€IS IMPACT IMPRESSIONS,, In 1977, EIS: Key to Environmental Impact Statements abstracted and indexed a total of 1,369 federally generated impact statements. Their subject distribution, broken down by €IS chapters, was as follows:

Air Transportation Defense Programs Energy Hazardous Substances Land Use Manufacturing Parks, Refuges, and

Forests Research and

Development Roads and Railroads Urban and Social

Wastes Water

Programs

No.

43 43 184 28 29 30

169

9 280

182 67 305

1,369

-

-

YO

3.1 3.1 13.4 2.0 2.0 2.2

12.4

0.7 20.4

13.3 4.9 22.3 99.8

-

~

Thus, water, land transportation, energy, urban and social programs, and parks, refuges, and forests created the greatest environmental concern or had the most profound environmental impact in 1977.

Four agencies accounted for better than 71 percent of all the im- pact statements produced in 1977. These were the Department of Transportation (mainly the Federal Highway Administration), 24.3 per- cent; Department of the Army (mainly the Corps of Engineers), 17.9 percent; Department of Agri- culture, 16.3 percent; and Depart- ment of Housing and Urban Devel- opment, 12.8 percent. Excluding USDA, whose environmental activ- ities tend to be primarily protective or defensive, we see that the Federal Government itself is the greatest source of potential hazard to the envi ronment.

Excerpted from recent editorials in €IS: Key to Environmental Impact Statements, a monthly abstracting and indexing pub- lication. Specimen copies and further information may be obtained from:

R( INFORMATION IE RESOURCES PRESS 2100 M Street, N.W. Washington, D. C. 20037 (202) 293-2605

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364 Environmental Science & Technology

~~

LETTERS

Tall Stacks; SO2 emissions

Dear Sir: The October 1977 issue of ES& T (p 946) reviewed briefly the Final Report of the OECD study on the long-range transport of air pollu- tants (“The use of tall stacks is not al- ways a satisfactory air pollution con- trol measure”).

As you may have seen from the ac- knowledgments in the Final Report, I made a substantial contribution to its drafting and was Secretary to the UK Department of the Environment Project Group for two years. You will have also seen my own review of the findings, published in Nature (268,

The research program’s Central Co-ordinating Unit (Norwegian In- stitute for Air Research) and I put considerable effort into preparing a report which we hoped would be com- pletely unambiguous even for the non-scientist. It was therefore with some considerable regret that I read the following particularly misleading passage in your review: “The belief that such tall stacks would so disperse pollutants that their concentration (my emphasis) would be negligible beyond 100 km was found to have little basis in fact.” The reputation of tall stacks as efficient dispersers of atmospheric pollutants was not called into question by the Report either explicitly or im- plicitly.

Indeed, the conclusions went some way to demonstrate the validity of such a control technology: annual mean sulfur dioxide concentrations range from about 20 pg/m3 close to the major source regions . . . to 2 pg/m3 or lower in the remote areas of Northern and Western Europe. Annual mean sulfate concentrations show a similar distribution with values between 0.5 and 10 pg/m3. Annual mean concen- trations of excess sulfate in precipita- tion range from about 5 mg S04=/L at sites close to the major source areas, to less than 1 mg S04=/L in the far north of Scandinavia. Strong acid in p e - cipitation shows a similar distribu- tion.” (Final Report, OECD Study on the Long Range Transport of Air Pollutants, pp 11.2-11.3). In the modeling work (the budget analysis) height of emission was not even con-

92-93).

sidered so your statement is again in- valid.

The article, “Exporting, importing SO2 Emissions” (ES& T, December 1977, p 1154), has a more detailed report of the OECD Document than the previous item. While the text is acceptably accurate, the table has fallen foul of editorial aesthetics at the cost of scientific accuracy. Readers are not informed that the figures are ac- curate to, at best, plus or minus 50%. Moreover, by omitting the total col- umn and the estimated deposition figures for certain, mainly Eastern bloc, countries, a false impression is given of the proportion of any one country’s emissions on depositions in any other country.

For example, if, in your version of the table, the separate depositions on Norway are added together, a total of 135 X 103 tons of sulfur is obtained. The contribution of the UK to that figure would then appear to be 45%. However, the total calculated deposi- tion in Norway according to Table 9.4 in the OECD report, is 250 X lo3 tons of sulfur. The proportional contribu- tion by the UK is then 25%. Clearly, by printing selected columns and lines from a table that was conceived as a whole, you have mislead your reader- ship. Indeed, in an area where, in ab- solute terms, values have little mean- ing, you have withdrawn from your audience the option of assessing ac- curately their relative importance.

R. A. Barnes Oxfordshire, Great Britain

Land-use impact of nondeterioration Dear Sir: Sobering implications of

the nondeterioration and nonattain- ment provisions of the Clean Air Act Amendments of 1977 are aptly pre- sented in the paper by Barbara J. Goldsmith and James R. Mahoney (“Implications of the 1977 Clean Air Act Amendments for Stationary Sources,” ES&T, February 1978, p 144). It should be obvious to any reader that obtaining permission to construct or modify a major source anywhere is going to be a difficult, costly, and time-consuming endeav- or.

I note two errors in Table 1 : (a) the 24-hour Class I SO2 increment should be 5, rather than 8; and (b) the annual NAAQS values for TSP should be separated into primary and secondary standards by leaving a space between 75 and 60. (Actually, there is a real question whether there is an annual secondary standard for TSP, since 36 F.R. 410.7, April 30, 1971, states that 60 is “a guide to be used in assessing implementation plans to achieve the 24-hour (secondary) standard.”)

Mandatory Class I PSD areas were listed in the Federal Register, 42 F.R. 55280-7, on October 14, 1977. There are 158 such areas in the US. , portions of which are included in 37 “states,” including the Virgin Islands, which is defined as a “State” in Section 302 (d) of the Clean Air Act. Areas range in size from the legal minimum 5000

acres (7.8 square miles) at Breton Wilderness, Louisiana, to 2 219 737 acres (3468 square miles) at Yellow- stone National Park. Wyoming- Montana-Idaho. Total mandatory Class I acreage is 29 433 876 (45 991 square miles), and the average size is 186 290 acres (291 square miles). The proportion of the 37 States’ total area, which consists of mandatory Class I areas is 1.49%, ranging from a low of 0.02% in Louisiana and Wisconsin to a high of 14.29% in the Virgin Islands.

Excluding Alaska, Virgin Islands, and Hawaii, 34 of the conterminous 48 States contain 15 1 mandatory Class I areas with total acreage of 27 165 195 (42 446 square miles), which is 1.7% of the total area of those States. The average size of such areas is 175 259 acres (274 square miles).

It should not be concluded from the above statistics, however, that growth and development will be prohibited or restricted only in these limited man- datory Class I areas. New Class I areas may be designated by Congress, States or Indian tribes a t any time; buffer zones of varying distances will be necessary around Class I areas to preclude exceeding of the small al- lowable increments or to protect “air quality related values”; and the na- tional goal of visibility protection in mandatory Class I Federal areas, as well as the stack-height limitations in the 1977 amendments, all will serve to extend the real impact of the PSD provisions. William H. Megonnell Nat ional Association of Electric Companies Washington, D.C. 20036

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Volume 12, Number 4, April 1978 365