Testing for fecal bacteria in Baltimore’s harbor and its watershed showed dramatic improvements last year, but scientists are unsure why the improvement happened.
The test scores were revealed in the Harbor Heartbeat report, replacing the annual Healthy Harbor report and reconstituted to focus on what has been done to improve water quality alongside the scores of the harbor’s health.
“The goal was to be able to look at the input into the system as well as the output,” said Adam Lindquist, director of the Waterfront Partnership’s Healthy Harbor project. “We want to know, are we fixing our sewer pipes, are we fixing more sewer pipes than we were before.”
The new report found that the amount of fecal bacteria in the water at 32 of 49 testing sites had improved from the year before, in some cases by as much as 100 percent.
But the reasons for the improvement were not obvious and Lindquist cautioned that more data would be needed to find out whether this finding was part of a trend or just a one-year blip.
Fecal bacteria levels can help determine whether water is safe for swimming and other human contact. It can turn up in waters after sewers overflow or break and from pet waste.
But while 2017 saw less rainfall than previous years, scientists ruled that out as a cause of the decrease, Lindquist said.
“We certainly have reason to believe (the decrease) is a larger trend,” he said. But, “We cannot say scientifically that these improvements are tied to any one particular (effort).”
If the fecal bacteria levels decrease is part of a trend, it could be part of Baltimore City’s efforts to improve sewage infrastructure as part of a consent decree between the city, the state department of the environment and the Environmental Protection Agency. Overall, the city will spend more than $1 billion on sewer projects.
Advocates hope that combining data with what has been done to improve water quality alongside measurements of the water’s quality will help show that there are efforts underway and that those efforts can lead to improvements.
As an example, the harbor’s trash wheel, affectionately called Mr. Trash Wheel, has collected 1.5 million pounds of trash, but the annual haul decreased last year. During the same period, the city rolled out new trash cans for residents and stepped up its street-sweeping efforts, limiting the amount of trash that would ultimately end up in the water.
“I want people to see the progress that’s being made and to have hope for the restoration of the Baltimore harbor,” Lindquist said. “The goal is to make sure that everyone knows that substantial work is being done.”
On the other hand, the report could also show where more work will be needed to make improvements.
Restoration projects such as rain gardens, tree plantings, asphalt removal, stream restoration, native plantings and even oyster reefs can help reduce pollutants in the water, including phosphorus, phosphate and sulfate pollution.
To improve those conditions there should be about 240 acres of restoration a year, but last year there were only 40 acres of restoration projects.