Environmental porous media are widely used to convey, attenuate, transform or contain pollutants in landfills,drainage layers, permeable reactive barriers, biocovers, biofilters and contaminated aquifers. They are still oftendesigned or assessed through initial material properties such as porosity, hydraulic conductivity, sorption capacity,batch leaching response or biological potential. This review argues that such a static interpretation is insufficientwhere flow, reaction, microbial activity and structural change reorganize the medium during operation. Thereviewed literature shows that environmental reactive porous media behave as evolving, biologically active andself-organizing process systems. Hydraulic redistribution, dissolution, precipitation, redox transformation, particleretention, biofilm development and gas transfer generate trajectories that can lead either to attenuation andfunctional stabilization or to clogging, bypass, passivation, remobilization and loss of contact. The paper developsa process-engineering synthesis in which performance is interpreted as the trajectory of coupled state variables,including hydraulic conductivity, connected porosity, residence-time distribution, accessible reactive capacity,active surface, biomass architecture, redox state and gas-transfer accessibility. The central conclusion is thatenvironmental engineering should move from static material control toward trajectory management. Control isconditional, not absolute: it requires observable or inferable state variables, diagnostic monitoring of activefeedbacks, admissible functional domains and operational levers capable of guiding endogenous porous-mediadynamics. This framework provides a common interpretation for attenuation, stabilization and control pathwaysacross waste-management systems, reactive barriers, biocovers and contaminated subsurface environments.