letters Getting oil off the beach
DEARSIR: I n your story o n oil spill technology (ES&T, August 1971, p 6 7 4 ) , a caption beneath a photograph of our mobile beach cleaner describes it as “an expensive substitute for straw.” While most people set u p “strawmen” you have set u p a straw beach. Straw is not the number one material for beach cleanup-it is used as an absorbent on the water and beach before the oil gets to the sand. Once the oil is on the beach, straw is not used. Whatever straw remains only complicates the cleanup process. Conventional methods of cleaning beaches consist of removing the contaminated sand and dumping it at an out-of-sight location or sprinkling the sand with detergent and letting the incoming tides wash off the oil. The latter method is all but banned and the sand dumping method will soon be barred (because of oil leaching from the sands). Meloy Laboratories’ Beach Cleaner, developed under EPA funds, is designed to save the sand and specifically to eliminate the costly process of shipping the sand to a distant site and dumping it where it will leach oil back into the environment. The dumped sand often has to be replaced with sand from a distant site. The price of dumping sand ranges from $10-$20/ton and that of new sand is about $5/ton, so that the total cost varies from $15 to $25/ton. Our mobile beach cleaner costs about $0.501’ ton to operate, in addition to doing it quicker and saving the sand. Thomas P. Meloy Meloy Laboratories Springfield, Vn. 22151 Air quality monitoring
DEAR SIR: The feature article in your August issue by Hochheiser, Burmann, and Morgan (“Atmospheric surveillance: The current state of air monitoring technology,” p 678) was a welcome contribution. The overview of the methods of monitoring is useful and the emphasis which the writers put on collaborative evaluation of the methodology is both important and timely. 978 Environmental Science & Technology
It must be emphasized further, though, that not only is collaborative evaluation important but so also is the manner in which such evaluation is effected. In the past, and until the recently mounted ASTM project Threshold was conceived, collaborative evaluations amounted to “test tank” projects which d o not test under real conditions in which the method must function, whether it is manual or automatic. There is a regrettable flaw in the section of this article on economic evaluation of the automatic instruments. It stems from the failure of the writers to stress the as yet non-ideal nature of these instruments and the resulting high cost of “break-in time” (well recognized by those who use them), the cost of personnel needed for continuing calibration and maintenance, and downtime. At the more economics-conscious “operators” level, these expenditures are significant and indeed place the automatic methods in a very high cost bracket. This is especially regrettable, since both the science and technology are well enough developed to make automation the way to go. Benjamin Levadie Div. of Environmental Protection State o f Vermont Barre. V t . 05641 Where all t h e sulfur goes
DEARSIR: The feature article, “Fuels management in an environmental age” (ES&T, January 1971, p 3 0 ) , was an excellent review of this subject. However, I believe a correction is in order where the article portrays the sulfur in blast furnace coke being released as hydrogen sulfide and burned to sulfur dioxide as an air pollutant. The sulfur involved is of considerable magnitude, as the article states that half the coal consumed by industry is used to make coke. H. H. Lowry, in Znd. Eng. Chem., 41, p 502 (1949), states that examination of papers reporting thousands of analyses of blast furnace gas has failed to disclose sulfur leaving the furnace in the gas. In a typical sulfur balance for a blast furnace, Lowry shows the sulfur output from the fur-
