Virginia Law

A. Bacteria criteria. All surface waters have criteria for fecal coliform bacteria. The bacteria criteria for shellfish waters are set forth in 9VAC25-260-160; the criteria applying to recreational waters are found in 9VAC25-260-170. The letter "a" in the special standards column next to a river basin section indicates that there are shellfish waters somewhere within that section and the bacteria criteria for shellfish waters applies to those shellfish waters. (It should be noted that even though the column contains the letter "a" the entire section may not be shellfish waters.)

B. Natural variation. In some cases natural water quality does not fall within the criteria set by these standards. (For example streams in some areas of the state may naturally exceed the usual pH range of 6.0 to 9.0.) In these instances the board may have set more appropriate criteria that reflect natural quality, and this special limit is shown in the special standards column.

C. Additional requirements. In other cases the basic water quality parameters of DO, pH, temperature, and bacteria have not been sufficient to protect water quality in certain areas, and effluent limits or treatment requirements have been established for these areas. This fact is also indicated in the special standards column. If the applicable standard was too long to print in its entirety in that column, the column contains only a lower case letter, and the standard itself will be found in the special standards 9VAC25-260-310 under that letter.

D. Other special standards or designations.

1. Public water supplies (PWS). Sections that are public water supplies are indicated in the special standards column with a PWS. This designation indicates that additional criteria are applicable in this section. See 9VAC25-260-140 B for applicable criteria. Taste and odor criteria to maintain acceptable taste, odor or aesthetic quality of drinking water apply at the drinking water intake.

2. Nutrient enriched waters (NEW). If a section contains a waterbody that has been designated as nutrient enriched in 9VAC25-260-350, the special standards column indicates this with the letters "NEW-" followed by a number. The appropriate waterway can be found listed in 9VAC25-260-350. The entire section is not necessarily nutrient enriched, only that portion specifically listed in 9VAC25-260-350.

3. Exceptional state waters (ESW). If a section contains a waterbody that has been designated as exceptional state waters in 9VAC25-260-30 A 3 the special standard column indicates this with ESW followed by a number. The appropriate waterway can be found listed in 9VAC25-260-30 A 3 c. The entire section within the basin table is not necessarily designated as exceptional state waters, only that portion specifically listed in 9VAC25-260-30 A 3 c.

4. If a section contains a waterbody that has been assigned a special standard (indicated by lower case letters in the special standards column), the appropriate waterway can be found listed in 9VAC25-260-310. The special standard does not necessarily apply to the entire section, only that portion specifically listed in 9VAC25-260-310.