Some Manhattan and Bronx residents are raising concerns about their drinking water, following a decision by the city’s Department of Environmental Protection to temporarily switch select neighborhoods’ water source. [Update, October 15: The New York City Department of Environmental Protection has stopped distributing water from the Croton Watershed to city residents—for now; see more details below.]

Nearly 175 Manhattan residents, mostly congregated near Gramercy Park and Harlem, have lodged complaints with the DEP since October 1, a substantial increase from the preceding months. 89 Bronx residents have made water quality complaints as well. Many have reported a “musty” or “stale” taste, while others have said they noticed a moldy odor.

Comparatively, only 38 people from Manhattan called 311 to complain about their drinking water in the entire month of September, according to the city’s open data. In the Bronx, 20 complaints were made last month.

Other data from 311 complaints on October 1-8 2018, complaints about any water quality per borough: - 76 in Manhattan, 56 in Bronx, 24 across other 3 boroughs. Clusters in Gramercy/PCVST, Harlem, Marble Hill. @TheTandV, @evgrieve see https://t.co/d6gJwWel1u pic.twitter.com/iauGOGuBcV — Jonny Garf (@JonnyGarf) October 11, 2018

“It smells and tastes like mold,” said one resident of Peter Cooper Village, who asked to remain anonymous. “Every once in a while your water has a bleach sort of smell to it, or if you’re used to hard water it’s like a metallic taste, but it’s not like that at all. It’s really very much like mold.”

The resident said she has a 7-year-old child, and that they’ve switched to drinking bottled water until the problem is resolved.

But according to the city’s Department of Environmental Protection, the issue is nothing to worry about. The change in smell and taste can be traced back to a change in water source and increased run-off from recent rains, said DEP Commissioner Vincent Sapienza.

“When we get heavy rains, there’s run-off from the watershed lands into the reservoir,” said Sapienza. “And that’s most likely the reason for that earthy taste.”

The DEP also decided to transfer some neighborhoods over to a mix of water from the Croton and Delaware Watersheds this month in order to temporarily shut down the Catskill Aqueduct for repairs. This 10-week shutdown will be the first of three before the Delaware Aqueduct is closed for several months for repairs in 2022, according to Commissioner Sapienza.

While the Croton System normally accounts for 10 percent of the city’s drinking water, the DEP says that percentage is set to increase to between 20 and 30 percent during the Catskill Aqueduct repairs.

DEP insists that the change in water source does not mean the water is unsafe to drink, clarifying that the “earthy/salty taste that people may be experiencing is a chemical change in the water, but not one that poses any threat to health,” according to a statement sent to local elected officials.

The changes in taste could also be attributed to the difference in the “geology around the Croton system,” the statement reads, which “allows the water to pick up more naturally-occurring minerals.”

Residents are being transitioned to the Croton-Delaware mix in anticipation of the Catskill Aqueduct shutdown scheduled for later this month, according to DEP spokesman Edward Timbers. He expected that residents will soon get used to the combination of water from the Croton System and the Delaware Watershed.

For local officials, receiving constituent complaints about water quality was unexpected. Spokespeople for local City Council Members, State Assembly Member Harvey Epstein, and Community Board 6 said DEP notified them of the change in water source only after they asked the DEP about the complaints.

“[What] concerns the Councilwoman most about this situation is that community concerns could have been more effectively addressed if elected officials and neighborhood leaders were notified of the situation prior to this change in water source,” said Jeremy Unger, spokesman for Councilwoman Carlina Rivera.

Instead, he continued, their office heard about the issue “from worried constituents who are noticing changes in the taste of their water.”

In a statement, City Councilmember Keith Powers said, “In the last week, I have been contacted by dozens of residents who reported changes to water that included odor, taste, and consistency. Those changes caused obvious concern for those who have experienced them. We have been in regular contact with the Department of Environmental Protection to ensure that the water is safe and regularly tested. However, I still believe it would be best to conduct additional testing to the water to relieve any outstanding concerns."

The DEP was not expecting to hear this many complaints, said Commissioner Sapienza, which is why locals weren’t notified beforehand.

“All of our analyses that we’ve done, and again, we do thousands of them every day, have come back that the water is safe to drink,” said Sapienza.

New York City boasts some of the best drinking water in the country, much of which has been allowed to go unfiltered by the Environmental Protection Agency. Unlike that water from the Catskills/Delaware Watershed, Croton water is filtered by the Croton Water Filtration Plant, which opened in 2015.

Update, October 15: The New York City Department of Environmental Protection has stopped distributing water from the Croton Watershed to city residents. That's after WNYC and Gothamist reported hundreds of locals in the Bronx and Manhattan said their water was tasting and smelling like mold.

Officials said Friday that the taste was the result of run-off from recent heavy rains, and insisted the water was safe to drink. But the department decided to stop using Croton Water over the weekend. A spokesman would not say what influenced the policy shift, but said the department plans to put Croton water back into distribution soon.

City data shows more than 200 residents in Croton distribution areas complained about their water in October, a drastic increase from proceeding months.