International Dredging Review

International Dredging Review

The environmental and health disaster that is the Caño Martin Peña is slowly marching toward resolution.

The approval process for the dredging of the channel which runs through the heart of San Juan and which has plagued the capitol city for decades should be complete by the end of 2015 making way for a $150 million commitment from the U.S. Army Corps of Engineers to finally begin addressing the problem.

That funding will go part of the way toward improving the situation in Caño Martin Peña but there is still a shortfall for a complete recovery.

The Caño Martin Peña is an estuarial channel that connects the San Juan Bay home to Puerto Rico’s primary port and series of lagoons that ring the city. It once was a yawning navigable waterway 400 feet wide in some places and 10 feet deep. Its problems began as the city’s population boomed in the early 20th century. Poor and working class people were directed to build along its banks and the channel became a receptacle of trash and raw sewage. Soon land reclamation had reduced the waterway to a relative trickle of around 33 feet wide and three feet deep which is how it remains today.

That downsized flow devastated the mangrove forests that once covered the channel and the fauna that lived there. The restricted water flow impacted other parts of the San Juan Bay and lagoon system and water quality suffered. Puerto Rican publications have reported that thousands of fish periodically die in the waterway because something obstructs its already poor circulation oxygen runs out and the fish suffocate.

Human health has also suffered: water samples from the channel show two million fecal coliform colonies in 100 ml samples or about 10000 times higher than the standard. This and other contamination correlates with a much higher level of sick people in the area: 31 percent of the people living in the communities around the channel suffer gastrointestinal problems nine percentage points higher than the general population. And young children living near the channel have more than twice the risk of developing bronchial asthma as their peers elsewhere on the island.

As these problems emerged and their link to the channel became clear local activists began advocating for the dredging of the channel. A public corporation Proyecto Enlace del Caño (Enlace) was formed to coordinate the cleanup and development of the area. They began lobbying for help from the U.S. Army Corps of Engineers with the hope of restoring the channel to a 100-foot-wide 10-foot-deep waterway. This would require not only substantial environmental dredging but also relocating hundreds of families and several major pieces of infrastructure including a bridge and several water sewage and power lines.

In the 1980s a $20 million dredging project along the western half of the channel was conducted removing 1.3 million cubic yards of dredged material and depositing it in an offshore placement site. This created a 200-footwide and 10-foot-deep channel for a public transportation project. But the relocation of families was poorly handled and is believed to have further impoverished the people who were moved from their homes which generated anger and a skepticism of the new dredging project years later. However Enlace has worked for over a decade to convince the public that the next project will be better managed and not have the same pitfalls as its predecessor. Through hundreds of public meetings it has slowly garnered public support for the project.


But the real logjam in the project has been getting it through the U.S. Army Corps of Engineers approval process. Enlace was tasked with funding and overseeing a feasibility report and declaration of environmental impact report that met Corps of Engineers standards; the Corps had to approve those documents in order for the $150 million in congressionally appropriated funds to be allocated.

The environmental impact statement (EIS) evaluated 10 project alternatives including channel widths of 75 100 125 150 175 and 200 feet and depths of 10 and 15 feet. A peer review of the draft feasibility report and EIS was conducted by Battelle Memorial Institute for Enlace and completed in December 2013.

“We’ve been working with the U.S. Army Corps of Engineers for several years now on this and basically the itinerary is to make sure the feasibility study is finished at least by the end of the year so we can begin preconstruction engineering” Enlace Executive Director Lyvia Rodriguez said.

Asked why it’s taken so long Rodriguez laughs.

In 2007 Congress conditionally authorized $150 million to dredge the Martin Peña. But that money was conditional on the Corps of Engineers approving the project – which required a feasibility document. However the $150 million that Congress had approved did not include any funding to evaluate the feasibility report in order to approve it.

This wasn’t resolved until 2012 when Enlace finally gave the Corps $350000 so it could review the report Enlace had provided them with. Since then progress has been made toward approval. There are seven different stages for approval Rodriguez said. “We’re in the fifth stage” she said. She anticipated that the final EIS will be published in the federal register by the end of July after which there will be a public comment period and final review. Then the final package will be prepared for the Secretary of the Army.

The next phase will be to execute the project partnership agreement with the Corps at which point the funding that was approved in 2007 will be allocated – and perhaps more if the local government gets its wish.

Early this year Puerto Rican governor Alejandro Garcia Padilla asked the U.S. government to underwrite the entire cost of the project which is anticipated to be $600 million. The Puerto Rican government had already spent $100 million over the last decade to restore the channel he argued and the federal government should come up with the rest. The commonwealth government has been facing its own financial crisis in recent times and has enlisted the help of members of Congress from other states to vote to fund the project.

Much work has already been done on the project. In 2007 a low bridge that would not have allowed dredging was replaced with a higher one by the Puerto Rico Highway Transportation Authority. This year the Puerto Rico Electrical Power Authority completed raising a 115-kilowatt line. And relocations of a sewer trunk and two water distribution lines that cut through the Caño are also funded and underway.

The major piece that has yet to be substantially addressed is the relocation of families. Over the last 15 years about 500 families have been relocated but about 320 other families live within the footprint of the project and must be relocated for this project. Thousands of other people live immediately around the project and will also eventually be relocated.

When the dredging does begin moving forward Enlace officials say that a company would be contracted to employ small clamshell mechanical dredges and barges to remove about 825200 cubic yards of material. About five to 10 percent of that material is believed to be large waste – dumped cars and stoves and other items that will be taken to the landfill or a recycler.


The rest of the sediment will have to be handled carefully because preliminary testing showed that the dredged material is heavily contaminated. That material could be relocated to other sites within the estuary including into several “artificial depressions” in nearby lagoons and channels that were created decades ago and which create unhealthy anaerobic conditions in the lagoon. These pits could be lined like a landfill then filled with dredged material and then capped and covered with sand and finally planted with mangrove forest. Depositing the dredged material into the depressions could solve both the problem of what to do with the contaminated material and the problem of the anaerobic pits.

The dredge would have to be relatively small due to the shallow water and low bridge clearances and would switch between an open bucket to excavate trash and an environmental bucket to excavate contaminated sediments. Sediments believed to be contaminated would be placed within shallow-water dump scows fitted with metal sieves to separate trash and debris from dredged material. That trash and debris would wind up in the landfill while the rest would be transported to the disposal sites. That grading would be performed using the dredge equipment as well as land-based excavation equipment.

In January Katia Aviles-Vasques environmental affairs officer for Proyecto Enlace told IDR about the specifics of the project: “The preferred bulkhead is a sheet pile cantilevered wall with no tie-backs and a concrete cap. That sheet pile could be installed with a vibratory hammer and a diesel steam or hydraulic pile hammer for sections of sheet pile that may not be able to be driven completely to the required tip elevation” she stated. “During dredging operations temporary slope angles would be maintained until the installation of the sheet pile. In support of the project’s goal of wetland (mangrove) restoration the channel cross section includes grading both the sides of the channel to permit the creation of habitat for mangrove planting.”

This process of disposing of the dredged material is expected to be among the most expensive parts of the project according to the peer review ranging (depending on the final option chosen) from $15 million to $53 million.