COMPLIANCE INFO_PR0440063_1990-2019

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Musco Family Olive Company TraPlant Page 2 of 2 25 August 2014 San Joaquin County We observed placement of the gravel on the pan lysimeter liner(see Photo#4). At that time we noticed a member of the work crew who was assisting placement of the gravel resting the sharp edge of his flat shovel on the pan lysimeter liner. The CQA Officer quickly instructed the work crew to not place sharp objects on the pan lysimeter liner. We also noticed that the contractor was using a backhoe with a bucket that had teeth on it to place the gravel in the pan lysimeter. We noticed that after the contractor had placed much of the gravel in the pan lysimeter the contractor wanted to use the bucket to spread the gravel evenly over the pan lysimeter liner. We quickly made a comment to the CQA Officer that the contractor should not be using any objects in close vicinity to any liner system where such objects could puncture/damage the liner. The CQA Officer immediately instructed the backhoe operator to not use the bucket with teeth around the liner. During placement of the gravel we noticed that it contained residual moisture (See Photo#6) and that we were concerned this might give false indication of a release from Pond C. The CQA Officer said that he would sample and analyze any moisture in the pan lysimeter following construction for chemical constituents such that it might be documented as to its chemical characteristics. We did not notice any free liquid seeping from the gravel pile. We were unable to observe completion of the pan lysimeter due to the amount of gravel that needed to be placed in the pan lysimeter prior to installation of a sand/filter layer (See Attachment 2) Prior to leaving the site around 2:00 PM we asked the CQA Officer to provide photo documentation of the remaining construction of the pan lysimeter. Photos#7 through 11 were provided by the CQA Officer in compliance with our request. Photo#7 shows that the contractor used a vibratory plate to compact the gravel. Photo#8 shows the filter fabric being installed above the compacted gravel. Photo#9 shows the sand layer being graded and compacted above the filter fabric. Photo#10 shows completion of the filter fabric above the sand completely encasing the sand layer in filter fabric. It also shows where a geomembrane patch had to be welded to the pan lysimeter liner in order to extend the liner up the pond berm wall, and where the contractor has to install soil in the form of wedges to provide a gradual transitional slope from the pond bottom to the bottom of the sump (See Photo#11). 5. Discussion: Based on the photos taken by Board staff and photos provided by the CQA Officer, it appears the pan lysimeter for Pond C was generally constructed according to the final plans for the project. The CQA documentation in the final CQA report will have to substantiate that the proper materials were used and certify that the pan lysimeter as constructed will meet the Title 27 requirements for an unsaturated zone monitoring system. 5. Recommendations/Conclusion: Based on two observations (placement of shovel edge on the lysimeter liner, and use of the backhoe bucket with teeth to spread gravel above the lysimeter liner), Board staff recommends that the CQA Officer and his assistants constantly emphasize to the contractors the fragile nature of the lin r system (primary, secondary and pan) and that the contractor carefully monitor and control the use of obje is such as knives or shovels as well as limit the movement by vehicles or equipment upon the liner system t t may amage the liner system. Vinoo Jain, Water Reso ces Control Engineer Title 27 Permitting and Mines Unit 3 Attachments Attachment 1. Pond C Pan Lysimeter (PL-C) Location Map Attachment 2. Final Plans- Detail of Pan Lysimeter Construction Attachment 3. Site Inspection Photos