Microtunneling under Hudson Bayou underway

Work to take four weeks, from 7 a.m. to 7 p.m. on weekdays and from 9 a.m. to 7 p.m. on Saturdays, city staff says

An aerial view shows neighborhoods along Hudson Bayou in Sarasota. Photo from Google Maps

The Lift Station 87 contractor has begun microtunneling under Hudson Bayou, the City of Sarasota announced on Jan. 30.

“This much-anticipated work” involves installation of segments of a 36-inch wastewater main under Hudson Bayou and Luke Wood Park “and is critical to the success of the Lift Station 87 project,” a city news release explains.

The microtunneling operation under Hudson Bayou is expected to last four weeks, the release notes. The contractor will work from 7 a.m. to 7 p.m., Monday through Friday; and from 9 a.m. to 7 p.m. on Saturdays, the release adds.

“This is where the rubber meets the road,” said Sarasota Utility Director Mitt Tidwell in the release. “We scheduled this work first to protect the city’s investment and minimize risks,” he added in the release. “Our microtunneling expert, Staheli Trenchless, is on site, and we look forward to completing this crucial phase of work.”

“Microtunneling is a specialized trenchless construction technique for installing pipelines under waterways, wetlands and roadways,” the release points out.

Crews launched the microtunnel-boring machine from a 30-foot-deep shaft on the south side of the Osprey Avenue bridge, the release continues. The contractor works from a control room to guide the machine to a tunnel shaft north of the bridge and to monitor all facets of the operation, the release says. After microtunneling under Hudson Bayou has been completed, the release continues, the machine will be placed in a 30-foot-deep shaft on the Lift Station 87 site, and it will be guided westward to the shaft on the north side of the bridge.

“The heads on the end of the boring machine cut through the earth, which is removed as the tunnel is created,” the release explains. The microtunnel-boring machine advances 20 to 40 feet per day, depending on underground conditions, the release adds. As the tunnel is created, a 60-inch diameter protective steel casing is put in place.

The new wastewater main will be installed after the tunnel —approximately 8 feet below the bottom of Hudson Bayou — has been created, the release adds.

Microtunneling under Hudson Bayou and Luke Wood Park is scheduled to be completed in June, the release points out. Work on Lift Station 87 is planned to begin in July.

Lift Station 87 will replace Lift Station 7, which is located at 935 Pomelo Ave. Once the entire project has been completed, wastewater flow will be redirected from Lift Station 7 to Lift Station 87, the release notes.

For more information about the Lift Station 87 project, go to www.liftstation87.com or call the project information line at 941-356-8071. Interested parties also may subscribe to email updates at www.egovlink.com/sarasota/subscriptions/subscribe.asp.