Regional efforts to restore the Chesapeake Bay have been under way since 1983. After a multiyear study by the U.S. Environmental Protection Agency, the agency and the states agreed to coordinate their efforts to reduce pollution in the Bay and restore its “living resources” — the fish, crabs, oysters and waterfowl that depend upon it. Here, in question-and-answer form, is a primer on the Bay and efforts to restore it.

Chesapeake Bay & Chesapeake Bay Program

Why is the Chesapeake Bay important?

The Chesapeake Bay is the nation’s largest estuary, an area where salt and fresh waters mix. Estuaries are among the most valuable and productive ecosystems on the planet and, acre-for-acre, the Chesapeake Bay is one of the most productive estuaries in the world. About 85 percent of all striped bass found along the East Coast are born in the Bay, and it is highly productive for other species, such as menhaden and blue crabs.

What is the Chesapeake Bay watershed?

A watershed is the area of land that drains into a given waterbody. The drainage area for the Chesapeake Bay covers about 64,000 square miles, stretching from Cooperstown in New York nearly into North Carolina, and from West Virginia to Delaware. About half of the drainage area is the Susquehanna River watershed, which supplies almost 50 percent of the freshwater flowing into the Bay.

What is the Chesapeake Bay Program?

The Chesapeake Bay Program is a voluntary partnership between the federal government and states that dates to 1983, when state governors and the EPA signed the first of several agreements committing them to work together to restore the Bay to health.

In 1987, they signed a more detailed agreement to reduce water pollution, improve habitat, manage fish species and take other actions to help restore the Bay. Additional agreements were signed in 2000 and 2014.

What is the Chesapeake Executive Council?

The Chesapeake Executive Council is the highest level coordinating body for the Chesapeake Bay Program. Initially, it included the governors of Maryland, Virginia and Pennsylvania; the mayor of the District of Columbia; the EPA administrator; and the chair of the Chesapeake Bay Commission, which represents state legislatures in the three states. In 2014, the governors of Delaware, West Virginia and New York signed the Chesapeake Bay Watershed Agreement and joined the Executive Council.

What is the main water quality problem in the Bay?

The Bay’s greatest pollutants are excess amounts of sediment and two nutrients, nitrogen and phosphorus. The nutrients spur algal blooms. When there is more algae than predators can consume, the excess algae die and sink to the bottom. The process of decay draws oxygen out of the water, often leaving too little oxygen to support fish, shellfish and other creatures. In severe cases, the oxygen is totally depleted, creating so-called “dead zones.”

Algae blooms also cloud the water, blocking the sunlight necessary to support underwater grass beds that provide important habitats for juvenile fish and crabs, as well as waterfowl. Murky water can also prevent predators from being able to find their prey.

Sediment also contributes to cloudy Bay water. In addition, it smothers important habitats for oysters, mussels and a variety of other bottom-dwelling creatures.

But aren’t nutrients good for plants & animals?

Yes. If it were not for nutrients, nothing would grow in the Bay or on the land. But the Bay has far more nutrients than it can handle. Compounding the problem is that 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. In the watershed, the loss of nutrient-absorbing forests and wetlands adds to the problem.

Where do nutrients & sediment come from?

Agriculture is the largest source of both nutrients and sediment. The nutrients nitrogen and phosphorus are key parts of fertilizer and animal waste which are, along with loose sediment from fields, washed into streams when it rains.

Wastewater treatment plants are also major sources of nitrogen and sediment, though their contributions have declined sharply in recent years as large plants have upgraded to new technologies.

Air pollution — nitrogen oxides from fossil fuel combustion and ammonia from agriculture — contributes between a quarter and a third of the nitrogen reaching the Bay, but has also been declining significantly as the result of clean air rules phased in over the last two decades.

Urban and suburban areas contribute smaller amounts of nitrogen and phosphorus but, as more land is developed, polluted stormwater runoff has become the fastest growing source of water pollution in the Bay watershed. It also contributes to the erosion of stream banks and shorelines.

Are nutrients a problem just in the Chesapeake?

Absolutely not. A 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. Similarly, nutrient and sediment pollution — and fecal coliform, which also tends to originate from nutrient sources — are major problems in many freshwater streams.

Is the Bay getting better?

In recent years, Bay water quality has generally been improving, though the improvement is not uniform throughout the estuary. In each of the last two years, the amount of underwater grasses — a key indicator of overall health — has been at the highest level observed in decades, as water clarity in many areas has improved. Dissolved oxygen levels have improved, and the size of the summertime “dead zone” has been greatly reduced. An annual report card produced by the University of Maryland Center for Environmental Science this year gave the Bay its highest ever score, though it was still only a C.

The Chesapeake Bay Clean Up Plan

  What is the TMDL or Total Maximum Daily Load?

A total maximum daily load describes a limit: the maximum amount of pollution that a body of water can receive and still meet federal water quality standards. Those standards are based on specific measurements: dissolved oxygen concentrations, water clarity and other parameters that are set to ensure waterways are safe, swimmable and fishable.

Once established, the daily “load” is then “allocated” to sources contributing to the problem, essentially setting a pollution limit for each source. When that source has a permit, such as wastewater treatment plant, meeting the TMDL requirement is typically required as part of the permit.

The federal Clean Water Act requires that a TMDL be written for all segments of waterways that fail to meet water quality standards. A list of those “impaired” segments is reported to the EPA by each state every two years. The agency may also add segments to the list if it has evidence that they are also impaired. States are required to write a TMDL for each impaired segment. If they don’t, the EPA is supposed to write one for them.

Why did the Bay need a TMDL?

Most of the Bay and the tidal portions of its tributaries do not meet water quality standards for dissolved oxygen, water clarity and chlorophyll a (a measure of algae). In many places, water has too little oxygen to support aquatic life, too much algae or is too murky to allow underwater grass beds to grow.

Why did it take until 2010 to issue the TMDL?

The EPA and the states did not begin developing the TMDL until it was clear that previous, voluntary efforts to meet pollution reduction goals would fail. It also took years to create, because it is the most complex TMDL ever written. It covers a 64,000-square-mile watershed, including portions of six states and the District of Columbia. It includes nearly 18 million people, 88,000 farms, almost 500 large wastewater treatment plants and hundreds of cities and town. In fact, the Bay TMDL is actually built upon 92 more localized TMDLs — the Bay and the tidal portions of its tributaries are divided in to 92 segments, each of which is impaired and requires a TMDL.

Because of the failure to meet earlier Bay cleanup goals set for 2000 and 2010, the Bay TMDL also includes unique features, such as interim pollution reduction targets and an ultimate deadline (2025) to implement all needed pollution control actions.

What is the Baywide maximum load for nutrients & sediment?

The target for nitrogen is 192.4 million pounds; for phosphorus it is 14.46 million pounds; and for sediment it is 7.34 billion pounds.

In 2009 — the starting point for measuring progress — about 260.2 million pounds of nitrogen entered the Bay and 19.2 million pounds of phosphorus, and 8.67 billion pounds of sediment.

Those “loads” were then divided among states and individual rivers in a way that would achieve ultimate Bay water quality goals.

Through the end of 2015, nitrogen levels had been reduced to 241.5 million pounds; phosphorus to 15.4 million pounds; and sediment to 8.04 billion pounds.

 Why is the TMDL different from earlier Bay cleanup efforts?

Previous cleanup efforts were based on largely voluntary agreements between the state and federal governments. The TMDL was designed to include many elements enforceable by the EPA because the earlier efforts failed. The TMDL requires detailed plans and accountability; and the EPA can apply “backstop” measures if a state does is not making adequate progress.

Under the TMDL, the EPA requires detailed watershed implementation plans, or WIPs, which describe how states will achieve nutrient and sediment goals. As part of those plans, states must identify the amount of reductions that will come from wastewater treatment plants, farms, animal feedlots, stormwater, septic systems and other sources.

In the plans, state must demonstrate they have the necessary regulations, permits or other enforceable agreements to reach the goals. An enforceable agreement may include voluntary, incentive-based programs with contracts specifying needed actions and how they will be funded.

To ensure programs stay on track, states must also set two-year milestones detailing the amount of nutrient and sediment reductions that will be achieved during that time, as well as changes in programs, such as more funding or regulations, needed to achieve those goals.

What if states fall short?

Unlike earlier Bay cleanup efforts, the EPA can take a variety of actions if states are falling short of their goals. For instance, the EPA could:

  • force greater nutrient reductions from regulated sources, such as wastewater treatment plants;
  • establish tougher regulatory programs for stormwater and large feedlots, known as concentrated animal feeding operations;
  • deny permits for new or expanding sources of nutrient and sediment discharges, unless states could show how those loads would be offset by other nutrient and sediment reductions beyond those already necessary to meet the TMDL. This could affect wastewater or industrial discharges, some construction permits, animal feedlots and other permitted sources; and
  • withhold funds a state receives through Clean Water Act grants and distribute it to other states that would use it more efficiently, or target the grant to a specific area, action or facility within a state.

Those actions largely target regulated sources. What if goals are missed because of unregulated sources of runoff?

Under the Clean Water Act, the EPA has little authority over nonpoint sources, such as runoff from farm fields, lawns or septic systems. As a result, EPA backstop actions target sources it has the authority to regulate. But those actions, such as requiring larger nutrient reductions from wastewater treatment plants, could be hugely expensive for local governments. The possibility of such expense could help spur states to enact tougher nonpoint source control programs.

Wasn’t the TMDL challenged in court?

Yes, but the courts decided in favor of the TMDL. A group of agricultural and development groups challenged the TMDL soon after it was issued, charging that it exceeded the EPA’s authority. Those arguments were rejected by both federal district and appeals courts, which noted that the TMDL was developed during years of meetings between states and the EPA, and was based on a reasonable interpretation of the Clean Water Act. Last year, the Supreme Court declined to hear an appeal.

Will the Bay be removed from the impaired waters list in 2025 if state cleanup strategies are fully implemented?

Probably not — at least not all of it. The 2025 goal is to have all of the needed practices in place to restore water quality to federal standards. Scientists expect that the benefits from these actions to improve local streams and rivers first, but will take more time to trickle downstream and produce widespread improvements in the Bay. Even if all of the needed actions are in place, it will take years for most of them to become fully effective: For example, cover crops absorb nitrogen, but it typically takes that nitrogen several years to reach a stream, so planting cover crops may not result in improvements to local streams for several years. Similarly, it may take years for a forested stream buffer to become established and provide its full range of benefits.

In addition, it may take the Bay itself years to respond to nutrient and sediment reduction efforts — scientists believe water quality may respond slowly until a “tipping point” or threshold is reached, at which point improvements may take place rapidly.

As a result, actually meeting the water quality standards in some segments could take another decade beyond 2025. During that time, all nutrient control practices would have to be maintained, and the impacts of all new growth would need to be offset to prevent backsliding.

The Midpoint Assessment

What is the Midpoint Assessment of the TMDL?

The Chesapeake Bay TMDL set an interim goal of implementing enough actions by the end of 2017 to achieve 60 percent of the needed nutrient and sediment reductions. It also called for re-evaluating progress at that time, reviewing new information and making any adjustments needed to achieve the 2025 goals. Those adjustments are to be reflected in new WIPs to be written by states next year.

Will the region reach its 2017 goal?

The watershed as a whole will not. Most states will meet at least part of their interim goals. Based on state reports through the end of 2015, the EPA projected that Delaware, the District of Columbia, Maryland, Virginia and West Virginia would meet their goals for nitrogen, phosphorus and sediment reductions. New York was expected to miss goals for all three pollutants, though, and Pennsylvania will miss the nitrogen and sediment goal.

What is likely to change in the Midpoint Assessment?

The 2025 nutrient reduction goals are not likely to change much, but updated computer models will likely result in refinements to tributaries and states based on new information.

The assessment is also reviewing new science that could produce changes. For instance:

  • Recent studies show that Conowingo Dam has largely stopped trapping sediment coming down the Susquehanna River and is now allowing more of it — along with the nutrients attached to the particles of silt — to reach the Bay. As a result, more nutrient and sediment reductions may be needed to offset that lost trapping capacity.
  • Warming water temperatures, new rainfall patterns and rising sea levels are all symptoms of a changing climate that could hamper the effectiveness of some pollution reduction efforts. But it may also bring more ocean water into the Bay, which would improve dissolved oxygen conditions.
  • New studies — coupled with water quality monitoring — show that phosphorus-saturated soils in many areas with large livestock populations, especially poultry, are sending more of the nutrient downstream than currently accounted for.
  • The review also includes updated information about the effectiveness of nutrient control practices, including an accounting of several practices not previously included in nutrient reduction estimates.

Role of local governments

What role does local leadership have in the cleanup effort?

Decisions made at the local level, such as land use planning, the regulation of septic systems and stormwater controls, can impact nutrient and sediment pollution. State and federal officials agree that the involvement of local leaders — not just local governments, but also conservation districts, watershed groups, river basin commissions and others — is essential for meeting Bay cleanup goals.

In a memorandum sent to states earlier this year, the EPA indicated that “effective local engagement” should be a critical part of WIPs to be written by states next year. In addition, those plans are to include local pollution reduction “planning goals.”

Will the EPA enforce those local goals?

No. The local goals are intended to help planning efforts. The EPA has said that responsibility for meeting nutrient reduction goals belongs with the states, not local governments.

Will local actions help local waters?

In many cases, yes. Actions that reduce runoff, whether improved stormwater controls or forest buffers along streams to reduce farm runoff, will improve water quality. But the level of benefit depends on the specific action and location. Many nutrient and sediment control efforts can be designed to also benefit local streams and rivers by reducing problems such as erosion and bacterial contamination.

What should local governments do?

The Bay Program’s Local Government Advisory Committee emphasizes these two steps:

1. Ensure that local actions are reported to the state. Each state is responsible for reporting to the EPA the actions it has taken to reduce nutrient and sediment pollution. Local government staff should report actions taken locally to state officials so that the state can accurately track progress.

The EPA uses this information, along with other data inputs such as septic data and agricultural census data, to run a model that informs the partnership about cumulative progress and additional actions required to meet state water quality standards. The model is periodically calibrated against water quality monitoring data collected throughout the watershed.

2. Help develop their state’s Watershed Implementation Plan. Local governments play a vital role in implementing a state’s WIP. And, the EPA expects each state to establish measurable local planning goals. These local planning goals, and strategies for achieving them, will be articulated in each state’s new WIPs next year. Therefore, local government leaders need to be involved in developing the WIP to ensure that the plans are realistic, reflect local priorities, benefit local communities and clearly identify the resources, such as funding and technical support, needed to get the job done.

Karl Blankenship is the founding editor of the Bay Journal and Bay Journal Media. You can reach him at

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