Document KGVzXL8bjB1MQajL67noMg44Q

NEW YORK 17 June 1, 19^8 Circular Letter No. S-21-48 Subject : Sludge Study Reference: Safety Manual Section XII TO OPERATION MANAGERS/" U-{ \ 0XV, COPY FOR iM* ! \ JtA-> A, JL Gentlemen_ : The paper on "Decontamination" distributed last year mentioned that buried material contaminated with organic lead compounds should not be disturbed. No mention was made of a time factor. In normal tank cleaning operations, sludge and scale are buried near the tank. Occasion ally areas where such material is buried must be disturbed to lay lines or perhaps to bury another accumulation of sludge and scale. It is desir able for us to be informed of the rate of change in lead hazard created by this material and if possible to know how long such material must be buried to eliminate the lead hazard if, in fact, it can be eliminated at all. It may be assumed that the hazard will be proportional to the quantity of organic lead material present. Since there is no valid reason to assume that any organic lead products in the tank will be evenly dis- : tributed throughout the sludge, sampling must be done in a very careful manner. Successive quartering would be the ideal method of sampling, but it is not practical. A large number of small samples, collected from well scattered points, will approach the results of successive quartering for a representative sample. The scattered points should be weighted according to the apparent mass distribution of the sludge and scale in the tank; that is, more small samples should be taken from large piles of sludge and scale than from areas relatively free from such material. For this reason, when the tank is safe for entry, the sample should be collected before workmen enter the tank to remove sludge and scale. The total volume collected should be one quart. A clean mason jar with glass top will be a satisfactory container. The following data should be obtained for each tank sampled: 1. Tank service 2. Time last cleaned 3. Thoroughness of last cleaning 2- - 4. Estimated through-put a. Product b. TEL 5. If a mixing tank, any record of lead discrepancies in mixing. The following factors will influence the regression rate from organic to inorganic forms of lead: 1. Use of decontaminating agents 2. Characteristics of soil a. pH (acid, alkaline, neutral) b. Porosity (rocky, clay, sand, loam) 3. Drainage 4. Amount of precipitation and surface water flowing over the area 5. Depth of sludge beneath surface 6. Winter and summer temperature of soil at depth of buried sludge. . The foregoing discusses action necessary when sludge is buried at the time of tank cleaning. The quart sample, properly identified, should be sent to Kettering Laboratory, attention of Dr. E. A. Kehoe. Copies of the report form (sample "A" attached) should be sent to Dr. Kehoe and to the. New York Office. Subsequent samples should be collected at six month intervals until the lead hazard ceases to exist. Again sampling must be done care fully in order to have material representative of the whole amount of sludge. A large number of small samples, totaling one quart should be taken from random locations throughout the body of sludge. Deports (sample "B" attached) accompanying these samples should identify the tank, the date the sludge was buried originally, the amount of rainfall or snow during the last six months, any unusual circumstance that might influence the regression of organic lead materials. It is desired that each region take samples in accordance with the above procedure at 25 different locations. These locations should be selected to give the widest geographic distribution possible. HS 0009694 -3It is possible that samples can be collected immediately of sludge that has been buried for a considerable period of time where the safety engineer has knowledge of its location, date buried, etc. Analysis of these samples will provide valuable information when correlated with the factors influencing the change of organic lead compounds as previ ously described. This information can be given on the form used for original samples with suitable comments under "Remarks". It is desired that this study be started as soon as possible. Tour cooperation in the careful planning, follow up of the details' involved, and collection of representative samples, will be appreciated. Attach. (2) KE 0009G95 SLUDGE SAMPLE REPORT (First Sample) Tank OwnerTank Location Date___________ Tank Service: (l) Mixing_, (2) Storage. Tank Last Cleaned ______ Thoroughly Cleaned: Yes _____ No Estimated Throughput: (l) Product ___________ bbls. per year (2) Average TEL __________ ml. per gallon Record of mixing discrepancy in this tank_______,____________________________ Were decontaminating agents used at time sludge was buried? Yes_____ No__ Type Soil: Acid_____ Alkaline _____ Neutral Porosity of Soil: Rocky__ __ Clay Sand_____ Loam Does most surface water drain off_____ or soak through ground Amount of annual precipitation in general area: Rain_____ inches/year Snow inches/year Is there any general flow of surface water from other sources flowing over area? Yes_____ No Average ground temperature at depth of sludge: Winter______ Summer_____ Remarks: (Describe any condition, not covered above, that may influence the conversion of organic lead to inorganic lead compounds.) (Form A^ KE 000369G SLUDGE SAMPLE REPORT (Follow up Sampling) Date Tank OwnerTank Location Date Sludge Buried _______________________ Precipitation Since Last Sample Collected; Ra4.ninches Snowinches Remarks: (Describe any unusual condition that may have influenced con version of organic lead to inorganic lead compounds.) (Form B) 0009697