Digest -- Introduction -- Better information on nonpoint sources of water pollution needed -- Insufficient emphasis and resources limit efforts to control nonpoint sources -- Appendix I. Environmental Protection Agency categories of nonpoint sources of water pollution -- Appendix II. Efforts to control agricultural nonpoint source pollution, Palouse River Basin, Washington -- Appendix III. Controlling nonpoint pollution from urban development, Rock Creek, Maryland -- Appendix IV. Effects of acid mine drainage, Kerber Creek, Colorado -- Appendix V. Abatement of acid mine drainage, Crooked Creek, Pennsylvania -- Appendix VI. Efforts to control water pollution caused by silviculture, Washington -- Appendix VII. Letter dated September 12, 1977, from the Assistant Administrator for Planning and Management, Environmental Protection Agency -- Appendix VIII. Principal EPA officials responsible for activities discussed in this report. "GAO reviewed overall efforts to controll nonpoint sources of pollution and concluded that progress has been minimal ... The Environmental Protection Agency should do more to plan solutions to nonpoint sources of water pollution ... The Agency agrees that a greater nonpoint source control effort at the Federal, State, and local level is needed. It believes, however, that the present program structure is the best possible, considering the various program constraints."--Page i-iii.