Chesapeake Bay Monitoring
9. management strategies and
the role of monitoring
The primary goal of the OEP monitoring program is to provide State managers and policy-makers with accurate and timely environmental data to be used in the development, implementation and assessment of strategies to control and improve water quality in the Bay. Components of the present OEP monitoring program are structured so that data required to address particular water quality management issues and questions (see Chapter 1) are readily available to decision-makers. However, measurable progress in resolving specific environmental problems can be expected only when this information is used to develop and implement effective management strategies, policies and standards. In the following sections, the process by which numerous, and sometimes conflicting, variables are incorporated into the environmental decision-making process is examined.
MONITORING DATA AND THE ENVIRONMENTAL DECISION-MAKING PROCESS
There are basically two ways in which monitoring data can be used in developing a management action. In a limited number of situations, environmental decisions can be made based directly on an inspection of the available monitoring results. These situations generally occur when desired uses of public health objectives have already been identified, or specific water quality criteria have been established. For example, managers can rapidly assess the significance of concentrations of heavy metals and organic compounds within the tissues of organisms living in the Bay since federal standards have been established for many of these compounds. Likewise, the major areas in the Chesapeake Bay exhibiting low dissolved oxygen problems can quickly be identified because the State has a standard in effect for this measurement. The rapid identification of environmentally stressed regions within the Bay and its tributaries may be used by managers to initiate water body closures, enforcement actions or special studies.
More typically, the use of monitoring data in making a management decision is less direct. A simple inspection of the data by itself is not sufficient to address cause and effect relationships, to understand the interaction of complex processes or to suggest direct management responses such as the establishment of a water quality standard. In most situations, the data are used in conjunction with the results of research efforts to support various analytical procedures intended to address specific management issues.
The application of both simple and sophisticated statistical techniques can provide significant insights into such issues as characterizing the present status of the Bay's key water quality indicators, detecting trends in water quality over time and providing managers with a "barometer" for assessing the response of the Bay system to management actions. Additionally, a statistical assessment of the available data can aid managers in determining criteria (numerical or descriptive limits) for water constituents which are designed to protect designated uses.
Another example is the use of physical, chemical and biological monitoring data in the development of a water quality computer model. This analytical tool allows managers to forecast the response of a water body to alternative point and nonpoint source control scenarios. The array of management options, such as the water quality response to various levels of nutrient or toxicant removal at point sources, can be evaluated using the model and then the most appropriate control measures can be selected and implemented.
But how is the most appropriate scheme selected? Is it simply the forecasted control option that produces the most desirable environmental outcome? How are other considerations factored into the final recommended strategy? Sound environmental management and policy decisions resulted from an in-depth assessment of the intended uses, scientific considerations, and economic impacts. The extent to which any one of these three variables dominates the formulation of a management policy or standard is determined by the degree of certainty associated with the variable.
Probably the most difficult and yet important task, is the proper treatment of the diverse and complex political/public factors considered in the development of environmental control programs. Without an accurate and complete understanding of what the objectives are, a successful management program can never be designed and implemented. Managers must be confident that they understand the often conflicting uses the public holds important for a body of water such as the Chesapeake Bay and it tributaries. Examples include recreation, propagation of fish and shellfish, water supply, waste disposal, industrial cooling water, and transportation. In addition to accommodating this diverse list of uses, the public expects that the waters of the Bay will also maintain a reasonable degree of aesthetic quality.
The greatest challenge confronting environmental managers is to meet the needs and expectations of the Bay's user communities without compromising the present and future health of the Bay. This challenge requires an in-depth understanding of the present health of the Bay system and an assessment of the management strategies required to meet these demands. The collection, interpretation and synthesis of data from a sound monitoring program, supplemented by special studies and selected research efforts, provides the necessary information to make this assessment.
When a management action or standard is implemented, managers should be at least reasonable confident that the imposition of such an action will have the anticipated beneficial environmental impact, and will thereby maintain the desired uses identified by the public. However, the complexity of physical, chemical and biological interactions occurring in a system as dynamic as an estuary, prevents managers from having absolute confidence in predicting the outcome of a management action before they develop and impose a policy or standard. Nevertheless, managers should strive to reduce the scientific uncertainty of their decision to a level at which substantive, although perhaps interim, decisions can be made. As long as the limitations of the resulting policy or standard are acknowledged, and the restrictiveness of the policy accurately reflects the level of scientific uncertainty, managers must continue to develop and implement appropriate environmental controls aimed at achieving the desired conditions.
This decision-making process should be viewed as an iterative exercise, in which new information is continually utilized to update management decisions. A monitoring program is critical in this iterative process because it provides an objective assessment of the success or failure of management decisions that have already been implemented. Since our knowledge is incomplete and the environment is continually changing, adjustments will always be necessary. As more information becomes available, the original decision can be changed, refined or even rescinded. These adjustments depend on a number of factors such as the quality and quantity of knowledge available when the standard was set, an evaluation of the environmental response to the implementation of the standard, an assessment of the public response, and a re-evaluation of the uses and benefits. When a policy is formulated or a standard is set, the regulatory authority implies that this decision has been based on the best evidence currently available, and that the response of the environment will be carefully reviewed. It is quite apparent, therefore, that this iterative approach to policy-making will work only if managers make a commitment to continue monitoring and research aimed at "fine-tuning" the initial decisions.
The purpose of any management action is to achieve a desired environmental response. When a management action such as the Upper Bay Phosphorus Control Policy is implemented (see example below), we should expect to see improvements in the problems that were addressed. For this example, the problems were low dissolved oxygen levels and frequent phytoplankton blooms. Traditionally, the most common approach to controlling eutrophication has been to remove nutrients at the point of discharge. Prior to implementing point source controls, and incurring the associated expense, there should be evidence that this control strategy will be effective. Effective management decisions must consider all other feasible control options. How certain are we that the observed water quality problems is reversible or controllable? Has the "problem" existed for centuries, and should the condition therefore be considered "natural"? The establishment of a nutrient control policy or standard implies that such an evaluation has been made and that the best evidence is that implementation of the standard or policy - as applied to point and nonpoint sources - will achieve the desired results.
The current OEP monitoring program, in conjunction with modeling studies and data from waste treatment plants, is capable of quantifying the contributions of nutrients emanating from nonpoint as well as point sources. This information can be used by decision-makers to determine the extent of control to be imposed on both sources. Furthermore, as a result of the initiation of the OEP monitoring program, it should be possible to more accurately ascertain what environmental conditions are controllable or "fixable", as well as identify those problems which may be beyond the reach of any management action.
Of the many different approaches that can be taken to improve water quality, almost all impose some costs on the public. These approaches include sewage treatment plant controls, industrial pre-treatment, detergent phosphate ban, land use restrictions and agricultural best management practices. For example, the public has already been asked to absorb the expense of primary and secondary levels of waste removal before effluents are discharged into the Bay system. According to surveys of citizen attitudes toward the environment, however, improvements to the Chesapeake in response to this current level of treatment have not been satisfactory in maintaining or restoring desired water quality conditions. Progress toward restoring the health of the Bay in the face of continued population growth, expanding industrial activities and changing land use will necessarily demand additional fiscal resources in the future.
Conventional biological waste treatment processes are often hard-pressed to hold constant or reduce pollutants entering the Bay and water quality managers frequently have to evaluate the possibility of requiring advanced treatment aimed at further removal of nutrients and toxicants. However, the costs associated with the implementation of advanced methods of waste treatment will impose an even greater economic burden on the public. Will the taxpayers agree to pay? If so, what level of assurance of a water quality response will they demand? The more we understand the Bay system, the more confidently we can predict the benefit associated with the cost of a given level of treatment.
A Specific Example - The Upper Bay Phosphorus Control Strategy
In the mid-70's, a major concern arose about the apparent trend of the Upper Chesapeake Bay towards eutrophication. Many individuals reported elevated water column phytoplankton levels which precluded or diminished certain desired uses of the Upper Chesapeake. These concerns were raised by people who had spent their entire lives on the Bay - observing it, studying it, or deriving their livelihood from it.
In general, it appeared that the ecology of the Upper Bay was changing from a system with a balance between phytoplankton and rooted aquatic plants, to one dominated by phytoplankton. In an attempt to quantify these qualitative statements, an assessment was made of the existing water quality monitoring data. This analysis confirmed the presence of very high phytoplankton levels in summer and an increasing trend since the 1950's. In addition, preliminary analysis indicated that the nutrient phosphorus, rather than nitrogen, appeared to be limiting phytoplankton growth during the critical summer period in the regions exhibiting a problem.
In order to provide managers with a basis for determining the causes of the phytoplankton problems in the Upper Bay, and to evaluate possible management actions to achieve desired water quality objectives, a mathematical water quality model was developed. The model was formulated in such a way that it was capable of addressing the interactions between nitrogen, phosphorus and phytoplankton biomass. At the conclusion of the development and testing process, which required water quality monitoring data, the model was utilized to project phytoplankton chlorophyll levels in the Chesapeake Bay based on various combinations of nutrient inputs to the Chesapeake Bay. The modeling results determined that the most significant sources of nutrients to the Bay were from the Baltimore Metropolitan Area and the Susquehanna River. This latter source, under high flow conditions, may completely dominate the nutrient distribution in the Upper Bay. The modeling exercise also confirmed that phosphorus is the primary nutrient that limits phytoplankton growth in the upper Chesapeake. If reductions in peak summer phytoplankton populations to levels observed in the 1950's were desired, significant reductions in phosphorus from major point sources in Maryland and the Susquehanna River would be necessary.
Using the results of the modeling and the assessment of monitoring data to provide an initial technical base, and capitalizing on the availability of federal and state funding, Maryland water quality managers developed the Upper Bay Nutrient Control Policy. This policy imposed a 2 mg/l total phosphorus effluent limitation on all large wastewater treatment facilities (greater than 0.5 million gallons per day (MGD) above Baltimore Harbor, and greater than 10 MGD between Baltimore Harbor and the Chesapeake Bay Bridge) discharging into the upper Bay. In addition, the policy provided for the imposition of even more stringent phosphorus requirements for the Bay tributaries where water quality deterioration was generally more severe than in the mainstem.
As with all major disciplines, water quality modeling is a continuously evolving process. To say that the water quality model developed in the Upper Bay study is the final technical answer to our Bay pollution problems is na´ve. However, the model did provide management with the technical guidance required to develop a rational environmental policy. In the last few years, OEP has taken part in the development of a comprehensive water quality monitoring, research and modeling program in the Bay and its tributaries. The monitoring component of the program quantifies river inputs, characterizes ambient water column and sediment conditions, evaluates the significance of key processes and quantifies resident plankton and benthic assemblages. The research component addresses sediment/water column interactions, animal/toxicant interactions and plankton dynamics. More advanced mathematical models are being developed to predict with greater confidence the biological and chemical response of the Bay to nutrient loadings. As our understanding of the Bay's natural processes are enhanced by incorporating the results of the monitoring, modeling and research programs, the existing upper Bay policy can be reviewed and appropriate adjustments and refinements made accordingly.
The information presented in this report demonstrates that the OEP Chesapeake Bay Water Quality Monitoring Program is producing an important body of information to guide the management and restoration of Chesapeake Bay. The monitoring program has already established some important facts about the present state of water quality in the Bay and its tributaries where a high degree of uncertainty previously existed. Using the monitoring data in conjunction with research and modeling will provide a sound technical base to permit water quality managers to move forward with greater certainty in formulating management strategies. This enhanced technical base will greatly increase the probability that our actions will yield the desired results - a healthy Chesapeake Bay for the citizens of Maryland.
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