2022-503-E-Planning-Schnabel Engineering South-Contract amendment 2 Lake Orange gate and spillway channel repairs

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Orange County Lake Orange Auxiliary Spillway Additional Services Project 20P2101 9.02 / September 21, 2022 Page 4 Schnabel Engineering South, P.C. Task 7 – Additional Auxiliary Spillway Investigations Based on the direction of Christopher Sandt, PE, we completed an additional investigation of the auxiliary spillway on July 6, 2022 and July 8, 2022 to obtain more information on the voids beneath the spillway slab and behind the spillway side walls. This investigation included the following: • Schnabel subcontracted with a local material testing and concrete coring company (ECS Carolinas, LLP) to core as many 3-inch-diameter cores through the auxiliary spillway sidewalls and slab as can be performed in one day. A representative from Schnabel was on-site to observe the concrete coring and select coring locations. Eight cores were performed, five through the sidewalls and three through the slab. The core hole locations are shown in Attachment 1. The concrete cores were backfilled with a sack mix concrete grout upon completion. • Schnabel performed a hand auger boring behind the right auxiliary spillway sidewall, north of the auxiliary spillway and downstream of the weir to evaluate the depth of soil materials behind the wall and obtain samples for laboratory testing for classification. The hand auger boring location is shown on Attachment 1. The hand auger boring was advanced to refusal. EXCLUSIONS Services not specifically identified above are not included in the scope of services under this agreement. The following services are not included in our proposed scope, but we can be provide a proposal for these services upon request: • Hydrologic and hydraulic analyses of the dam; • Structural or stability analyses of the intake tower or auxiliary spillway; • Preparation of breach inundation mapping and an Emergency Action Plan (EAP); • Preparation of an Operation and Maintenance (O&M) Manual; • Environmental studies or permitting; • Surveys; and • Attendance at meetings. SCHEDULE The field work detailed herein was performed on July 6, 2022 and July 8, 2022. The draft repair design submittal is currently in progress. The final repair design submittal will be submitted up to 3 weeks after comments are received on the draft submittal. FEES There is no change in fees based on the proposed modifications discussed herein. We understand the remaining $31,280 of our modified contract value of $50,100 lump sum fee will be paid in equal distributions upon completion of the Tasks 3, 4, 5, and 7. The fees for work requested beyond the scope of services included herein will be based on our current unit prices at the time the work is authorized or a negotiated lump sum. Services will be billed for the lump sum fee upon completion of scope of services detailed herein and delivery of the deliverable. DocuSign Envelope ID: 94DC2E6B-A091-44C2-A636-AEC6DE85AB37