|The legal requirement to "Save the Bay" is based on a Federal law, the Clean Water Act. The 1972 law was a major expansion of the requirements in the 1948 Federal Water Pollution Control Act. The law mandates that polluters must get permits before discharging any pollutant from a "point source" (basically, pipes or man-made ditches) into navigable waters, and provides authority for the Environmental Protection Agency (EPA) to establish standards for issuing/rejecting permits.
How clean is clean? That depends of what is defined as a pollutant, and if the Chesapeake Bay has too much of those pollutants.
Litter is unsightly, and litter does not improve water quality, but litter is not killing the bay. Placing empty soda cans in recycling bins is environmentally responsible behavior, but recycling empty plastic water bottles and soda cans has no significant impact of the health of the Chesapeake Bay.
At different times, various forms of pollution have been major concerns - bacteria, pesticides, oil leaks from tankers, heavy metals, and acid mine runoff. Today, those threats are all relatively minor, though the Chesapeake Bay still receives excessive amounts of E.coli bacteria from cow manure, pesticides from suburban lawns and farms, mercury released into the atmosphere by coal-fired power plants upwind, plus estrogen and other hormones/antibiotics that human bodies have excreted and wastewater treatment plants have passed downstream. Such contaminants affect the health of the plants and animals that live in the bay, but they are not the primary causes of the bay's problems.
Two factors from farms, cities, and suburbs upstream are the primary causes of damage to the bay:
Reducing litter, heavy metals, chemicals, and bacteria would improve esthetics and water quality, but the key to saving the bay is to reduce the input of two nutrients (nitrogen and phosphorous) plus sediment. Particles of sediment are especially troublesome. They carry nitrogen and phosphorous downstream, suffocate oysters and other creatures trying to live at the bottom of the bay, and block sunlight from reaching submerged aquatic vegetation.
Since the 1930's, the sediments in stormwater and other pollutants have suppressed the marsh grasses (often Spartina species) and the underwater grasses (Submerged Aquatic Vegetation or SAV) that are essential to the health of the bay. The natural bands of SAV surrounding the points of land and islands have shrunk, and SAV has disappeared from extensive areas on the bottom of the Bay.
There is no secret regarding the cause. Silt from urban/suburban construction, plus erosion after the clearing of forests or plowing of cropland, has physically coated the SAV and blocked the transmission of light that is essential for plant growth. Once colonists began clearing forests and planting tobacco, the flow of silt increased, with so much deposition downstream that in some cases (such as at Dumfries) the colonial harbors were blocked.
West Virginia, Pennyslvania, New York, Delaware, and the District of Columbia send pollution downstream to the bay, plus the two states (Virginia and Maryland) in which the bay is located
Source: Environmental Protection Agency (EPA), Chesapeake Bay TMDL
After the 1983 Chesapeake Bay Agreement was signed, implementation of Best Management Practices for development upstream provided inadequate mitigation. Sediment continued to pour into the Chesapeake Bay after every major storm.
As determined by the US Geological Survey:1
Adding fertilizer triggers grass to grow on suburban lawns. Force-feeding nutrients (nitrogen and phosphorous) into the Chesapeake Bay also triggers growth of algae and cyanobacteria (formerly known as blue-green algae). Algae/cyanobacteria, when alive and photosynthesizing, will produce oxygen during daylight hours - but after algae/cyanobacteria die, the decay process strips oxygen from the water.
Excessive amounts of algae/cyanobacteria decomposing on the bottom of the bay results in excessively-low dissolved oxygen levels. Crabs, oysters, fish, and other living creatures need a certain level of dissolved oxygen in order to live underwater.
Only tube worms can survive at 1 milligram/liter. At lower levels, everything will die and the result has been "dead zones" in the deep channels of the Chesapeake Bay.
dissolved oxygen levels greater than 6mg/liter support all forms of life, but less than 1mg/liter will create a dead zone
Source: Environmental Protection Agency (EPA), Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries (Figure 2)
The Environmental Protection Agency has determined in a Total Maximum Daily Level (TMDL) study how much nitrogen, phosphorous, and sediment the bay can absorb. EPA has allocated limits for each pollutant to each of the states in the watershed, plus the District of Columbia.
For the Chesapeake Bay, impairment is measured by three specific water quality criteria: dissolved oxygen, water clarity and Chlorophyll A. Reducing nitrogen, phosphorous, and sediment levels in water flowing into the bay will affect the measurements of dissolved oxygen, water clarity and Chlorophyll A in the bay itself.
At some point, perhaps the year 2040, Virginia and Maryland plan to remove their portions of the bay from the Clean Water Act Section 303(d) list of "dirty waters." The states and EPA may declare success, claim the bay meets Federal water quality standards, and do nothing more. On the other hand, if pollutants such as heavy metals still result in the bay being listed as unsuitable for one or more of its designated uses, the states will have to continue to work at meeting Clean Water Act water quality standards.
There is a relationship between the three water standards (dissolved oxygen, water clarity, and Chlorophyll A) and the three major polutants (nitrogen, phosphorous, and sediment).
Chlorophyll A measures the amount of algae and cyanobacteria (formerly known as blue-green algae) floating in the water. The higher the concentration of algae, the greater the level of Chlorophyll A. Using Chlorophyll A allows EPA to measure the impact of nutrients and sediments that are deposited in the Chesapeake Bay. High concentrations of algae/cyanobacteria and sediment in the water will also reduce the water clarity.
Virginia officials have challenged the use of the Chlorophyll A standard for the lower James River, since reducing that level will require upgrading wastewater treatment plants in the James River watershed. Reducing nutrients in the James River will affect primarily the river itself and the mouth of the Chesapeake Bay, so Virginia has argued that the $2 billion additional cost of meeting the Chlorophyll A standard will exceed the benefit.2
Based on the Clean Water Act, the Environmental Protection Agency (EPA) has developed a process for determining how much pollution a waterbody can absorb before violating water quality standards. In a Total Maximum Daily Load (TMDL) analysis, EPA determines the limits for different pollutants, and require polluters to reduce discharges below the TMDL limits so the water body meets standards for the six designated uses in Virginia:
Chesapeake Bay tidal water habitats with different water quality criteria for different purposes
Source: Environmental Protection Agency (EPA), Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries (Figure 1)
sediment (and fresh water) washing downstream from DC to Mason Neck, after rainstorm
(note that Virginia-Maryland boundary is not in middle of river)
Source: US Fish and Wildlife Service, Critical Habitat Mapper
In 1980, Virginia and Maryland established the Chesapeake Bay Commission, and Pennsylvania joined in 1985. The intent was to establish a state-based approach to managing the Chesapeake Bay. Excluding the Federal government increased the potential that state-to-state negotiations, rather than Federal mandates, could reduce pollution sufficiently.
In 1983, the EPA published Chesapeake Bay - A Profile of Envirionmental Change. That report documented the declining condition of the bay and emphasized that under the Clean Water Act, the Chesapeake Bay and its tributaries were required to meet Federal water quality standards.
The Federal law mandate for meeting water quality standards and the EPA report spurred the governors of Pennsylvania, Maryland, and Virginia (plus the mayor of the District of Columbia, the head of the EPA, and the head of the Chesapeake Bay Commission) to sign the 1983 Chesapeake Bay Agreement.
The 1983 Chesapeake Bay Agreement was signed on the Fairfax campus of George Mason University. That agreement did little more than create a Chesapeake Executive Council and state that future actions would be taken. Still, the agreement served as a starting point for a multi-state commitment to "do something" in order to comply with the Clean Water Act. The agreement also put everyone on notice that the Federal government would require action, and EPA would play a role.
Four years later, the signers of the 1983 Chesapeake Bay Agreement signed the 1987 Chesapeake Bay Agreement. In it, the signers specified actions they would take to clean up the bay. A key part of the 1987 agreement was the promise that the signing parties would reduce by 40%, the nitrogen and phosphorous entering the main stem of the Chesapeake Bay, and achieve that reduction by the year 2000.
An obvious target for nitrogen reduction was human waste. Sewage includes high levels of nitrogen that was incorporated in cell walls of plants, but then excreted by humans. Human bodies have different membranes for cell walls, and do not absorb most of the nitrogen in plant food.
The first wastewater treatment plants were designed to reduce levels of bacteria, but not to reduce levels of nitrogen. Through the National Pollutant Discharge Elimination System (NPDES) permit regulations, EPA required wastewater treatment plants to reduce nitrogen and phosphorous in their discharges.
Banning detergents with phosphorous had a major impact; that stopped the addition of much phosphorous whenever clothes were washed. In addition, chemical processes were implemented at wastewater treatment plants to extract most of the remaining phosphorous that was flushed from houses and businesses.
New "biological nutrient reduction" (BNR) technology was implemented at sewage plants. BNR systems used bacteria to convert excessive nitrates (NO3-) in human sewage into harmless N2 gas molecules that escaped into the atmosphere.
It was very expensive to upgrade old wastewater treatment plants and build new facilities that could eliminate nutrients as well as E. coli bacteria. Federal grants soothed much of the political pain, but ratepayers saw increased monthly bills for sewage treatment.
progress towards nitrogen reductions were not adequate by 2009, so the TMDL defined a schedule to reduce that pollutant (plus phosphorous and sediment) by 2025
Source: Chesapeake Bay Program, Nitrogen Loads to the Bay
There was wide public support for better water quality, but environmental advocates did not recognize how enlarging the capacity of facilities treating sewage would affect land use patterns. Developers welcomed the opportunity to expand sewage treatment capabilities, because expanded wastewater plants facilitated new development in the watershed. The "green" money that produced cleaner water also spurred the clearing of forests, and the conversion of farmland into suburbia throughout the Chesapeake Bay watershed.
To implement its 1987 promises, Virginia passed the Chesapeake Bay Preservation Act in 1988. State agencies issued regulations to enforce the state law in jurisdictions defined as "Tidewater" Virginia. That definition did not include the entire Chesapeake Bay watershed; most of the state west of the Fall Line was excluded. (For example, Loudoun County and points upstream on the Potomac River - including the entire Shenandoah River watershed - were excluded.)
To minimize how many local jurisdictions would be affected and thus minimize potential opposition to unfunded mandates, most of the acreage and most of the jurisdictions in Virginia's portion of the Chesapeake Bay watershed were excluded from the Chesapeake Bay regulations.
The state code listed 29 counties, 17 cities, and no towns as being within the boundaries of Tidewater Virginia. As a result, new subdivisions in Fairfax and Prince William county must protect existing vegetatated buffers along perennial streams, but the state's "Ches Bay regs" imposed no such requirement for development in the City of Manassas, City of Manassas park, Fauquier County, or other jurisdictions west of the Fall Line.
The initial regulations focused on avoiding new pollution. Existing sources of nitrogen, phosphorous, or sediment were left for a later day.
In the 1990's, Virginia developed its Tributary Strategies to address existing nutrients and sediment flowing into the tributaries, which then flowed to the bay. That approach was formalized in 1992 amendments to the Chesapeake Bay Agreement.
The Tributary Strategies recognized that the only way to reduce the pollution in the bay was to reduce pollution in the tributaries, before pollution got to the bay. If upstream jurisdictions treated wastewater, intercepted agricultural runoff enriched with nutrients, and reduced the volume of urban stormwater, then tributary streams might meet water quality standards. If the tributaries, such as the Potomac and James Rivers, delivered clean water to the bay without excessive levels of nitrogen, phosphorous, and sediment, then the bay itself might meet water quality standards someday.
If the tributaries delivered "dirty" water, however, the bay itself has little capacity to recover. The bay does get oxygenated through wind blowing across the water, and bacteria are killed when exposed to the sun's ultraviolet light, but the volume of pollution delivered by the tributaries exceeds the capacity of the natural processes in the bay to clean itself.
Streams flowing through farmland and suburbanized/urbanized areas are different from sewer systems. Sewer systems are artificial streams contained in pipes, and there are wastewater treatment plants at the end to reduce pollution flowing through the pipes. In contrast, water flowing through stormwater ditches along roads is not treated in equivalent facilities, nor is "non-point pollution" (runoff from farm fields, roads, or other developed land without a stormwater system).
Rain that flows down a suburban or city gutter and enters a stormwater drain will flow directly to the Chesapeake Bay without being processed; stormwater is untreated. Wastewater facilities kill bacteria, remove nutrients, and eliminate sediments from the sewage piped from houses to Blue Plains (the world's largest wastewater treatment plant on the Potomac River in DC) and equivalent facilities. In contrast, runoff from farms and parking lots does not flow through any human-built treatment plants.
Litter reveals the difference. Throw a cigarette butt into a toilet, and it will be caught at the wastewater treatment plant and end up in a landfill or incinerator. Throw a styrofoam cup into a stormwater drain, and the cup will flow downstream, pushed in surges by different storms, until particles of styrofoam reach the bay.
agricultural Best Management Practice (BMP) to reduce runoff from farm fields
Source: US Department of Agriculture - Natural Resources Conservation Service, Johanns Announces Additional Conservation Security Program Activities
Other pollution in the stormwater will also flow to the bay; stormwater ponds produce insufficient nutrient reduction. Some debris and a small amount of sediment settles out in stormwater ponds temporarily, but later storms can send that material downstream in a pulse of pollution. Rapid suburbanization in the bay watershed has increased impervious surface, and runoff flows so fast that new sediment loads have overwhelmed the tributaries and the bay itself.
Best Management Practice (BMP) for development: stormwater pond
whatever flows into a stormwater drain reaches the Chsapeake Bay, untreated
Though there are no treatment plants cleaning up the water at the end of natural rivers before they flow into the Chesapeake Bay, there are two natural processes that clean the bay's water - oxygenation by plants, and filtering by oysters and other wildlife. The dramatic declines in Submerged Aquatic Vegetation (SAV) and the oyster/menhaden population have eliminated key natural processes that once filtered the water column and increased dissolved oxygen in the bay.
The effort to "Save the Bay" is a cultural as well as physical geography story. All states in the Chesapeake Bay watershed have increased the ability of wastewater treatment plants to capture pollution before it flows into tributaries, but different states have chosen different ways to reduce sediment/nitrogen/phosphorous from non-point sources.
Maryland increased taxes and regulations to reduce non-point pollution from construction projects, farms, and existing developments. Landowners now pay annual fees based on the amount of impervious surface that sends water unnaturally fast downstream, and political campaigns often reference the "rain tax."
Virginia chose to rely upon voluntary action by farmers and land developers to reduce non-point pollution. State grants were directed to farmers in the Piedmont and Shenandoah Valley portions of the Chesapeake Bay watershed to implement "Best Management Practices" (BMP's), such as fencing cattle away from streams. Between the fences and streams, protected vegetated buffers intercept runoff and trap the nutrients from manure.
The state could build wastewater treatment plants to treat stormwater flowing through urban gutters, but the most cost-effective technique to reduce pollution in streams is to prevent the pollution from entering the stream in the first place. The Tributary Strategies proposed in the 1990's were expected to stimulate wastewater plant operators, farmers, and developers to negotiate sediment/nitrogen/phosphorous reductions within each watershed until each tributary met the Clean Water Act requirements.
Virginia did adopt "Ches Bay regs" in Tidewater counties that required new developments with impervious surface to have lower impacts on streams. Those regulations mandated preservation of 100-foot buffers of undisturbed vegetation along each side of a perennial (flowing year-round) stream. The buffers were intended to serve as Resource Protection Areas (RPA's), using natural vegetation to capture a substantial percentage of the sediment, nutrients, and other pollutants before they entered the stream and ultimately flowed to the Chesapeake Bay.
RPA's affected land use at the local level, though only jurisdictions in Tidewater (as defined by the Code of Virginia) were required to identify and protect RPA's. Rezonings of specific parcels, site plan approvals, and inspection of building sites are actions taken by town/county/city officials rather than state/Federal officials. Federal/state efforts to "Save the Bay" have forced local government to adopt new requirements affecting development, and the "Save the Bay" efforts depend upon local governments to implement and enforce those requirememts.
By 1999, it was obvious that the states and District of Columbia had failed to reduce nutrients and sediment enough to meet Clean Water Act water quality standards in the Chesapeake Bay. Since 1983, suburban development had continued unchecked in the Chesapeake Bay watershed, especially in Northern Virginia. Forests and fields, with slow runoff patterns, had been replaced by impervious surfaces where rainfall raced off rooftops/parking lots. The surging rush of rainwater carved into streambanks, etching new channels and carrying sediment downstream to the Chesapeake Bay.
In addition to excessive levels of sediment, excessive levels of nutrients (nitrogen and phosphorous) continued to wash downstream into the Chesapeake Bay from wastewater treatment plants, fertilized lawns, and farms generating cattle and chicken/turkey manure.
In particular, Combined Animal Feed Operations (CAFO's) for poultry generated more manure than farmers could apply effectively as fertilizer on local fields. When applied at levels required to eliminate the need for nitrogen fertilizer, the phosphorous in the poultry manure exceeded the capacity of the soil to absorb it. Especially on the Eastern Shore, over-application of poultry litter resulted in excessive phosphoroust enrichment of the Chesapeake Bay.
In 1999, two organizations (the American Canoe Association, Inc. and the American Littoral Society) sued in Federal court, claiming the states were not making sufficient progress. They requested a judge to force the states to meet the requirements of the Clean Water Act, and to force states to implement more than just voluntary action by polluters.
That lawsuit triggered the third signing of a Chesapeake Bay Agreement, replacing the 1987 version (as amended in 1992). In June, 2000, the District of Columbia, Maryland, Pennsylvania, Virginia, and the Environmental Protection Agency (EPA) signed the Chesapeake 2000 Agreement. In that document, the different levels of government promised to restore the water quality of the Bay, and the Chesapeake 2000 Agreement set objectives beyond just optional promises. (A 2014 Chesapeake Bay Agreement, still including a signature for the Chesapeake Bay Commission, defined a new set of specific outcomes for reducing pollution in the bay.)
To settle the 1999 lawsuit, the parties agreed that the bay's water quality must improve and become "fishable and swimmable." If not, the Clean Water Act required EPA to list the Bay as "impaired waters" under Section 303(d) of the Clean Water Act. The government agencies agreed that such a listing would require the states and District of Columbia to craft a multi-jurisdictional limit on pollution, through the Total Maximum Daily Load (TMDL) process to protect the Bay's aquatic living resources.
New Jersey is outside of the Chesapeake Bay watershed
Source: US Geological Survey, satellite map of Chesapeake Bay
not all of the states in the Chesapeake Bay watershed signed the 1983 agreement (missing in 1983: West Virginia, New York, Delaware)
Source: US Fish and Wildlife Service, Chesapeake Bay Program
The 1999 lawsuit and the Chesapeake 2000 Agreement set the stage for mandatory, Federally-guided action if the states were not able to make adequate progress on their own. The consent order, accepted by the states and EPA, resulted in a new Chesapeake 2000 Agreement, a promise to complete TMDL studies to define the acceptable level of pollution in Bay tributaries and the Bay itself, a new deadline allowing another 10 years to reduce pollution. By 2010, the bay was supposed to be so clean, EPA would not list it as an impaired water based on Section 303(d) of the Clean Water Act (the "dirty water" list).
After committing to the Chesapeake 2000 Agreement, Virginia continued to rely upon voluntary actions to mitigate existing pollution. Many news releases were issued in praise of small projects, and each theoretical reduction in pollution (as predicted by computer models) was highlighted as significant.
However, in 2008 the National Oceanic and Atmospheric Administration (NOAA) declared a "blue crab disaster" in the Chesapeake Bay, based on a 41 percent decline in harvest from the late 1990's. EPA's 2008 Bay Health and Restoration Assessment said "the overall health averaged 38 percent, with 100 percent representing a fully restored ecosystem." By 2009 it was obvious once again that the deadline to remove the Chesapeake Bay from the dirty waters list would be missed.3
In 2010, a Federal judge ruled that the states and District of Columbia had failed to meet the terms in the 1999 consent order, and EPA had to complete a TMDL for the various segments of the Chesapeake Bay. The TMDL study allocated total amounts of sediment, nitrogen, and phosphorous reductions to the various states, and each state (and DC) developed a Watershed Implementation Plan (WIP) to implement the required reductions.
Those WIP's identified specific actions that would be completed, with milestones to be measured by EPA every two years. If a state failed to make progress, EPA defined "backstop" measure to implement on its own initiative. One backstop was to set a lower pollution threshold for permitted Municipal Separate Storm Sewer System (MS4) systems. EPA's leverage: if a state was unable to reduce polluted runoff as planned from private agricultural lands, local/state agencies would have to cut pollution from MS4 stormwater systems to make up the difference.
Virginia did not choose to divide up its total pollution budgets and allocate certain amounts to individual jurisdictions. The Chesapeake Bay computer models lacked the capability to provide such granular detail with any reliability, so the state did not establish quantifiable jurisdiction-specific thresholds for nitrogen, phosphorous, and sediment generated by from different towns/counties/cities. Instead, the Virginia WIP simply required local jurisdictions to implement Best Management Practices, such as nutrient management plans for publicly-owned land.
blue crabs - one reason people who do not have waterfront property might be motivated to Save the Bay
Source: National Park Service
Virginia's Watershed Implementation Plan (WIP) identified how the state expects to reach 60% of the required reductions of sediment, nitrogen, and phosphorous, by 2017. The remaining 40% will be eliminated by 2025, as described in the Phase II WIP.
Action strategies in Virginia's Phase I WIP include:4
nitrogen reductions required by 2010 TMDL
Source: Chesapeakestat Water Quality: Overview
Since population in the watershed will continue to grow, saving the bay will require reducing the pollution produced per person by more than 20-25%. "Business as usual" will not be adequate. Simply recycling plastic bottles will not be adequate. Even with substantial changes in farming practices, urban/suburban development, as wastewater processing, restoration will take decades. As described by EPA in their Frequently Asked Questions about the Bay TMDL:5
Degrading the water quality took about a century, and restoration may not be declared successful until the middle of the 21st Century. If progress is acceptable, then by 2025 all mitigation measures are supposed to be in place... and sometime later, the Chesapeake Bay may recover.
If states fail to make adequate progress towards limiting pollution, EPA may impose "consequences" or "backstops," such as tighter pollution limits in NPDES permits for stormwater systems. Backstops are expected to create enough pain to force states to make politically-difficult choices that reduce pollution, even though the reductions would upset politically-powerful interest groups.
To increase public support for tough decisions by the states, various groups are conducting outreach efforts are asking people who live far from the Chesapeake Bay shoreline (but still in the watershed) to increase their advocacy for saving the bay. Those outreach efforts to places such as the Shenandoah Valley highlight the value of seafood from the bay, such as blue crabs. The assumption is that most people away from the shoreline have only a marginal interest in the bay's problems, so discussion of the science or the economic reasons to reduce pollution would have no impact - but those people could be motivated if "saving the bay" meant "saving a seafood dinner."
The dramatic declines in the harvest of fish, oysters, and crabs over the last 80 years has transformed the economics of waterfront communities. Most of the watermen who once made a decent living from crabbing, fishing, and especially tonging/dredging oysters are unable to make a living from the bay now. As the children in the families of watermen get out of high school and choose to enter college or other professions, a 300-year old way of life on the Bay is nearing extinction.
Virginia relied upon voluntary efforts to "Save the Bay" for 25 years after signing the 1983 Chesapeake Bay Agreement. The political power of urban areas and farm-dominated rural counties in Virginia successfully blocked regulation of subdivision development and traditional farming practices.
As a result of delay, the economy and social patterns of waterfront communities along the shoreline of the Chesapeake Bay were damaged by unchecked urban sprawl in Hampton Roads and Northern Virginia/Southern Maryland, and by agriculture in the Shenandoah and Susquehanna river valleys. Virginia adopted mandatory controls on pollution, effective enough to allow the bay to recover, only after a Federal judge forced compliance with the Clean Water Act in 2010.
The Chesapeake Bay can be saved, but not if the stressors continue to increase - and as population increases, stressors will increase. There is no mechanism in the American political system to limit population growth in the watershed, so reducing the stressors is not a realistic option.
Restoring the bay by the year 2040 will be expensive, and changing behavior of people living in the watershed so they generate less pollution per capita will not be easy. Still, implementing the practices and projects proposed in the WIP's triggered by the TMDL should capture enough pollution before it reaches the tributaries of the bay, so maximum daily limits are not exceeded and the bay can be "saved."
The cost to Save the Bay were estimated in 2004 by the Chesapeake Bay Watershed Blue Ribbon Finance Panel to be $6 billion annually. In 2014, the benefits were estimated by the Chesapeake Bay Foundation to be $22 billion annually. Though both numbers are less-than-solid, the basic argument made by advocates for cleaner water is that the costs of restoring the Chesapeake Bay clearly are justified by the increased benefits; it would be a wise investment to reduce sediment, nitrogen, and phosphorous levels so the bay and its tributaries met Clean Water Act standards.6