New York's Statue of Liberty gets full trenchless treatment31 July 2015
Home to America’s most beloved statue, one of the country’s most popular tourist destinations, New York’s Liberty Island, will receive trenchless treatment to upgrade its water and sewage lines.
The new design will use Horizontal Directional Drilling (HDD) to install 731 metre long water and sewer lines through the bedrock of New York Harbour. More than 900 metres of water pipe and almost a kilometre of sewer force main will be installed using pipe-bursting techniques within Liberty State Park.
Engineering firm Hatch Mott McDonald (HMM) began working on the project in 2012, designing replacements for the existing water and sewer lines that were last updated in 1997.
HMM performed eight geotechnical borings to determine the quality of bedrock, recommended the use of conductor castings on each end of the HDD crossings and designed temporary systems to maintain service during construction.
Unlike usual trenchless operations, the project is particularly challenging due to the limited construction area on the island and the costly risk of any problems encountered. With more than four million paying visitors each year, HMM along with Liberty State Park and Liberty Island have done well to keep the Island open for business and maintaining visitor access during construction.