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Phase II Environmental Site Assessment CANNERY PARK SUBDIVISION UNITS 7 & 9 DISPOSAL PONDS Stockton, California WKA No. 10020.09 Page 2 February 22, 2021 Scope of Services The purpose of the activities comprising this Scope of Services is to evaluate soil for concentrations of total lead in excess of the HERO Note 3, residential exposure threshold of 80 mg/kg. The following sections describe activities by WKA to collect soil samples from locations that are uniformly distributed over the Site and that are representative of soil up to a depth of ten feet below ground surface. Health and Safety Plan and Underground Services Alert WKA will prepare a Site-specific Health and Safety Plan, mark the proposed sample areas, and notify Underground Service Alert (USA) to request a Dig Permit. WKA will begin sampling activities after receiving clearance from the responding utilities, which will happen no sooner than 72 hours after notifying USA. This proposal includes no cost for a geophysical survey to search for underground utilities that Underground Service Alert team members do not identify. WKA will request additional budget authorization if the USA response is suspected to have insufficiently verified buried utility locations or if our information discovers buried utilities. We conclude. Soil Sample Collection Figure 1 shows the 15 sample locations that will be uniformly distributed over the 7.5 acres comprising the Site. This will be accomplished using an equal-area grid that will be modeled over the Site. WKA will use geographic information system (GIS) techniques to identify sample location coordinates and a high accuracy global positioning system receiver (GPSr) to locate sample coordinates in the field. WKA proposes to collect soil from each location using a Gator-mounted drilling machine that WKA will operate under its California Contractor License Number 9574461 C57 HAZ . WKA will use the drilling machine to auger to a maximum depth of 10 feet below ground surface. WKA will visually monitor drill cuttings for evidence of metallic pieces or red coloration that ATC reported to be evidence of elevated lead concentrations. WKA will use manually operated soil sampling tools to collect soil within the intervals of two to 21/2 , five to 51/2 , eight to 81/2 , and ten to 101/2 feet below ground surface (bgs). WKA will clean the soil sampling tools before each use by washing them in a solution of clean water and a surfactant, then rinsing the tools in three baths of clean water. The above-described sample collection activity will result in WKA having collected 60 soil samples. WKA will place each soil sample into a laboratory-provided container that will be sealed using a Teflon Ty-lined lid. WKA will label each sample container to indicate a unique 1AS