Discolored Water May Stain Your Clothes

The Cambridge Water and Fire Departments have this say about fire hydrant testing which is currently under way:

Hydrant testing may disturb the sediment that naturally occurs in the water piping system. Water from your faucets and toilet may appear rust colored from this disturbance. Rust discoloration may last for several hours after the tests have been completed. Discolored water does not usually present a health hazard, however; the Water Department recommends that anyone who has doubts about the rust colored water should not drink it. You may wish to store tap water or two-gallon containers in your refrigerator for the day of the test.

We also suggest that the residents check their water before doing laundry because the discolored water may stain your clothes. If your laundry is stained, the Water Department will provide you with a wash additive to remove the stains.

Wow, "does not usually present a health hazard" and "may stain your clothes" means you better check the schedule.