The Upper Tisa Valley. Preparatory proposal for Ramsay

water. The levels of total nitrogen hardly surpass those of the inorganic nitrogen,
implying that the amount of nitrogen present in organic forms is insignificant.
Figure 13. Frequency of high stages within the year (5)
In terms of the average orthophosphate content readily available to the plants,
the water was of Class II quality, in terms of the peak levels of Class III quality at the
border station, while of Class IV „highly polluted” at Balsa. The total P concentrations
show and even poorer situation. Both the average and the peak levels increase with
distance from the border station, the level at the border being acceptable, but
„polluted” farther downstream.
Primary production depends basically on the amount of inorganic nitrogen and
phosphorus form present and is described most simply in terms of the chlorophyll a
levels. The average concentrations do not surpass the limit value of the acceptable
quality class. The peak concentration is low at the border station, but increases more
than seven fold below the tributaries, turning the water of Class IV „polluted” quality.
Bacterial pollution in the Tisa indicates very poor conditions. The coliform
counts per millilitre are typically those of the polluted highly polluted quality classes.
In terms of the average counts of faecal coli and streptococci the quality is acceptable.
The peak values at the border station and below the tributaries indicate Class IV,
polluted quality, while a slight improvement, lower counts were noted in the samples
taken farther downstream.
The concentration of the various organic trace pollutants, such as phenoles,
detergents, hydrocarbons is very low, close to the detection limit in Tisa water. In
terms thereof the water is of excellent, Class I quality.
Of the inorganic trace pollutants, neither the average, nor the peak
concentration of copper, arsenic, lead and chromium surpass the limit values of the
quality classes I-II.
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