ABSTRACT
One o f t h e charges f o r t h i s workshop was t o keep i n mind t h a t we a r e l o o k i n g a t processes assoc ia ted w i t h t h e f a t e and t r a n s p o r t o f chemicals ( p e s t i c i d e s and n i t r o g e n ) t h a t may pose a t h r e a t t o s u r f a c e and groundwater resources. I n t h i s b r i e f rev iew, I w i l l emphasize some p a r t i c u l a r aspects o f hydro logy t h a t I b e l i e v e should be c l e a r l y understood by anyone want ing t o make judgements on t h e e f f e c t s o f conserva t ion t i l l a g e on wate r q u a l i t y .
