ACTION 6: MANAGEMENT MODEL FORMULATION, SCENARIO ANALYSIS, AND BMP DEVELOPMENT

Action 6 is concerned with studying realistic pollutant source allocation scenarios which will incorporate the following:

  • Existing and foreseen point and non-point sources
  • Estimation of pollutant release rates under various alternative policies concerning the issuance of permits and pollution prevention / control measures
  • Water management goals and constraints including socioeconomic parameters

A major component of this Action will also be to define water use requirements. Water quality management scenarios may therefore concern, not only measures to control pollutant releases but also measures to optimise water resource allocations between human and environmental water requirements. Further, this Action aims at:

  1. Determining best management practices (BMPs) and quantitative cost-effective measures to achieve good ecological status of water-stressed watersheds and sustainability of reservoirs and dams. Innovative policy approaches such as optimization methods and techniques will be used to determine cost-effective measures with the objective being to enhance water quality.
  2. Demonstrating that the BMP approach and a cost-effective management plan will contribute to policy changes by monitoring the processes for the expected results. This would involve determining alternative or adaptive quantitative measures in accordance with the following directives: the Water Framework Directive., the Urban Waste-water Treatment Directive, the Bathing-water Directive, the Drinking-water Directive, the Plant Protection Products, and the IPPC Directive.

Essentially, the preceding work (Actions 1-5 of this proposal) can be brought into a cohesive framework by the introduction of the concept of water quality management and control. While models of the physical environment (i.e. via the use of such computer-modelling environments as BASINS – described in Actions 1 and 2) are constructed to 1) improve understanding of the processes that contribute to water quality variations and 2) to form a basis for predicting the effects of engineering control devices on water quality, water management models are concerned with integrating the physical, chemical and biological environment with the economic, social, and political environment. Meaningful water quality management requires an analytical framework that will provide a basis for decision making. The components of the framework include a model of the cause/effect relationships between waste inputs and water quality outputs (as introduced in Actions 3, 4, and 5 of this proposal); water quality (or more precisely water use) objectives and the costs and benefits of achieving various levels of water quality. If a framework can be devised, then various changes in waste loading, river flow, or other characteristics can be examined relative to the change in costs and resulting improvement in water quality. In addition, the consequences of changes in water quality objectives (for example, as these were set as indicative TMDLs in Action 5 of this proposal) can be analysed from a cost/benefit view point. Water quality management models therefore must incorporate not only the physical cause/effect mechanisms but also waste control considerations and economic influences of a given program. For simple systems, the management program is trivial. For other complex multi – waste source problems, a rational implementation program is not always obvious. To achieve this, a mathematical (optimization) model will be constructed. This optimization model will be flexible enough so as to allow for the examination of a range of different scenarios relating to the suggested TMDLs (from Action 5). For example, if certain TMDLs for specific pollutants are expected to be achieved in a watershed, the optimization framework will be able to consider the integrated releases from the various pollutant sources (point and non-point) and identify the cost-effective allocation of allowable discharges from each source.

Specific management scenarios to be examined may include Uniform Treatment (UT) options of the area of interest, or Zoned Uniform Treatment (ZUT). While UT (i.e. the approach in which each waste discharger is required to remove an equal percent of the waste before discharge) has been traditionally used as a method of control by many regulatory programs (partly because of ease of administration, engineering practicality and a misguided sense of equity), the examination of a program where a series of classifications or categories are formed and within each category all waste sources are required to treat to the same level (ZUT). Examples of such categorization (i.e. zoning) can be according to the type of polluting activity, geographical subdivisions of the area, size of specific activity, etc. Solutions of these scenarios would represent the non-inferior trade-off between cost and allowable loading of a pollutant. By repeating this for different pollutants while constraining the loading from the other pollutants, the effectiveness of a discharge allocation strategy of different pollutants simultaneously can be evaluated. This is critical in regions where more than one environmental goal needs to be met at minimum cost. Scenarios will be discussed with competent authorities and other stakeholders throughout the project such that final scenarios incorporate these views and opinions enhancing the possibility of acceptance and subsequent implementation of the resulting policies and measures. Finalised scenarios complete with pollutant allocations and proposed policies and BMPs will be disseminated to competent authorities and other stakeholders for review. A «Primer on Water Quality Management for the Kalo Horio catchment», will subsequently be produced which will constitute the final deliverable of this Action. Stakeholder reviews will be incorporated as appendix to this report.