Nearly 100 dump trucks would make its way through Ridgewood each day for nine months, while homes around the hospital could have their foundations crack as a result of a doubling of Valley Hospital, a geotechnical expert testified Monday night at the latest council "H-Zone" expansion hearing.
Laurence Keller, of Whitestone Associates, told the council he had concerns with what he considered a major excavation project. According to plans presented to the planning board, workers would excavate 17 feet below ground water, displacing 500,000 of gallons of water each day that would require bedrock removal and on-site shoring.
"It's certainly been done before and it's certainly been done many times," Keller said of the project. "Is it extraordinary? It's not over the top, it's certainly been done...it's just a challenge."
It could be a challenge to property owners nearby as well, potentially impacting up to 400 homeowners. Because of the removal of water from the site, runoff could crack the foundations of homes within an estimated 1,000-1,500 foot radius, Keller said.
Residents nearby may not be able to build in-ground pools or additions to their homes as a result, he said prompted by Mayor Keith Killion's question. The project also has the potential of affecting aquafiers serving the area and could strain the current stormwater infrastructure, Keller said.
"My concern with the water, my challenge with the water, is the amount of it," the expert stated. "It's 500,00 gallons per day. It's a lot of water to tax any system, it's a lot of water to draw from somewhere else. When you start to pool water from that far an area, from that big a radius, you start to have concerns – are there spills, is there contamination you pool in across property boundaries?"
Under the plan presented, Keller said pneumatic blasters used to chip away at bedrock would be "very loud" and may potentially impact learning environments at B.F. Twelve trucks an hour could compound the issue, he added.
Asked by Councilman Paul Aronsohn to rate the project on a one-to-ten scale, Keller rebuffed. The challenges, he said, are "universally consistent" with below-grade construction. "Is it a red light, green light or yellow light? I'd give it a yellow light," he said.
Keller recommended "a mechanism to address problems before they occur" with safeguards and action plans, something Valley reps agreed with.
"We have taken seriously the considerations Mr. Keller raised and moved on with refining the design to minimize the impacts," Valley Hospital VP of Facilities Maria Mediago said. Mediago said a thorough developer's agreement would address the minutia, adding that the hospital buildings are closer than residential properties to the potential groundwater concerns, so the hospital would be wise to take great care.
Mediago remarked during public comment that between the months of April and August 2010 the water level had actually dropped three feet. She also stated all pits and excavation sites "would all remain on Valley property," refuting the possibility easements onto residential properties would be needed.
Still, opposition group the Concerned Residents of Ridgewood (CRR) was unimpressed. Attorney John J. Lamb said the technical nature of the Monday meeting proves the best forum would have been the Board of Adjustment, not the council.
"The geo-technical expert stated that many questions remain unanswered," CRR president Pete McKenna said in a statement. "I must say that as a citizen of this planet I'm concerned that the Planning Board would approve something this outrageous in size and scale and not know what the impact on our vital water resources will be."
The next meeting will be November 3 at the RHS Campus Center.