Projekt 05HS022 Identifizierung und Vermeidung der hot ... - BLE

0. Extended Summary
1. Point sources have been identified as important source of pesticide inputs in surface waters,
with regional differences. The actual inputs are presumably higher than those detected
in this project: The compound glyphosate, resp. its metabolite AMPA, was not analyzed
(for economical reasons). However, glyphosate is one of the pesticides with the
highest sales volumes in Germany and considerable losses from point sources as well as
from treated areas are most likely. The STP sampling covered only the discharge of dry
weather conditions due to the fact that during heavy rain events excess water reaches the
surface waters networks directly via storm overflows.
2. Obviously mitigation measures already implemented were not sufficient to reduce pointsource
pesticide inputs into surface waters to the necessary extent. High variations between
the different STPs show that there is apparently an important potential for mitigation
of point-source pesticide emissions.
3. Handling of pesticides and sprayers on farmyards should be addressed by specific mitigation
measures, including every individual operation like storage and handling of compounds
as well as preparation of spray mixture and in- and outside cleaning of equipment.
4. Mitigation strategies should be specially developed and designed for risk situation. The
present study shows that identification of “hot spots” is relatively difficult. Neither the
number of sprayers within an STP catchment could be identified as an explaining variable
for the high variance in pesticide loads, nor could structural differences in agriculture - but
these variables could nevertheless be important in individual cases.
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