MicrobialcontrolofthegeochemicalbehaviorofheavymetalsandAsincontaminatedsubsurfacewasinvestigatedthroughactivationofindigenousbacteriabyorganicsupplyunderanaerobiccondition.TheresultsindicatedthatdissolvedCd,PbandZnweremicrobiallyremovedfromsolutions,whichwaslikelyduetotheformationofmetalsulfidesafterreductionofnaturalsulfatebyindigenoussulfate-reducingbacteria.ThesoilcontainingalargeamountofsulfateresultedincompleteremovalofdissolvedAsafter25days,whilethereweregradualincreasesindissolvedAsconcentrationinthesoilswhichshowedlowsulfateconcentrations.Subsequentexperimentswithsulfatesupplywereconductedtoidentifytheeffectsofsulfateamendmenttostimulatemicrobialsulfatereductiononheavymetalbehaviors.