WATER
QUALITY YARDSTICK?
Under the Indo-Duch collaboration, a project on development of bio-monitoring
methodology for Indian River water quality evaluation was initiated in 1988 the
Central Board Pollution Control Board carried out a pilot study on the river Yamuna.
With monthly intervals, a number of biological and physico- chemical parameters
were determined at 15 stations, which were later reduced to 11 locations along
the river Yamuna from Delhi up-steam to Etawah downstream. The main objective
for this study was to formulate strategic methods, which can be accepted in scientific
and legislative framework for water quality evaluation. The outcome of the study
was a generally applicable yardstick for indication of actual water quality, and
can be used in water quality management programme in the country.
AMOEBA
PRESENTATION
The proposed yardstick consists of an "AMOEBA" (A Method
of Ecological; & Biological Assessment) presentation of 8 different indices;
POLLUTIONAL LOAD (STRESS) INDICES
- Bacterial
Pollution Index (BPI)
- Nutrient
Pollution Index (BPI)
- Organic
Pollution Index (OPI)
- Industrial
Pollution Index (IPI)
- Pesticides
Pollution Index (PPI)
|
EFFECT
(STRAIN) INDICES
- Benthic Saprobity
Index (BSI)
- Biological
Diversity Index (BDI)
- Production
Respiration (PRI)
|
Each
of these indices derived from a set of one or more monitoring parameters and may
very according to regional requirements. The detail methods of derivation is presented
in a manual, jointly prepared by the CPCB and RIVM, Netherlands.
WATER
QUALITY YARDSTICK:
The outcome of all the 8 indices, calculated for the
study stretch of river Yamuna in the from of N "AMOEBA' presentation is shown.
Levels of each index with respect to their target values at all the 11 locations
of the river Yamuna.
FIELD OF APPLICATION IN WATER POLLUCTION CONTROL.:
As mentioned earlier that rational formulation of any pollution control programme
of a water body needs to define water quality objectives (target) for that water
body in a sound scientific manner. These objectives are used as yardstick to identify
the areas, which are in need of restoration; extent of pollution control needed,
prioritization of pollution control programmes, and effectiveness of pollution
control efforts. The yardstick, which was developed by CPCB, is very much useful
for the above purpose.
WATER QUALITY MAP IN GERMANY:
In
Germany, bio monitoring is used since almost 30 years from now, for water quality
assessment. The whole system is based upon saprobity index, which takes into account
the abundancy of the species of macrozoobenthos and their ecological range. This
was possible because the species of macrozoobenthos were very well known to the
scientist and the correlation between organic load and the occurrence of different
species was well established. In other European countries, like Italy, Spain,
France, and United Kingdom, a biotic index based on family or genus level is used.
It was calibrated and modified for each region. For system of water quality classes
preferably an uneven number is taken. For example, in Germany 4 classes with 3
intermediate classes have been used. To show the results of the investigated water
bodies in an easily and understandable way, maps are drawn and each. The maps
based on Bio-monitoring show clearly, where the water is polluted and where action
for Improvement has to be taken. It is a very useful and powerful tool for decision
makers. Map 1 shows the water quality map of the state of North-Rhine-Westphalia,
Germany in 1969/1970. The red stretches 9excessively polluted river stretches)
are quit high and only some blue, unpolluted stretches are present. The water
quality map of the same State after 15 years shows clearly in Map 2 of that the
decision makers had taken action. In most of the river stretches, quality had
improved which is indicated by a colour change on the river stretches. Attempts
are now underway in India at CPCB to utilize the existing taxonomical and chemical
data on river Yamuna to evolve a system of classification of river stretches.
