need at various life stages, and which areas are used during those life stages. Likewise, research has shown how much light fresh water, and salt water species of underwater grasses need to survive. Using that information, the new standards will set specific oxygen or light goals that are needed in different parts of the Bay.
How big will the new goals for nutrient reductions be?
Big. Preliminary estimates suggest that to meet the dissolved oxygen standards, the final number will need to limit nitrogen inputs to something less than 200 million pounds a year for nitrogen, and less than 16 million pounds for phosphorus. Final numbers will likely be lower as reductions needed to meet other standards are factored in. Those are significant reductions from the present estimated annual loadings of 285 million pounds of nitrogen, and 19 million pounds of phosphorus.
Will reductions be equal across the board?
No. Different rivers influence the Bay differently: Rivers from the Potomac north have the biggest influence on dissolved oxygen, for example. Other rivers have varying degrees of problems with water clarity, and chlorophyll concentrations. Final reductions for each river will be based on both its impact to Baywide problems and the amount of reductions needed to meet standards within the tidal portion of that river.
How will nutrient loads be divided?
Using computer models and agreed-upon rules for dividing loads, the Bay Program early next year will allocate loads for each of nine major river basins, and for states within each river basin. After that, the states will likely set targets for subbasins within those rivers. Then, states — or citizen tributary teams within the states — will write nutrient reduction strategies to achieve the goal.
When will the new goals be set?
The process for setting new water quality standards, and getting public input on the standards, is behind schedule. It is anticipated the draft river-specific numbers will be available early next year, with the final state and river specific goals set in April. The development of tributary strategies is expected to take about a year beyond that.
Will new types of reductions be needed?
Yes. In April, the Bay Program will likely establish some kind of goal for sediments as well, based on studies that show dirt is also a factor in clouding shallow water areas.
How much will this cost? Who will pay?
Preliminary estimates suggest cleanup efforts could cost a billion dollars or more a year. Exactly who pays will depend on actions outlined in tributary strategies. An ad-hoc group has been formed involving state officials, the Chesapeake Bay Commission the Chesapeake Bay Foundation and others to seek additional federal support for cleanup efforts. This effort helped to greatly increase funding in the Farm Bill for conservation programs that will help pay for runoff control programs on agricultural lands. Legislation that would provide grants for wastewater treatment plant upgrades using state-of-the-art nutrient control technology has also been introduced.
Does the Bay Program process mean there will be no lawsuits?
No. There are many possible scenarios for lawsuits. For example, the regulated community could challenge the scientific basis for the new water quality standards — which would affect their permit requirements — in court. Environmental groups have questioned the legality of the whole process, saying the Clean Water Act requires the states and EPA to develop and implement TMDLs — not create a process which avoids a formal TMDL for a number of years. Bay officials hope their process, which involves public review of new water quality standards and locally developed tributary strategies, will build support among stakeholders to cooperatively clean up the Bay and head off potential suits.
What happens in 2010?
At this point, no one really knows. Even if all of the necessary actions are taken to achieve needed nutrient reductions, it is unlikely the new water quality standards would be met. That’s because many of the nutrients that will enter the Bay in 2010 are already on their way. Instead of running off the land, they seep into the ground and enter the groundwater, beginning a long, slow journey that can take years — even decades — to complete.
Some say the Chesapeake should be removed from the impaired water bodies list if computer models suggest the actions taken as of 2010 will ultimately clean up the Bay. Others say the it should not be delisted until water quality monitoring actually shows standards have been met. In that case, a TMDL may have to be written, but it would have already been implemented and regulations might be avoided.
What if adequate reductions are not made?
Under the Virginia consent decree, a TMDL would be required for the Bay in 2011, and the states would need to begin implementing it, which could mean new regulations and even new legislation.
Does the job end in 2010?
No. The nutrient loads assigned to the rivers are intended as maximum limits, or “caps,” which must be maintained if the health of the Bay is to be preserved. Even when the reductions are achieved, ongoing efforts will be needed to offset the impacts of population growth in the region.