The U.S. Army Corps of Engineers and the contractor for the new lock at Sault Ste. Marie, Mich. say blasting activities needed for project construction are set to start later this month, and precautions are being put in place to protect ships, boaters, the general public and even certain species of fish.
The Corps of Engineers, Detroit District, contracted Kokosing Alberici Traylor, LLC (KAT) to complete Phase 3 construction of the New Lock at the Soo.
The work includes excavation and installation of a shaft and tunnel scheduled for this year, the Corps of Engineers said in a news release.
“The project team will blast as the means to fracture the existing bedrock to be excavated and removed,” Rachel Miller, the New Lock contracting officer’s representative said.
“All blasting will be completed within the Corps of Engineers Soo Locks facility on the island north of the existing decommissioned Sabin Lock.”
Blasting activities will take place from late July through the remainder of the year on a semi-regular basis, according to the release.
The release states that the contractor is permitted to conduct blasting Monday through Sunday during daylight hours (sunrise to sunset). The Corps of Engineers said it did not anticipate blasting to be conducted on any Sundays at this time.
“For 2023 blasting activities, the Corps of Engineers does not anticipate impacts to any public roadways or land areas outside of the Soo Locks facility,” Mick Awbrey, New Lock chief said.
“However, each blast will be evaluated to ensure the safety of the public. During blasting, guards will be posted at all access points to ensure no persons will be allowed within 300 feet of the blast radius.”
Marine traffic on the St. Marys River will not be allowed within 1,000 ft. (about 300 metres) at the time of any blast detonations for recreational boats, fishermen, swimmers, and the "general waterborne public".
Red Flag Vessels, transporting bulk fuel or other hazardous materials, will not be allowed within 2,000 feet (about 600 metres) during blasts. All exclusion zones are coordinated with the Soo Locks Lockmaster as well as the U.S. Coast Guard.
“Prior to blasting, an airhorn will be sounded five long times indicating that the blast will occur in five minutes. At one minute before a blast, an airhorn will be sounded five short times. Then the blast will be detonated.”
After the detonation the "master blaster" will confirm the completion of the blast and give the ‘all clear’ consisting of one long sound from an airhorn or siren, according to the engineers.
“The New Lock at the Soo construction contract includes measures to monitor and control vibrations due to blasting,” Hal Harrington, Detroit District Biologist said.
“Two fish species use the tailrace area directly north of the blasting location for spawning – Atlantic Salmon and Lake Sturgeon. The vibration monitoring locations and limitations on peak particle vibrations for the contract have been restricted to account for these spawning areas.
The contractor is required to design and control all blasts to meet a maximum PPV of 1 inches per second at both spawning locations. This limitation is specifically in place to prevent negative impacts to fish.”
The Corps of Engineers said the goal during New Lock at the Soo construction is to “minimize or eliminate negative impacts to the community and other affected parties”.
The safety measures being enacted to clear marine vessels within the affected areas will be applied immediately preceding and during blasts. Additionally, there will be no permanent explosive storage or overnight explosive storage on site at the Soo Locks facility, the release states, adding that, “The safety of all accessing the waterways is a priority.”
A public meeting about the blasting will be held in the Superior Room of Lake Superior State University, 650 W. Easterday Ave., Sault Ste. Marie. The public meeting is scheduled from 6 to 7 p.m. Monday, July 10.
Those who prefer to attend virtually can join the meeting at NewLockattheSooTeams.
A slideshow presentation will be briefed by the Corps of Engineers as well as KAT’s blasting specialist, blasting consultant, and vibration specialist. The presentation slides will be made available after the public meeting at this link.
After the presentation, the public will have the opportunity to ask general questions about their concerns dealing with the blasting operations, “magnitude of seismic motion, airblast overpressure, and potential for flyrock debris”.
Additional blasting activities in the chamber of the existing decommissioned Sabin Lock are scheduled for the 2024 spring-summer-fall construction season.
These blasting activities will differ in scope and location from the shaft and tunnel blasting but will implement many of the same mitigating measures.
The Corps of Engineers will provide additional notice related to the lock chamber blasting approximately 30 days in advance. To find more information on the New Lock at the Soo, visit the Corps of Engineers Detroit District website.
- SooToday
