Document 91DwOY2mGYypqZxKgG9r7238L

Lead In scale Cross tank #501, Gulf Hoflalng Company, Toledo, Ohio* This tank w&s recently cleaned and then was dismantled for scrap* Side Scale {Area of 100 sq, ft* or 12 sheets) Analysis Humber 3.0A-59&9 Sample total 81 gse Sample analysed * 10*0 gjaa Organic Fb 0*0002/s (0.2 ssg/lQO grss) ^ Inorganic Fb * 0.33^' (380 tas/100 gaia) Bottom Seale (Area of 100 sq* ft. or 6 sheets) Analysis Ihenber i+QA-5970 Sample total Sample' used 255 g * 10 asa Organic Fb 0.0005^ (0*5 rag/100 gm)v' Inorganic Fb 2.2^ (2200 ag/100 gras) Samples Heoeiveds Il-l4l;0 Samples Reportedi 11-26-30 i a iov. 9, 194-0 Dr. Robert X&hoe. Dear Dr. Kehoe: I am submitting two samples of scale scraped from bottom and side sheets of leaded gasoline storage tank, recently cleaned and then dismantled for scrap by the Gulf Refining Co., Toledo, Ohio. The tank #501, of 55000 bbl.. capacity had been used for the storage of leaded gasoline for the past six years and had not been cleaned during that time. The method of cleaning was as follows. The tank was stripped of gasoline, then all of the remaining water was pumped off. high pressure steam was introduced through the bottom manhole for 84 hours, having the roof manhole open at ail times. After the sank had cooled, one large roof sheet and two lower side sheets on opposite sides of the tank vie re removed. Two large pics 5* x 15* x S' deep were dug on each side of the tank, the position being close to the bank where the side sheets had been removed so that the sludge and scale could be flushed directly into the pits. Tor two days, working about seven hours per day, bhe men standing on the outside flushed the tank with high pressure water, -washing the sludge into the pits. The excess water was pumped from the pits through the refinery sewer to tne refinery separator. The third day, the men properly equipped entered tank and via shed down the scale from the roof, side sheets and superstructure and flushed this scale into the Pits. The fourth day all remaining scale and sludge was swept from around the base of the steel supports and the angle ewe the edge of Lhe tank. This was flushed into the pits and again the entire tank was flushed with high pressure water for about an hour. I then made an inspection and found the sides, bottom and especially the seams of the side and bottom sheets free of sludge. The tank was cut down with a torch, first removing the roof sheets. The sides were cut vertically, that is from top to bottom, through the angle iron continuing across the bottom sheets until uhe cuts met. This left the sides with part of the bottom in six sections and these vie re then pulled to the ground and later cut. into smaller sections six by fifteen feet and the inside surfaces then coated with oil. After these sections were on the ground I was able oo make a very close inspection and tnere appeared to be no more scale or sludge in the seams than on tne sheeps themselves. HE" 0022389 N22496.01 2- - I took a sample, #1 of scale scraped from bottom sheets. This v:as scraped from six different sheets in various locations in the tank and represents the amount of scale possible to secure from an area of approximately one hundred square feet. Sample #2 is from the side sheets. This was taken from twelve sheets, four each of first, second and third ring of the tank in various locations and also represents the amount of scale \ possible to secure from &n area of approximately one hundred square \ feet. ___ _____ This tank, I believe was as thoroughly cleaned as is possible with only the use of high pressure water. In pulling the super structure, roof and side sheets down there was very little dust. I have tried to give all of the information that might be needed and anything in addition I will be glad to supply if possible. Very truly yours, L-I. D. Siebenthaler H 0022390