A significant amout of pesticide runoff is from extreme storm events. A farmer may apply pesticide in strict accordance with the label and only as much fertilizer as needed, but if there is a heavy downpour the next day, much of it will wash into the stream. There is not much that can be done about such occurances. The question of significance of urban-residential pesticide usage was raised. Over application was recognized as a concern, but nonpesticide contamination in urban runoff waters is also a real challenge.
Commercial applicators control the amount used.
Well maintained lawns reduce the amount of runoff. Natural lawns were applauded. Green lawn syndrome was questioned as everything we put on lawns ends up in water. This is not always the current intent. Comment was made that agribusiness is controlling research agendas at universities.