The special standards are shown in small letters to correspond to lettering in the basin tables. The special standards are as follows:
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.
b. Policy for the Potomac Embayments. At its meeting on September 12, 1996, the board adopted a policy (9VAC25-415. Policy for the Potomac Embayments) to control point source discharges of conventional pollutants into the Virginia embayment waters of the Potomac River, and their tributaries, from the fall line at Chain Bridge in Arlington County to the Route 301 bridge in King George County. The policy sets effluent limits for BOD5, total suspended solids, phosphorus, and ammonia, to protect the water quality of these high profile waterbodies.g. Occoquan watershed policy. At its meeting on July 26, 1971 (Minute 10), the board adopted a comprehensive pollution abatement and water quality management policy for the Occoquan watershed. The policy set stringent treatment and discharge requirements in order to improve and protect water quality, particularly since the waters are an important water supply for Northern Virginia. Following a public hearing on November 20, 1980, the board, at its December 10-12, 1980 meeting, adopted as of February 1, 1981, revisions to this policy (Minute 20). These revisions became effective March 4, 1981. Additional amendments were made following a public hearing on August 22, 1990, and adopted by the board at its September 24, 1990, meeting (Minute 24) and became effective on December 5, 1990. Copies are available upon request from the Department of Environmental Quality.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. |
n. No sewage discharges, regardless of degree of treatment, should be allowed into the James River between Bosher and Williams Island Dams.o. The concentration and total amount of impurities in Tuckahoe Creek and its tributaries of sewage origin shall be limited to those amounts from sewage, industrial wastes, and other wastes that are now present in the stream from natural sources and from existing discharges in the watershed.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.
v. The maximum temperature of the New River and its tributaries (except trout waters) from the Montgomery-Giles County line upstream to the Virginia-North Carolina state line shall be 29°C (84°F).x. Clinch River from the confluence of Dumps Creek at river mile 268 at Carbo downstream to river mile 255.4. The special water quality criteria for copper (measured as total recoverable) in this section of the Clinch River are 12.4 µg/l for protection from chronic effects and 19.5 µg/l for protection from acute effects. These site-specific criteria are needed to provide protection to several endangered species of freshwater mussels.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: 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 = 4.0 mg/l | June 1 - September 30 |
Instantaneous minimum = 3.2 mg/l at temperatures <29°C Instantaneous minimum = 4.3 mg/lat temperatures = 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 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 |
(1) The site-specific numerical chlorophyll a criteria apply to the tidal James River segments (excludes tributaries) JMSTF2, JMSTF1, JMSOH, JMSMH, and JMSPH, the boundaries of which are described in EPA 903-R-05-004.(2) For segments JMSOH, JMSMH, and JMSPH, the median of same-day samples collected one meter or less in a segment should be calculated to represent the chlorophyll a expression of a segment over that day, and the median of same-month chlorophyll a values should be calculated to represent the chlorophyll a expression of a segment over that month. The seasonal geometric mean shall be calculated from the monthly chlorophyll a values for a segment.(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 |
9 Va. Admin. Code § 25-260-310
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. 6/27/2017; Amended, Virginia Register Volume 36, Issue 02, eff. 9/16/2019; Volume 36, Issue 11, eff. 1/9/2020; Errata, 36:22 VA.R. 2411 June 22, 2020; Amended, Virginia Register Volume 39, Issue 9, eff. 4/18/2023.Statutory Authority: § 62.1-44.15 of the Code of Virginia; Clean Water Act (33 USC § 1251 et seq.); 40 CFR Part 131.
The amended version of this section by Virginia Register Volume 40, Issue 24, eff. 6/26/2024 is not yet available.