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<br />Amendment No. 1 to Last revised 9/13/2023 <br />Consulting Services Agreement between <br />City of San Leandro and Terraphase Engineering, Inc for Soil Risk Analysis <br /> Page 2 of 5 <br /> <br />transects. Qualitative assessment of sludge stiffness will be recorded at each location and each <br />location will be located using a sub-meter accuracy global positioning system (GPS) receiver. <br /> <br />Six, relatively undisturbed tube samples of the sediment will be c ollected (if feasible) for <br />geotechnical characterization using an ARTS Manufacturing sediment sampler. The samples will <br />be collected from locations where the sludge is felt to be the softest. Bulk samples in two five - <br />gallon buckets will also be collected. <br /> <br />If tube samples can be collected, the geotechnical samples will be analyzed for shear strength, <br />gradation, moisture content/density and Atterberg Limits. If tube samples cannot be collected, the <br />samples will be analyzed for moisture content and Atterberg Limits and we may reconstitute <br />samples for shear strength testing. <br /> <br />Ten sediment samples will be collected on a grid, with five samples each in the central portion and <br />eastern portions of the polishing pond. No additional samples will be collected from the western <br />portion of the pond. <br /> <br />Environmental samples will be collected using a Petite Ponar sampler, which will be lowered from <br />the side of the raft. This type of sampler typically collects between 6 and 12 inches of sediment. <br />We will allow the sampler to dewater before opening it to remove the sediment. The sample will be <br />placed in a plastic tub, where it will be manually homogenized using a stainless-steel trowel or <br />similar tool. Samples will then be placed in laboratory-provided jars. The jars will be labeled and <br />placed in a cooler for transport to the analytical laboratory, under chain -of-custody procedures. <br /> <br />Samples will be analyzed as follows: <br /> <br /> Title 22 Metals using EPA Method 6010 <br /> Deionized-water-extracted (DI-WET) Metals using modified EPA Method 1311 and EPA <br />Method 6010 <br /> Total petroleum hydrocarbon (gasoline, diesel, motor oil) using EPA Method 8015 <br /> Moisture content using ASTM D2216 <br /> Polychlorinated Biphenyls (PCBs) using EPA Method 8082 <br /> Organochlorine Pesticides using EPA Method 8081 Analysis will be performed on a <br />standard 1-week turnaround time. <br /> <br />The sampler and all non-disposable equipment will be decontaminated between sample locations. <br />We estimate that the sampling will take approximately 8 hours. Therefore, we have budgeted for <br />one field day for two people, or a total of 24 labor hours. The costs associated with the boat rental <br />(daily cost, delivery, pick up, etc.) are not included herein because the work will be done in <br />conjunction with the separately proposed geotechnical sampling. <br /> <br />Task 6 – Data Management and Reporting <br />DocuSign Envelope ID: A3E467C7-B7E3-497F-8715-3F2DF618BEDB