Environmental impact assessment (EIA) aims to identify, estimate and evaluate the environmental impacts of a project before its execution. The goal is to alleviate the potential negative effects before any liabilities are made. Systematic assessment and evaluation also covers the economic performance of the bio-based production, different environmental loads, etc. Environmental criteria are particularly important in the design and implementation of large-scale bio-based production systems, to take into account any negative environmental effects associated with all aspects of the transportation, storage and production activities. Comparative analysis of alternative types of feedstock and/or processes and technologies facilitates making the optimal choice. Box 3.4.1 outlines how environmental assessment studies can help optimize various aspects of bio-based systems prior to project execution, according to Balaman.
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The study or evaluation of environmental impact involves a set of steps/activities. They include screening, scoping, prediction and mitigation, management and monitoring, and audit. The methodologies that are applicable to each particular case depend on the objectives of the various activities. The definition of the term methodology adopted here is the one used by Canter: "structured approaches for achieving one or more of the basic activities".
Screening, or impact identification, aims to outline the most important changes (i.e. impacts) that a project is expected to cause in the environment. This step identifies how environmentally sensitive the project is based on the key sources of impact and types of impact, e.g. biological and physico-chemical, as well as social, health and economic aspects. This will determine whether an EIA is needed and if so to what detail.
The specifics identified at the screening stage serve to determine the key environmental issues to be assessed (scoping) and, consequently, to select appropriate methodologies for the assessment. The identified problems serve as a basis for early mitigation measures and help target the subsequent steps of EIA at the most important issues. Scoping also identifies the key interest groups and any public concerns. The main EIA techniques used in scoping are baseline studies (data about the existing environment and environmental conditions), checklists, matrices and network diagrams (means of data representation).
Experts make predictions of the expected impact to help decision-makers take informed decisions and provide relevant information for the general public. The assessment stage focuses on the potential environmental and socio-economic effects of the project, and evaluates and compares the alternatives identified in the previous stages.
Alternative ways to mitigate (minimize) the effects through optimized design and environmental management are identified and compared. The technique used to assess the accuracy of predictions is mathematical modeling. The models should be appropriately chosen depending on the available data. For example, these could be ecological models to predict changes in aquatic biota as a result of toxic substance discharge. When there are limited/insufficient data, it is common practice to use expert judgment, or expert advice, to complement the modeling methods. The EIA results are typically presented using checklists, matrices, network diagrams, graphical comparisons and overlays, to allow easy interpretation of results and comparison of alternatives.
For example, Rapid Impact Assessment Matrix (RIAM) is a systematic approach using qualitative data that can be expressed in a semi-quantitative way. In this method a multidisciplinary team performs analysis of physico-chemical, biological, human and economic data in a common matrix. The resulting interactive impact profile allows the practitioner to make a rapid comparison of alternative options.
Finally, a summarized EIA report is produced, which is filed for review by the competent authority to receive approval for execution or recommendations for further improvements. Following approval for execution, there needs to be strict monitoring to make sure that the Environmental Management Plan is accurately implemented. By comparing the predicted and the actual impacts it is possible to identify problems early and take appropriate action. A flowchart of the EIA stages is shown in Figure 3.4.1 (more 3.4.1).
An Environmental Audit is carried out some time after implementation/completion of the project. The audit includes analyses of the technical, procedural and decision-making aspects of the EIA. The purpose of the audit is to determine whether the recommendations and requirements in the EIA steps have been incorporated successfully into project implementation.
In EIA it is sometimes important to undertake cumulative impact assessment to take into account the cumulative impacts of multiple and successive environmental and social impacts, which may have an additive effect. Examples of cumulative impact are the increases in pollutant concentrations in a water body or their bioaccumulation in fish. Mitigation of cumulative impacts often requires the collaborative efforts of different stakeholders, including governments.
Another popular methodology for conducting environmental impact analysis is the so-called Battelle Environmental Evaluation System. It is based on a hierarchical assessment of environmental quality indicators. Product environmental life cycle analysis (LCA) is often applied to identify and quantify the impact of industrial-scale biomass-based systems and production chains on the environment, e.g. projects for generation of bio-fuel, bio-chemicals and other bio-products. Specific methods have been developed for EIA of genetically modified organisms. More complicated approaches for EIA based on fuzzy logic are also being explored (more 3.4.2).
Recent advancements in biotechnology have contributed towards more sustainable aquaculture and a greater diversity of bioproducts of marine origin. This is achieved owing to better assessment of chemical and biological interactions between aquaculture and the environment, development of mitigation strategies, efficient microbial bioremediation processes and improved microbial control of intensive production systems.
Pond water quality needs to be well-managed and balanced by aquaculturists. For a summary of typical ranges of water-quality indicators for representative aquaculture water sources, effluents, and recovered aquaculture sludge versus runoff waters, municipal sewage, and various industrial and agricultural wastes. An overview of coastal aquaculture-specific monitoring parameters and characteristics for which data may be collected is given in Annex 4 of the FAO Guidelines for the Promotion of Environmental Management of Coastal Aquaculture Development.