Hyperion 1&5 Outfall Inspections

Ballard was awarded a multi-year contract to supply diving services, Remotely Operated Underwater Vehicle (ROV) services, and vessel services for the Hyperion Wastewater Treatment Plant. The purpose of this project execution was to ensure the proper maintenance was performed on the necessary infrastructure, within and around the wastewater treatment plant.

Scope of Work
The structures consist of a one-mile, five-mile, and seven-mile outfall. The work is comprised of:

  1. Port Identification and Location 
  2. Plugging and/or Puffing Ports
  3. Status of Four Special Effluent Ports
  4. North and South Diffuser End Structure Areas
  5. WYE Structure
  6. Main Barrel
  7. North and South Transition Structures
  8. Offshore Bell Joint Repairs
  9. Epoxy Bumper Joint Separation
  10. Main Barrel Re-ballast Stone Levels
  11. Inshore Bell Joint Repairs

Ballard concludes each service with a draft report for the owner’s review. Once approved, the video of the inspections and associated findings are presented to the engineering team.

Innovative Solutions
During Ballard’s work window, planning around weather to perform all in-water activities was crucial. Ballard’s Safety Manager worked with the Project Manager to establish an “External Variables and Weather Metrics” table that would assist the field personnel in determining if operations were safe enough to conduct. Variables considered were vessel traffic, fog, sea state, currents, tides, wind, and visibility (underwater and topside). Limited visibility also posed a challenge for the project. To mitigate this, Ballard mounted two imaging sonars on the ROV. One was in the “profiling” view to map areas of scouring and spalling in the section view, and one in the “sector” view which is a forward-looking sonar used to navigate around the structure and determine ROV location. An underwater position system was also used to monitor the position of the ROV related to the structure.

The execution of this contract took place in 2010 and every year since this date, there has been work performed on the various sites. The proper inspection and tracking of the condition of these outfalls have ensured that the Hyperion Wastewater Treatment Plant will continue to serve the City of Los Angeles for future decades.

Client: City of Los Angeles
Location: Play Del Ray, CA
Diver Depth: 220ft


• Biological survey
• Cathodic survey
• Light work ROV
• Limited access ROV
• High resolution multi-beam imaging
• Offshore services
• Sonar
• Surface supplied air diving
• Underwater inspection