Geogrid Retrofit at African Burial Ground National Memorial Is Out of Sight and Enviro-Friendly

A stainless steel fiber-based geotextile was rolled over the ground at the lower Manhattan African Burial Ground National Memorial site in October of 2012 as a retrofit to combat ongoing problems with burrowing rodents. The fabric was secured with spikes, stakes and edging. A layer of soil and sod were the finishing touches.
Photos: GMT, Inc

When construction began on a federal office building in Lower Manhattan in 1991, a 6.6-acre of land between Duane Street and Elk Street was discovered to be a Colonial-era burial site for about 400 Africans, mostly slaves. See April 2010 LASN feature "Lights in the City".

The burials here were from the 1690s to about 1794. Africans could not be buried within the city walls, so a hilly area known as the Kalch-Hook became their burial grounds. Kalch-Hook was the name the Dutch gave to a pond that was lower Manhattan's main source of drinking water before the 17th century, but later became a polluted area. It's believed some 15,000 men, women and children of African heritage were buried in the Kalch-Hook environs between the late 1600s and the mid 1790s. When British troops occupied New York City (Nov. 1776 to Nov. 1783) it's estimated New York City had an African and African-descendant community of about 10,000.

In 2003, Congress appropriated funds for a memorial on the 6-acre site. The design competition attracted more than 60 proposals. The African Burial Ground National Memorial site officially opened February 27, 2006.

Although LASN published a feature on the memorial, we just now learned about a recent retrofit to the site, which is invisible to visitors. To protect these sacred grounds it was necessary to lay a stainless steel fiber-based geotextile (Xcluder Geo from GMT, Inc.) on the ground plane as a long-term solution to form an impenetrable barrier to keep rodents from burrowing.

African Burial Ground National Memorial Team
Architect: AARRIS Architects
Landscape Architect: Elizabeth Kennedy Landscape Architects
Architectural Lighting: Domingo Gonzalez Associates, Nancy Lok, LC, LEED AP
Construction Manager: HRH Construction
Electrical Contractor: B & G Electrical
Engineers: MGJ Engineering