Subsurface flow constructed wetland (SSF CW) removed perchloroethene (PCE) robustly.
Hydroponic plant root mat filter (HPRMF) removed PCE less efficient than the SSF CW.
The carcinogenic metabolite vinyl chloride was not detected in HPRMF but in SSF CW.
Accumulation of PCE metabolites in SSF CW was somewhat reduced by tidal operation.
Redox potential and dissolved oxygen concentration were higher in the HPRMF.