WHY THE CAD PROJECT IS NECESSARY

                                                                                  By

                                                                                                  Duffy Duffield

This week the City of Newport Beach was informed that the federal government had approved funding for our dredging project. It took five trips to Washington DC and one virtual trip this year to finally receive the good news. Congratulations to all those who worked to get this done!  

Newport Harbor’s main channels have been federally controlled since 1936. The U.S. Army Corps is responsible to maintain an authorized design depth of 10-20 feet (depending on the particular channel). 

Newport Harbor is actually an estuary with many thousands of acres upstream delivering sediment, vegetation (organic) and trash (inorganic) to the Lower Bay both in dry water flows (no rain, daily runoff) and rain events. 

The U.S. Army Corps and the EPA, along with several other agencies including the Santa Ana Regional Water Quality Control Board and the California Coastal Commission, control the dredging projects in our FEDERAL CHANNELS, therefore the City must comply with their strict rules and regulations. Our harbor has not been comprehensively dredged to its design depth since 1936. In 2012, 600,000 cubic yards of accumulated sediment was removed from Newport Harbor with 130,000 cubic yards deemed “unsuitable for ocean disposal” and barged to a confined aquatic disposal (CAD) site at the Port of Long Beach where it was used as fill and buried. To be clear:  Unsuitable material is not considered “toxic” nor “contaminated” per the stringent definitions of the EPA. There are different criteria for determining whether sediments are harmful to animals in the harbor vs. in the ocean. Our sediments are not harmful to the animals that live in the harbor nor to those that live in the ocean. Because of the large volume of material that we need to dredge, however, EPA was concerned that this larger volume could skew the results so they preferred the safer alternative of keeping the material in the harbor.

Unfortunately, there are no plans in the foreseeable future at the Ports of Long Beach/Los Angeles to expand operations, so there is no opportunity now or in the future to dispose our unsuitable sediment at a remote CAD site elsewhere.   

The City has identified areas within the channels of Newport Harbor where approximately 106,000 cubic yards of unsuitable material still remain – areas adjacent to Lido Island, the peninsula, and along W. Coast Highway. Dredging this unsuitable material using an excavator, then barging to a shore-side processing area (assuming one were available), then trucking to a landfill, would potentially cost at least $21 million and require 8,800 truck trips (assume 12 cubic yards per truck). For many reasons, including the impact of the volume of truck trips within the community and the lack of availability of a shore-side processing area, we cannot truck the unsuitable material to a land fill or a confined disposal facility (CDF) without causing tremendous impacts to our infrastructure and our residents.   

The EPA set a mercury limit of 1.0 part per million for sediment to be placed at the federal disposal site six miles offshore referred to as “LA-3.” Our channels have sediment with mercury values between 1.5 to 5 parts per million in some areas. This is something from our industrial past and not associated with our current watershed best management practices. Because the tests did not show any impacts to the animals, the City negotiated with the EPA an increase from 1.0 to 1.5 parts per million that could be placed offshore resulting in a huge cost savings. EPA agreed with the test results yet they did not have any long term (20 plus years) studies to determine the correct mercury number as a threshold for ocean disposal. The City and the U.S. Army Corps worked feverishly with the EPA to allow a higher threshold for ocean placement, but ultimately, the EPA remained at 1.5. This EPA agreement also required the City develop an overall dredging plan (Sediment Management Plan) for the next several decades – a plan that also included a CAD site. Conversely, if no CAD is developed, then the option to place 1.5 parts per million is not an option and a more restrictive level would be imposed.   

Every day in Newport Harbor, humans and wildlife are exposed to this unsuitable material especially when sediment is stirred whether during natural rain flow events or navigating at lower tides. It is not buried. Rather, this unsuitable sediment sits on top of the harbor floor and can be found in the channels adjacent to private homes and public beaches. We have been living with this material since WWII, and while there have been no human or wildlife health issues as a result, the City would like to move it deeper underground so that we are not exposed to it.

SEDIMENT TESTING

Several aquatic animals were studied while living in the unsuitable sediment (under strict laboratory testing protocols developed by the EPA and regulatory agencies) for weeks and then removed to measure any toxicity or biological effects. All results were negative which means that those same animals were healthy and were not affected nor harmed by the unsuitable material. The tests also focused on the animal’s ability to absorb the mercury from the sediments, and those tests also showed no impacts. 

The living organisms, vegetation and wildlife in Newport Harbor are healthy and flourishing. The 2012 removal of 600,000 cubic yards of material radically improved water quality and resulted in the return of several fish species not seen for decades in the Newport Harbor. Additionally, our eelgrass beds have consistently grown to 112 acres per our most recent 2020 survey – they have not shrunk – proving with evidence that dredging makes a healthy harbor.  

OTHER HARBORS WITH CAD SITES

Long Beach, Port Hueneme, Boston Harbor, New Bedford, Chesapeake Bay, Humboldt Bay Harbor and Baltimore Harbor have implemented CAD sites in which to place their unsuitable material with the approvals from the regulatory agencies including the EPA, U.S. Army Corps of Engineers and U.S. Fish and Wildlife etc. These projects were all successful and are being monitored and measured into the future. 

The CAD method is safe and economically feasible. If we choose not to construct a CAD site, the harbor will continue to have those 106,000 cubic yards of unsuitable material stirred up from the bottom and choking our beautiful and valuable harbor forever. Likewise, we will be prevented from dredging our channels down to their intended depths so that they can be fully utilized now and in the future.