  Cleaning pollution from a heterogeneous flow environment is far from simple.
We consider the flow capture problem, which has flows and sinks in a
heterogeneous environment, and investigate the problem of positioning pollutant
capture units. We show that arrays of capture units carry a high risk of
failure without accounting for environmental heterogeneity and chaos in their
placement, design, and operation. Our idealized 2-dimensional models reveal
salient features of the problem. Maximum capture efficiency depends on the
required capture rate: long term efficiency decreases as the number of capture
units increases, whereas short term efficiency increases. If efficiency is
important, the capture process should begin as early as feasible. Knowledge of
transport controlling flow structures offers predictability for unit placement.
We demonstrate two heuristic approaches to near-optimally position capture
units.
