BALTIMORE — During a hearing Thursday afternoon, Baltimore Department of Public Works officials revealed what they believe are the contributing factors behind an E. coli contamination in the water system earlier this month.
DPW said there were multiple possible contributing factors, including large water mains out of service in the area — one at a massive sinkhole on E. North Avenue — and that the contamination was overall a result of aging infrastructure.
When the sinkhole formed, it exposed a nearly century-old, 48-inch water main, officials said.
For the safety of crews addressing the sinkhole, the main was shutdown. At the same time, a large valve had to be replaced on Kirk Avenue in East Baltimore.
The Vernon Pumping Station at the foot of Druid Hill Park started exclusively drawing water from nearby Druid Lake to serve the impacted area, causing the water level in the lake to drop. Officials grew concerned about the quality of the water and decided to shut down the pumping station, instead using Lake Ashburton to supply water.
In February, a 48-inch water main at the toe of Lake Ashburton was impacted by a separate sinkhole. Since officials were planning to abandon that main once tanks have been installed in the lake, DPW decided to cut and cap the infrastructure and abandon it in place.
Officials believe this reduced the blending and churn in the lake, reducing the levels of chlorine in the water.
On Sept. 5, DPW issued a Boil Water Advisory for parts of West Baltimore and southwest Baltimore County after E. coli and coliform were found in water samples taken at several locations near the Harlem Park neighborhood.
Two days later, the warning was reduced to a 56-square block area of West Baltimore after 24 of 25 tests taken across the city and county came back negative.
On Sept. 9, the Boil Water Advisory was fully lifted after DPW flushed the water system at 100 locations.