The D.C. Water and Sewer Authority is conducting its annual program to flush water mains throughout the city, a procedure designed to remove sediment and improve water quality.

From 10 p.m. to 6:30 a.m. Sunday through Thursday, WASA crews are opening fire hydrants in designated neighborhoods and flushing water.

The water supply to customers is not shut off during the flushing.

Customers might notice some water discoloration early in the morning. If that happens, WASA recommends that residents open the cold water tap and allow the water to flow slowly until it is clear.

Customers should not run hot water or do laundry during the flushing. If the hot water becomes discolored, WASA recommends flushing the hot water tank by opening the valve at the bottom of the tank.

The flushing program will continue through November.

These neighborhoods, with boundary streets, are scheduled for flushing the week starting Sunday, according to information provided by WASA:

* ANC 4C (work area in Northwest, bounded by Ingraham Street, Georgia Avenue, Allison Street and 14th Street).

* ANC 4C (work area in Northwest, bounded by Ingraham Street, Illinois Avenue, Buchanan Street and Georgia Avenue).

* ANC 1E (work area in Northwest, bounded by Park Road, 16th Street, Irving Street and Adams Mill Road).

* ANC 1A (work area in Northwest, bounded by Spring Road, Georgia Avenue, Kenyon Street and Holmead Place).

* ANC 3D (work area in Northwest, bounded by Reservoir Road, 44th Street, P Street and Canal Road).

* ANC 3B (work area in Northwest, bounded by Whitehaven Parkway, Wisconsin Avenue, Reservoir Road and 39th Street).

* ANC 3B (work area in Northwest, bounded by S Street, 31st Street, P Street and 35th Street).

* ANC 3B (work area in Northwest, bounded by R Street, 28th Street, Q Street and 31st Street).

* ANC 2D (work area bounded by Independence Avenue, Fourth Street NW, M Street SW and Maine Avenue SW).

* ANC 2A (work area in Southwest, bounded by Maryland Avenue, Third Street, E Street and Fourth Street).

* ANC 8E (work area in Southeast, bounded by Martin Luther King Avenue, Wheeler Road, Mississippi Avenue and Sixth Street).

* ANC 8A (work area in Southeast, bounded by Milwaukee Place, Martin Luther King Avenue, Firth Sterling Avenue and Raleigh Street).

* ANC 7B (work area in Southeast, bounded by Fort Dupont Street, Southern Avenue, Pennsylvania Avenue and Alabama Avenue).

* ANC 8E (work area bounded by Fourth Street SE, Atlantic Street SE and Second Street SW).

* ANC 7A (work area in Southeast, bounded by Massachusetts Avenue, 35th Street, Anacostia Avenue and Minnesota Avenue).

* ANC 7A (work area in Southeast, bounded by F Street, Minnesota Avenue, Nash Place and Fairlawn Avenue).

* ANC 2D (work area in Southwest, bounded by E Street, South Capitol Street, M Street and Fourth Street).

* ANC 6C (work area in Southeast, bounded by Fairlawn Avenue, Nash Place, Minnesota Avenue and Ridge Place).

* ANC 6C (work area bounded by Ridge Place SE, Minnesota Avenue NE, W Street SE and Fairlawn Avenue SE).

* ANC 7B (work area in Southeast, bounded by Alabama Avenue, Branch Avenue, Southern Avenue and Naylor Road).

* ANC 7B (work area in Southeast, bounded by Park Drive, Branch Avenue, Alabama Avenue and 28th Street).

* ANC 7D (work area in Northeast, bounded by Nannie Helen Burroughs Avenue, 50th Street, East Capitol Street and 47th Street).

* ANC 7C (work area in Northeast, bounded by Dix Street, 57th Street, East Capitol Street and 50th Street).

* ANC 8A (work area in Southeast, bounded by W Street, Martin Luther King Avenue, Stevens Road and South Capitol Street).

For information, call the WASA Water Quality Office, 202-612-3440, 8 a.m.- 4 p.m. In an emergency, call WASA's 24-hour hotline, 202-612-3400.