Washington Suburban Sanitary Commission officials say water restrictions for 1.8 million residents in Montgomery and Prince George’s counties will last at least until Tuesday morning.

The water agency had hoped to lift the restrictions Monday, but testing on an eight-foot water main that nearly busted in Potomac will stretch through the night.

Officials say customers should abide by the restrictions — consume water only when necessary and don’t use it outdoors — until they announce otherwise.

As of Monday afternoon, 266 WSSC customers received warnings and four were given $500 citations for a second violation.