Lagoon Dewatering Set to Start as Soon as Final Test Results Are In
• Indemnification Agreement Between State Parks and City Ready for Council Ratification on July 23
BY SUZANNE GULDIMANN
Initial testing is reportedly almost complete and the dewatering phase of State Parks Malibu Lagoon Restoration and Enhancement Plan is expected to begin as early as Wednesday, after the Malibu Surfside News goes to press.
The City of Malibu received a response from California Coastal Commission staff on July 9 to a letter outlining the city's dewatering plan concerns.
"Your letter raised several concerns about the details of the dewatering plan, including concerns regarding the adequacy of the seepage rate calculations and the water storage capacity of the temporary basins used to contain the lagoon water that will be treated prior to discharge to the Pacific Ocean in compliance with the National Pollutant Discharge Elimination System Permit approved by the Regional Water Quality and Control Board," the CCC letter states.
"In response, we note that the seepage rate calculations, storage basin capacities, and pumping rates estimated in the dewatering plan were prepared and analyzed by the project engineers in order to ensure that holding capacity within the basins is adequate…in the event that unexpected conditions are encountered in the field that result in the need for increased capacity, the applicant would be required to sumbit revised plans for the review and approval of the executive director, to additional treatment filtration system components to handle pumping rates or add additional capacity to the storage basins."
The CCC staff letter dismisses concerns raised by the city regarding the potential for tidal flows or surges to impact the dewatering outflow. "The pipeline will be located outside of the surf zone and is not expected to be acted upon by wave action," the letter states. "The water filtration system and dewatering operations will be continually monitored during dewatering operations by the applicant and/or project contractors to assure the system is operating properly and the discharge pipeline does not become dislodged."
CCC staff rejected the city's request for twice daily testing at the discharge site if "disinfection monitoring results exceed the previous day's monitoring results." The letter states "In this case, the approved dewatering plan provides that the applicant will perform daily testing requirements for several constituents. Moreover, the testing frequency meets all NPDES permit requirements."
The CCC letter states that alleged "new" project components, including a plan to place portions of several mature sycamore trees removed during the demolition phase of the project "on channel slopes along the eastern lagoon edge" is not a new project activity, "but was identified and discussed in the staff report for this project and was approved by the Coastal Commission on October 12, 2012."
Project critics have stated that they are concerned that the logs, intended to provide "fish habitat and erosion control" have the potential to end up in the surf zone during winter storm floods, creating a potential hazard for surfers and property.
The city will, however, be indemnified by State Parks for the dewatering portion of the project. A report prepared for the city council by Malibu City Manager Jim Thorsen states that the indemnification agreement has been negotiated and will be ready for ratification at the July 23 council meeting.
The report states that the "mitigation and monitoring requirements may not fully reduce the risks associated with the release of harmful pathogens to a level of insignificance…failure to meet water quality standards in the creek and lagoon could subject the city to enforcement activities and financial penalties from the state or Regional Water Quality and Control Boards, and lawsuits from private citizens who are also authorized under the Clean Water Act to enforce the provisions on the NPDES permit."
The agreement "provides that State Parks will indemnify the city for impairment to the quality of water that is discharged from the outlet pipe of the filtration system that State Parks is operating as part of the Lagoon Project."
Members of the surfing community have repeatedly questioned whether the dewatering plan would be adequate to treat bacteria, including MRSA, that could potentially exist in layers of sediment at the bottom of the old lagoon channels that are being drained and dredged.
While some lagoon critics have indicated that they are encouraged that the revised dewatering plan appears more robust than the initial concept others continue to call for additional testing, including impartial third-party monitoring.
The dewatering plan and the indemnification agreement are available online at www.malibucity.com