Dirty Yellow Water in South Slope

Yuck:

On Brooklynian, 8thandprez (no longer at 8th and Prez) reports discolored/yellow tap water in South Slope for the past week or so (cold water only): “It’s happening to all of the units in our apt building.”

There are a couple of possibilities here:

• A pipe that is corroded and needs to be replaced. Since it’s only the cold water, the the problem could be somewhere in the supply line.
• Work on a main sewer line is leading to the discoloration.
• Someone is peeing in the water.

Other reports of yellow/discolored water are coming in from Sheepshead and another Brooklynian at the corner of South Slope/Windsor Terrace; and yet another at a condo in North Slope. 8thandprez has called DEP and hasn’t received any response yet. Anybody have a more detailed knowledge of this subject? If so, drop some science here: Discolored/yellow tap water – South Slope? (Brooklynian)