(3) Immediate reconvening of the 1957 Enforcement Conference on the Potomac to focus attention on the timetables for controlling pollution in the estuary in the light of water quality standards and also to consider problems of agricultural pollution, sediment, nutrients, dredging and vessel wastes. (4) Strengthening of the continuing surveillance program on all streams in the Basin to insure compliance with water quality standards and to help correct abuses from leaks, spills, and illegal or accidental polluting discharges. Active participation by local, State and interstate agencies with the Federal Government in contingency plans for spills of oil and other hazardous substances in the Basin also is required. (5) Adoption and implementation of regulations and requirements by local and State authorities for control of pollution from boats and marinas. Legislation under consideration by the Congress would permit establishing national standards for control of pollution by vessels. (6) Adoption and implementation by State and local authorities of a policy that will prevent significant quality deterioration in high quality waters. b. Accomplishment of these measures will go far toward assuring a clean Potomac. However, to protect the Basin's waters over the long run, even more must be done. (1) First must come research and investigations to seek better methods of control where existing information and technology are inadequate. This includes: (a) Continuation of current pilot plant demonstration studies of advanced waste treatment processes at Piscataway, Prince William County, Virginia, and District of Columbia waste treatment plants and completion of the chemical, biological, and physical studies of the estuary to establish a basis for upgrading water quality to the maximum feasible degree. (b) Continuation of investigations and demonstration projects to evaluate costs and effectiveness of methods of treating and controlling combined and storm sewer discharges from urban areas, particularly Washington, D.C., to provide cheaper and more effective solutions as partial alternatives to present long-range programs of separation of sanitary from storm sewers in the metropolitan area. (c) Initiation of an engineering study or demonstration project to investigate practicable and acceptable means of disposing of sludge from conventional and advanced waste treatment plants. (d) More complete delineation of sources of nutrients to the free-flowing streams of the Basin and evaluation of methods of nutrient control or reduction. Continued research on nutrient-algal relationships to better define the principal chemical factors which result in nuisance algal growths, particularly in the Potomac estuary.