The Problem Of Groundwater And Wood Piles In Boston, An Unending Need For Vigilant Surveillance

The stately rowhouse buildings in many areas of Boston were founded on wood piles in the 1800s. Preservation of wood pile foundations requires that groundwater levels remain high enough to inundate the tops of wood pile foundations. This has become a major problem in some areas of the Back Bay, the South End and Fenway neighborhoods of Boston. Costs for wood pile repair in the last 25 years totals more than $20 million. Old infrastructure and impervious surfaces are primary sources that have been identified as leading to lowering of groundwater. City government has established the Boston Groundwater Trust to measure and report groundwater levels, which now uses a network of 800 observation wells. However, the elevation of wood pile tops is not reliably known. Research is underway to investigate possible use of remote sensing methods. Recharging is also being required at new developments and major renovations, but more recharging needs to be done by individual property owners as well. A program to aggressively search for the causes of lowered groundwater and make necessary repairs to infrastructure and building basements is underway. Much of the ‘leg-work’ has been done by co-op students from the Wentworth civil engineering technology program, who have searched for observation wells, monitored observation well installations, measured water levels in wells eight times a year, investigated recharge systems to replenish groundwater, made numerous grain size tests on fill samples and most recently designed an alternative and far less expensive ‘foundation replacement’ system. The groundwater and wood pile problems are unique in their extent throughout Boston’s filled land areas, which leaves us with a never-ending need for vigilant surveillance in the struggle to preserve these vital foundations for thousands of rowhouse buildings.