Early explorers described the Chesapeake as a “faire Bay” teeming with fish, shellfish and waterfowl. Its clear waters allowed sunlight to reach underwater grass meadows that sometimes grew at depths of 10 feet.
Today, it’s often difficult to see much more than a couple of feet into the Bay. Algae blooms are a common occurrence, sometimes killing underwater sea grass meadows by blotting out their sunlight.
When those blooms die, they sink and suck oxygen out of the water. In most years, any fish venturing into deep parts of the Bay would choke because of the lack of oxygen.
The Chesapeake has probably been too altered for the first scenario to be attainable. But the second scenario isn’t acceptable.
In the coming months, officials from state and federal agencies will decide where, between those two extremes, the Bay should end up by the end of the decade.
The stakes are high: Preliminary estimates indicate that far greater nutrient and sediment reductions will be needed to clean up the Bay. The Chesapeake Bay Foundation recently estimated the cleanup cost at $6.5 billion.
To help ensure the public is up-to-date on decisionmaking, the Bay Program has established a time line in which key bits of information will be available to the public and comment periods will be established.
Basically, two key actions will take place this year:
- New water quality criteria for the Bay will be established.
- New nutrient and sediment reductions will be set to attain those criteria.
Those actions stem from the Chesapeake 2000 Agreement, which calls for reducing nutrient and sediment pollution enough by 2010 to remove the Bay from the EPA’s list of “impaired” waters — those that fail to meet water quality standards.
Before that can happen, the Bay states must establish new water quality standards. That’s because old water quality standards for dissolved oxygen, which called for having 5 parts per million of oxygen throughout the Chesapeake, cannot be achieved.
In fact, scientists say deep areas of the Bay, where oxygen concentrations are restricted by natural factors, probably never maintained such high oxygen levels, even before the region was settled.
At the same time, existing dissolved oxygen standards are not protective enough for some habitats, such as migratory fish spawning areas.
The new standards will define what constitutes a clean Bay that, once achieved, can be removed from the impaired waters list.
Standards consist of two parts: a designated use, and a water quality criteria needed to maintain that use. Water quality criteria are usually expressed as measurable numbers that set either the maximum concentration of a pollutant that can exist in the water while still supporting a designated use, or the minimum amount of a critical element, such as oxygen.
Under the Clean Water Act, the minimum designated use is that the water be “fishable and swimmable.” Existing designated uses in the Bay don’t go much beyond that.
That will dramatically change this year. The Bay Program’s new effort would create far more specific designated uses, covering such things as spawning habitats for migratory fish, shallow water habitats for species such as grass beds and crabs, deep water habitats for bottom-feeding fish, and so on. Establishing more specific designated uses, officials say, will help ensure critical resources are better protected.
Ultimately, water quality managers must determine exactly where the designated uses will apply in the Bay. Then they will apply new numeric criteria for dissolved oxygen, water clarity or chlorophyll a, that will attain the water quality needed to support each use.
For example, a shallow water designated use intended to support underwater Bay grasses would have water clarity criteria that allow light to penetrate to a specific depth so grasses can grow. An open water habitat designated use may have specific criteria for chlorophyll a — needed as food to fuel the food chain — and dissolved oxygen.
A key issue will be how those designated uses are mapped. “If you don’t draw those lines correctly, then you can declare victory and go home with the current Bay,” said Mike Hirshfield, vice president for resource protection with the Chesapeake Bay Foundation.
Rich Batiuk, associate director for science with the EPA’s Bay Program Office, agreed that people “should be watchful” of the process.
To set designated uses, Batiuk said the Bay Program is using — where available — monitoring information to show what type of habitats and water quality conditions once existed. For example, aerial photos from the 1930s show where vast expanses of Bay grasses were once found. That can help to determine where some shallow water designated uses should be established.
But some monitoring data aren’t available, or — in many cases — the monitoring is so recent that it only shows current degraded conditions. So monitoring will be coupled with the use of computer models to indicate what types of conditions can be restored in different parts of the Bay and its tidal tributaries. “We don’t want to stay just within the realm of what what we’ve seen in monitored conditions,” Batiuk said.
Those model runs show where cleanup actions would allow suitable water quality for different designated uses, and where such uses could not be attained. For example, a cove with poor circulation — factors conducive to high algae growth — may not be able to achieve water quality conditions needed to support a shallow water designated use.
Once designated uses are mapped, the Bay Program can use its computer models to determine the amount of nutrient and sediment reductions that will meet the water quality criteria in that area.
Results of these exercises will be available throughout the year, both in the Bay Journal and on the Bay Program’s web site: www.chesapeakebay.net
Criteria Time Line
Here is the time frame that is anticipated:
June 2001: Draft water quality criteria should be available for public review through the summer. Ultimately, Maryland, Virginia, Delaware and the District of Columbia (the jurisdictions with tidal waters) are expected to adopt the criteria as water quality standards by 2003.
Summer 2001: Bay water quality monitoring data will be used to map where the draft criteria are not presently being attained and to determine the degree of non-attainment.
Summer 2001: The Bay Program’s computer models will be used to ensure that the draft criteria can be attained within the appropriate designated use habitat. The main concern is whether there are natural factors that would block criteria from being met in certain areas.
Late Summer 2001: The draft criteria will be revised, if needed, and finalized. They will again be submitted for public review through the end of the year.
Spring & Summer 2001: Computer models will be used to help determine how different watersheds, and jurisdictions, affect water quality in neighboring areas. At the same time, efforts will be under way to determine the potential for future nutrient and sediment reductions beyond those already undertaken.
Summer & Fall 2001: Computer models will be used to establish the range of basinwide nutrient and sediment reductions that will be needed to attain the water quality criteria across all tidal waters. At the same time, the models will be used to determine the needed reductions from different regions and individual rivers. The intent in to find what level of basinwide action is needed, and then identify where additional regional-specific reductions will be needed to achieve the criteria.
Fall 2001: Draft nutrient and sediment reduction allocations will be assigned to major drainage basins.
December 2001: Final nutrient and sediment allocations will be assigned to the nine major tributaries and to individual states for the three multijurisdictional tributary basins — Susquehanna, Potomac and the Eastern Shore.
Early 2002: The criteria will be published in the Federal Register by the EPA for a 45-day review period. After that, the EPA can establish them as regional nutrient criteria which the states can adopt as water quality standard.