This report outlines design considerations that are unique to environmental engineering concrete structures and associated buildings. Environmental engineering concrete structures are defined in ACI 350 as concrete structures intended for conveying@ storing@ or treating water@ wastewater@ or other nonhazardous liquids@ and for the secondary containment of hazardous liquids. Applicable building codes and other industry standards should be consulted for load and design considerations not included herein. The engineer should check with the local building department to confirm the applicable building code for the project location and determine if there are any local amendments.The structural design recommendations given herein should be regarded as common industry practice and are recommended for general use. Any special structural features@ unusual loading conditions@ or unusual exposure conditions may require special design considerations to achieve a higher level of performance than implied by these minimum recommendations.