We are thrilled at the quality of the porous asphalt street paving installation that GEO designed for the Dihua Sewage Treatment Plant LID retrofit project in Taipei, Taiwan. Kudos to Chao Jan Construction Ltd, they are true professionals.  Power washing at regular intervals will clean small particles of debris that have blocked the tiny holes in the asphalt, preventing water from draining through the pavement. Taiwan has higher humidity than colder climate so GEO has suggested more frequent cleaning cycles  because of mossy or moldy growth that blocks the holes.