Households in the City of Boston and surrounding communities should avoid consuming tap water that has not been boiled first until further notice, according to a warning from the Massachusetts Water Resources Authority (MWRA) and reemphasized by AIDS Action Committee of Massachusetts. Though the warning applies to everyone in the aftermath of a recently discovered water main break, it is especially important for people with immune deficiency, including people living with HIV.

The break in a 10-foot diameter water main near Recreation Road in Weston was discovered May 1 and quickly became “catastrophic,” nearly doubling the flow of the adjacent Charles River. To maintain water for uses like firefighting, flushing and showers, the state had to use emergency water sources that are not safe for drinking. The emergency may end within a few days; at that point, people in the affected areas will need to follow instructions to flush the pipes of houses and other buildings to remove the unsafe water.

In the meantime, MWRA is recommending that water be boiled for at least one minute before it is safe to drink. Residents and visitors should also avoid using unboiled tap water to cook, prepare baby formula, brush teeth or prepare food.