Work crews have at least two more months of sewer and street repair ahead of them near the intersection where a giant sinkhole had opened up on the East Side.
The massive hole opened May 9 near Phalen Boulevard and Johnson Parkway. Metropolitan Council Environmental Services, which operates the regional wastewater collection and treatment system, plans to update nearby property owners this week about their progress.
A legislative aide in city council member Dan Bostrom’s office said calls from concerned residents dropped off in late June, when the Met Council partially reopened the intersection. The repairs also released some odors, which have diminished.
The regional sanitary sewer pipe, which was installed in 1989, carries 12 million gallons of sewage daily from as far north as Forest Lake to the Metropolitan Wastewater Treatment Plant on the east side of the Mississippi River, across from Holman Field, St. Paul’s downtown airport.
An initial inspection found severe corrosion along the pipe bordering Prosperity Avenue. The top of the 54-inch diameter pipe had collapsed, causing soil to cascade about 25 feet down from street level.
In addition to the 30-foot-long sewer break, crews soon discovered that 2,000 feet of sewer to the north and south showed various degrees of corrosion.
About 150 feet of sewer at the sinkhole site has been replaced, according to the report to property owners, and another 380 feet has been outfitted with a new lining.
The existing pipe under Prosperity will receive a new lining.
Crews will install a new manhole in front of 1008 Prosperity Ave., which is closed to traffic. Residents to the north can reach their homes from Magnolia, and those to the south have access from Ames.
Crews will also be cleaning sinkhole soil and sewer debris that has collected in the bottom of the sewer, and they’ll be restoring the affected street and landscaping in the area.
Residents should watch for parking restrictions, some late-night or 24-hour operations and construction equipment. The curing of the new sewer liner may cause a resin smell on top of some sewer odor related to the repairs. Property owners are being asked to make sure there is water in all of their drain traps to help contain odors in underground pipes.
“It was a sewer designed to have 100 or 125 years of life expectancy, and when you get 25 years out of it, that’s a little disappointing,” Bostrom said.