Environmental Engineering Reference
In-Depth Information
• Wrong sample collection and preservation procedures, leading to unreliable information
output.
• Lack of proper data storage, records handling, and unsuitable reporting format, leading
to unsatisfactory information utilization.
• Lack of a quality assurance program, leading to unreliable information output.
• Lack of regular evaluation of the objectives and the different steps of the cycle, leading
to unsuitability of the program to match changed site conditions.
2.2
Formulation of objectives and goals
Monitoring programs for water pollution assessment are mainly prepared to assess water
quality and compare it with accepted and approved requirements or regulations, to detect
trends and to provide information for the prediction and simulation of water quality
changes. They may be applied to assess the status of natural water bodies, the quality of
effluents, which are discharged into them, or both. We may be certain that a water body
under consideration is polluted only in the case when its water quality is assessed and
does not comply with prescribed regulations, guidelines or standards. Also, monitoring
programs are applied to control and operate water and wastewater treatment plants, to
choose a suitable treatment scheme during the preliminary stages of the design of these
plants, or they may form part of a research project in the field of water quality
management. Examples of different types of monitoring programs and discussion of
problems encountered in the every day application are presented in Chapter 3.
The accepted and legislated standards and regulations play a key role in the pollution
control process, and correspondingly in the formulation of the objectives of a pollution
assessment program. If the main objective of a monitoring program is to control and
prevent water pollution, the design of the program should be based on a thorough
examination of the existing standards, regulations and guidelines.
It is important to define not only the purpose of the measurement but also the
geographical scope of the measurement program and its duration. A map defining the
geographical scope of the measurement program should also indicate all effluent source
and tributary confluence points. Recently, geographical information systems (GIS)
become a substitute of the maps, which allows to record and store information and to use
this information as modules of more complex models for assessment, evaluation and
control of water pollution.
2.3
The network design
Although some water bodies are monitored continuously, routinely and comprehensively,
it is unreasonable to expect that every water body will be perpetually monitored at all
locations. In general, the process of monitoring is expensive and time-consuming;
therefore care must be taken to design an optimum network of sampling locations,
reflecting expected changes of water quality. In all cases, the selected sample site
locations will be determined by the objectives of the program and should be
interconnected in a way that allows for comparison and data analyses. The heterogeneous
distribution of quality parameters within water systems should be considered when
sampling point locations are chosen. Generally, sampling locations near the boundaries of
