9 Va. Admin. Code § 25-260-310
a. Shellfish waters. In all open ocean or estuarine waters capable of propagating shellfish or in specific areas where public or leased private shellfish beds are present, including those waters on which condemnation classifications are established by the Virginia Department of Health, the following criteria for fecal coliform bacteria will apply:
The geometric mean fecal coliform value for a sampling station shall not exceed an MPN (most probable number) or MF (membrane filtration using mTEC culture media) of 14 per 100 milliliters (ml) of sample and the estimated 90th percentile shall not exceed an MPN of 43 per 100 ml for a 5-tube decimal dilution test or an MPN of 49 per 100 ml for a 3-tube decimal dilution test or MF test of 31 CFU (colony forming units) per 100 ml.
The shellfish area is not to be so contaminated by radionuclides, pesticides, herbicides, or fecal material that the consumption of shellfish might be hazardous.
m. The following effluent limitations apply to wastewater treatment facilities treating an organic nutrient source in the entire Chickahominy watershed above Walker's Dam (this excludes discharges consisting solely of stormwater):
| CONSTITUENT | CONCENTRATION |
|---|---|
| 1. Biochemical oxygen demand 5-day | 6 mg/l monthly average, with not more than 5% of individual samples to exceed 8 mg/l. |
| 2. Settleable solids | Not to exceed 0.1 ml/l monthly average. |
| 3. Suspended solids | 5.0 mg/l monthly average, with not more than 5% of individual samples to exceed 7.5 mg/l. |
| 4. Ammonia nitrogen | Not to exceed 2.0 mg/l monthly average as N. |
| 5. Total phosphorus | Not to exceed 0.10 mg/l monthly average for all discharges with the exception of Tyson Foods, Inc., which shall meet 0.30 mg/l monthly average and 0.50 mg/l daily maximum. |
| 6. Other physical and chemical constituents | Other physical or chemical constituents not specifically mentioned will be covered by additional specifications as conditions detrimental to the stream arise. The specific mention of items 1 through 5 does not necessarily mean that the addition of other physical or chemical constituents will be condoned. |
u. Maximum temperature for the New River Basin from the Virginia-West Virginia state line upstream to the Giles-Montgomery County line:
The maximum temperature shall be 27°C (81°F) unless caused by natural conditions; the maximum rise above natural temperatures shall not exceed 2.8°C (5°F).
This maximum temperature limit of 81°F was established in the 1970 water quality standards amendments so that Virginia temperature criteria for the New River would be consistent with those of West Virginia, since the stream flows into that state.
z. A site specific dissolved copper aquatic life criterion of 16.3 µg/l for protection from acute effects and 10.5 µg/l for protection from chronic effects applies in the following area:
(3) For segment JMSTF2, chlorophyll a data collected in the "upper zone" (from the upstream boundary at the fall line to approximately river mile 95 (N37° 23' 15.27" / W77° 18' 45.05" to N37° 23' 19.31" / W77° 18' 54.03")) should be pooled, in the manner described in subdivision bb (2) of this section, separately from chlorophyll a data collected in the "lower zone" (from river mile 95 to the downstream boundary of JMSTF2). The seasonal geometric mean for each of these zones should be calculated from their respective monthly chlorophyll a values. To calculate the seasonal segment-wide geometric mean, an area-weighted average of the zonal geometric means should be calculated using the following equation:
Upper Zone Geometric Mean x 0.41 + Lower Zone Geometric Mean x 0.59
(4) For segment JMSTF1, chlorophyll a data collected in the "upper zone" (from the upstream boundary of JMSTF1 to approximately river mile 67 (N37° 17' 46.21" / W77° 7' 9.55" to N37° 18' 58.94" / W77° 6' 57.14")) should be pooled, in the manner described in subdivision bb (2) of this section, separately from chlorophyll a data collected in the "lower zone" (between river mile 67 to the downstream boundary of JMSTF1). The seasonal geometric mean for each of these zones should be calculated from their respective monthly chlorophyll a values. To calculate the seasonal segment-wide geometric mean, an area-weighted average of the zonal geometric means should be calculated using the following equation:
Upper Zone Geometric Mean x 0.49 + Lower Zone Geometric Mean x 0.51
cc. For Mountain Lake in Giles County, chlorophyll a shall not exceed 6 µg/L at a depth of six meters and orthophosphate-P shall not exceed 8 µg/L at a depth of one meter or less.
dd. For Lake Drummond, located within the boundaries of Chesapeake and Suffolk in the Great Dismal Swamp, chlorophyll a shall not exceed 35 µg/L and total phosphorus shall not exceed 40 µg/L at a depth of one meter or less.
ee. Maximum temperature for these seasonally stockable trout waters is 26°C and applies May 1 through October 31.
ff. Maximum temperature for these seasonally stockable trout waters is 28°C and applies May 1 through October 31.
gg. Little Calfpasture River from the Goshen Dam to 0.76 miles above its confluence with the Calfpasture River has a stream condition index (A Stream Condition Index for Virginia Non-Coastal Streams, September 2003, Tetra Tech, Inc.) of at least 20.5 to protect the subcategory of aquatic life that exists in this river section as a result of the hydrologic modification. From 0.76 miles to 0.02 miles above its confluence with the Calfpasture River, aquatic life conditions are expected to gradually recover and meet the general aquatic life uses at 0.02 miles above its confluence with the Calfpasture River.
hh. Maximum temperature for these seasonally stockable trout waters is 31°C and applies May 1 through October 31.
ii. In the wadeable portions of the mainstem sections of the Shenandoah River, North Fork Shenandoah River, and South Fork Shenandoah River listed in the table in this subdivision, a determination of persistent nuisance filamentous algae impeding the recreation use should be made when exceedances of either of the specified benthic chlorophyll-a concentration thresholds occur in more than one recreation season (May 1 to October 31) in three years. "Wadeable" constitutes a stream that can be crossed and sampled safely during a given sampling event occurring within the recreation season.
| Segment | Two-Month Median (mg/m2) | Seasonal Median (mg/m2) |
| Shenandoah River from its confluence of the North Fork and South Fork Shenandoah Rivers downstream to the Virginia-West Virginia state line | 150 | 100 |
| North Fork Shenandoah River from its confluence with Fort Run downstream to its confluence with the South Fork Shenandoah River | 150 | 100 |
| South Fork Shenandoah River from its confluence with the North and South Rivers downstream to its confluence with the North Fork Shenandoah River | 150 | 100 |
jj. The selenium chronic criteria for the protection of freshwater aquatic life apply in the following waters:
Knox Creek watershed in Buchanan County:
(4) Abners Fork and tributaries.
| Media Type | Fish Tissue1 | Water Column4 | ||
| Criterion Element | Egg-ovary2 | Fish Whole-body or Muscle3 | Monthly Average Exposure | Intermittent Exposure5 |
| Magnitude | 15.1 mg/kg dw | 8.5 mg/kg dw whole-body or 11.3 mg/kg dw muscle (skinless, boneless filet) | 1.5 µg/L in lentic aquatic systems 3.1 µg/L in lotic aquatic systems | WQCint = (WQC30-day - Cbkgrnd(1-fint))/ fint |
| Duration | Instantaneous measurement6 | Instantaneous measurement6 | 30 days | Number of days/month with an elevated concentration |
| Frequency | Not to be exceeded | Not to be exceeded | Not more than once in three years on average | Not more than once in three years on average |
| mg/kg dw = milligrams per kilogram dry weight | ||||
| 1. Fish tissue elements are expressed as steady state. 2. Egg-ovary supersedes any whole-body, muscle, or water column element when fish egg-ovary concentrations are measured , except as noted in footnote 4. 3. Fish whole-body or muscle tissue supersedes water column element when both fish tissue and water concentrations are measured , except as noted in footnote 4. 4. Water column values are based on dissolved total selenium in water and are derived from fish tissue values via bioaccumulation modeling. When selenium inputs are increasing, water column values are the applicable criterion element in the absence of steady-state condition fish tissue data. In fishless waters, compliance may be assessed using methods consistent with Aquatic Life Ambient Water Quality Criterion for Selenium – Freshwater, EPA-822-R-21-006. 5. Where WQC30-day is the water column monthly element for either lentic (still) or lotic (flowing) waters; Cbkgrnd is the average background selenium concentration; and fint is the fraction of any 30-day period during which elevated selenium concentrations occur, with fint assigned a value greater than or equal to 0.033 (corresponding to one day). 6. Fish tissue data provide instantaneous point measurements that reflect integrative accumulation of selenium over time and space in fish populations at a given site. |
Little Creek to the Route 60 (Shore Drive) bridge including Little Channel, Desert Cove, Fishermans Cove, and Little Creek Cove.
Hampton Roads Harbor including the waters within the boundary lines formed by I-664 (Monitor-Merrimac Memorial Bridge Tunnel) and I-64 (Hampton Roads Bridge Tunnel), Willoughby Bay, and the Elizabeth River and its tidal tributaries.
This criterion reflects the acute and chronic copper aquatic life criterion for saltwater in 9VAC25-260-140 B X a water effect ratio. The water effect ratio was derived in accordance with 9VAC25-260-140 F.
aa. The following site-specific dissolved oxygen criteria apply to the tidal Mattaponi and Pamunkey Rivers and their tidal tributaries because of seasonal lower dissolved oxygen concentration due to the natural oxygen depleting processes present in the extensive surrounding tidal wetlands. These criteria apply June 1 through September 30 to Chesapeake Bay segments MPNTF, MPNOH, PMKTF, PMKOH and are implemented in accordance with subsection D of 9VAC25-260-185. These criteria supersede the open water criteria listed in subsection A of 9VAC25-260-185.
| Designated use | Criteria Concentration/Duration | Temporal Application |
| Open water | 30 day mean is greater than or equal to 4.0 mg/l | June 1 - September 30 |
| Instantaneous minimum is greater than or equal to 3.2 mg/l at temperatures less than 29°C Instantaneous minimum is greater than or equal to 4.3 mg/l at temperatures greater than or equal to 29°C |
A site-specific pH criterion of 5.0-8.0 applies to the tidal freshwater Mattaponi Chesapeake Bay segment MPNTF to reflect natural conditions.
bb. The following site-specific seasonal mean criteria should not be exceeded in the specified tidal James River segment more than twice in six years. Should consecutive exceedances of the same seasonal mean criterion occur in a waterbody segment after the effective date, January 9, 2020, of these chlorophyll a criteria, the department will examine additional lines of evidence, including the occurrence of harmful algae blooms, physicochemical monitoring and phytoplankton datasets, and fish kill reports in the evaluation of the appropriate assessment category for the waterbody segment. The department will develop guidance for inclusion in the Water Quality Assessment Guidance Manual to address evaluating the appropriate assessment category when consecutive exceedances of the same seasonal mean criterion occur. The department will determine if additional monitoring for harmful algal blooms is warranted.
| Designated Use | Chlorophyll a µ/l | Chesapeake Bay Program Segment | Temporal Application |
| Open water | 8 | JMSTF2 | March 1 - May 31 (spring) |
| 10 | JMSTF1 | ||
| 13 | JMSOH | ||
| 7 | JMSMH | ||
| 8 | JMSPH | ||
| 21 | JMSTF2 | July 1 - September 30 (summer) | |
| 24 | JMSTF1 | ||
| 11 | JMSOH | ||
| 7 | JMSMH | ||
| 7 | JMSPH |
The following site-specific chlorophyll a concentrations at the specified duration should not be exceeded more than 10% of the time over six summer seasons in the specified area of the tidal James River. These criteria protect against aquatic life effects due to harmful algal blooms. Such effects have not been documented in the upper portion of JMSTF2 or in JMSOH.
| Chlorophyll a µg/l | Chesapeake Bay Program Segment | Spatial Application | Duration |
| -- | JMSTF2 | Upstream boundary of JMSTF2 to river mile 95 | -- |
| 52 | JMSTF2 | River mile 95 to downstream boundary of JMSTF2 | 1-month median |
| 52 | JMSTF1 | Upstream boundary of JMSTF1 to river mile 67 | 1-month median |
| 34 | JMSTF1 | River mile 67 to downstream boundary of JMSTF1 | 1-month median |
| -- | JMSOH | Entire segment | -- |
| 59 | JMSMH | Entire segment | 1-day median |
| 20 | JMSPH | Entire segment | 1-day median |
The special standards are shown in small letters to correspond to lettering in the basin tables. The special standards are as follows:
§ 62.1-44.15 of the Code of Virginia; 33 USC § 1251 et seq.; 40 CFR 131.
Derived from VR680-21-07.1, eff. May 20, 1992; amended July 1, 1992; amended, Virginia Register Volume 13, Issue 12, eff. April 2, 1997; Volume 14, Issue 4, eff. December 10, 1997; Volume 19, Issue 23, eff. August 27, 2003; Volume 20, Issue 9, eff. February 12, 2004; Volume 22, Issue 11, eff. January 12, 2006; Volume 24, Issue 4, eff. August 14, 2007; Volume 26, Issue 12, eff. February 1, 2010; Volume 32, Issue 26, eff. June 27, 2017; Volume 36, Issue 11, eff. January 9, 2020; Errata, 36:22 VA.R. 2411 June 22, 2020; Volume 39, Issue 9, eff. April 18, 2023; Volume 41, Issue 23, eff. September 25, 2025; Errata, 42:3 VA.R. 473 September 22, 2025.