For the second straight year, the acreage of local waters condemned for shellfish harvesting has shown a sharp decline.

The total area of condemned waters in Gloucester and Mathews counties as of Aug. 1, 2010, was 4,053 acres, a 30 percent drop from the July 1, 2009 total of 5,822 acres.

In turn that 2009 figure was a sharp drop from the acreage of 12 months prior to that, July 1, 2008, which totaled 7,224 acres, according to figures prepared by the Virginia Department of Health, Division of Shellfish Sanitation.

However, a number of perennially dirty waters are always on the list, including Put-In Creek in Mathews, which was condemned in 1927—and has never been considered clean since. This closure occurred during one of Virginia’s first inspections of public waters, according to the Mathews Journal of Dec. 8, 1927.

Other bodies of water that usually appear on the list include Sarah’s Creek at Gloucester Point, large parts of the upper East River and Ware, N...