What you should know about archaeological finds on construction sites

Updated Jan 2, 2016

The recent discovery of long buried crypts during a routine water main replacement project in New York City’s Washington Square Park should serve as a reminder to developers and their contractors that a review of archaeological records should be an important part of their due diligence prior to beginning construction, according to CBRE Valuation & Advisory Services group.

Archeological finds during construction are not uncommon, especially in urban settings where over 500 years of American history and thousands of years of Native American relics may lie buried a few feet below the surface.

In the U.S., builders are obligated to report archaeological finds if the project requires a federal, state, or occasionally local permit, license or funding that triggered compliance with historic preservation laws, according to Cris Kimbrough, PhD, PMP, and archaeologist and Managing Director at CBRE Telecom Advisory Services. If archaeological resources are identified during construction/development for a project that has gone through the federal/state/local historic preservation process, all work must stop until further preservation measures can be determined and completed.

There are few rules governing artifacts that are encountered on private land because U.S. law is very much focused on the protection of private property. As a consequence, artifacts located in areas where no historic preservation rules are in place are at risk. This does not apply to human remains, however. Human remains always have to be reported to the local authorities and treated appropriately.

In the case of the Washington Square project, the crypts were covered up and the water main project will be re-routed around them.

The State Historic Preservation Office (SHPO) maintains records on identified archaeological resources in each state. In addition, museums and colleges/universities may also have records, but these are most often registered with the SHPO or held in lieu of SHPO archaeological files. These files are not accessible to the public and can only be viewed by qualified individuals—usually a qualified archaeologist or other historic preservation specialist.

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Most states have a project review process wherein staff at the SHPO reviews the project plans and their files to determine if there are any potential direct or indirect impacts to historic and archaeological resources. If there are, SHPO may request archaeological or other studies be completed prior to construction. Native American tribes also maintain archaeological and other Traditional Cultural Properties (TCP) records, but access to these files is almost always restricted. Tribes are consulted regarding their cultural resources as part of the federal historic preservation process, and most state preservation processes.

If artifacts are discovered as part of the pre-development review process, then additional archaeological surveys may be required. The federal process dictates that impacts to historic and archaeological resources should be avoided, minimized, and/or mitigated—in that order.

With telecom projects, which make up the bulk of Ms. Kimbrough’s investigations and are usually quite small, carriers are usually asked to move the tower site if artifacts are found. In the rare, although increasingly more common instance that this is not possible, an additional survey is usually completed to better understand the archaeological resource in question and suggestions are made for moving forward with the project as is or minimizing the effects of the project on the resource. If significant impacts to the archaeological resource cannot be avoided, then the impact on the resource must be mitigated. This mitigation is often in the form of extensive excavation, data analysis, public outreach, etc. will likely have to be employed.

“Developers often talk about losing a project to SHPO, but often it is just a matter of working through the process and being creative,” says Kimbrough

Archaeological due diligence is usually not a part normal Phase I or Phase II Environmental Site Assessments. Builders should be aware of federal/state/local historic preservation laws and comply. An initial project review with the SHPO, when required, involves hiring qualified environmental and cultural resource management consultants who understand at a high level what the applicable historic preservation processes are.


Editor’s Note: This guide provided by CBRE Valuation & Advisory Services.