2025-11-03 PL-CRC-2025-000038 HIFL Draft AIS Testing Strategy

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extensive complex of pit caves that included pre-Contact Native Hawaiian archaeological deposits and burials. Post-Contact sites relating to the commercial sugarcane industry,irrigation ditches, military complexes, and the Barbers Point Lighthouse have also been identified (Figure 11, attached). The proposed AIS testing strategy for the O`ahu portion of the project area consists of eight(8) test trenches (BP-01 through BP-08), each measuring 5 m long by 0.7 m wide (Figure 12, attached).Two test trenches (BP-06 and BP-07) target the locations of the two BMHs, one test trench (BP-08) targets the handhole location which interfaces the fiber optic conduits emerging from the BMHs, and the remaining test trenches (BP-01 through BP-05) are distributed along the length of the fiber optic conduit trench.Test trenches BP-06 through BP-08 are proposed as optional test trenches as these specific locations are also part of the proposed AIS testing strategy for the upcoming O`ahu Subsea Cable Telecommunications Project.The HIFL and O`ahu Subsea Cable Telecommunication Projects are being coordinated to maximize use of shared infrastructure to the extent possible.As such,the location of the HDD boreholes and BMHs shown for the HIFL Project is consistent with the corresponding infrastructure included in the O`ahu Subsea Cable Telecommunication Project. Should the HIFL Project AIS testing proceed prior to that of the O`ahu Subsea Cable Telecommunications Project AIS testing,test trenches BP-06 through BP-08 will be excavated as part of the HIFL Project. Should the O`ahu Subsea Cable Telecommunications Project AIS testing proceed prior to the HIFL Project AIS testing,the results of the relevant test trenches will be included within the HIFL Project AIS report. As the O`ahu portion of the project area is located within an area containing a culturally sensitive substrate (coral outcrop),the relative density of AIS test trenches is higher within this portion of the HIFL project area than in areas with less sensitive soils and substrates (Figure 13, attached). Maui Cable Landing Site (Kahului Harbor and UH Maui College) The proposed cable landfall on the island of Maui is located at Kahului Harbor, and the proposed CLS is located at UH Maui College (UHMC) (Figure 14, attached). Project ground disturbance at the cable landfall will include the excavation and installation of a BMH, measuring 23 ft by 17 ft by 12 ft deep (7 m x 5.2 m x 3.7 m),and the excavation of approximately 760 linear ft(231.6 m), at a depth of 4 ft(1.2 m), for the installation of a fiber optic conduit, extending from the BMH to existing utility infrastructure located within the Kahului Beach Road ROW.Within the Kahului Beach Road ROW, during construction activities,a pit measuring 10"in diameter by 8 feet deep will be needed to confirm the depth of the existing Force Main utility. Project ground disturbance at UHMC will include the excavation and installation of a foundation for a CLS (new modular structure), measuring 43 ft by 34 ft by 7 ft deep (13.1 m x 10.4 m x 2.1 m) and an adjacent generator foundation pad,measuring 9 ft by 4 ft by 2 ft deep (2.7 m x 1.2 m x 0.6 m),along with the excavation of approximately 265 linear ft(80.8 m), at a depth of 4 ft(1.2 m), for the installation of conduits for utility connections between the CLS and UHMC existing infrastructure. Previous archaeological studies have identified historic properties that reflect both pre-and post- Contact activities in Kahului.The Maui portions of the HIFL project area are situated in fill land and Puuone sands, and a number of burials in the vicinity reflect the traditional use of coastal sand dunes as a burial area. Other pre-Contact historic properties in the area include subsurface cultural deposits and habitation complexes. Post-Contact historic properties include features associated with commercial sugarcane agriculture and related infrastructure,the development of Kahului Town, and the impacts of WWII (Figure 15). Pacific Legacy completed a field inspection of these portions of the HIFL project area and did not identify any potential historic properties. The proposed AIS testing strategy for the Maui portion of the project area consists of seven (7) test trenches (KH-01 through KH-07), each measuring 5 m long by 0.7 m wide. Three test trenches target the Kahului Harbor portion of the project area and include one test trench in the location of Pacific Page 3 of 41 Legacy Hso pY'MCn am l