( Wells ( ( are ( ( drilled down ) ( to ( an ( aquifer ( to ( ( draw groundwater ) ( to ( the surface ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Wells)) (VP (VBP are) (VP (VBN drilled) (PRT (RP down)) (PP (TO to) (NP (DT an) (NN aquifer) (S (VP (TO to) (VP (VB draw) (NP (NN groundwater)) (PP (TO to) (NP (DT the) (NN surface)))))))))) (. .)))
Wells are drilled down to an aquifer to draw groundwater to the surface.
(ROOT (S (NP (DT A) (-LRB- -LRB-) (NN n) (-RRB- -RRB-)) (ADVP (RB well)) (VP (VBZ is) (NP (NP (DT a) (NN hole)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN dug) (CC or) (VBN drilled) (PP (IN through) (NP (NP (DT the) (NN ground)) (ADVP (RB down) (PP (TO to) (NP (DT an) (NN aquifer)))))))))))) (. .)))