An interdisciplinary environmental education program was introduced on an experimental basis into high school social studies and science courses in an effort to produce competencies in environmental problem solving. Ninth and tenth grade classes in a suburban school district in Atlanta participated in the study. The ninth graders were of average reading ability, and the tenth graders were of low reading ability. Experimental materials included four interdisciplinary student modules (textbook, slides, audio tapes, and maps) and four teacher's guides. Ninth grade modules contained geography and biology content; tenth grade modules contained chemistry and American history content. There were four treatment groups in each grade: one studied an environmental module in science class only; one studied a module in social studies class only; one studied modules in both classes; and the control groups did not study the modules at all. Pre- and posttest results were analyzed to see if there was a significant difference of posttest performance among the four groups at each grade level. Although student groups which had the combined treatment in both grades produced the highest mean scores, the ninth grade students scored significantly higher than tenth grade students. This may be because the ninth graders were of average reading ability, whereas the tenth grade groups were noted to have reading difficulties. More research using the modules with slow learners is needed. (Author/AV)