We observe ongoing weaknesses in the quality of science underpinning environmental impact assessment (EIA) in Canada. This is frustrating because approaches for strong scientific practice in EIA were published decades ago. A major failing has been the lack of scientific support from
outside the EIA practitioner community. We argue for a re-conception of science associated with EIA that includes a rigorous scholarship of application inside EIA and a vigorous scholarship of integration outside it. Cases of exemplary organizational structures and science applications in
the Canadian forest sector are given. To turn EIA from the often bitter battleground of shallow impact debates to an enterprise of strong accumulation of effects knowledge, we urge the relevant communities of researchers and practitioners to become embedded communities of practice and reform
the way science contributes to EIA.