Seawater Intake Remediation

Situated within a national marine sanctuary along the Pacific Coast, Power Engineering Construction's ADCI-certified dive team, supported by topside crew, dive vessels, and construction barge, upgraded the structural support system of two 950-foot-long parallel seawater intake pipelines.

The seawater intake system is two parallel 16-inch diameter High-Density Polyethylene (HDPE) pipes extending 950 feet offshore, initially supported by concrete blocks placed at 15-foot intervals on the seabed. With varying levels of age deterioration of the existing support system, a comprehensive renovation became necessary to ensure the continuous and sound operation of the system while maintaining its minimal ecological footprint.

Divers utilized a two-pronged approach, each determined by seafloor geology. In the Surf Zone (5 to 20 feet below sea level) and Intake Zone (55 feet and deeper), concrete block supports were retrofitted with stainless steel brackets that secure them to the seabed. In the Sand Zone (20 to 55 feet below sea level), concrete blocks were replaced with socketed pipe-and-beam support systems designed for the sandy seabed's stability and long-term reliability.

The project adhered to rigorous marine protection regulations and included continual surveillance, observation, and monitoring, ensuring the protection of marine life without any environmental incidents.

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