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threat to life, property, or the environment. Seeding activities were also to be suspended immediately whenever the National Weather Service issued a severe thunderstorm or tornado warning which the project of- ficials believed could be related to clouds in the target area. In addition, seeding would either not be undertaken or would be terminated whenever the HIPLEX radar facility was inoperative or when the air-to- ground communications equipment was inoperative. In preparing for Project FACE, NOAA considered the possible environ- mental impact of the seeding activity. The effects of'increased rain- fall on crops was studied, and particular attention was given to the tomato crops. The effects of the seeding agent, silver iodide, were also noted. The EIS for Project FACE stated the following: "Tomatoes are grown in the target area during the winter, spring and early summer. This is a rain-sensitive crop, particularly during ripening stage. Obviously increased rainfall from seeding at this time would have an adverse effect on this crop. As in pre- vious years NOAA will closely coordinate the scheduling of the seeding activities with the agricultural and other interests in the target area, and attempt to keep all other interested citizens informed on the nature of the project. "There are no known adverse effects from the silver iodide (AgI) -used for seeding. The U.S. Public Health Service Drinking Water Standards of 1962 require that the 'silver content of drinking water be less than 0.05 parts per million'; there are no standards with regard to iodide. On an average day of seeding approximately 1.5 x 104 gm of silver iodide are expended and 3.0 x 1013 gm of rain falls. If this silver iodide is evenly distributed in the rainwater, the silver content of the water would be 0.5 parts per billion ---- well within the U.S. Public Health Standards for drinking water. Measurements of silver in rainwater during FACE 1973 and 1975 substantiated this expectation. The silver iodide that does not combine with water should stay in the atmosphere for days, months, or years and be dispersed over a very large area with proportionately sma1ler'concentrations. In the event that the experiments are successful and cloud seeding is carried out on a regular, operational basis, the environmental impact should be reassessed." Nonfederal Activities Among the States, legislation and regulation on weather modification vary from none to complete. A few States require the preparation of environmental impact reports prior to initiation of weather modifica- tion projects. In general, State-directed programs address the potential adverse effects of weather modification and provide for strict supervision and evaluation of projects. At the local level, privately sponsored efforts to clear fog, increase precipitation, or 14