Document 6BxoXkBz4pgjLmLLDrobB8bL4

Monsanto from .n.mc * location, tg^ E. Stewart/ Krummrlch OAT April 25, 1972 *U8JECT : REFERENCE : PCB - CONTROL PROGRAM MONITORING - - - - - - TO : Mr. Art Leisy COMPANY CONFIDENTIAL cc Messrs. Bill Engman Clarrie Buckley Julio Munoz Bob MeCutchan Bill Caraway Comments related to monitoring sewer streams that are to be monitored for PCB's are as follows: 1. Treatment Plant Influent - Losses measured at this point will be obtained from a composite sample collected with an isokinetic flip-flop sampler. It was agreed with the Environmental Control Group that this sample would be more accurate than the multi-handled sample taken from the drum as was done in the past. Comparative analyses in the past would indicate results from the flip-flop to be more uniform and slightly higher than from the drum. A statistical method for recording and reporting losses will be developed to better indicate trends rather than individual peaks and valleys normally present when plotting individual data points. This change in sampling procedure will go into effect on 5/1/72. 2. Treatment Plant Effluent - Same as with influent. 5. Aroclor Department Parshall Flume - Project to be completed about 5/51/72. An isokinetic flip-flop sampler will be installed with the additional refine ment that sampling will be proportional to flow. A project will be prepared to permit pumping from the north settling basin to the south basin. All water flow from the Aroclor department will flow through and be sampled at the Parshall flume. 4. , Incinerator Sewer - A flip-flop continuous sampler will be installed at 2-L or 2-K to monitor losses from the area. DSW 295988 STLCOPCB4065932 Mr. Art Leisy PCB - CONTROL PROGRAM MONITORING Page 2 4/25/72 WGK 5. Hip Track Washes - Will be grab sampled on a spot basis. All washes pass through a settling trailer before passing to the sewer. Trailer contained about 6" of organics when measured on 4/18/72. Technical Services Department /tm i. DSW 295989 STLCOPCB4065933