Even in early June, Baltimore public works officials were adamant that the repair of a sinkhole at Lake Montebello would be completed “before summer,” which would have been just a few weeks.

It was a small tweak to the early spring timeline they had maintained since city officials discovered the sinkhole near the water filtration plant almost a year ago. For months, engineers within the Department of Public Works gave the impression the repairs were going mostly as planned, sending periodic updates to city and state agencies with reports of clear and chlorine-free water and a functioning bypass. They also sent external emails to anyone who signed up, including residents, that suggested repairs were running smoothly.

Today, the sinkhole still hasn’t been repaired. In September, the city told The Baltimore Banner the department was going to “move forward on this project in a safe and timely manner” after it ran geotechnical field reports, which investigate soil conditions. Beyond that, the department did not provide further information, so The Baltimore Banner followed up with a public information request for email exchanges among city officials to figure out what is going on.

City officials said Wednesday they now expect work to be completed next spring.

Among hundreds of emails reviewed by The Baltimore Banner were concerns about the stability of the soil that caused unexpected delays, a “mandatory, high-priority meeting” where city officials worried about “losing the lake” due to erosion, and a halt to the repairs for much of July and August.

One city official from DPW’s office of engineering and construction wrote in an early September email to the department’s Interim Director Richard Luna that even a “late fall completion, given the current conditions,” was ambitious. Contractors and officials needed time to review geotechnical reports before they could determine a possible completion timeline and share it publicly, he said.

In a different email thread, one city employee said: “The Montebello sinkhole is not cooperating — not sure if the soil is to blame or if the contractor is a little out of his/her depth (no pun intended).”

The same day the department found the sinkhole, former public works Director Jason Mitchell, who resigned in late April but recently rejoined the agency as a contractor, asked the city’s Board of Estimates for an additional $14 million for an existing agreement with Pure Engineering Services that would help the department assess, analyze and monitor the water main.

The public works department has previously told The Baltimore Banner it would cost $10 million to fix the sinkhole.

Briefing notes obtained in the emails showed the department told the Board of Estimates the sinkhole occurred as a result of a partial failure of an aging stormwater main. As part of this main collapsed, “the soil around it eroded away and exposed an 84-inch water main.” At that point, a timeline for complete remediation was “uncertain,” but city officials said it could install a temporary 48-inch water main bypass, which would allow the department to supply water to East Baltimore and parts of Baltimore County in four to six weeks.

City officials, according to emails from the leading project manager, also collected samples from the sinkhole to review water quality and checked on erosion and sediment control, particularly with the forecast for heavy rains. The water was found to be clear and chlorine-free. By Dec. 14, the bypass was in full operation with no reported issues.

But about two weeks later, contractors from Garney Construction reported the diameter of the sinkhole had gotten “slightly larger” and that “portions of the orange construction fence fell into the void.” The edge of the sinkhole area is about 100 feet away from the edge of lake.

In January, contractors started excavating the site about 15 feet away from the edge of the sinkhole and 15 feet deep, where they would install a “support of excavation”— a temporary “earth retaining wall” that is required to stabilize the site, particularly so that workers can repair the storm drain.

Charlie Wallis, from the Maryland Department of Environment, in one of the emails told Cherod Hicks, the city’s engineer on the project, the description of the sinkhole reminded him of “a piping failure that can be experienced along the spillway of a dam.”

“While this sinkhole isn’t on the dam, it is somewhat close,” he said in the email. “This sinkhole may represent a more expansive problem for the large storm drain.”

“Druid had a similar situation a decade ago,” Wallis continued. “In that case numerous large water main leaks over the years had created sinkholes. It may be that the City should consider a geophysical evaluation of the area to see just how prevalent voids are below ground.”

Before installing the retaining wall, contractors had to fill the sinkhole with “uncompacted soil.”

Heavy rainfall in mid-February caused the weight of the soil to collapse into the “empty space just below,” the water main. The spill halted some work during the week of Feb. 20, leading to a “minor setback.” The city worked with Garney Construction to reduce the amount of sediment entering the stream channel. Still, the repairs were still slated to be completed by early spring.

Come April, an additional failure of the drain “set the project back some,” according to an email from Kimberly Eshleman, director of the Office of Public Health Preparedness. The city now estimated they would complete the repair of the sinkhole by June 1.

“The support of excavation (SOE) is still being finalized,” the email read. “The revised plans are to account for the additional 25 feet of structural failure of the 108 inch brick storm drain upstream of the failure.”

At that time, the bypass was still operating at “modeled performance,” with water levels having decreased “slightly” but still above critical levels. There had been no reported customer impacts of low pressure through the public works department or 311.

James Wallace, at the time deputy chief of Baltimore City Fire Department, called for a “mandatory, high-priority meeting” asking for updates on the sinkhole on July 8. Wallace and Mayor Brandon Scott, who also attended the meeting, were concerned that the city could “lose Lake Montebello” due to the erosion of the soil.

On July 8, contractors discovered that significant soil movement had occurred after digging 15 feet deep as part of the work to build the retaining wall. The soil, the briefing read, moved one inch, then moved an additional three inches. Heavy rainfall in the forecast could have made the soil unstable.

The city placed 20 soil monitors at the maintenance building and the soil mill. While the public works department said there was no reason to be concerned about the water supply, they worried summer storms could cause flooding in nearby intersections, including at 35th Street and Hillen Road.

Construction on the sinkhole was “temporarily suspended” on July 16 for the safety of workers at the site, the facility and the protection of the 48-inch bypass, the emails said. The city decided to wait for geophysical investigations that were assessing soil conditions before proceeding with the repair of the drain. The replacement of the water main was delayed until mid-November.

In August, contractors also identified “a couple upstream sections of pipe” that they intended to replace due to structural cracking. The initial report showed some deficiency “in mass to the west of where the sinkhole has been excavated and benched back.”

The water analyzer’s office has also come up with some contingency plans if the 84-inch water transmission main went down, and it will be activated if they lose the 48-inch bypass. If they do lose the 48-inch bypass, it would impact water pressure in “at least all of East Baltimore.”

The department of public works said in a Oct. 11 statement that the evaluation of the soil concluded in the last week of September.

“Based on those assessments, DPW has drafted a tentative plan to resume soil stabilization efforts in November. Once that phase is complete, the repair of the drains and the reinstallation of the 84-inch water transmission main will commence in January. The agency anticipates the project completion in the Spring of next year.”

clara.longo@thebaltimorebanner.com