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 8B (work area in Southeast, bounded by Alabama Avenue, Shipley Terrace, Southern Avenue and Naylor Road).

* 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 8C, (work area in Southeast, bounded by Portland Street, Martin Luther King Avenue, Firth Sterling Avenue and Raleigh Street).

* ANC 8C (work area in Southeast, bounded by Alabama Avenue, 6th Street, Mississippi Avenue and Martin Luther King Avenue).

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

* ANC 7B (work area in Southeast, bounded by Massachusetts Avenue, 39th Street, Pennsylvania Avenue and 33rd Street).

* ANC 4C (work area in Northwest, bounded by Allison Street, 8th Street, Taylor Street and 14th Street).

* 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 1A (work area in Northwest, bounded by Oak Street, 16th Street and Park Road).

* 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 7B (work area in Southeast, bounded by Pennsylvania Avenue, 29th Street, Naylor Road, and 27th Street).

* ANC 7B (work area in Southeast, bounded by Anacostia Avenue, 37th Place, Pennsylvania Avenue and Minnesota Avenue).

* ANC 7A (work area in Southeast, bounded by H Street, Southern Avenue, Massachusetts Avenue and Ridge Road).

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

* ANC 7A (work area in Southeast, bounded by East Capitol Street, Southern Avenue, B Street and 51st Street).

* ANC 7A (work area in Northeast, bounded by Benning Road, East Capitol Street and Minnesota Avenue).

* ANC 7D (work area in Northeast, bounded by Grant Street, 44th Street, Benning Road and Minnesota Avenue).

* ANC 8A (work area in Southeast, bounded by Howard Road, Stanton Road, Sheridan Road and Wade Road).

* ANC 8A (work area in Southeast, bounded by Alabama Avenue, 21st Street, Southern Avenue and 13th Street).

* 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 8E (work area bounded by 4th Street SE, Atlantic Street SE and 2nd Street SW).

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.