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<br />L. M, ALEXANDER <br /> <br />It's a real challenge to be sure-for those of you who might not have been to the area, here is <br />1~~sl~6, what it looks like. In the third ~lide the plant will be some 3Y2 miles straight out from Lake Powell <br />out toward that cliff jutting up on the skyline. <br /> <br />We ~articipants are giving full attention ourselves, and are calling on the experts in the field to <br />optimize the following necessary elements of the Navajo plant: <br /> <br />1. Air purity <br />2. Noise abatement <br />3, Water purity <br />4, Dust suppression in, the coal and ash handling <br />5, Appearance or aesthetic values <br /> <br />Let me give you a preliminary progress report on each,of these: <br /> <br /> <br />1. Air Purity <br /> <br />When fossil fuels are burned, chemical oxidatioti occurs as combustible elements of the fuel are <br />converted to gaseous products are not presently believed to be harmful (oxygen, nitrogen, carbon <br />dioxide, and water vapor), and therefore, apparently are not factors in air pollution, The gases of <br />concern, in terms of their potential harmful effects (oxides of sulphur and nitrogen), make ,\p only an <br />extremely small percentage of the gases emitted, <br /> <br />We start witl1 a fortunate situation at Page using the Black Mesa coals, They have an average ash <br />content of 7,93% whereas at our units at Four CorJiers, the ash content runs from 21 to 24%. Vet <br />look what we are able to do on the new Unit No, 4i at Four Corners, It is just going into service, <br />Slid. 19 equipped with a precipitator with a designed removal efficiency of 97.5%, The first slide is the plume <br />Slide 20 with the precipitator out of service. The remaining plume in the second slide with the precipitator in <br />service is mainly harmless water vapor, <br /> <br />At Navajo our water service contract with the Secretary of the Interior requires that we install a <br />system with a designed removal of 99,5% of the parti~ulate matter-up from 97,5%. <br /> <br />Now, let's examine those stack effluents whidh *ill escape. <br /> <br />With the high efficiency of the precipitators we will be installing, we expect to remove all but <br />one-half of one percent of the ash produced. The recommended maximum ground level concentration <br />of particulate matter per federal government regulations is 80 micrograms 1M3, Standards which have <br />been proposed for most of the urban areas of thd lJnited States lie in the range of 70 to 120 micro, <br />grams 1M3, Our current estimate is that our tniax,imum ground level concentration of particulate <br />matrer will be less than one,half of the permitted ll\1al'imums-more on this later, <br />, <br />I <br />Sulphur content is very low in the Black Me~a Coals we will be using-O,51% for the average <br />grade coal with a rejection limit of 1.34%, Many' of the coals being burned in the east run from <br />2 - 5% sulphur, <br /> <br />We will adjust stack height t<? insure adequate 'dispersion of the oxides of sulphur. By adequate <br />we mean sufficient to meet a grou'nd level concentra!tion criteria recommended by federal government <br />of not to exceed 1110th part per million for greater,~han 1% of the time, Preliminary studies indicate <br />a stack height of 700 - 800 feet will be required, <br /> <br />.26'- <br /> <br />