The area of Gloucester and Mathews waterways where shellfish harvesting is not permitted due to poor water quality grew by more than 400 acres in the past year.

The total area of these condemned waters is 5,714 acres as of July 1. The total 12 months ago was 5,296.9 acres. Large increases of condemned area in a few waterways and small increases in many helped to overtake improvements in others.

The totals fluctuate regularly and are rarely the same from one year to another, according to annual reports compiled by the Gazette-Journal for nearly 30 years.

The Division of Shellfish Sanitation of the Virginia Department of Health conducts at least six samplings each year of local waters to determine the concentration of fecal coliforms in those waters. This is the most frequent check of water quality and usually the determining factor in condemnation, DSS said.

In addition, all waterways are subjected to shoreline surveys every 8-9 years, DSS said. The surveyors visit all properties in...