Army Corps Explains What is Dredging Placement Area (USA)

“We work with our partners to manage resources and dredging activities in a sustainable manner, one which leaves behind the smallest footprint, while continually seeking ways to reduce, mitigate or eliminate potential negative impacts.” – Alicia Rea, U.S. Army Corps of Engineers, Galveston District.

Q: What is a placement area (PA)?

A: placement area is a federally-authorized disposal site for dredged material.

Each year, the U.S. Army Corps of Engineers Galveston District dredges approximately 30 to 40 million cubic yards of material from Texas channels to fulfill its mission of keeping waterways open for navigation and commerce (benefiting 28 ports handling 400 million tons of commerce annually). As part of the dredging process, the material collected is placed in approved disposal sites or used for other environmentally-acceptable purposes. The most common PAs are confined. Other PAs include semi-confined, unconfined, and beneficial use sites for marsh restoration, in addition to beach nourishment.

Q: What is taken into consideration when establishing a PA? Determining continued use?

A: PAs are established based on both cost and environmental considerations. The Corps identifies the least expensive cost placement alternative that is environmentally acceptable and coordinates development of its dredged material disposal plans with partner state and federal resource agencies. The public is also included in this process (for review and comment) when the Corps coordinates an Environmental Assessment (EA) or Environmental Impact Statement (EIS).

The Corps shares a strong partnership with the U.S. Fish and Wildlife Service, Texas Parks and Wildlife Department, National Marine Fisheries Service, Environmental Protection Agency, and other state and federal resource agencies to deliver innovative, resilient and sustainable services in support of the nation.

Q: How are PA locations determined?

A: The distance from the waterway to the proposed PA is an important factor when selecting a site for disposal, as longer distances increase the overall cost of the project. Once potential sites have been identified and coordinated with partnering agencies, the local sponsor must obtain ownership of the property and/or provide USACE the required real estate easements.

Q: Many PAs have been in use for decades. Are EAs and EISs conducted every time a PA is created or an existing PA is used?

A: All USACE Galveston District projects are executed in compliance with the National Environmental Policy Act (NEPA) – the federal legislation that requires compliance with environmental laws and regulations. As existing projects change and new PAs are needed, new NEPA documentation and coordination is initiated. Once NEPA coordination is completed and the PA is formally designated for dredged material disposal, the Corps does not (and is not required to) initiate new NEPA coordination each time the PA is used.

Environmental compliance for dredging projects requires sediment testing prior to dredging jobs to ensure sediment is not contaminated. While the “rule-of-thumb” is to test each channel segment every five years, the Corps may opt not to test as frequently if previous years’ results indicate no signs of contamination.

Q: Are all PA’s made into beneficial use (BU) projects?

A: The Corps employs environmentally and economically responsible ways to use dredged materials to benefit local communities and improve eroded coastlines through marsh restoration, beach nourishment and other beneficial uses when possible; however, not all material is used beneficially as not all dredged material is suitable for beneficial use. The Corps’ disposal plans require that PAs be established to facilitate disposal of material economically and using the most environmentally acceptable options. When BU placement is not possible due to cost, the Corps seeks cost-share partners including state agencies and non-governmental organizations to use as much material as possible beneficially. Annually, USACE Galveston uses 3-4 million cubic yards of dredged material to benefit Texas coastal ecosystems.

Q: What happens if a new protected species or sensitive natural resource is found in a designated PA?

A: A new protected species or sensitive natural resource found in a designated PA would be considered a “changed condition” that would require coordination with resource agencies. Outcomes of that coordination could result in a change in the use of the PA and/or designation of new PAs. Depending on the outcome, the changes could require development of an EA or EIS to be coordinated with state and federal resource agencies and the public. The Corps continues to work closely with partners and environmental experts to identify alternate methods of disposal while working within its authorized limitations to complete dredging projects and avoid permanent damages to environmental resources.

By Alicia Rea and Carolyn Murphy, U.S. Army Corps of Engineers, Galveston District

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Dredging Today Staff, February 9, 2012; Image: usace