Vol. 31 Iss. 22 (Proposed Regulation) 9VAC25-260, Water Quality Standards June 29, 2015

REGULATIONS
Vol. 31 Iss. 22 - June 29, 2015

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TITLE 9. ENVIRONMENT

STATE WATER CONTROL BOARD

Chapter 260

Proposed Regulation

Title of Regulation: 9VAC25-260. Water Quality Standards (amending 9VAC25-260-5, 9VAC25-260-50, 9VAC25-260-140, 9VAC25-260-155, 9VAC25-260-185, 9VAC25-260-187, 9VAC25-260-310, 9VAC25-260-390, 9VAC25-260-400, 9VAC25-260-410, 9VAC25-260-415, 9VAC25-260-440, 9VAC25-260-450, 9VAC25-260-460, 9VAC25-260-470, 9VAC25-260-510, 9VAC25-260-520, 9VAC25-260-530, 9VAC25-260-540).

Statutory Authority: § 62.1-44.15 of the Code of Virginia; Clean Water Act (33 USC § 1251 et seq.); 40 CFR Part 131.

Public Hearing Information:

July 29, 2015 - 2 p.m. - Department of Environmental Quality, Piedmont Regional Office, 4949-A Cox Road, Glen Allen, VA 23060

Public Comment Deadline: August 28, 2015.

Agency Contact: David Whitehurst, Department of Environmental Quality, 629 East Main Street, P.O. Box 1105, Richmond, VA 23218, telephone (804) 698-4121, FAX (804) 698-4032, TTY (804) 698-4021, or email david.whitehurst@deq.virginia.gov.

Basis: The Clean Water Act authorizes restoration and maintenance of the chemical, physical, and biological integrity of the nation's waters. Section 303(c)(1) of the Clean Water Act requires that the states hold public hearings for the purpose of reviewing applicable water quality standards and, as appropriate, modifying and adopting standards.

The federal regulations at 40 CFR Part 131 authorize requirements and procedures for developing, reviewing, revising, and approving water quality standards by the states as authorized by § 303(c) of the Clean Water Act. 40 CFR Part 131 specifically requires the states to adopt criteria to protect designated uses.

The State Water Control Law (§ 62.1-442. et seq. of the Code of Virginia) authorizes protection and restoration of the quality of state waters, safeguarding the clean waters from pollution, prevention and reduction of pollution, and promotion of water conservation. Section 62.1-44.15 (3a) requires the State Water Control Board to establish standards of quality and to modify, amend, or cancel any such standards or policies. It also requires the board to hold public hearings from time to time for the purpose of reviewing the water quality standards, and, as appropriate, adopting, modifying or canceling such standards.

The authority to adopt standards as provided by the provisions in the previously referenced citations is mandated, although the specific standards to be adopted or modified are discretionary to the federal Environmental Protection Agency (EPA) and the Commonwealth.

Purpose: The rulemaking is essential to the protection of health, safety, or welfare of the citizens of the Commonwealth because proper water quality standards protect water quality and living resources of Virginia's waters for consumption of fish and shellfish, recreational uses, and conservation in general.

These standards will be used in setting Virginia Pollutant Discharge Elimination System Permit limits and for evaluating the waters of the Commonwealth for inclusion in the Clean Water Act § 305(b) water quality characterization report and on the § 303(d) list of impaired waters. Waters not meeting standards will require development of a total maximum daily load under the Clean Water Act at § 303(e). The Water Quality Standards are the cornerstone for all of these other programs. The goal is to provide the citizens of the Commonwealth with a technical regulation that is protective of water quality in surface waters, reflects recent scientific information, reflects agency procedures, and is reasonable and practical.

The environment will benefit because implementation of these amendments will result in better water quality in the Commonwealth for recreation, consumption of fish and shellfish, and protection of aquatic life.

Substance: The proposed amendments are as follows:

1. 9VAC25-260-5 - Include a definition of "wetlands."

2. 9VAC25-260-50 - Amend section so that the pH criteria in lakes and reservoirs only apply to the epilimnion of thermally stratified lakes when those lakes are stratified.

3. 9VAC25-260-140 - An amendment to the cadmium criteria for the protection of freshwater aquatic life is based on more recent EPA guidance issued in 2001 and updated with additional revisions included in a report published by the U.S Geological Survey in 2010. The proposed cadmium criteria are more stringent by about 50% compared to the existing Virginia criteria, but less stringent than EPA's 2001 recommendations.

Freshwater aquatic life criteria for lead are being amended to include a conversion factor. All current Virginia aquatic life criteria for metals except for lead include a conversion factor that allow for the criteria to be expressed as the dissolved fraction of the metal. The dissolved fraction is the most biologically available portion that contributes to potential toxicity. Staff recommends applying a conversion factor recommended by EPA as being applicable to the Virginia criteria for lead. This will make the criteria more stringent by approximately 5.0% to 22% because it is expressed as dissolved lead without the inclusion of any particulate lead that may be present.

Amendments are proposed to update eight human health criteria parameters due to changes in either oral slope factors for carcinogens or reference doses for noncarcinogens, which are utilized in risk assessment calculations from which the criteria are derived. The updates to the methodology for calculating human health criteria makes new criteria concentrations for carbon tetrachloride, methylene chloride, nitrobenzene, and tetrachloroethylene increase between 88% and 1779%. Updates for cyanide, Hexachloroethane, pentachlorophenol, and trichloroethylene decrease between 64% and 97% compared to the current criteria.

Acrolein and carbaryl are new proposed criteria to protect the aquatic life use. Acrolein is a biocide frequently used in recirculating process water systems for slime control and carbaryl is the active ingredient in the commonly available pesticide Sevin®.

The proposed inclusion of a "Biotic Ligand Model" for copper intended to be used on a site-specific basis. The model accounts for waterbody site-specific physiochemical characteristics for organic carbon, pH, temperature, alkalinity, calcium, chloride, magnesium, potassium, sodium, and sulfate instead of just hardness like the current criteria. Potentially it could be used in lieu of a water effects ratio study.

An amendment is proposed to delete the manganese criterion for waters designated as public water supply. The manganese criterion is based on a federally recommended secondary maximum contaminant level (SMCL) that is intended to be applied to treated drinking water as supplied to the consumers to prevent laundry staining.

4. 9VAC25-260-155 - The proposed amendments include new nationally recommended aquatic life criteria for ammonia in freshwater. Like the current criteria, the proposed criteria are calculated as a function of temperature and pH and accounts for the presence or absence of trout and early life stages of fish. The recalculated ammonia criteria incorporate toxicity data for freshwater mussels in the family Unionidae, which are the most sensitive organisms in the recalculation data base. The new criteria are more restrictive primarily because more recent toxicity data show that mussels and snails (including endangered species) are very sensitive to ammonia and the current ammonia criteria do not provide sufficient protection for these species. Site specific options to calculate criteria omitting mussel toxicity data are proposed to be used in waters where a demonstration has been made that mussels are absent; however, consultation with U.S. Fish and Wildlife Services and the Department of Game and Inland Fisheries indicate freshwater mussels should be considered ubiquitous in Virginia and likely to be present in any perennial waterbody.

5. 9VAC25-260-310 - The proposal amends special standard "m" to include language to clarify that the effluent limitations applicable to all wastewater treatment facilities in the Chickahominy River watershed above Walker's Dam only apply to treatment facilities treating an organic nutrient source.

Staff is proposing two new special standards ("ee" and "ff") to set a a recommended maximum temperature of 26^oC for Tinker Creek and 28^oC for sections of the Roanoke River from May 1 – October 31 that are stocked with trout only during the winter months. Current maximum temperature criteria for stockable trout waters of 21^oC apply year-round.

6. 9VAC25-260-390 through 9VAC25-260-540 - Proposed amendments delete the public water supply designation for an old raw water intake on the James River in Chesterfield County previously utilized by the American Tobacco Company. Consultation with the Virginia Department of Health (VDH) indicates no known active intake for potable water has been there in the past 35 years and VDH could not find any records about a domestic water intake at that location in years prior to 1978. The property where the intake is located has changed hands several times over the years and is now owned by Sustainability Park, LLC.

There are proposed clarifications and corrections to delineations for trout stream designations, basin section description clarifications, additions of new Class VII swamp waters, water authority name changes, and other miscellaneous corrections.

Issues: The primary advantage to the public is that the updated numerical toxics criteria are based on better scientific information to protect water quality and human health. The disadvantage is that criteria that become more stringent may result in increased costs to the regulated community. However, the goal is to set realistic, protective goals in water quality management and to maintain the most scientifically defensible criteria in the water quality standards regulation. EPA has also provided guidance that these criteria are "approvable" under the Clean Water Act.

The advantage to the agency or the Commonwealth from the adoption of these amendments will be more accurate and scientifically defensible permit limits, assessments and clean up plans (TMDLs). These are discussed under the "Purpose" section where the goals of the proposal, the environmental benefits, and the problems the proposal is intended to solve are discussed.

The regulated community will find the amendments pertinent to their operations, particularly where the numerical criteria are more stringent since that may require additional capital or operating costs for control in their discharge.

There is no disadvantage to the agency or the Commonwealth that will result from the adoption of these amendments.

Department of Planning and Budget's Economic Impact Analysis:

Summary of the Proposed Amendments to Regulation. Federal and state mandates in the Clean Water Act at § 303(c), 40 CFR 131 and the Code of Virginia in § 62.1-44.15 (3a) require that water quality standards be adopted, modified or cancelled every three years. Consequently, the State Water Control Board (Board) proposes numerous changes to the Water Quality Standards (9VAC25-260). Proposed amendments that potentially have economic impact include the following: 1) more stringent ammonia limits for municipal dischargers to comply with revised ammonia criteria, 2) more stringent cadmium criteria for the protection of freshwater aquatic life, 3) more stringent lead criteria, 4) updating eight human health criteria parameters, 5) reclassifying 24 waters from Class III (non-tidal free flowing waters) to Class VII (swamp waters), 6) adding site specific maximum temperature criteria for four trout-stocked waters, and 7) deleting the manganese criterion for public water supplies.

Result of Analysis. The benefits will clearly exceed costs for some proposed changes.

Estimated Economic Impact. The Water Quality Standards (9VAC25-260) are used in setting Virginia Pollutant Discharge Elimination System Permit limits and for evaluating the waters of the Commonwealth for inclusion in the Clean Water Act § 305(b) water quality characterization report and on the § 303(d) list of impaired waters. Waters not meeting standards require development of a Total Maximum Daily Load (TMDL) under the Clean Water Act at § 303(e). The Boards proposed amendments are designed to enable Virginia to comply with the Clean Water Act and to reduce unnecessary costs when possible.

Several of the proposed changes will be beneficial by creating better water quality in the Commonwealth for recreation, consumption of fish and shellfish, and protection of aquatic life, as well as human health. Other proposed changes will be beneficial by lowering costs for affected facilities. The proposed increase in criteria stringencies will increase costs for some facilities.

The primary and most widespread potential cost increase associated with the proposed amendments would be from meeting more stringent ammonia limits for municipal dischargers to comply with revised ammonia criteria. The facilities most likely to be affected are those in the Chesapeake Bay watershed with design flows less than 0.1 million gallons/day (MGD) located east of Interstate 95 and those with design flows less than 0.5 MGD west of I-95. Permittees with discharges outside of the Bay watershed, particularly those facilities that are large in volume compared to the receiving stream, may also have similar potential for financial impacts.

Ammonia Chesapeake Bay Facilities - There are approximately 220 discharge permits issued in the Chesapeake Bay watershed with either ammonia limits or ammonia monitoring requirements. Although ammonia limits or monitoring requirements are in the permits, it may be assumed those facilities with ammonia limits east of Interstate 95 with a design flow equal to or greater than 0.1 MGD and those with ammonia limits west of I-95 with a design flow equal to or greater than 0.5 MGD either currently have requirements or will be required to nitrify/denitrify to comply with the Water Quality Planning Management Regulation (9VAC25-720 et seq.) and the Chesapeake Bay Total Maximum Daily Load Watershed Implementation Plan. Those facilities utilizing a nitrification/denitrification wastewater treatment process to meet total nitrogen concentration limits greatly reduce the ammonia concentrations in effluent to very low levels and consequently will most likely meet the more stringent ammonia criteria without additional effort.

There are approximately 20 facilities east of Interstate 95 with flows less than 0.1 MGD. It is anticipated that these facilities have the greatest likelihood to incur impacts due to more stringent ammonia criteria. Of these, 17 now have numeric ammonia limits and it is likely they have nitrification capability to meet current limits; however an upgrade and/or operational procedure modification may be necessary to comply with newer, more stringent ammonia limits.

There are approximately 119 facilities west of I-95 with design flows less than 0.5 MGD. It is anticipated that these facilities have the greatest likelihood to incur impacts due to more stringent ammonia criteria. All but 2 have numeric ammonia limits now and it is likely that the facilities with numeric limits have nitrification capability to meet current limits; however an upgrade and/or operational procedure modification may be necessary to comply with newer, more stringent ammonia limits. It is not known how many of these would install a simple nitrification system or an advanced nitrification/denitrification system.

Ammonia Non-Bay Facilities - There are approximately 150 discharge permits issued outside of the Chesapeake Bay watershed with either ammonia limits or ammonia monitoring requirements. It appears likely that those with only monitoring requirements will incur costs should more stringent effluent limits be necessary. All but 8 have numeric ammonia limits now and it is likely these facilities have nitrification capability to meet current limits; however an upgrade and/or operational procedure modification may be necessary to comply with newer, more stringent ammonia limits.

Costs Associated with Meeting Ammonia Criteria - A simple nitrification system costs about $372,000 for a 0.10 million gallon/day (MGD) sewage treatment plant. The cost of an advanced treatment system capable of both nitrification and denitrification (nitrogen removal) can range from $750,000 to $8,195,000 depending on the current level of treatment and volume of discharge. These costs are one-time capital expenditures and are unlikely to recur during the useful life of the equipment; however, operations and maintenance costs would be ongoing. Operations and maintenance for nitrification/denitrification could be $23,000 for a 0.10-MGD plant to $195,000 for a 0.60-MGD plant.

For a totally new 0.7 MGD plant, roughly 50% of the cost of the new oxidation ditch, and 100% of the submerged diffused outfall, etc., is attributed toward the cost for ammonia removal. In this case, roughly 9% of the total cost can be attributed to ammonia removal or roughly $500,000 of the $5,655,000 bid price.

A volume upgrade from 4.0 to 6.5 MGD, the cost attributable to ammonia removal is more complicated because the oxidation ditch volume is set, with no expansion of the aerator volume, but there is a hydraulic increase of the overall facility. Roughly 30% of the aeration system, filter, and digester upgrade costs, and 100% of the IFAS costs are attributable to ammonia removal. This adds up to about $1,720,700 or roughly 13% of the overall bid price of $13,278,600. It is estimated the cost per gallon of ammonia removal in the examples given above for the new construction is $0.71/gallon and cost per gallon for the upgrade is $0.26/gallon.

Cadmium - The Board proposes to amend the cadmium criteria for the protection of freshwater aquatic life to be approximately 50 percent more stringent than the current requirement but not as stringent as the United States Environmental Protection Agency's (EPA's) 2011 recommendation. There are a total of 24 active discharge permits with either numeric cadmium limits or monitoring requirements. Of these, 13 have monitoring requirements only. Monitoring requirements without discharge limits typically result from a permit review using a Reasonable Potential Analysis that indicates the facility may have a particular parameter in its effluent, ergo the monitoring requirement. The monitoring data is used in subsequent permit reissuances to determine if discharge limits should be included. Given that the cadmium freshwater criteria are becoming more stringent it is assumed facilities with only monitoring requirements may be the most likely to be affected.

Lead - The Board proposes to include a conversion factor for lead criteria to be consistent with other Virginia aquatic life criteria for metals to allow for the criteria to be expressed as the dissolved fraction of the metal. This change would make the criteria more stringent by approximately 5 through 22 percent. There are a total of 26 active permits with either numeric lead limits or monitoring requirements. Of these, 14 have monitoring requirements only. Amending the freshwater lead criteria will change the parameter to be expressed as the dissolved portion of lead (current expression is total recoverable). Significant impacts to dischargers are not anticipated as permit limits for lead are calculated using the total recoverable form.

Amendments to Parameters for the Protection of Human Health - The Board proposes to update eight human health criteria parameters which would increase the concentrations for carbon tetrachloride, methylene chloride, nitrobenzene and tetrachloroethylene between 88 and 1779 percent. In contrast, the changes for cyanide, hexachloroethane, pentachlorophenol, and trichloroethylene would decrease between 64 and 97 percent. The cost savings from the less stringent criteria would likely approximately equal the cost increases from the more stringent criteria. In balance, the proposed change in criteria are expected to be more protective of human health without significantly increasing cost.

Reclassifying Waters from Class III to Class VII - The Board proposes to reclassify 24 waters from Class III (non-tidal free flowing waters) to the more appropriate Class VII (swamp waters). This will potentially save approximately $18,000 each, in that Class III would inappropriately require a pH or TMDL study. In aggregate, this proposed change would produce approximately $432,000¹ in savings.

Trout and Water Temperature - All waters classed as Stockable Trout Waters (Class V) have a year-round maximum temperature criterion of 21°C. The Department of Game and Inland Fisheries stocks trout during the winter in some warm-water rivers and streams. Given the naturally occurring temperatures of these warm-water rivers and streams, trout are not expected to survive the following summer. Application of 21°C maximum temperature year-round is inappropriate and does not reflect the natural thermal regime of these waters during the warmer seasons.

Thus the Board proposes to add site specific maximum temperature criteria that apply during warm months: May 1 to October 31. There are four waters to which this applies. This will enable facilities to avoid having to obtain unnecessary TMDLs, producing at least $72,000 in savings.

Manganese - Deletion of the manganese criterion for public water supplies could have a similar impact in the form of cost savings due to unnecessary TMDL studies not being done.

Businesses and Entities Affected. The proposed amendments particularly affect municipal wastewater facilities and sewage treatment plants, and industrial plants that discharge to surface waters of the Commonwealth. The estimated number of potentially affected facilities due to proposed amendments to the ammonia, lead, cadmium, and human health criteria is 435 and includes those facilities with effluent limitations and those with monitoring requirements but no limits.

There are approximately 352 active Virginia Pollutant Discharge Elimination System (VPDES) permits with effluent limitations for ammonia. A significant number of those facilities may receive more stringent ammonia limits, as well as the potential for new facilities to receive limits, as the proposed water quality criteria are implemented. Significant Dischargers of nutrients (POTWs ≥ 0.1 MGD east of the fall line and ≥ 0.5 MGD west of the fall line) within the Chesapeake Bay watershed have mostly upgraded to remove Total Nitrogen and in doing so convert ammonia-N to nitrate-N. The proposed water quality criteria will therefore mostly impact smaller facilities in the Chesapeake Bay watershed and any municipal facility outside of the Chesapeake Bay watershed. As a matter of practice, wastewater treatment plants designed to meet an ammonia limitation are generally designed to fully nitrify (remove all ammonia) so lower limitations do not necessarily mean that a wastewater treatment plant upgrade would be required. For most conventional activated sludge plants not currently using nutrient reduction technology, it may just require optimizing operational procedures to meet the new limitation. The largest potential impact is expected to be on facilities that discharge to very small receiving streams and older plants that do not treat wastewater using the activated sludge process.

There are 10 active VPDES permits with effluent limitations for cadmium. Fourteen have monitoring requirements but no limits. There are 10 active VPDES permits with effluent limitations for lead. Eighteen have monitoring requirements but no limits. There are 7 active VPDES permits with effluent limitations for human health parameters. Twenty-four have monitoring requirements but no limits.

Localities Particularly Affected. The Counties of Caroline, Carroll, Charles City, Chesterfield, Essex, Gloucester, Greensville, Hanover, Henrico, King George, King & Queen, King William, New Kent, Northumberland, Middlesex, Westmoreland and the City of Suffolk are affected by amendments to reclassify certain water bodies as swamp waters. Botetourt County and the Cities of Roanoke and Salem are affected by the additional of special standards ee and ff to certain trout waters. Orange and Powhatan counties are affected by the application of special nutrient standards to two lakes. The remainder of the amendments are either applicable statewide or are not expected to impose any identified disproportionate material impact to a locality.

Projected Impact on Employment. For industrial plants that would face additional costs under the proposed amendments, the increased costs may be large enough to discourage expansion or the building of new plants. This would have a negative impact on employment. As described above, there are waters in Virginia where the proposed amendments will reduce compliance costs. For industrial plants located on these waters, the reduced costs could encourage expansion or the building of a new plant. This would have a positive impact on employment.

Effects on the Use and Value of Private Property. Depending on their particular situation in regard to the location of their discharge and the concentration of specific substances, pH, or temperature in the water at that location, firms with industrial plants that discharge to surface waters of the Commonwealth may face either increased or reduced costs.

Small Businesses: Costs and Other Effects. Some of the industrial plants that discharge to surface waters of the Commonwealth will be associated with small businesses. Some may face increased costs and others may encounter reduced costs, depending on their particular situation in regard to the location of their discharge and the concentration of specific substances, pH, or temperature in the water at that location.

Small Businesses: Alternative Method that Minimizes Adverse Impact. There are no clear alternative methods that would both comply with the Clean Water Act and cost less.

Real Estate Development Costs. The proposed amendments do not directly affect real estate development costs.

Legal Mandate. General: The Department of Planning and Budget (DPB) has analyzed the economic impact of this proposed regulation in accordance with § 2.2-4007.04 of the Code of Virginia and Executive Order Number 14 (2010). Section 2.2-4007.04 requires that such economic impact analyses determine the public benefits and costs of the proposed amendments. Further the report should include but not be limited to:

• the projected number of businesses or other entities to whom the proposed regulatory action would apply,

• the identity of any localities and types of businesses or other entities particularly affected,

• the projected number of persons and employment positions to be affected,

• the projected costs to affected businesses or entities to implement or comply with the regulation, and

• the impact on the use and value of private property.

Small Businesses: If the proposed regulatory action will have an adverse effect on small businesses, § 2.2-4007.04 requires that such economic impact analyses include:

• an identification and estimate of the number of small businesses subject to the proposed regulation,

• the projected reporting, recordkeeping, and other administrative costs required for small businesses to comply with the proposed regulation, including the type of professional skills necessary for preparing required reports and other documents,

• a statement of the probable effect of the proposed regulation on affected small businesses, and

• a description of any less intrusive or less costly alternative methods of achieving the purpose of the proposed regulation.

Additionally, pursuant to § 2.2-4007.1, if there is a finding that a proposed regulation may have an adverse impact on small business, the Joint Commission on Administrative Rules is notified at the time the proposed regulation is submitted to the Virginia Register of Regulations for publication. This analysis shall represent DPB's best estimate for the purposes of public review and comment on the proposed regulation.

_________________

¹ $18,000 x 24 = $432,000

Agency's Response to Economic Impact Analysis: The Department of Environmental Quality has reviewed the economic impact analysis prepared by the Department of Planning and Budget and has no comment.

Summary:

The proposed amendments include (i) increasing the stringency of ammonia limits for municipal dischargers to comply with revised ammonia criteria, (ii) increasing the stringency of cadmium criteria for the protection of freshwater aquatic life, (iii) increasing the stringency of lead criteria, (iv) updating eight human health criteria parameters, (v) reclassifying 24 waters from Class III (nontidal free flowing waters) to Class VII (swamp waters), (vi) adding site-specific maximum temperature criteria for four trout-stocked waters, and (vii) deleting the manganese criterion for public water supplies.

Part I
Surface Water Standards with General, Statewide Application

9VAC25-260-5. Definitions.

The following words and terms when used in this chapter shall have the following meanings unless the context clearly indicates otherwise:

"Algicides" means chemical substances, most commonly copper-based, used as a treatment method to control algae growths.

"Board" means State Water Control Board.

"Chesapeake Bay and its tidal tributaries" means all tidally influenced waters of the Chesapeake Bay; western and eastern coastal embayments and tributaries; James, York, Rappahannock and Potomac Rivers and all their tidal tributaries to the end of tidal waters in each tributary (in larger rivers this is the fall line); and includes subdivisions 1, 2, 3, 4, 5, and 6 of 9VAC25-260-390, subdivisions 1, 1b, 1d, 1f and 1o of 9VAC25-260-410, subdivisions 5 and 5a of 9VAC25-260-415, subdivisions 1 and 1a of 9VAC25-260-440, subdivisions 2, 3, 3a, 3b and 3e of 9VAC25-260-520, and subdivision 1 of 9VAC25-260-530. This definition does not include free flowing sections of these waters.

"Criteria" means elements of the board's water quality standards, expressed as constituent concentrations, levels, or narrative statements, representing a quality of water that supports a particular use. When criteria are met, water quality will generally protect the designated use.

"Department" or "DEQ" means the Virginia Department of Environmental Quality.

"Designated uses" means those uses specified in water quality standards for each ~~water body~~ waterbody or segment whether or not they are being attained.

"Drifting organisms" means planktonic organisms that are dependent on the current of the water for movement.

"Epilimnion" means the upper layer of nearly uniform temperature in a thermally stratified man-made lake or reservoir listed in 9VAC25-260-187 B.

"Existing uses" means those uses actually attained in the ~~water body~~ waterbody on or after November 28, 1975, whether or not they are included in the water quality standards.

"Lacustrine" means the zone within a lake or reservoir that corresponds to nonflowing lake-like conditions such as those near the dam. The other two zones within a reservoir are riverine (flowing, river-like conditions) and transitional (transition from river to lake conditions).

"Man-made lake or reservoir" means a constructed impoundment.

"Mixing zone" means a limited area or volume of water where initial dilution of a discharge takes place and where numeric water quality criteria can be exceeded but designated uses in the ~~water body~~ waterbody on the whole are maintained and lethality is prevented.

"Natural lake" means an impoundment that is natural in origin. There are two natural lakes in Virginia: Mountain Lake in Giles County and Lake Drummond located within the boundaries of Chesapeake and Suffolk in the Great Dismal Swamp.

"Passing organisms" means free swimming organisms that move with a mean velocity at least equal to the ambient current in any direction.

"Primary contact recreation" means any water-based form of recreation, the practice of which has a high probability for total body immersion or ingestion of water (examples include but are not limited to swimming, water skiing, canoeing and kayaking).

"Pycnocline" means the portion of the water column where density changes rapidly because of salinity and/or temperature. In an estuary the pycnocline is the zone separating deep, cooler more saline waters from the less saline, warmer surface waters. The upper and lower boundaries of a pycnocline are measured as a change in density per unit of depth that is greater than twice the change of the overall average for the total water column.

"Secondary contact recreation" means a water-based form of recreation, the practice of which has a low probability for total body immersion or ingestion of waters (examples include but are not limited to wading, boating and fishing).

"Swamp waters" means waters with naturally occurring low pH and low dissolved oxygen caused by: (i) low flow velocity that prevents mixing and reaeration of stagnant, shallow waters and (ii) decomposition of vegetation that lowers dissolved oxygen concentrations and causes tannic acids to color the water and lower the pH.

"Use attainability analysis" means a structured scientific assessment of the factors affecting the attainment of the use which may include physical, chemical, biological, and economic factors as described in 9VAC25-260-10 H.

"Water quality standards" means provisions of state or federal law which consist of a designated use or uses for the waters of the Commonwealth and water quality criteria for such waters based upon such uses. Water quality standards are to protect the public health or welfare, enhance the quality of water and serve the purposes of the State Water Control Law (§ 62.1-44.2 et seq. of the Code of Virginia) and the federal Clean Water Act (33 USC § 1251 et seq.).

"Wetlands" means those areas that are inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas.

9VAC25-260-50. Numerical criteria for dissolved oxygen, pH, and maximum temperature.***

CLASS	DESCRIPTION OF WATERS	DISSOLVED OXYGEN (mg/l)****		pH	Max. Temp. (°C)
CLASS	DESCRIPTION OF WATERS	Min.	Daily Avg.	pH	Max. Temp. (°C)
I	Open Ocean	5.0	‑‑	6.0-9.0	‑‑
II	Tidal Waters in the Chowan Basin and the Atlantic Ocean Basin	4.0	5.0	6.0-9.0	‑‑
II	Tidal Waters in the Chesapeake Bay and its tidal tributaries	see 9VAC25-260-185		6.0-9.0
III	Nontidal Waters (Coastal and Piedmont Zones)	4.0	5.0	6.0-9.0	32
IV	Mountainous Zones Waters	4.0	5.0	6.0-9.0	31
V	Stockable Trout Waters	5.0	6.0	6.0-9.0	21
VI	Natural Trout Waters	6.0	7.0	6.0-9.0	20
VII	Swamp Waters	*	*	3.7-8.0*	**

*This classification recognizes that the natural quality of these waters may fluctuate outside of the values for D.O. and pH set forth above as water quality criteria in Class I through VI waters. The natural quality of these waters is the water quality found or expected in the absence of human-induced pollution. Water quality standards will not be considered violated when conditions are determined by the board to be natural and not due to human-induced sources. The board may develop site specific criteria for Class VII waters that reflect the natural quality of the waterbody when the evidence is sufficient to demonstrate that the site specific criteria rather than narrative criterion will fully protect aquatic life uses. Virginia Pollutant Discharge Elimination System limitations in Class VII waters shall not cause significant changes to the naturally occurring dissolved oxygen and pH fluctuations in these waters.

**Maximum temperature will be the same as that for Classes I through VI waters as appropriate.

***The water quality criteria in this section do not apply below the lowest flow averaged (arithmetic mean) over a period of seven consecutive days that can be statistically expected to occur once every 10 climatic years (a climatic year begins April 1 and ends March 31). See 9VAC25-260-310 and 9VAC25-260-380 through 9VAC25-260-540 for site specific adjustments to these criteria.

****For a thermally stratified man-made lake or reservoir in Class III, IV, V or VI waters that are listed in 9VAC25-260-187, these dissolved oxygen and pH criteria apply only to the epilimnion of the ~~water body~~ waterbody. When these waters are not stratified, the dissolved oxygen and pH criteria apply throughout the water column.

9VAC25-260-140. Criteria for surface water.

A. Instream water quality conditions shall not be acutely¹ or chronically² toxic except as allowed in 9VAC25-260-20 B (mixing zones). The following are definitions of acute and chronic toxicity conditions:

"Acute toxicity" means an adverse effect that usually occurs shortly after exposure to a pollutant. Lethality to an organism is the usual measure of acute toxicity. Where death is not easily detected, immobilization is considered equivalent to death.

"Chronic toxicity" means an adverse effect that is irreversible or progressive or occurs because the rate of injury is greater than the rate of repair during prolonged exposure to a pollutant. This includes low level, long-term effects such as reduction in growth or reproduction.

B. The following table is a list of numerical water quality criteria for specific parameters.

Table of Parameters^{6, 7}
PARAMETER CAS Number	USE DESIGNATION
	AQUATIC LIFE				HUMAN HEALTH
	FRESHWATER		SALTWATER		Public Water Supply³	All Other Surface Waters⁴
	Acute¹	Chronic²	Acute¹	Chronic²	Public Water Supply³	All Other Surface Waters⁴
Acenapthene (μg/l) 83329					670	990
Acrolein (μg/l) 107028	3.0	3.0			6.1	9.3
Acrylonitrile (μg/l) 107131 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.51	2.5
Aldrin (μg/l) 309002 Known or suspected carcinogen; human health criteria at risk level 10^-5.	3.0		1.3		0.00049	0.00050
Ammonia (μg/l) 766-41-7 Chronic criterion is a 30-day average concentration not to be exceeded more than once every three ~~(3)~~ years on the average. (see 9VAC25-260-155)
Anthracene (μg/l) 120127					8,300	40,000
Antimony (μg/l) 7440360					5.6	640
Arsenic (μg/l)⁵ 7440382	340	150	69	36	10
Bacteria (see 9VAC25-260-160 and 170)
Barium (μg/l) 7440393					2,000
Benzene (μg/l) 71432 Known or suspected carcinogen; human health criteria at risk level 10^-5.					22	510
Benzidine (μg/l) 92875 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.00086	0.0020
Benzo (a) anthracene (μg/l) 56553 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.038	0.18
Benzo (b) fluoranthene (μg/l) 205992 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.038	0.18
Benzo (k) fluoranthene (μg/l) 207089 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.038	0.18
Benzo (a) pyrene (μg/l) 50328 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.038	0.18
Bis2-Chloroethyl Ether (μg/l) 111444 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.30	5.3
Bis2-Chloroisopropyl Ether (μg/l) 108601					1,400	65,000
Bis2-Ethylhexyl Phthalate (μg/l) 117817 Known or suspected carcinogen; human health criteria at risk level 10^-5. Synonym = Di-2-Ethylhexyl Phthalate.					12	22
Bromoform (μg/l) 75252 Known or suspected carcinogen; human health criteria at risk level 10^-5.					43	1,400
Butyl benzyl phthalate (μg/l) 85687					1,500	1,900
Cadmium (μg/l)⁵ 7440439 Freshwater values are a function of total hardness as calcium carbonate (CaCO₃) mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER ~~[e ^{{1.128[In(hardness)] – 3.828}}]~~ [e ^{{0.8407[In(hardness)] – 3.279}}] Freshwater chronic criterion (μg/l) WER ~~[e ^{{0.7852[In(hardness)] – 3.490}}]~~ [e ^{{0.6247[In(hardness)] – 3.384}}] CF_c WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm CF_c= conversion factor (chronic) CF_c = 1.101672-[(ln hardness)(0.041838)]	~~3.9~~ 1.8 CaCO₃ = 100	~~1.1~~ 0.55 CaCO₃ = 100	40 X WER	8.8 X WER	5
Carbon tetrachloride (μg/l) 56235 Known or suspected carcinogen; human health criteria at risk level 10^-5.					~~2.3~~ 4.3	16 30
Carbaryl (μg/l) 63252	2.1	2.1	1.6
Chlordane (μg/l) 57749 Known or suspected carcinogen; human health criteria at risk level 10^-5.	2.4	0.0043	0.09	0.0040	0.0080	0.0081
Chloride (μg/l) 16887006 Human ~~Health~~ health criterion to maintain acceptable taste and aesthetic quality and applies at the drinking water intake. Chloride criteria do not apply in Class II transition zones (see subsection C of this section).	860,000	230,000			250,000
Chlorine, Total Residual (μg/l) 7782505 In DGIF class i and ii trout waters (9VAC25-260-390 through 9VAC25-260-540) or waters with threatened or endangered species are subject to the halogen ban (9VAC25-260-110).	19 See 9VAC25-260-110	11 See 9VAC25-260-110
Chlorine Produced Oxidant (μg/l) 7782505			13	7.5
Chlorobenzene (μg/l) 108907					130	1,600
Chlorodibromomethane (μg/l) 124481 Known or suspected carcinogen; human health criteria at risk level 10^-5.					4.0	130
Chloroform (μg/l) 67663					340	11,000
2-Chloronaphthalene (μg/l) 91587					1,000	1,600
2-Chlorophenol (μg/l) 95578					81	150
Chlorpyrifos (μg/l) 2921882	0.083	0.041	0.011	0.0056
Chromium III (μg/l)⁵ 16065831 Freshwater values are a function of total hardness as calcium carbonate CaCO₃ mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion μg/l WER [e^{{0.8190[In(hardness)]+3.7256}}] (CF_a) Freshwater chronic criterion μg/l WER [e^{{0.8190[In(hardness)]+0.6848}}] (CF_c) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140.F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CF_a= 0.316 CF_c=0.860	570 (CaCO₃ = 100)	74 (CaCO₃ = 100)			100 (total Cr)
Chromium VI (μg/l)⁵ 18540299	16	11	1,100	50
Chrysene (μg/l) 218019 Known or suspected carcinogen; human health criteria at risk level 10^-5.					~~0.0038~~ 0.038	0.018
Copper (μg/l)⁵ 7440508 Freshwater values are a function of total hardness as calcium carbonate CaCO₃mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER [e^{{0.9422[In(hardness)]-1.700}}] (CF_a) Freshwater chronic criterion (μg/l) WER [e ^{{0.8545[In(hardness)]-1.702}}] (CF_c) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F. e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CF_a = 0.960 CF_c = 0.960 Alternate copper criteria in freshwater: the freshwater criteria for copper can also be calculated using the EPA 2007 Biotic Ligand Model (See 9VAC25-260-140 G ). Acute saltwater criterion is a 24-hour average not to be exceeded more than once every three years on the average.	13 CaCO₃ = 100	9.0 CaCO₃ = 100	9.3 X WER	6.0 X WER	1,300
Cyanide, Free (μg/l) 57125	22	5.2	1.0	1.0	~~140~~ 4.2	~~16,000~~ 480
DDD (μg/l) 72548 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.0031	0.0031
DDE (μg/l) 72559 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.0022	0.0022
DDT (μg/l) 50293 Known or suspected carcinogen; human health criteria at risk level 10^-5. Total concentration of DDT and metabolites shall not exceed aquatic life criteria.	1.1	0.0010	0.13	0.0010	0.0022	0.0022
Demeton (μg/l) 8065483		0.1		0.1
Diazinon (μg/l) 333415	0.17	0.17	0.82	0.82
Dibenz (a, h) anthracene (μg/l) 53703 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.038	0.18
1,2-Dichlorobenzene (μg/l) 95501					420	1,300
1,3-Dichlorobenzene (μg/l) 541731					320	960
1,4 Dichlorobenzene (μg/l) 106467					63	190
3,3 Dichlorobenzidine (μg/l) 91941 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.21	0.28
Dichlorobromomethane (μg/l) 75274 Known or suspected carcinogen; human health criteria at risk level 10^-5.					5.5	170
1,2 Dichloroethane (μg/l) 107062 Known or suspected carcinogen; human health criteria at risk level 10^-5.					3.8	370
1,1 Dichloroethylene (μg/l) 75354					330	7,100
1,2-trans-dichloroethylene (μg/l) 156605					140	10,000
2,4 Dichlorophenol (μg/l) 120832					77	290
2,4 Dichlorophenoxy acetic acid (2,4-D) (μg/l) 94757					100
1,2-Dichloropropane (μg/l) 78875 Known or suspected carcinogen; human health criteria at risk level 10^-5.					5.0	150
1,3-Dichloropropene (μg/l) 542756 Known or suspected carcinogen; human health criteria at risk level 10^-5.					3.4	210
Dieldrin (μg/l) 60571 Known or suspected carcinogen; human health criteria at risk level 10^-5.	0.24	0.056	0.71	0.0019	0.00052	0.00054
Diethyl Phthalate (μg/l) 84662					17,000	44,000
2,4 Dimethylphenol (μg/l) 105679					380	850
Dimethyl Phthalate (μg/l) 131113					270,000	1,100,000
Di-n-Butyl Phthalate (μg/l) 84742					2,000	4,500
2,4 Dinitrophenol (μg/l) 51285					69	5,300
2-Methyl-4,6-Dinitrophenol (μg/l) 534521					13	280
2,4 Dinitrotoluene (μg/l) 121142 Known or suspected carcinogen; human health criteria at risk level 10^-5.					1.1	34
Dioxin 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (μg/l) 1746016					5.0 E-8	5.1 E-8
1,2-Diphenylhydrazine (μg/l) 122667 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.36	2.0
Dissolved Oxygen (μg/l) (See 9VAC25-260-50)
Alpha-Endosulfan (μg/l) 959988 Total concentration alpha and beta-endosulfan shall not exceed aquatic life criteria.	0.22	0.056	0.034	0.0087	62	89
Beta-Endosulfan (μg/l) 33213659 Total concentration alpha and beta-endosulfan shall not exceed aquatic life criteria.	0.22	0.056	0.034	0.0087	62	89
Endosulfan Sulfate (μg/l) 1031078					62	89
Endrin (μg/l) 72208	0.086	0.036	0.037	0.0023	0.059	0.060
Endrin Aldehyde (μg/l) 7421934					0.29	0.30
Ethylbenzene (μg/l) 100414					530	2,100
Fecal Coliform (see 9VAC25-260-160)
Fluoranthene (μg/l) 206440					130	140
Fluorene (μg/l) 86737					1,100	5,300
Foaming Agents (μg/l) Criterion measured as methylene blue active substances. Criterion to maintain acceptable taste, odor, or aesthetic quality of drinking water and applies at the drinking water intake.					500
Guthion (μg/l) 86500		0.01		0.01
Heptachlor (μg/l) 76448 Known or suspected carcinogen; human health criteria at risk level 10^-5.	0.52	0.0038	0.053	0.0036	0.00079	0.00079
Heptachlor Epoxide (μg/l) 1024573 Known or suspected carcinogen; human health criteria at risk level 10^-5.	0.52	0.0038	0.053	0.0036	0.00039	0.00039
Hexachlorobenzene (μg/l) 118741 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.0028	0.0029
Hexachlorobutadiene (μg/l) 87683 Known or suspected carcinogen; human health criteria at risk level 10^-5.					4.4	180
Hexachlorocyclohexane Alpha-BHC (μg/l) 319846 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.026	0.049
Hexachlorocyclohexane Beta-BHC (μg/l) 319857 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.091	0.17
Hexachlorocyclohexane (μg/l) (Lindane) Gamma-BHC 58899 Known or suspected carcinogen; human health criteria at risk level 10^-5.	0.95		0.16		0.98	1.8
Hexachlorocyclopentadiene (μg/l) 77474					40	1,100
Hexachloroethane (μg/l) 67721 Known or suspected carcinogen; human health criteria at risk level 10^-5.					14 5.0	33 12
Hydrogen sulfide (μg/l) 7783064		2.0		2.0
Indeno (1,2,3,-cd) pyrene (μg/l) 193395 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.038	0.18
Iron (μg/l) 7439896 Criterion to maintain acceptable taste, odor or aesthetic quality of drinking water and applies at the drinking water intake.					300
Isophorone (μg/l) 78591 Known or suspected carcinogen; human health criteria at risk level 10^-5.					350	9,600
Kepone (μg/l) 143500		zero		zero
Lead (μg/l)⁵ 7439921 Freshwater values are a function of total hardness as calcium carbonate CaCO₃mg/l and the water effect ratio. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER [e^{{1.273[In(hardness)]-1.084}}](CF_a) Freshwater chronic criterion (μg/l) WER [e ^{{1.273[In(hardness)]-3.259}}](CF_c) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CF_a= 1.46203-[(ln hardness)(0.145712)] CF_c = 1.46203-[(ln hardness)(0.145712)]	~~120~~ 94 CaCO₃ = 100	14 11 CaCO₃ = 100	240 X WER	9.3 X WER	15
Malathion (μg/l) 121755		0.1		0.1
Manganese (μg/l) 7439965 ~~Criterion to maintain acceptable taste, odor or aesthetic quality of drinking water and applies at the drinking water intake.~~					50
Mercury (μg/l)⁵ 7439976	1.4	0.77	1.8	0.94
Methyl Bromide (μg/l) 74839					47	1,500
Methyl Mercury (Fish Tissue Criterion mg/kg) ⁸ 22967926					0.30	0.30
Methylene Chloride (μg/l) 75092 Known or suspected carcinogen; human health criteria at risk level 10^-5. Synonym = Dichloromethane					46 170	~~5,900~~ 22,000
Methoxychlor (μg/l) 72435		0.03		0.03	100
Mirex (μg/l) 2385855		zero		zero
Nickel (μg/l)⁵ 744002 Freshwater values are a function of total hardness as calcium carbonate CaCO₃ mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER [e ^{{0.8460[In(hardness)] + 1.312}}] (CF_a) Freshwater chronic criterion (μg/l) WER [e ^{{0.8460[In(hardness)] - 0.8840}}] (CF_c) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CF_a= 0.998 CF_c= 0.997	180 CaCO₃ = 100	20 CaCO₃ = 100	74 X WER	8.2 X WER	610	4,600
Nitrate as N (μg/l) 14797558					10,000
Nitrobenzene (μg/l) 98953					17 68	~~690~~ 2,800
N-Nitrosodimethylamine (μg/l) 62759 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.0069	30
N-Nitrosodiphenylamine (μg/l) 86306 Known or suspected carcinogen; human health criteria at risk level 10^-5.					33	~~160~~ 60
N-Nitrosodi-n-propylamine (μg/l) 621647 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.050	5.1
Nonylphenol (μg/l) ~~1044051~~ 84852153	28	6.6	7.0	1.7
Parathion (μg/l) 56382	0.065	0.013
PCB Total (μg/l) 1336363 Known or suspected carcinogen; human health criteria at risk level 10^-5.		0.014		0.030	0.00064	0.00064
Pentachlorophenol (μg/l) 87865 Known or suspected carcinogen; human health criteria risk level at 10^-5. Freshwater acute criterion (μg/l) e ^{(1.005(pH)-4.869)} Freshwater chronic criterion (μg/l) e^{(1.005(pH)-5.134)}	8.7 pH = 7.0	6.7 pH = 7.0	13	7.9	~~2.7~~ 0.80	30 9.1
pH See 9VAC25-260-50
Phenol (μg/l) 108952					10,000	860,000
Phosphorus Elemental (μg/l) 7723140				0.10
Pyrene (μg/l) 129000					830	4,000
Radionuclides
Gross Alpha Particle Activity (pCi/L)					15
Beta Particle & Photon Activity (mrem/yr) (formerly man-made radionuclides)					4
Combined Radium 226 and 228 (pCi/L)					5
Uranium (μg/L)					30
Selenium (μg/l)⁵ 7782492 WER shall not be used for freshwater acute and chronic criteria. Freshwater criteria expressed as total recoverable.	20	5.0	290 X WER	71 X WER	170	4,200
Silver (μg/l)⁵ 7440224 Freshwater values are a function of total hardness as calcium carbonate (CaCO₃) mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER [e^{{1.72[In(hardness)]-6.52}}] (CF_a) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = natural antilogarithm ln = natural logarithm CF = conversion factor a (acute) or c (chronic) CF_a = 0.85	3.4; CaCO₃ = 100		1.9 X WER
Sulfate (μg/l) Criterion to maintain acceptable taste, odor or aesthetic quality of drinking water and applies at the drinking water intake.					250,000
Temperature See 9VAC25-260-50
1,1,2,2-Tetrachloroethane(μg/l) 79345 Known or suspected carcinogen; human health criteria at risk level 10^-5).					1.7	40
Tetrachloroethylene (μg/l) 127184 Known or suspected carcinogen; human health criteria at risk level 10^-5).					~~6.9~~ 130	33 620
Thallium (μg/l) 7440280					0.24	0.47
Toluene (μg/l) 108883					510	6,000
Total Dissolved Solids (μg/l) Criterion to maintain acceptable taste, odor or aesthetic quality of drinking water and applies at the drinking water intake.					500,000
Toxaphene (μg/l) 8001352 Known or suspected carcinogen; human health criteria at risk level 10^-5.	0.73	0.0002	0.21	0.0002	0.0028	0.0028
Tributyltin (μg/l) 60105	0.46	0.072	0.42	0.0074
1, 2, 4 Trichlorobenzene (μg/l) 120821					35	70
1,1,2-Trichloroethane (μg/l) 79005 Known or suspected carcinogen; human health criteria at risk level 10^-5.					5.9	160
Trichloroethylene (μg/l) 79016 Known or suspected carcinogen; human health criteria at risk level 10^-5.					25 7.0	~~300~~ 82
2, 4, 6-Trichlorophenol (μg/l) 88062 Known or suspected carcinogen; human health criteria at risk level 10^-5.^.					14	24
2-(2, 4, 5-Trichlorophenoxy) propionic acid (Silvex) (μg/l) 93721					50
Vinyl Chloride (μg/l) 75014 Known or suspected carcinogen; human health criteria at risk level 10^-5.					0.25	24
Zinc (μg/l)⁵ 7440666 Freshwater values are a function of total hardness as calcium carbonate (CaCO₃) mg/l and the WER. The minimum hardness allowed for use in the equation below shall be 25 and the maximum, hardness shall be 400 even when the actual ambient hardness is less than 25 or greater than 400. Freshwater acute criterion (μg/l) WER [e ^{{0.8473[In(hardness)]+0.884}}] (CF_a) Freshwater chronic criterion (μg/l) WER [e^{{0.8473[In(hardness)]+0.884}}] (CF_c) WER = Water Effect Ratio = 1 unless determined otherwise under 9VAC25-260-140 F e = ~~base e exponential function.~~ natural antilogarithm ln = ~~log normal function~~ natural logarithm CF = conversion factor a (acute) or c (chronic) CF_a= 0.978 CF_c = 0.986	120 CaCO₃ = 100	120 CaCO₃ = 100	90 X WER	81 X WER	7,400	26,000

¹One hour average concentration not to be exceeded more than once every 3 years on the average, unless otherwise noted.

²Four-day average concentration not to be exceeded more than once every 3 years on the average, unless otherwise noted.

³Criteria have been calculated to protect human health from toxic effects through drinking water and fish consumption, unless otherwise noted and apply in segments designated as PWS in 9VAC25-260-390~~-540~~ through 9VAC25-260-540.

⁴Criteria have been calculated to protect human health from toxic effects through fish consumption, unless otherwise noted and apply in all other surface waters not designated as PWS in 9VAC25-260-390~~-540~~ through 9VAC25-260-540.

⁵Acute and chronic saltwater and freshwater aquatic life criteria apply to the biologically available form of the metal and apply as a function of the pollutant's water effect ratio (WER) as defined in 9VAC25-260-140 F (WER X criterion). Metals measured as dissolved shall be considered to be biologically available, or, because local receiving water characteristics may otherwise affect the biological availability of the metal, the biologically available equivalent measurement of the metal can be further defined by determining a water effect ratio (WER) and multiplying the numerical value shown in 9VAC25-260-140 B by the WER. Refer to 9VAC25-260-140 F. Values displayed above in the table are examples and correspond to a WER of 1.0. Metals criteria have been adjusted to convert the total recoverable fraction to dissolved fraction using a conversion factor. Criteria that change with hardness have the conversion factor listed in the table above.

⁶The flows listed below are default design flows for calculating steady state ~~waste load~~ wasteload allocations unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.

Aquatic Life:
Acute criteria	1Q10
Chronic criteria	7Q10
Chronic criteria (ammonia)	30Q10
Human Health:
Noncarcinogens	30Q5
Carcinogens	Harmonic mean

The following are defined for this section:

"1Q10" means the lowest flow averaged over a period of ~~one~~ 1 day which on a statistical basis can be expected to occur once every 10 climatic years.

"7Q10" means the lowest flow averaged over a period of ~~seven~~ 7 consecutive days that can be statistically expected to occur once every 10 climatic years.

"30Q5" means the lowest flow averaged over a period of 30 consecutive days that can be statistically expected to occur once every ~~five~~ 5 climatic years.

"30Q10" means the lowest flow averaged over a period of 30 consecutive days that can be statistically expected to occur once every 10 climatic years.

"Averaged" means an arithmetic mean.

"Climatic year" means a year beginning on April 1 and ending on March 31.

⁷The criteria listed in this table are two significant digits. For other criteria that are referenced to other sections of this regulation in this table, all numbers listed as criteria values are significant.

⁸The fish tissue criterion for methylmercury applies to a concentration of 0.30 mg/kg as wet weight in edible tissue for species of fish ~~and/or~~ and shellfish resident in a waterbody that are commonly eaten in the area and have commercial, recreational, or subsistence value.

C. Application of freshwater and saltwater numerical criteria. The numerical water quality criteria listed in subsection B of this section (excluding dissolved oxygen, pH, temperature) shall be applied according to the following classes of waters (see 9VAC25-260-50) and boundary designations:

CLASS OF WATERS	NUMERICAL CRITERIA
I and II (Estuarine Waters)	Saltwater criteria apply
II (Transition Zone)	More stringent of either the freshwater or saltwater criteria apply
II (Tidal Freshwater), III, IV, V, VI and VII	Freshwater criteria apply

The following describes the boundary designations for Class II, (estuarine, transition zone and tidal freshwater waters) by river basin:

1. Rappahannock Basin. Tidal freshwater is from the fall line of the Rappahannock River to the upstream boundary of the transition zone including all tidal tributaries that enter the tidal freshwater Rappahannock River.

Transition zone upstream boundary – N38° 4' 56.59"/-W76° 58' 47.93" (430 feet east of Hutchinson Swamp) to N38° 5' 23.33"/-W76° 58' 24.39" (0.7 miles upstream of Peedee Creek).

Transition zone downstream boundary – N37° 58' 45.80"/-W76° 55' 28.75" (1,000 feet downstream of Jenkins Landing) to N37° 59' 20.07/-W76° 53' 45.09" (0.33 miles upstream of Mulberry Point). All tidal waters that enter the transition zone are themselves transition zone waters.

Estuarine waters are from the downstream boundary of the transition zone to the mouth of the Rappahannock River (Buoy 6), including all tidal tributaries that enter the estuarine waters of the Rappahannock River.

2. York Basin. Tidal freshwater is from the fall line of the Mattaponi River at N37° 47' 20.03"/W77° 6' 15.16" (800 feet upstream of the Route 360 bridge in Aylett) to the upstream boundary of the Mattaponi River transition zone, and from the fall line of the Pamunkey River at N37° 41' 22.64"/W77° 12' 50.83" (2,000 feet upstream of Totopotomy Creek) to the upstream boundary of the Pamunkey River transition zone, including all tidal tributaries that enter the tidal freshwaters of the Mattaponi and Pamunkey Rivers.

~~Mattaponni~~ Mattaponi River transition zone upstream boundary – N37° 39' 29.65"/W76° 52' 53.29" (1,000 feet upstream of Mitchell Hill Creek) to N37° 39' 24.20"/W76° 52' 55.87" (across from Courthouse Landing).

Mattaponi River transition zone downstream boundary – N37° 32' 19.76"/W76° 47' 29.41" (old Lord Delaware Bridge, west side) to N37° 32' 13.25"/W76° 47' 10.30" (old Lord Delaware Bridge, east side).

Pamunkey River transition zone upstream boundary – N37° 32' 36.63"/W76° 58' 29.88" (Cohoke Marsh, 0.9 miles upstream of Turkey Creek) to N37° 32' 36.51"/W76° 58' 36.48" (0.75 miles upstream of creek at Cook Landing).

Pamunkey River transition zone downstream boundary – N37° 31' 57.90"/W76° 48' 38.22" (old Eltham Bridge, west side) to N37° 32' 6.25"/W76° 48' 18.82" (old Eltham Bridge, east side).

All tidal tributaries that enter the transition zones of the Mattaponi and Pamunkey Rivers are themselves in the transition zone.

Estuarine waters are from the downstream boundary of the transition zones of the Mattaponi and Pamunkey Rivers to the mouth of the York River (Tue Marsh Light) including all tidal tributaries that enter the estuarine waters of the York River.

3. James Basin. Tidal ~~Freshwater~~ freshwater is from the fall line of the James River in the City of Richmond upstream of Mayo Bridge to the upstream boundary of the transition zone, including all tidal tributaries that enter the tidal freshwater James River.

James River transition zone upstream boundary – N37° 14' 28.25"/W76° 56' 44.47" (at Tettington) to N37° 13' 38.56"/W76° 56' 47.13" (0.3 miles downstream of Sloop Point).

Chickahominy River transition zone upstream boundary – N37° 25' 44.79"/W77° 1' 41.76" (Holly Landing).

Transition zone downstream boundary – N37° 12' 7.23"/W76° 37' 34.70" (near Carters Grove Home, 1.25 miles downstream of Grove Creek) to N37° 9' 17.23"/W76° 40' 13.45" (0.7 miles upstream of Hunnicutt Creek). All tidal waters that enter the transition zone are themselves transition zone waters.

Estuarine waters are from the downstream transition zone boundary to the mouth of the James River (Buoy 25) including all tidal tributaries that enter the estuarine waters of the James River.

4. Potomac Basin. Tidal ~~Freshwater~~ freshwater includes all tidal tributaries that enter the Potomac River from its fall line at the Chain Bridge (N38° 55' 46.28"/W77° 6' 59.23") to the upstream transition zone boundary near Quantico, Virginia.

Transition zone includes all tidal tributaries that enter the Potomac River from N38° 31' 27.05"/W77° 17' 7.06" (midway between Shipping Point and Quantico Pier) to N38° 23' 22.78"/W77° 1' 45.50" (one mile southeast of Mathias Point).

Estuarine waters includes all tidal tributaries that enter the Potomac River from the downstream transition zone boundary to the mouth of the Potomac River (Buoy 44B).

5. Chesapeake Bay, Atlantic Ocean, and small coastal basins. Estuarine waters include the Atlantic Ocean tidal tributaries, and the Chesapeake Bay and its small coastal basins from the Virginia state line to the mouth of the bay (a line from Cape Henry drawn through Buoys 3 and 8 to Fishermans Island), and its tidal tributaries, excluding the Potomac tributaries and those tributaries listed ~~above~~ in subdivisions 1 through 4 of this subsection.

6. Chowan River Basin. Tidal freshwater includes the Northwest River and its tidal tributaries from the Virginia-North Carolina state line to the free flowing portion, the Blackwater River and its tidal tributaries from the Virginia-North Carolina state line to the end of tidal waters at approximately state route 611 at river mile 20.90, the Nottoway River and its tidal tributaries from the Virginia-North Carolina state line to the end of tidal waters at approximately Route 674, and the North Landing River and its tidal tributaries from the Virginia-North Carolina state line to the Great Bridge Lock.

Transition zone includes Back Bay and its tributaries in the City of Virginia Beach to the Virginia-North Carolina state line.

D. Site-specific modifications to numerical water quality criteria.

1. The board may consider site-specific modifications to numerical water quality criteria in subsection B of this section where the applicant or permittee demonstrates that the alternate numerical water quality criteria are sufficient to protect all designated uses (see 9VAC25-260-10) of that particular surface water segment or body.

2. Any demonstration for site-specific human health criteria shall be restricted to a reevaluation of the bioconcentration or bioaccumulation properties of the pollutant. The exceptions to this restriction are for site-specific criteria for taste, odor, and aesthetic compounds noted by double asterisks in subsection B of this section and nitrates.

3. Procedures for promulgation and review of site-specific modifications to numerical water quality criteria resulting from subdivisions 1 and 2 of this subsection.

a. Proposals describing the details of the site-specific study shall be submitted to the board's staff for approval prior to commencing the study.

b. Any site-specific modification shall be promulgated as a regulation in accordance with the Administrative Process Act (§ 2.2-4000 et seq. of the Code of Virginia). All site-specific modifications shall be listed in 9VAC25-260-310 (Special standards and requirements).

E. Variances to water quality standards.

1. A variance from numeric criteria may be granted to a discharger if it can be demonstrated that one or more of the conditions in 9VAC25-260-10 H limit the attainment of one or more specific designated uses.

a. Variances shall apply only to the discharger to whom they are granted and shall be reevaluated and either continued, modified or revoked at the time of permit issuance. At that time the permittee shall make a showing that the conditions for granting the variance still apply.

b. Variances shall be described in the public notice published for the permit. The decision to approve a variance shall be subject to the public participation requirements of the Virginia Pollutant Discharge Elimination System (VPDES) Permit Regulation, 9VAC25-31 (Permit Regulation).

c. Variances shall not prevent the maintenance and protection of existing uses or exempt the discharger or regulated activity from compliance with other appropriate technology or water quality-based limits or best management practices.

d. Variances granted under this section shall not apply to new discharges.

e. Variances shall be submitted by the department's Division of Scientific Research or its successors to the U.S. Environmental Protection Agency for review and approval/ or disapproval.

f. A list of variances granted shall be maintained by the department's Division of Scientific Research or its successors.

2. None of the variances in this subsection shall apply to the halogen ban section (9VAC25-260-110) or temperature criteria in 9VAC25-260-50 if superseded by § 316(a) of the Clean Water Act requirements. No variances in this subsection shall apply to the criteria that are designed to protect human health from carcinogenic and noncarcinogenic toxic effects (subsection B of this section) with the exception of the metals, and the taste, odor, and aesthetic compounds noted by double asterisks and nitrates, listed in subsection B of this section.

F. Water effect ratio.

1. A water effects ratio (WER) shall be determined by measuring the effect of receiving water (as it is or will be affected by any discharges) on the bioavailability or toxicity of a metal by using standard test organisms and a metal to conduct toxicity tests simultaneously in receiving water and laboratory water. The ratio of toxicities of the metal(s) in the two waters is the WER (toxicity in receiving water divided by toxicity in laboratory water = equals WER). Once an acceptable WER for a metal is established, the numerical value for the metal in subsection B of this section is multiplied by the WER to produce an instream concentration that will protect designated uses. This instream concentration shall be utilized in permitting decisions.

2. The WER shall be assigned a value of 1.0 unless the applicant or permittee demonstrates to the department's satisfaction in a permit proceeding that another value is appropriate, or unless available data allow the department to compute a WER for the receiving waters. The applicant or permittee is responsible for proposing and conducting the study to develop a WER. The study may require multiple testing over several seasons. The applicant or permittee shall obtain the department's Division of Scientific Research or its successor approval of the study protocol and the final WER.

3. The Permit Regulation at 9VAC25-31-230 C requires that permit limits for metals be expressed as total recoverable measurements. To that end, the study used to establish the WER may be based on total recoverable measurements of the metals.

4. The Environmental Protection Agency views the WER in any particular case as a site-specific criterion. Therefore, the department's Division of Scientific Research or its successor shall submit the results of the study to the Environmental Protection Agency for review and approval/disapproval within 30 days of the receipt of certification from the state's Office of the Attorney General. Nonetheless, the The WER is established in a permit proceeding, shall be described in the public notice associated with the permit proceeding, and applies only to the applicant or permittee in that proceeding. The department's action to approve or disapprove a WER is a case decision, not an amendment to the present regulation.

The decision to approve or disapprove a WER shall be subject to the public participation requirements of the Permit Regulation, Part IV (9VAC25-31-260 et seq.). A list of final WERs will be maintained by the department's Division of Scientific Research or its successor.

5. A WER shall not be used for the freshwater and saltwater chronic mercury criteria or the freshwater acute and chronic selenium criteria.

G. Biotic Ligand Model for copper. On a case-by-case basis, EPA's 2007 copper criteria (EPA-822-F-07-001) biotic ligand model (BLM) for copper may be used to determine alternate copper criteria for freshwater sites. The BLM is a bioavailability model that uses receiving water characteristics to develop site-specific criteria. Site-specific data for 10 parameters are needed to use the BLM. These parameters are temperature, pH, dissolved organic carbon, calcium, magnesium, sodium, potassium, sulfate, chloride, and alkalinity. If sufficient data for these parameters are available, the BLM can be used to calculate alternate criteria values for the copper criteria. The BLM would be used instead of the hardness-based criteria and takes the place of the hardness adjustment and the WER. A WER will not be applicable with the BLM.

9VAC25-260-155. Ammonia surface water quality criteria.

A. The Department of Environmental Quality, after consultation with the Virginia Department of Game and Inland Fisheries and the U.S. Fish and Wildlife Service, has determined that the majority of Virginia freshwaters are likely to contain, or have contained in the past, freshwater mussel species in the family Unionidae and contain early life stages of fish during most times of the year. Therefore, the ammonia criteria presented in subsections B and C of this section are designed to provide protection to these species and life stages. In an instance where it can be adequately demonstrated that either freshwater mussels or early life stages of fish are not present in a specific waterbody, potential options for alternate, site-specific criteria are presented in subsection D of this section. Acute criteria are a one-hour average concentration not to be exceeded more than once every three years¹ on the average, and chronic criteria are 30-day average concentrations not to be exceeded more than once every three years on the average².

A. B. The ~~one-hour average concentration of total ammonia nitrogen (in mg N/L) in freshwater shall not exceed, more than once every three years on the average¹, the~~ acute criteria for total ammonia (in mg N/L) for freshwaters with trout absent or present are below:

Acute Ammonia Freshwater Criteria Total Ammonia Nitrogen (mg N/L)
pH	~~Trout Present~~	~~Trout Absent~~
~~6.5~~	~~32.6~~	~~48.8~~
~~6.6~~	~~31.3~~	~~46.8~~
~~6.7~~	~~29.8~~	~~44.6~~
~~6.8~~	~~28.1~~	~~42.0~~
~~6.9~~	~~26.2~~	~~39.1~~
~~7.0~~	~~24.1~~	~~36.1~~
~~7.1~~	~~22.0~~	~~32.8~~
~~7.2~~	~~19.7~~	~~29.5~~
~~7.3~~	~~17.5~~	~~26.2~~
~~7.4~~	~~15.4~~	~~23.0~~
~~7.5~~	~~13.3~~	~~19.9~~
~~7.6~~	~~11.4~~	~~17.0~~
~~7.7~~	~~9.65~~	~~14.4~~
~~7.8~~	~~8.11~~	~~12.1~~
~~7.9~~	~~6.77~~	~~10.1~~
~~8.0~~	~~5.62~~	~~8.40~~
~~8.1~~	~~4.64~~	~~6.95~~
~~8.2~~	~~3.83~~	~~5.72~~
~~8.3~~	~~3.15~~	~~4.71~~
~~8.4~~	~~2.59~~	~~3.88~~
~~8.5~~	~~2.14~~	~~3.20~~
~~8.6~~	~~1.77~~	~~2.65~~
~~8.7~~	~~1.47~~	~~2.20~~
~~8.8~~	~~1.23~~	~~1.84~~
~~8.9~~	~~1.04~~	~~1.56~~
~~9.0~~	~~0.885~~	~~1.32~~

The acute criteria for trout present shall apply to all Class V-Stockable Trout Waters and Class VI-Natural Trout Waters as listed in 9VAC25-260-390 through 9VAC25-260-540. The acute criteria for trout absent apply to all other fresh waters.

To calculate total ammonia nitrogen acute criteria values in freshwater at different pH values than those listed in this subsection, use the following ~~formulas~~ equations and round the result to two significant digits:

Where trout are ~~present~~ absent:

Acute Criterion Concentration (mg N/L) =

~~0.275~~			+	~~39.0~~
~~(1 + 10^7.204-pH)~~				~~(1 + 10^pH-7.204)~~

	0.7249 X (	0.0114			+	1.6181	) X MIN
		1 + 10^7.204-pH				1 + 10^pH-7.204

Where MIN = 51.93 or 23.12 X 10^{0.036 X (20 – T)}, whichever is less.

T = Temperature in ^oC

Or where trout are ~~absent~~ present, whichever of the below calculation results is less:

Acute Criterion Concentration (mg N/L) =

~~0.411~~	+	~~58.4~~
~~(1 + 10^7.204-pH)~~	+	~~(1 + 10^pH-7.204)~~

(	0.275	+	39.0	)
	1 + 10^7.204-pH		1 + 10^pH-7.204

	0.7249 X (	0.0114	+	1.6181	) X (23.12 X 10^{0.036X(20 – T)})
	0.7249 X (	1 + 10^7.204-pH	+	1 + 10^pH-7.204	) X (23.12 X 10^{0.036X(20 – T)})

T = Temperature in ^oC

¹The default design flow for calculating steady state waste load allocations for the acute ammonia criterion is the 1Q10 (see 9VAC25-260-140 B footnote 10) unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.

B. C. The ~~30-day average concentration of~~ chronic criteria for total ammonia nitrogen (in mg N/L) where freshwater mussels and early life stages of fish are present in freshwater ~~shall not exceed, more than once every three years on the average², the chronic criteria~~ are below:

Chronic Ammonia Freshwater Criteria Early Life Stages of Fish Present Total Ammonia Nitrogen (mg N/L)
	~~Temperature (°C)~~
pH	0	14	16	18	20	22	24	26	28	30
~~6.5~~	~~6.67~~	~~6.67~~	~~6.06~~	~~5.33~~	~~4.68~~	~~4.12~~	~~3.62~~	~~3.18~~	~~2.80~~	~~2.46~~
~~6.6~~	~~6.57~~	~~6.57~~	~~5.97~~	~~5.25~~	~~4.61~~	~~4.05~~	~~3.56~~	~~3.13~~	~~2.75~~	~~2.42~~
~~6.7~~	~~6.44~~	~~6.44~~	~~5.86~~	~~5.15~~	~~4.52~~	~~3.98~~	~~3.50~~	~~3.07~~	~~2.70~~	~~2.37~~
~~6.8~~	~~6.29~~	~~6.29~~	~~5.72~~	~~5.03~~	~~4.42~~	~~3.89~~	~~3.42~~	~~3.00~~	~~2.64~~	~~2.32~~
~~6.9~~	~~6.12~~	~~6.12~~	~~5.56~~	~~4.89~~	~~4.30~~	~~3.78~~	~~3.32~~	~~2.92~~	~~2.57~~	~~2.25~~
~~7.0~~	~~5.91~~	~~5.91~~	~~5.37~~	~~4.72~~	~~4.15~~	~~3.65~~	~~3.21~~	~~2.82~~	~~2.48~~	~~2.18~~
~~7.1~~	~~5.67~~	~~5.67~~	~~5.15~~	~~4.53~~	~~3.98~~	~~3.50~~	~~3.08~~	~~2.70~~	~~2.38~~	~~2.09~~
~~7.2~~	~~5.39~~	~~5.39~~	~~4.90~~	~~4.31~~	~~3.78~~	~~3.33~~	~~2.92~~	~~2.57~~	~~2.26~~	~~1.99~~
~~7.3~~	~~5.08~~	~~5.08~~	~~4.61~~	~~4.06~~	~~3.57~~	~~3.13~~	~~2.76~~	~~2.42~~	~~2.13~~	~~1.87~~
~~7.4~~	~~4.73~~	~~4.73~~	~~4.30~~	~~3.78~~	~~3.32~~	~~2.92~~	~~2.57~~	~~2.26~~	~~1.98~~	~~1.74~~
~~7.5~~	~~4.36~~	~~4.36~~	~~3.97~~	~~3.49~~	~~3.06~~	~~2.69~~	~~2.37~~	~~2.08~~	~~1.83~~	~~1.61~~
~~7.6~~	~~3.98~~	~~3.98~~	~~3.61~~	~~3.18~~	~~2.79~~	~~2.45~~	~~2.16~~	~~1.90~~	~~1.67~~	~~1.47~~
~~7.7~~	~~3.58~~	~~3.58~~	~~3.25~~	~~2.86~~	~~2.51~~	~~2.21~~	~~1.94~~	~~1.71~~	~~1.50~~	~~1.32~~
~~7.8~~	~~3.18~~	~~3.18~~	~~2.89~~	~~2.54~~	~~2.23~~	~~1.96~~	~~1.73~~	~~1.52~~	~~1.33~~	~~1.17~~
~~7.9~~	~~2.80~~	~~2.80~~	~~2.54~~	~~2.24~~	~~1.96~~	~~1.73~~	~~1.52~~	~~1.33~~	~~1.17~~	~~1.03~~
~~8.0~~	~~2.43~~	~~2.43~~	~~2.21~~	~~1.94~~	~~1.71~~	~~1.50~~	~~1.32~~	~~1.16~~	~~1.02~~	~~0.897~~
~~8.1~~	~~2.10~~	~~2.10~~	~~1.91~~	~~1.68~~	~~1.47~~	~~1.29~~	~~1.14~~	~~1.00~~	~~0.879~~	~~0.773~~
~~8.2~~	~~1.79~~	~~1.79~~	~~1.63~~	~~1.43~~	~~1.26~~	~~1.11~~	~~0.973~~	~~0.855~~	~~0.752~~	~~0.661~~
~~8.3~~	~~1.52~~	~~1.52~~	~~1.39~~	~~1.22~~	~~1.07~~	~~0.941~~	~~0.827~~	~~0.727~~	~~0.639~~	~~0.562~~
~~8.4~~	~~1.29~~	~~1.29~~	~~1.17~~	~~1.03~~	~~0.906~~	~~0.796~~	~~0.700~~	~~0.615~~	~~0.541~~	~~0.475~~
~~8.5~~	~~1.09~~	~~1.09~~	~~0.990~~	~~0.870~~	~~0.765~~	~~0.672~~	~~0.591~~	~~0.520~~	~~0.457~~	~~0.401~~
~~8.6~~	~~0.920~~	~~0.920~~	~~0.836~~	~~0.735~~	~~0.646~~	~~0.568~~	~~0.499~~	~~0.439~~	~~0.386~~	~~0.339~~
~~8.7~~	~~0.778~~	~~0.778~~	~~0.707~~	~~0.622~~	~~0.547~~	~~0.480~~	~~0.422~~	~~0.371~~	~~0.326~~	~~0.287~~
~~8.8~~	~~0.661~~	~~0.661~~	~~0.601~~	~~0.528~~	~~0.464~~	~~0.408~~	~~0.359~~	~~0.315~~	~~0.277~~	~~0.244~~
~~8.9~~	~~0.565~~	~~0.565~~	~~0.513~~	~~0.451~~	~~0.397~~	~~0.349~~	~~0.306~~	~~0.269~~	~~0.237~~	~~0.208~~
~~9.0~~	~~0.486~~	~~0.486~~	~~0.442~~	~~0.389~~	~~0.342~~	~~0.300~~	~~0.264~~	~~0.232~~	~~0.204~~	~~0.179~~

To calculate total ammonia nitrogen chronic criteria values in freshwater when ~~fish~~ freshwater mussels and early life stages of fish are present at different pH and temperature values than those listed in this subsection, use the following ~~formulas~~ equation and round the result to two significant digits:

Chronic Criteria Concentration =

(	~~0.0577~~	+	~~2.487~~	)	~~x MIN~~
	~~(1 + 10^7.688-pH)~~		~~(1 + 10^pH-7.688)~~

~~Where MIN = 2.85 or 1.45 x 10^0.028(25-T), whichever is less.~~

0.8876 X (	0.0278	+	1.1994	) X (2.126 X 10^{0.028 X (20 - MAX(T,7))})
	1 + 10^7.688-pH		1 + 10^pH-7.688

Where MAX = 7 or temperature in degrees Celsius, whichever is greater.

T = temperature in °C

²The default design flow for calculating steady state waste load allocations for the chronic ammonia criterion where early life stages of fish are present is the 30Q10 (see 9VAC25-260-140 B footnote 10) unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.

D. Site-specific considerations and alternate criteria. If it can be adequately demonstrated that freshwater mussels or early life stages of fish are not present at a site, then alternate site-specific criteria can be considered using the information provided in this subsection. Recalculated site-specific criteria shall provide for the attainment and maintenance of the water quality standards of downstream waters.

1. Site-specific modifications to the ambient water quality criteria for ammonia to account for the absence of freshwater mussels or early life stages of fish shall be conducted in accordance with the procedures contained in this subdivision. Because the department presumes that most state waterbodies have freshwater mussels and early life stages of fish present during most times of the year, the criteria shall be calculated assuming freshwater mussels and early life stages of fish are present using subsections B and C of this section unless the following demonstration that freshwater mussels or early life stages of fish are absent is successfully completed. Determination of the absence of freshwater mussels requires special field survey methods. This determination must be made after an adequate survey of the waterbody is conducted by an individual certified by the Virginia Department of Game and Inland Fisheries (DGIF) for freshwater mussel identification and surveys. Determination of absence of freshwater mussels will be done in consultation with the DGIF. Early life stages of fish are defined in subdivision 2 of this subsection. Modifications to the ambient water quality criteria for ammonia based on the presence or absence of early life stages of fish shall only apply at temperatures below 15°C.

a. During the review of any new or existing activity that has a potential to discharge ammonia in amounts that may cause or contribute to a violation of the ammonia criteria contained in subsection B of this section, the department may examine data from the following approved sources in subdivisions 1 a (1) through (5) of this subsection or may require the gathering of data in accordance with subdivisions 1 a (1) through (5) on the presence or absence of early life stages of fish in the affected waterbody.

(1) Species and distribution data contained in the Virginia Department of Game and Inland Fisheries Wildlife Information System database.

(2) Species and distribution data contained in Freshwater Fishes of Virginia, 1994.

(3) Data and fish species distribution maps contained in Handbook for Fishery Biology, Volume 3, 1997.

(4) Field data collected in accordance with U.S. EPA's Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers, Second Edition, EPA 841-B-99-002. Field data must comply with all quality assurance and quality control criteria.

(5) The American Society for Testing and Materials (ASTM) Standard E-1241-88, Standard Guide for Conducting Early Life-Stage Toxicity Tests with Fishes.

b. If data or information from sources other than subdivisions 1 a (1) through (5) of this subsection are considered, then any resulting site-specific criteria modifications shall be reviewed and adopted in accordance with the site-specific criteria provisions in 9VAC25-260-140 D, and submitted to EPA for review and approval.

c. If the department determines that the data and information obtained from subdivisions 1 a (1) through (5) of this subsection demonstrate that there are periods of each year when no early life stages are expected to be present for any species of fish that occur at the site, the department shall issue a notice to the public and make available for public comment the supporting data and analysis along with the department's preliminary decision to authorize the site-specific modification to the ammonia criteria. Such information shall include, at a minimum:

(1) Sources of data and information.

(2) List of fish species that occur at the site as defined in subdivision 3 of this subsection.

(3) Definition of the site. Definition of a "site" can vary in geographic size from a stream segment to a watershed to an entire eco-region.

(4) Duration of early life stage for each species in subdivision 1 c (2) of this subsection.

(5) Dates when early life stages of fish are expected to be present for each species in subdivision 1 c (2) of this subsection.

(6) Based on subdivision 1 c (5) of this subsection, identify the dates (beginning date, ending date), if any, where no early life stages are expected to be present for any of the species identified in subdivision 1 c (2) of this subsection.

d. If, after reviewing the public comments received in subdivision 1 c of this subsection and supporting data and information, the department determines that there are times of the year where no early life stages are expected to be present for any fish species that occur at the site, then the applicable ambient water quality criteria for ammonia for those time periods shall be calculated using the table in this subsection, or the formula for calculating the chronic criterion concentration for ammonia when early life stages of fish are absent.

e. The department shall maintain a comprehensive list of all sites where the department has determined that early life stages of fish are absent. For each site the list will identify the waterbodies affected and the corresponding times of the year that early life stages of fish are absent. This list is available either upon request from the Office of Water Quality Programs at 629 East Main Street, Richmond, VA 23219, or from the department website at http://www.deq.virginia.gov/programs/water/waterqualityinformationtmdls/waterqualitystandards.aspx.

2. The duration of the "early life stages" extends from the beginning of spawning through the end of the early life stages. The early life stages include the prehatch embryonic period, the post-hatch free embryo or yolk-sac fry, and the larval period, during which the organism feeds. Juvenile fish, which are anatomically similar to adults, are not considered an early life stage. The duration of early life stages can vary according to fish species. The department considers the sources of information in subdivisions 1 a (1) through (5) of this subsection to be the only acceptable sources of information for determining the duration of early life stages of fish under this procedure.

3. "Occur at the site" includes the species, genera, families, orders, classes, and phyla that are usually present at the site; are present at the site only seasonally due to migration; are present intermittently because they periodically return to or extend their ranges into the site; or were present at the site in the past or are present in nearby bodies of water, but are not currently present at the site due to degraded conditions, and are expected to return to the site when conditions improve. "Occur at the site" does not include taxa that were once present at the site but cannot exist at the site now due to permanent physical alteration of the habitat at the site.

4. Any modifications to ambient water quality criteria for ammonia in subdivision 1 of this subsection shall not likely jeopardize the continued existence of any federal or state listed, threatened, or endangered species or result in the destruction or adverse modification of such species' critical habitats.

5. Site-specific modifications to the ambient water quality criteria for ammonia to account for the absence of freshwater mussels shall be conducted in accordance with the procedures contained in this subdivision. Because the department presumes that most state waterbodies have freshwater mussel species, the criteria shall be calculated assuming mussels are present using subsections B and C of this section unless the demonstration that freshwater mussels are absent is successfully completed and accepted by DEQ and DGIF.

6. Equations for calculating ammonia criteria for four different site-specific scenarios are provided below as follows: (i) acute criteria when mussels are absent but trout are present, (ii) acute criteria when mussels and trout are absent, (iii) chronic criteria when mussels are absent and early life stages of fish are present, and (iv) chronic criteria when mussels and early life stages of fish are absent. Additional information regarding site-specific criteria can be reviewed in appendix N (pages 225-242) of the EPA Aquatic Life Ambient Water Quality Criteria to Ammonia--Freshwater 2013 (EPA 822-R-13-001).

a. Acute criteria: freshwater mussels absent and trout present.

To calculate total ammonia nitrogen acute criteria values (in mg N/L) in freshwater with freshwater mussels absent (procedures for making this determination are in subdivisions 1 through 5 of this subsection) and trout present, use the equations below. The acute criterion is the lesser of the calculation results below. Round the result to two significant digits.

(	0.275	+	39	)
	1 + 10^7.204-pH		1 + 10^pH-7.204

0.7249 X (	0.0114	+	1.6181	) X (62.15 X 10^{0.036X(20 – T)})
	1 + 10^7.204-pH		1 + 10^pH-7.204

b. Acute criteria: freshwater mussels absent and trout absent.

To calculate total ammonia nitrogen acute criteria values (in mg N/L) in freshwater where freshwater mussels are absent and trout are absent, use the following equation. Round the result to two significant digits.

0.7249 X (	0.0114	+	1.6181	) X MIN
	1 + 10^7.204-pH		1 + 10^pH-7.204

Where MIN = 51.93 or 62.15 X 10^{0.036 X (20 – T)}, whichever is less.

T = Temperature in ^oC.

c. Chronic criteria: freshwater mussels absent and early life stages of fish present.

~~C. The 30-day average concentration of~~ The chronic criteria for total ammonia nitrogen (in mg N/L) where ~~early life stages of fish~~ freshwater mussels are absent (procedures for making this determination are in subdivisions 1 through 4 5 of this subsection) in freshwater shall not exceed~~, more than once every three years on the average³, the chronic criteria~~ concentration values calculated using the equation below:. Round the result to two significant digits.

Chronic Ammonia Freshwater Criteria Early Life Stages of Fish Absent Total Ammonia Nitrogen (mg N/L)
	~~Temperature (°C)~~
pH	~~0-7~~	8	9	10	11	12	13	14	15	16
~~6.5~~	~~10.8~~	~~10.1~~	~~9.51~~	~~8.92~~	~~8.36~~	~~7.84~~	~~7.35~~	~~6.89~~	~~6.46~~	~~6.06~~
~~6.6~~	~~10.7~~	~~9.99~~	~~9.37~~	~~8.79~~	~~8.24~~	~~7.72~~	~~7.24~~	~~6.79~~	~~6.36~~	~~5.97~~
~~6.7~~	~~10.5~~	~~9.81~~	~~9.20~~	~~8.62~~	~~8.08~~	~~7.58~~	~~7.11~~	~~6.66~~	~~6.25~~	~~5.86~~
~~6.8~~	~~10.2~~	~~9.58~~	~~8.98~~	~~8.42~~	~~7.90~~	~~7.40~~	~~6.94~~	~~6.51~~	~~6.10~~	~~5.72~~
~~6.9~~	~~9.93~~	~~9.31~~	~~8.73~~	~~8.19~~	~~7.68~~	~~7.20~~	~~6.75~~	~~6.33~~	~~5.93~~	~~5.56~~
~~7.0~~	~~9.60~~	~~9.00~~	~~8.43~~	~~7.91~~	~~7.41~~	~~6.95~~	~~6.52~~	~~6.11~~	~~5.73~~	~~5.37~~
~~7.1~~	~~9.20~~	~~8.63~~	~~8.09~~	~~7.58~~	~~7.11~~	~~6.67~~	~~6.25~~	~~5.86~~	~~5.49~~	~~5.15~~
~~7.2~~	~~8.75~~	~~8.20~~	~~7.69~~	~~7.21~~	~~6.76~~	~~6.34~~	~~5.94~~	~~5.57~~	~~5.22~~	~~4.90~~
~~7.3~~	~~8.24~~	~~7.73~~	~~7.25~~	~~6.79~~	~~6.37~~	~~5.97~~	~~5.60~~	~~5.25~~	~~4.92~~	~~4.61~~
~~7.4~~	~~7.69~~	~~7.21~~	~~6.76~~	~~6.33~~	~~5.94~~	~~5.57~~	~~5.22~~	~~4.89~~	~~4.59~~	~~4.30~~
~~7.5~~	~~7.09~~	~~6.64~~	~~6.23~~	~~5.84~~	~~5.48~~	~~5.13~~	~~4.81~~	~~4.51~~	~~4.23~~	~~3.97~~
~~7.6~~	~~6.46~~	~~6.05~~	~~5.67~~	~~5.32~~	~~4.99~~	~~4.68~~	~~4.38~~	~~4.11~~	~~3.85~~	~~3.61~~
~~7.7~~	~~5.81~~	~~5.45~~	~~5.11~~	~~4.79~~	~~4.49~~	~~4.21~~	~~3.95~~	~~3.70~~	~~3.47~~	~~3.25~~
~~7.8~~	~~5.17~~	~~4.84~~	~~4.54~~	~~4.26~~	~~3.99~~	~~3.74~~	~~3.51~~	~~3.29~~	~~3.09~~	~~2.89~~
~~7.9~~	~~4.54~~	~~4.26~~	~~3.99~~	~~3.74~~	~~3.51~~	~~3.29~~	~~3.09~~	~~2.89~~	~~2.71~~	~~2.54~~
~~8.0~~	~~3.95~~	~~3.70~~	~~3.47~~	~~3.26~~	~~3.05~~	~~2.86~~	~~2.68~~	~~2.52~~	~~2.36~~	~~2.21~~
~~8.1~~	~~3.41~~	~~3.19~~	~~2.99~~	~~2.81~~	~~2.63~~	~~2.47~~	~~2.31~~	~~2.17~~	~~2.03~~	~~1.91~~
~~8.2~~	~~2.91~~	~~2.73~~	~~2.56~~	~~2.40~~	~~2.25~~	~~2.11~~	~~1.98~~	~~1.85~~	~~1.74~~	~~1.63~~
~~8.3~~	~~2.47~~	~~2.32~~	~~2.18~~	~~2.04~~	~~1.91~~	~~1.79~~	~~1.68~~	~~1.58~~	~~1.48~~	~~1.39~~
~~8.4~~	~~2.09~~	~~1.96~~	~~1.84~~	~~1.73~~	~~1.62~~	~~1.52~~	~~1.42~~	~~1.33~~	~~1.25~~	~~1.17~~
~~8.5~~	~~1.77~~	~~1.66~~	~~1.55~~	~~1.46~~	~~1.37~~	~~1.28~~	~~1.20~~	~~1.13~~	~~1.06~~	~~0.990~~
~~8.6~~	~~1.49~~	~~1.40~~	~~1.31~~	~~1.23~~	~~1.15~~	~~1.08~~	~~1.01~~	~~0.951~~	~~0.892~~	~~0.836~~
~~8.7~~	~~1.26~~	~~1.18~~	~~1.11~~	~~1.04~~	~~0.976~~	~~0.915~~	~~0.858~~	~~0.805~~	~~0.754~~	~~0.707~~
~~8.8~~	~~1.07~~	~~1.01~~	~~0.944~~	~~0.885~~	~~0.829~~	~~0.778~~	~~0.729~~	~~0.684~~	~~0.641~~	~~0.601~~
~~8.9~~	~~0.917~~	~~0.860~~	~~0.806~~	~~0.756~~	~~0.709~~	~~0.664~~	~~0.623~~	~~0.584~~	~~0.548~~	~~0.513~~
~~9.0~~	~~0.790~~	~~0.740~~	~~0.694~~	~~0.651~~	~~0.610~~	~~0.572~~	~~0.536~~	~~0.503~~	~~0.471~~	~~0.442~~

~~At 15°C and above, the criterion for fish early life stages absent is the same as the criterion for fish early life stages present.~~

To calculate total ammonia nitrogen chronic criteria values in freshwater when fish early life stages are absent at different pH and temperature values than those listed in this subsection, use the following formulas:

~~Chronic Criteria Concentration =~~

(	~~0.0577~~	+	~~2.487~~	)	~~x 1.45(10^{0.028(25-MAX)})~~
	~~(1 + 10^7.688-pH)~~		~~(1 + 10^pH-7.688)~~

~~MAX = temperature in °C or 7, whichever is greater.~~

0.9405 X (	0.0278	+	1.1994	) X MIN
	1 + 10^7.688-pH		1 + 10^pH-7.688

Where MIN = 6.920 or 7.547 X 10^{0.028 x (20 – T)}whichever is less

T = temperature in °C

³The default design flow for calculating steady state waste load allocations for the chronic ammonia criterion where early life stages of fish are absent is the 30Q10 (see 9VAC25-260-140 B footnote 10) unless statistically valid methods are employed that demonstrate compliance with the duration and return frequency of the water quality criteria.

1. Site-specific modifications to the ambient water quality criteria for ammonia to account for the absence of early life stages of fish shall be conducted in accordance with the procedures contained in this subdivision. Because the department presumes that most state waterbodies have early life stages of fish present during most times of the year, the criteria shall be calculated assuming early life stages of fish are present using subsection B of this section unless the following demonstration that early life stages are absent is successfully completed. Early life stages of fish are defined in subdivision 2 of this subsection. Modifications to the ambient water quality criteria for ammonia based on the presence or absence of early life stages of fish shall only apply at temperatures below 15°C.

~~(1) Species and distribution data contained in the Virginia Department of Game and Inland Fisheries Wildlife Information System database.~~

~~(2) Species and distribution data contained in Freshwater Fishes of Virginia, 1994.~~

~~(3) Data and fish species distribution maps contained in Handbook for Fishery Biology, Volume 3, 1997.~~

~~(5) The American Society for Testing and Materials (ASTM) Standard E-1241-88, Standard Guide for Conducting Early Life-Stage Toxicity Tests with Fishes.~~

~~(1) Sources of data and information.~~

~~(2) List of fish species that occur at the site as defined by subdivision 3 of this subsection.~~

~~(3) Definition of the site. Definition of a "site" can vary in geographic size from a stream segment to a watershed to an entire eco-region.~~

~~(4) Duration of early life stage for each species in subdivision 1 c (2) of this subsection.~~

~~(5) Dates when early life stages of fish are expected to be present for each species in subdivision 1 c (2) of this subsection.~~

e. The department shall maintain a comprehensive list of all sites where the department has determined that early life stages of fish are absent. For each site the list will identify the waterbodies affected and the corresponding times of the year that early life stages are absent. This list is available either upon request from the Office of Water Quality Programs at P.O. Box 1105, Richmond, Virginia 23218 or from the department website http://www.deq.virginia.gov/wqs.

3. "Occur at the site" includes the species, genera, families, orders, classes, and phyla that: are usually present at the site; are present at the site only seasonally due to migration; are present intermittently because they periodically return to or extend their ranges into the site; were present at the site in the past or are present in nearby bodies of water, but are not currently present at the site due to degraded conditions, and are expected to return to the site when conditions improve. "Occur at the site" does not include taxa that were once present at the site but cannot exist at the site now due to permanent physical alteration of the habitat at the site.

4. Any modifications to ambient water quality criteria for ammonia in subdivision 1 of this subsection shall not likely jeopardize the continued existence of any federal or state listed, threatened or endangered species or result in the destruction or adverse modification of such species' critical habitat.

d. Chronic criteria: freshwater mussels absent and early life stages of fish absent.

The chronic criteria for total ammonia nitrogen (in mg N/L) where freshwater mussels are absent and early life stages of fish are absent (procedures for making this determination are in subdivisions 1 through 5 of this subsection in freshwater shall not exceed concentration values calculated using the equation below. Round the result to two significant digits.

0.9405 X (	0.0278	+	1.1994	) X(7.547 X 10^{0.028 X (20 -} ^MAX(T,7)))
	1 + 10^7.688-pH		1 + 10^pH-7.688

Where MAX = 7 or temperature in degrees Celsius, whichever is greater.

T = temperature in °C

D. E. The one-hour average concentration of total ammonia nitrogen (in mg N/L) in saltwater shall not exceed, more than once every three years on the average, the acute criteria below:

Acute Ammonia Saltwater Criteria Total Ammonia Nitrogen (mg N/L) Salinity = 10 g/kg
	Temperature °C
pH	0		5		10		15		20		25		30		35
7.00	231.9		159.8		110.1		75.88		52.31		36.08		24.91		17.21
7.20	146.4		100.9		69.54		47.95		33.08		22.84		15.79		10.93
7.40	92.45		63.73		43.94		30.32		20.94		14.48		10.03		6.97
7.60	58.40		40.28		27.80		19.20		13.28		9.21		6.40		4.47
7.80	36.92		25.48		17.61		12.19		8.45		5.88		4.11		2.89
8.00	23.37		16.15		11.18		7.76		5.40		3.78		2.66		1.89
8.20	14.81		10.26		7.13		4.97		3.48		2.46		1.75		1.27
8.40	9.42		6.54		4.57		3.20		2.27		1.62		1.18		0.87
8.60	6.01		4.20		2.95		2.09		1.50		1.09		0.81		0.62
8.80	3.86		2.72		1.93		1.39		1.02		0.76		0.58		0.46
9.00	2.51		1.79		1.29		0.95		0.71		0.55		0.44		0.36
Salinity = 20 g/kg
		Temperature °C
pH		0		5		10		15		20		25		30		35
7.00		247.6		170.5		117.5		80.98		55.83		38.51		26.58		18.36
7.20		156.3		107.7		74.21		51.17		35.30		24.37		16.84		11.66
7.40		98.67		68.01		46.90		32.35		22.34		15.44		10.70		7.43
7.60		62.33		42.98		29.66		20.48		14.17		9.82		6.82		4.76
7.80		39.40		27.19		18.78		13.00		9.01		6.26		4.37		3.07
8.00		24.93		17.23		11.92		8.27		5.76		4.02		2.83		2.01
8.20		15.80		10.94		7.59		5.29		3.70		2.61		1.86		1.34
8.40		10.04		6.97		4.86		3.41		2.41		1.72		1.24		0.91
8.60		6.41		4.47		3.14		2.22		1.59		1.15		0.85		0.65
8.80		4.11		2.89		2.05		1.47		1.07		0.80		0.61		0.48
9.00		2.67		1.90		1.36		1.00		0.75		0.57		0.46		0.37
Salinity = 30 g/kg
	Temperature °C
pH	0		5		10		15		20		25		30		35
7.00	264.6		182.3		125.6		86.55		59.66		41.15		28.39		19.61
7.20	167.0		115.1		79.31		54.68		37.71		26.03		17.99		12.45
7.40	105.5		72.68		50.11		34.57		23.87		16.50		11.42		7.92
7.60	66.61		45.93		31.69		21.88		15.13		10.48		7.28		5.07
7.80	42.10		29.05		20.07		13.88		9.62		6.68		4.66		3.27
8.00	26.63		18.40		12.73		8.83		6.14		4.29		3.01		2.13
8.20	16.88		11.68		8.10		5.64		3.94		2.78		1.97		1.42
8.40	10.72		7.44		5.18		3.63		2.56		1.82		1.31		0.96
8.60	6.83		4.77		3.34		2.36		1.69		1.22		0.90		0.68
8.80	4.38		3.08		2.18		1.56		1.13		0.84		0.64		0.50
9.00	2.84		2.01		1.45		1.06		0.79		0.60		0.47		0.39

To calculate total ammonia nitrogen acute criteria values in saltwater at different pH and temperature values than those listed in this subsection, use the following formulas:

I =	19.9273S
	(1000 - 1.005109S)

Where I = molal ionic strength of water

S = Salinity ppt (g/kg)

The regression model used to relate I to pKa (negative log of the ionization constant) is

pKa = 9.245 + ~~.138I~~ 0.138(I)

pKa as defined by these equations is at 298 degrees Kelvin (25°C). T °Kelvin = °C + 273

To correct for other temperatures:

pKa^S_T = pKa^S₂₉₈ + ~~.0324(298 - T °Kelvin)~~ 0.0324(298 - T °Kelvin)

The unionized ammonia fraction (UIA) is given by:

UIA =	1
	_{1 + 10}(pKa^S_T-pH)

The acute ammonia criterion in saltwater is given by:

Acute =	~~.233~~ 0.233
	UIA

Multiply the acute value by ~~.822~~ 0.822 to get the ammonia-N acute criterion.

E. F. The 30-day average concentration of total ammonia nitrogen (in mg N/L) in saltwater shall not exceed, more than once every three years on the average, the chronic criteria below:

Chronic Ammonia Saltwater Criteria Total Ammonia Nitrogen (mg N/L) Salinity = 10 g/kg
		Temperature °C
pH		0		5			10			15			20			25			30		35
7.00		34.84		24.00			16.54			11.40			7.86			5.42			3.74		2.59
7.20		21.99		15.15			10.45			7.20			4.97			3.43			2.37		1.64
7.40		13.89		9.57			6.60			4.55			3.15			2.18			1.51		1.05
7.60		8.77		6.05			4.18			2.88			2.00			1.38			0.96		0.67
7.80		5.55		3.83			2.65			1.83			1.27			0.88			0.62		0.43
8.00		3.51		2.43			1.68			1.17			0.81			0.57			0.40		0.28
8.20		2.23		1.54			1.07			0.75			0.52			0.37			0.26		0.19
8.40		1.41		0.98			0.69			0.48			0.34			0.24			0.18		0.13
8.60		0.90		0.63			0.44			0.31			0.23			0.16			0.12		0.09
8.80		0.58		0.41			0.29			0.21			0.15			0.11			0.09		0.07
9.00		0.38		0.27			0.19			0.14			0.11			0.08			0.07		0.05
Salinity = 20 g/kg
	Temperature °C
pH	0		5			10		15			20			25			30			35
7.00	37.19		25.62			17.65		12.16			8.39			5.78			3.99			2.76
7.20	23.47		16.17			11.15		7.69			5.30			3.66			2.53			1.75
7.40	14.82		10.22			7.04		4.86			3.36			2.32			1.61			1.12
7.60	9.36		6.46			4.46		3.08			2.13			1.47			1.02			0.71
7.80	5.92		4.08			2.82		1.95			1.35			0.94			0.66			0.46
8.00	3.74		2.59			1.79		1.24			0.86			0.60			0.43			0.30
8.20	2.37		1.64			1.14		0.79			0.56			0.39			0.28			0.20
8.40	1.51		1.05			0.73		0.51			0.36			0.26			0.19			0.14
8.60	0.96		0.67			0.47		0.33			0.24			0.17			0.13			0.10
8.80	0.62		0.43			0.31		0.22			0.16			0.12			0.09			0.07
9.00	0.40		0.28			0.20		0.15			0.11			0.09			0.07			0.06
Salinity = 30 g/kg
	Temperature °C
pH	0		5		10				15			20			25			30				35
7.00	39.75		27.38		18.87				13.00			8.96			6.18			4.27				2.95
7.20	25.09		17.29		11.91				8.21			5.67			3.91			2.70				1.87
7.40	15.84		10.92		7.53				5.19			3.59			2.48			1.72				1.19
7.60	10.01		6.90		4.76				3.29			2.27			1.57			1.09				0.76
7.80	6.32		4.36		3.01				2.08			1.44			1.00			0.70				0.49
8.00	4.00		2.76		1.91				1.33			0.92			0.64			0.45				0.32
8.20	2.53		1.75		1.22				0.85			0.59			0.42			0.30				0.21
8.40	1.61		1.12		0.78				0.55			0.38			0.27			0.20				0.14
8.60	1.03		0.72		0.50				0.35			0.25			0.18			0.14				0.10
8.80	0.66		0.46		0.33				0.23			0.17			0.13			0.10				0.08
9.00	0.43		0.30		0.22				0.16			0.12			0.09			0.07				0.06

To calculate total ammonia nitrogen chronic criteria values in saltwater at different pH and temperature values than those listed in this subsection, use the following formulas:

I =	19.9273S
	(1000 - 1.005109S)

Where I = molal ionic strength of water

S = Salinity ppt (g/kg)

The regression model used to relate I to pKa (negative log of the ionization constant) is

pKa = 9.245 + ~~.138I~~ 0.138(I)

pKa as defined by these equations is at 298 degrees Kelvin (25°C). T °Kelvin = °C + 273

To correct for other temperatures:

pKa^S_T = pKa^S₂₉₈ + ~~0324(298 - T °Kelvin)~~ 0.0324(298 - T °Kelvin)

The unionized ammonia fraction (UIA) is given by:

UIA =	1
	_{1 + 10}(pKa^S_T-pH)

The chronic ammonia criterion in saltwater is given by:

Chronic =	~~.035~~ 0.035
	UIA

Multiply the chronic value by ~~.822~~ 0.822 to get the ammonia-N chronic criterion.

¹The default design flow for calculating steady state wasteload allocations for the acute ammonia criterion for freshwater is the 1Q10 (see 9VAC25-260-140 B footnote 10) unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.

²The default design flow for calculating steady state wasteload allocations for the chronic ammonia criterion for freshwater is the 30Q10 (see 9VAC25-260-140 B footnote 10) unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of the water quality criteria.

9VAC25-260-185. Criteria to protect designated uses from the impacts of nutrients and suspended sediment in the Chesapeake Bay and its tidal tributaries.

A. Dissolved oxygen. The dissolved oxygen criteria in the below table apply to all Chesapeake Bay waters according to their specified designated use and supersede the dissolved oxygen criteria in 9VAC25-260-50.

Designated Use	Criteria Concentration/Duration	Temporal Application
Migratory fish spawning and nursery	7-day mean ≥ 6 mg/l (tidal habitats with 0-0.5 ppt salinity)	February 1 - May 31
	Instantaneous minimum ≥ 5 mg/l
Open water¹	30 day mean ≥ 5.5 mg/l (tidal habitats with 0-0.5 ppt salinity)	year-round²
	30 day mean ≥ 5 mg/l (tidal habitats with > 0.5 ppt salinity)
	7 day mean ≥ 4 mg/l
	Instantaneous minimum ≥ 3.2 mg/l at temperatures < 29°C Instantaneous minimum ≥ 4.3 mg/lat temperatures ≥ 29°C
Deep water	30 day mean ≥ 3 mg/l	June 1 - September 30
	1 day mean ≥ 2.3 mg/l
	Instantaneous minimum ≥ 1.7 mg/l
Deep channel	Instantaneous minimum ≥ 1 mg/l	June 1 - September 30
¹In applying this open water instantaneous criterion to the Chesapeake Bay and its tidal tributaries where the existing water quality for dissolved oxygen exceeds an instantaneous minimum of 3.2 mg/l, that higher water quality for dissolved oxygen shall be provided antidegradation protection in accordance with 9VAC25-260-30 A 2. ²Open-water dissolved oxygen criteria attainment is assessed separately over two time periods: summer (June 1- September 30) and nonsummer (October 1-May 31) months.

B. Submerged aquatic vegetation and water clarity. Attainment of the shallow-water submerged aquatic vegetation designated use shall be determined using any one of the following criteria:

Designated Use	Chesapeake Bay Program Segment	SAV Acres¹	Percent Light-Through-Water²	Water Clarity Acres¹	Temporal Application
Shallow ~~Water Submerged Aquatic Vegetation Use~~ water submerged aquatic vegetation use	CB5MH	7,633	22%	14,514	April 1 - October 31
	CB6PH	1,267	22%	3,168	March 1 - November 30
	CB7PH	15,107	22%	34,085	March 1 - November 30
	CB8PH	11	22%	28	March 1 - November 30
	POTTF	2,093	13%	5,233	April 1 - October 31
	POTOH	1,503	13%	3,758	April 1 - October 31
	POTMH	4,250	22%	10,625	April 1 - October 31
	RPPTF	66	13%	165	April 1 - October 31
	RPPOH	4	13%	10	April 1 - October 31
	RPPMH	1700	22%	5000	April 1 - October 31
	CRRMH	768	22%	1,920	April 1 - October 31
	PIAMH	3,479	22%	8,014	April 1 - October 31
	MPNTF	85	13%	213	April 1 - October 31
	MPNOH	-	-	-	-
	PMKTF	187	13%	468	April 1 - October 31
	PMKOH	-	-	-	-
	YRKMH	239	22%	598	April 1 - October 31
	YRKPH	2,793	22%	6,982	March 1 - November 30
	MOBPH	15,901	22%	33,990	March 1 - November 30
	JMSTF2	200	13%	500	April 1 - October 31
	JMSTF1	1000	13%	2500	April 1 - October 31
	APPTF	379	13%	948	April 1 - October 31
	JMSOH	15	13%	38	April 1 - October 31
	CHKOH	535	13%	1,338	April 1 - October 31
	JMSMH	200	22%	500	April 1 - October 31
	JMSPH	300	22%	750	March 1 - November 30
	WBEMH	-	-	-	-
	SBEMH	-	-	-	-
	EBEMH	-	-	-	-
	ELIPH	-	-	-	-
	LYNPH	107	22%	268	March 1 - November 30
	POCOH	-	-	-	-
	POCMH	4,066	22%	9,368	April 1 - October 31
	TANMH	13,579	22%	22,064	April 1 - October 31
¹The assessment period for SAV and water clarity acres shall be the single best year in the most recent three consecutive years. When three consecutive years of data are not available, a minimum of three years within the data assessment window shall be used.
²Percent ~~Light through Water~~ light-through-water = 100e^(-KdZ) where K_d is water column light attenuation coefficient and can be measured directly or converted from a measured secchi depth where K_d = 1.45/secchi depth. Z = depth at location of measurement of K_d.

C. Chlorophyll a.

Designated Use	Chlorophyll a Narrative Criterion	Temporal Application
Open ~~Water~~ water	Concentrations of chlorophyll a in free-floating microscopic aquatic plants (algae) shall not exceed levels that result in undesirable or nuisance aquatic plant life, or render tidal waters unsuitable for the propagation and growth of a balanced, indigenous population of aquatic life or otherwise result in ecologically undesirable water quality conditions such as reduced water clarity, low dissolved oxygen, food supply imbalances, proliferation of species deemed potentially harmful to aquatic life or humans or aesthetically objectionable conditions.	March 1 - September 30
*See 9VAC25-260-310 special standard bb for numerical chlorophyll criteria for the tidal James River.

D. Implementation.

1. Chesapeake Bay program segmentation scheme as described in Chesapeake Bay Program, 2004 Chesapeake Bay Program Analytical Segmentation Scheme-Revisions, Decisions and Rationales: 1983–2003, CBP/TRS 268/04, EPA 903-R-04-008, Chesapeake Bay Program, Annapolis, Maryland, and the Chesapeake Bay Program published 2005 addendum (CBP/TRS 278-06; EPA 903-R-05-004) is listed below and shall be used as the spatial assessment unit to determine attainment of the criteria in this section for each designated use.

Chesapeake Bay Segment Description	Segment Name¹	Chesapeake Bay Segment Description	Segment Name¹
Lower Central Chesapeake Bay	CB5MH	Mobjack Bay	MOBPH
Western Lower Chesapeake Bay	CB6PH	Upper Tidal Fresh James River	JMSTF2
Eastern Lower Chesapeake Bay	CB7PH	Lower Tidal Fresh James River	JMSTF1
Mouth of the Chesapeake Bay	CB8PH	Appomattox River	APPTF
Upper Potomac River	POTTF	Middle James River	JMSOH
Middle Potomac River	POTOH	Chickahominy River	CHKOH
Lower Potomac River	POTMH	Lower James River	JMSMH
Upper Rappahannock River	RPPTF	Mouth of the James River	JMSPH
Middle Rappahannock River	RPPOH	Western Branch Elizabeth River	WBEMH
Lower Rappahannock River	RPPMH	Southern Branch Elizabeth River	SBEMH
Corrotoman River	CRRMH	Eastern Branch Elizabeth River	EBEMH
Piankatank River	PIAMH	Lafayette River	LAFMH
Upper Mattaponi River	MPNTF	Mouth of the Elizabeth River	ELIPH
Lower Mattaponi River	MPNOH	Lynnhaven River	LYNPH
Upper Pamunkey River	PMKTF	Middle Pocomoke River	POCOH
Lower Pamunkey River	PMKOH	Lower Pocomoke River	POCMH
Middle York River	YRKMH	Tangier Sound	TANMH
Lower York River	YRKPH
¹First three letters of segment name represent Chesapeake Bay segment description, letters four and five represent the salinity regime of that segment (TF = Tidal Fresh, OH = Oligohaline, MH = Mesohaline, and PH = Polyhaline) and a sixth space is reserved for subdivisions of that segment.

2. The assessment period shall be the most recent three consecutive years. When three consecutive years of data are not available, a minimum of three years within the data assessment window shall be used.

3. Attainment of these criteria shall be assessed through comparison of the generated cumulative frequency distribution of the monitoring data to the applicable criteria reference curve for each designated use. If the monitoring data cumulative frequency curve is completely contained inside the reference curve, then the segment is in attainment of the designated use. The reference curves and procedures to be followed are published in the USEPA, Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries, EPA 903-R-03-002, April 2003 and the 2004 (EPA 903-R-03-002 October 2004) , 2007 (CBP/TRS 285-07, EPA 903-R-07-003), 2007 (CBP/TRS 288/07, EPA 903-R-07-005), 2008 (CBP/TRS 290-08, EPA 903-R-08-001), and 2010 (CBP/TRS 301-10, EPA 903-R-10-002) addenda. An exception to this requirement is in measuring attainment of the SAV and water clarity acres, which are compared directly to the criteria.

9VAC25-260-187. Criteria for man-made lakes and reservoirs to protect aquatic life and recreational designated uses from the impacts of nutrients.

A. The criteria in subsection B of this section apply to the man-made lakes and reservoirs listed in this section. Additional man-made lakes and reservoirs may be added as new reservoirs are constructed or monitoring data become available from outside groups or future agency monitoring.

B. Whether or not algicide treatments are used, the chlorophyll a criteria apply to all waters on the list. The total phosphorus criteria apply only if a specific man-made lake or reservoir received algicide treatment during the monitoring and assessment period of April 1 through October 31.

The 90th percentile of the chlorophyll a data collected at one meter or less within the lacustrine portion of the man-made lake or reservoir between April 1 and October 31 shall not exceed the chlorophyll a criterion for that ~~water body~~ waterbody in each of the two most recent monitoring years that chlorophyll a data are available. For a ~~water body~~ waterbody that received algicide treatment, the median of the total phosphorus data collected at one meter or less within the lacustrine portion of the man-made lake or reservoir between April 1 and October 31 shall not exceed the total phosphorus criterion in each of the two most recent monitoring years that total phosphorus data are available.

Monitoring data used for assessment shall be from sampling location(s) within the lacustrine portion where observations are evenly distributed over the seven months from April 1 through October 31 and are in locations that are representative, either individually or collectively, of the condition of the man-made lake or reservoir.

Man-made Lake or Reservoir Name	Location	Chlorophyll a (μg/L)	Total Phosphorus (μg/L)
~~Able~~ Abel Lake	Stafford County	35	40
Airfield Pond	Sussex County	35	40
Amelia Lake	Amelia County	35	40
Aquia Reservoir (Smith Lake)	Stafford County	35	40
Bark Camp Lake (Corder Bottom Lake, Lee/Scott/Wise Lake)	Scott County	35	40
Beaver Creek Reservoir	Albemarle County	35	40
Beaverdam Creek Reservoir (Beaverdam Reservoir)	Bedford County	35	40
Beaverdam Reservoir	Loudoun County	35	40
Bedford Reservoir (Stony Creek Reservoir)	Bedford County	35	40
Big Cherry Lake	Wise County	35	40
Breckenridge Reservoir	Prince William County	35	40
Briery Creek Lake	Prince Edward County	35	40
Brunswick Lake (County Pond)	Brunswick County	35	40
Burke Lake	Fairfax County	60	40
Carvin Cove Reservoir	Botetourt County	35	40
Cherrystone Reservoir	Pittsylvania County	35	40
Chickahominy Lake	Charles City County	35	40
Chris Green Lake	Albemarle County	35	40
Claytor Lake	Pulaski County	25	20
Clifton Forge Reservoir (Smith Creek Reservoir)	Alleghany County	35	20
Coles Run Reservoir	Augusta County	10	10
Curtis Lake	Stafford County	60	40
Diascund Creek Reservoir	New Kent County	35	40
Douthat Lake	Bath County	25	20
Elkhorn Lake	Augusta County	10	10
Emporia Lake (Meherrin Reservoir)	Greensville County	35	40
Fairystone Lake	Henry County	35	40
Falling Creek Reservoir	Chesterfield County	35	40
Fluvanna Ruritan Lake	Fluvanna County	60	40
Fort Pickett Reservoir	Nottoway/Brunswick County	35	40
Gatewood Reservoir	Pulaski County	35	40
Georges Creek Reservoir	Pittsylvania County	35	40
Goose Creek Reservoir	Loudoun County	35	40
Graham Creek Reservoir	Amherst County	35	40
Great Creek Reservoir	Lawrenceville	35	40
Harrison Lake	Charles City County	35	40
Harwood Mills Reservoir	York County	60	40
Hidden Valley Lake	Washington County	35	40
Hogan Lake	Pulaski County	35	40
Holiday Lake	Appomattox County	35	40
Hungry Mother Lake	Smyth County	35	40
Hunting Run Reservoir	Spotsylvania County	35	40
J. W. Flannagan Reservoir	Dickenson County	25	20
Kerr Reservoir, Virginia portion (Buggs Island Lake)	Halifax County	25	30
Keysville Reservoir	Charlotte County	35	40
Lake Albemarle	Albemarle County	35	40
Lake Anna	Louisa County	25	30
Lake Arrowhead	Page County	35	40
Lake Burnt Mills	Isle of Wight County	60	40
Lake Chesdin	Chesterfield County	35	40
Lake Cohoon	Suffolk City	60	40
Lake Conner	Halifax County	35	40
Lake Frederick	Frederick County	35	40
Lake Gaston, (Virginia portion)	Brunswick County	25	30
Lake Gordon	Mecklenburg County	35	40
Lake Keokee	Lee County	35	40
Lake Kilby	Suffolk City	60	40
Lake Lawson	Virginia Beach City	60	40
Lake Manassas	Prince William County	35	40
Lake Meade	Suffolk City	60	40
Lake Moomaw	Bath County	10	10
Lake Nelson	Nelson County	60	40
Lake Nottoway (Lee Lake, Nottoway Lake)	Nottoway County	35	40
Lake Orange	Orange County	60	40
Lake Pelham	Culpeper County	35	40
Lake Prince	Suffolk City	60	40
Lake Robertson	Rockbridge County	35	40
Lake Smith	Virginia Beach City	60	40
Lake Whitehurst	Norfolk City	60	40
Lake Wright	Norfolk City	60	40
Lakeview Reservoir	Chesterfield County	35	40
Laurel Bed Lake	Russell County	35	40
Lee Hall Reservoir (Newport News Reservoir)	Newport News City	60	40
Leesville Reservoir	Bedford County	25	30
Little Creek Reservoir	Virginia Beach City	60	40
Little Creek Reservoir	James City County	25	30
Little River Reservoir	Montgomery County	35	40
Lone Star Lake F (Crystal Lake)	Suffolk City	60	40
Lone Star Lake G (Crane Lake)	Suffolk City	60	40
Lone Star Lake I (Butler Lake)	Suffolk City	60	40
Lunga Reservoir	Prince William County	35	40
Lunenburg Beach Lake (Victoria Lake)	Town of Victoria	35	40
Martinsville Reservoir (Beaver Creek Reservoir)	Henry County	35	40
Mill Creek Reservoir	Amherst County	35	40
Modest Creek Reservoir	Town of Victoria	35	40
Motts Run Reservoir	Spotsylvania County	25	30
Mount Jackson Reservoir	Shenandoah County	35	40
Mountain Run Lake	Culpeper County	35	40
Ni Reservoir	Spotsylvania County	35	40
North Fork Pound Reservoir	Wise County	35	40
Northeast Creek Reservoir	Louisa County	35	40
Occoquan Reservoir	Fairfax County	35	40
Pedlar Lake	Amherst County	25	20
Philpott Reservoir	Henry County	25	30
Phelps Creek Reservoir (Brookneal Reservoir)	Campbell County	35	40
Powhatan Lakes (Upper and Lower)	Powhatan County	35	40
Ragged Mountain Reservoir	Albemarle County	35	40
Rivanna Reservoir (South Fork Rivanna Reservoir)	Albemarle County	35	40
Roaring Fork	Pittsylvania County	35	40
Rural Retreat Lake	Wythe County	35	40
Sandy River Reservoir	Prince Edward County	35	40
Shenandoah Lake	Rockingham County	35	40
Silver Lake	Rockingham County	35	40
Smith Mountain Lake	Bedford County	25	30
South Holston Reservoir	Washington County	25	20
Speights Run Lake	Suffolk City	60	40
Spring Hollow Reservoir	Roanoke County	25	20
Staunton Dam Lake	Augusta County	35	40
Stonehouse Creek Reservoir	Amherst County	60	40
Strasburg Reservoir	Shenandoah County	35	40
Stumpy Lake	Virginia Beach	60	40
Sugar Hollow Reservoir	Albemarle County	25	20
Swift Creek Lake	Chesterfield County	35	40
Swift Creek Reservoir	Chesterfield County	35	40
Switzer Lake	Rockingham County	10	10
Talbott Reservoir	Patrick County	35	40
Thrashers Creek Reservoir	Amherst County	35	40
Totier Creek Reservoir	Albemarle County	35	40
Townes Reservoir	Patrick County	25	20
Troublesome Creek Reservoir	Buckingham County	35	40
Waller Mill Reservoir	York County	25	30
Western Branch Reservoir	Suffolk City	25	20
Wise Reservoir	Wise County	25	20

C. When the board determines that the applicable criteria in subsection B of this section for a specific man-made lake or reservoir are exceeded, the board shall consult with the Department of Game and Inland Fisheries regarding the status of the fishery in determining whether or not the designated use for that ~~water body~~ waterbody is being attained. If the designated use of the subject ~~water body~~ waterbody is not being attained, the board shall assess the ~~water body~~ waterbody as impaired in accordance with § 62.1-44.19:5 of the Code of Virginia. If the designated use is being attained, the board shall assess the ~~water body~~ waterbody as impaired in accordance with § 62.1-44.19:5 of the Code of Virginia until site-specific criteria are adopted and become effective for that ~~water body~~ waterbody.

D. If the nutrient criteria specified for a man-made lake or reservoir in subsection B of this section do not provide for the attainment and maintenance of the water quality standards of downstream waters as required in 9VAC25-260-10 C, the nutrient criteria herein may be modified on a site-specific basis to protect the water quality standards of downstream waters.

Part VII
Special Standards and Scenic Rivers Listings

9VAC25-260-310. Special standards and requirements.

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 ~~State~~ 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.

c. Cancelled.

d. Cancelled.

e. Cancelled.

f. Cancelled.

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.

h. Cancelled.

i. Cancelled.

j. Cancelled.

k. Cancelled.

l. Cancelled.

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~~ 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~~ solids	Not to exceed 0.1 ml/l monthly average.
3. Suspended ~~Solids~~ solids	5.0 mg/l monthly average, with not more than 5% of individual samples to exceed 7.5 mg/l.
4. Ammonia ~~Nitrogen~~ nitrogen	Not to exceed 2.0 mg/l monthly average as N.
5. Total ~~Phosphorus~~ 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~~ physical and ~~Chemical Constituents~~ 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 which are now present in the stream from natural sources and from existing discharges in the watershed.

p. Cancelled.

q. Cancelled.

r. Cancelled.

s. Cancelled.

t. Cancelled.

u. Maximum temperature for the New River Basin from 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).

w. Cancelled.

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.

y. Tidal freshwater Potomac River and tidal tributaries that enter the tidal freshwater Potomac River from Cockpit Point (below Occoquan Bay) to the fall line at Chain Bridge. During November 1 through February 14 of each year the 30-day average concentration of total ammonia nitrogen (in mg N/L) shall not exceed, more than once every three years on the average, the following chronic ammonia criterion:

(	0.0577	+	2.487	)	x 1.45(10^{0.028(25-MAX)})
	1 + 10^7.688-pH		1 + 10^pH-7.688

MAX = temperature in °C or 7, whichever is greater.

The default design flow for calculating steady state ~~waste load~~ wasteload allocations for this chronic ammonia criterion is the 30Q10, unless statistically valid methods are employed which demonstrate compliance with the duration and return frequency of this water quality criterion.

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~~
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 numerical chlorophyll a criteria apply March 1 through May 31 and July 1 through September 30 as seasonal means to the tidal James River (excludes tributaries) segments JMSTF2, JMSTF1, JMSOH, JMSMH, JMSPH and are implemented in accordance with subsection D of 9VAC25-260-185.

Designated Use	Chlorophyll a µ/l	Chesapeake Bay Program Segment	Temporal Application
Open ~~Water~~ water	10	JMSTF2	March 1 - May 31
	15	JMSTF1
	15	JMSOH
	12	JMSMH
	12	JMSPH
	15	JMSTF2	July 1 - September 30
	23	JMSTF1
	22	JMSOH
	10	JMSMH
	10	JMSPH

cc. For Mountain Lake in Giles County, chlorophyll a shall not exceed 6 µg/L at a depth of 6 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. ~~Reserved.~~ Maximum temperature for these seasonally stockable trout waters is 26°C and applies May 1 through October 31.

ff. ~~Reserved.~~ 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 ~~here~~ 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.

9VAC25-260-390. Potomac River Basin (Potomac River Subbasin).

Potomac River Subbasin

SEC.	CLASS	SP. STDS.	SECTION DESCRIPTION
1	II	a	Tidal tributaries of the Potomac River from Smith Point to Upper Machodoc Creek (Baber Point).
1a	III		All free flowing portions of tributaries to the Potomac River from Smith Point to the Route 301 Bridge in King George County unless otherwise designated in this chapter.
	VII		Swamp waters in Section 1a
			Lodge Creek and its tributaries from the head of tidal waters to their headwaters.
			Mattox Creek and its tributaries from the head of tidal waters to their headwaters.
			Monroe Creek and tributaries from the head of tidal waters at Route 658 to their headwaters.
			Pine Hill Creek and its tributaries from the confluence with Rosier Creek to their headwaters.
			Popes Creek and Canal Swamp (a tributary to the tidal portion of Popes Creek) and their tributaries from the head of tidal waters to their respective headwaters.
			Thompson Branch and its tributaries from the head of tidal waters to their headwaters.
1b	III	b	All free flowing portions of tributaries to the Potomac River from the Route 301 Bridge in King George County to, and including, Potomac Creek, unless otherwise designated in this chapter.
1c	III	PWS,b	Potomac Creek and its tributaries from the Stafford County water supply dam ~~(Able~~ (Abel Lake Reservoir) to their headwaters.
2	II	a	Tidal Upper Machodoc Creek and the tidal portions of its tributaries.
2a	III		Free flowing portions of Upper Machodoc Creek and its tributaries.
3	II	b	Tidal portions of the tributaries to the Potomac River from the Route 301 Bridge in King George County to Marlboro Point.
4	II	b,d	Tidal portions of the tributaries to the Potomac River from Marlboro Point to Brent Point (to include Aquia Creek and its tributaries).
4a	III	b,d	Free flowing portions of tributaries to the Potomac River in Section 4 up to the Aquia Sanitary District Water Impoundment.
4b	III	PWS,b~~, d~~	Aquia Creek from the Aquia Sanitary District Water Impoundment, and other tributaries into the impoundment, including Beaverdam Run and the Lunga Reservoir upstream to their headwaters.
5	II	b	Tidal portions of tributaries to the Potomac River from Brent Point to Shipping Point, including tidal portions of Chopawamsic Creek and its tidal tributaries.
5a	III	b	Free flowing portions of Chopawamsic Creek and its tributaries upstream to Quantico Marine Base water supply dam.
5b	III	PWS,b	Chopawamsic Creek and its tributaries above the Quantico Marine Base water supply intakes at the Gray and Breckenridge Reservoirs to their headwaters.
6	II	b, y	Tidal portions of tributaries to the Potomac River from Shipping Point to Chain Bridge.
7	III	b	Free flowing portions of tributaries to the Potomac River from Shipping Point to Chain Bridge, unless otherwise designated in this chapter.
7a	III	g	Occoquan River and its tributaries to their headwaters above Fairfax County Water Authority's water supply impoundment, unless otherwise designated in this chapter.
7b	III	PWS,g	The impounded waters of Occoquan River above the water supply dam of the Fairfax County Water Authority to backwater of the impoundment on Bull Run and Occoquan River, and the tributaries of Occoquan above the dam to points 5 miles above the dam.
7c	III	PWS,g	Broad Run and its tributaries above the water supply dam of the City of Manassas upstream to points 5 miles above the dam.
7d			(Deleted)
7e	III	PWS,g	Cedar Run and its tributaries from the Town of Warrenton's raw water intake to points 5 miles upstream (Fauquier County).
7f	III	PWS,g	The Quantico Marine Base Camp Upshur and its tributaries' raw water intake on Cedar Run (located approximately 0.2 mile above its confluence with Lucky Run) to points 5 miles upstream.
7g	III	PWS,g	The proposed impounded waters of Licking Run above the multiple purpose impoundment structure in Licking Run near Midland (Fauquier County) upstream to points 5 miles above the proposed impoundment.
7h	III	PWS,g	The proposed impounded waters of Cedar Run above the proposed multiple purpose impoundment structure on the main stem of Cedar Run near Auburn (Fauquier County), to points 5 miles above the impoundment.
8	III	PWS	Tributaries to the Potomac River in Virginia between Chain Bridge and the Monacacy River from their confluence with the Potomac upstream 5 miles, to include Goose Creek to the City of Fairfax's raw water intake, unless otherwise designated in this chapter.
8a	VI	PWS	Big Spring Creek and its tributaries in Loudoun County, from its confluence with the Potomac River upstream to their headwaters. (The temperature standard for natural trout water may be exceeded in the area above Big Spring and Little Spring at Routes 15 and 740 due to natural conditions). This section was given a PWS designation due to the Town of Leesburg's intake on the Potomac as referenced in Section 8b ~~below~~.
	iii		Big Spring Creek from its confluence with the Potomac River upstream to Big Spring.
8b	III	PWS	Those portions of Virginia tributaries into the Potomac River that are within a 5 mile distance upstream of the Town of Leesburg's intake on the Potomac River, unless otherwise designated in this chapter.*
8c	III	PWS	Those portions of Virginia tributaries into the Potomac River that are within a 5 mile distance upstream of the County of Fairfax's intake on the Potomac River.*
9	III		Broad Run, Sugarland Run, Difficult Run, Tuscarora Creek, ~~Sycoline~~ Sycolin Creek, and other streams tributary to streams in Section 8 from a point 5 miles above their confluence with the Potomac River to their headwaters, unless otherwise designated in this chapter.
9a	III	PWS	All the impounded water of Goose Creek from the City of Fairfax's water supply dam upstream to backwater, and its tributaries above the dam to points 5 miles above the dam.
9b	III	PWS	The Town of Round Hill's (inactive-early ~~1980's)~~ 1980s) raw water intake at the Round Hill Reservoir, and including the two spring impoundments located northwest of the town on the eastern slope of the Blue Ridge Mountains.
9c	III	PWS	Unnamed tributary to Goose Creek, from Camp Highroad's (inactive-late ~~1980's)~~ 1980s) raw water intake (Loudoun County) located in an old quarry to its headwaters.
9d	III	PWS	Sleeter Lake (Loudoun County).
10	III		Tributaries of the Potomac River from the Monacacy River to the West Virginia-Virginia state line in Loudoun County, from their confluence with the Potomac River upstream to their headwaters, unless otherwise designated in this chapter.
10a	III	PWS	North Fork Catoctin Creek and its tributaries from Purcellville's raw water intake to their headwaters.
10b	III		South Fork Catoctin Creek and its tributaries from its confluence with the North Fork Catoctin Creek to its headwaters.
11	IV	pH-6.5-9.5	Tributaries of the Potomac River in Frederick and Clarke Counties, Virginia, unless otherwise designated in this chapter.
	V		Stockable Trout Waters in Section 11
	***	pH-6.5-9.5	Back Creek (upper) from Rock Enon 4 miles upstream.
	***	pH-6.5-9.5	Back Creek (lower) from Route 600 to the mouth of Hogue Creek - 2 miles.
	***	hh	Hogue Creek from Route 679 upstream 6 miles to the Forks below Route 612.
	vi	pH-6.5-9.5	Opequon Creek (in Frederick County) from its confluence with Hoge Run upstream to the point at which Route 620 first crosses the stream.
	vi	pH-6.5-9.6	Turkey Run (Frederick County) from its confluence with Opequon Creek 3.6 miles upstream.
	VI		Natural Trout Waters in Section 11
	ii	pH-6.5-9.5	Bear Garden Run from its confluence with Sleepy Creek 3.1 miles upstream.
	iii	pH-6.5-9.5	Redbud Run from its confluence with Opequon Creek 4.4 miles upstream.
11a	IV	pH-6.5-9.5	Hot Run and its tributaries from its confluence with Opequon Creek to its headwaters.
	V		Stockable Trout Waters in Section 11a
	vi	pH-6.5-9.5	Clearbrook Run from its confluence with Hot Run 2.1 miles upstream.
12	IV	ESW-6	South Branch Potomac River and its tributaries, such as Strait Creek, and the North Fork River and its tributaries from the Virginia-West Virginia state line to their headwaters.
	V		Stockable Trout Waters in Section 12
	vi		Frank Run from its confluence with the South Branch Potomac River 0.8 mile upstream.
	vii	pH-6.5-9.5	South Branch Potomac River (in Highland County) from 69.2 miles above its confluence with the Potomac River 4.9 miles upstream.
	VI		Natural Trout Waters in Section 12
	ii		Blights Run from its confluence with Laurel Fork (Highland County) upstream including all named and unnamed tributaries.
	ii		Buck Run (Highland County) from its confluence with Laurel Fork upstream including all named and unnamed tributaries.
	ii		Collins Run from its confluence with Laurel Fork upstream including all named and unnamed tributaries.
	ii		Laurel Fork (Highland County) from 1.9 miles above its confluence with the North Fork South Branch Potomac River upstream including all named and unnamed tributaries.
	iii	pH-6.5-9.5	Laurel Run (Highland County) from its confluence with Strait Creek upstream including all named and unnamed tributaries.
	ii		Locust Spring Run from its confluence with Laurel Fork upstream including all named and unnamed tributaries.
	ii		Lost Run from its confluence with Laurel Fork upstream including all named and unnamed tributaries.
	ii		Mullenax Run from its confluence with Laurel Fork upstream including all named and unnamed tributaries.
	ii		Newman Run from its confluence with Laurel Fork upstream including all named and unnamed tributaries.
	ii		Slabcamp Run from its confluence with Laurel Fork upstream including all named and unnamed tributaries.
	iii	pH-6.5-9.5	Strait Creek (Highland County) from its confluence with the South Branch Potomac River upstream to the confluence of West Strait Creek.

9VAC25-260-400. Potomac River Basin (Shenandoah River Subbasin).

Shenandoah River Subbasin

SEC.	CLASS	SP. STDS.	SECTION DESCRIPTION
1	IV	pH-6.5-9.5	Shenandoah River and its tributaries in Clarke County, Virginia, from the Virginia-West Virginia state line to Lockes Landing, unless otherwise designated in this chapter.
1a	IV	PWS pH-6.5-9.5	Shenandoah River and its tributaries from river mile 24.66 (latitude 39°16'19"; longitude 77°54'33") approximately 0.7 mile downstream of the confluence of the Shenandoah River and Dog Run to 5 miles above Berryville's raw water intake, unless otherwise designated in this chapter.
	V		Stockable Trout Waters in Section 1a
	vi	pH-6.5-9.5	Chapel Run (Clarke County) from its confluence with the Shenandoah River 5.7 miles upstream.
	vi	pH-6.5-9.5	Spout Run (Clarke County) from its confluence with the Shenandoah River (in the vicinity of the Ebenezer Church at Route 604) to its headwaters.
1b			(Deleted)
1c	IV	pH-6.5-9.5	Shenandoah River and its tributaries from a point 5 miles above Berryville's raw water intake to the confluence of the North and South Forks of the Shenandoah River.
	VI		Natural Trout Waters in Section 1c
	iii	pH-6.5-9.5	Page Brook from its confluence with Spout Run, 1 mile upstream.
	***	pH-6.5-9.5	Roseville Run (Clarke County) from its confluence with Spout Run upstream including all named and unnamed tributaries.
	iii	pH-6.5-9.5	Spout Run (Clarke County) from its confluence with the Shenandoah River (in the vicinity of Calmes Neck at ~~Rts~~ Routes 651 and 621), 3.9 miles upstream.
	***	pH-6.5-9.5	Westbrook Run (Clarke County) from its confluence with Spout Run upstream including all named and unnamed tributaries.
1d			(Note: Moved to ~~section~~ Section 2b).
2	IV	~~EWS-12.14.15~~ ESW-12,14,15	South Fork Shenandoah River from its confluence with the North Fork Shenandoah River, upstream to a point 5 miles above the Town of Shenandoah's raw water intake and its tributaries to their headwaters in this section, unless otherwise designated in this chapter.
	V		Stockable Trout Waters in Section 2
	vii	pH-6.5-9.5	Bear Lithia Spring from its confluence with the South Fork Shenandoah River 0.8 miles upstream.
	vi	pH-6.5-9.5	Flint Run from its confluence with the South Fork Shenandoah River 4 miles upstream.
	***	pH-6.5-9.5	Gooney Run from the mouth to its confluence with Broad Run above Browntown (in the vicinity of Route 632).
	***	pH-6.5-9.5, hh	Hawksbill Creek from Route 675 in Luray to 1 mile above Route 631.
	VI		Natural Trout Waters in Section 2
	ii	pH-6.5-9.5	Big Creek (Page County) from its confluence with the East Branch Naked Creek upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Big Ugly Run from its confluence with the South Branch Naked Creek upstream including all named and unnamed tributaries.
	ii		Boone Run from 4.6 miles above its confluence with the South Fork Shenandoah River (in the ~~vicinity)~~ vicinity of Route 637) upstream including all named and unnamed tributaries.
	iii	pH-6.5-9.5	Browns Run from its confluence with Big Run upstream including all named and unnamed tributaries.
	ii		Cub Run (Page County) from Pitt Spring Run upstream including all named and unnamed tributaries.
	***	pH-6.5-9.5	Cub Run from its mouth to Pitt Spring Run.
	i	pH-6.5-9.5	East Branch Naked Creek from its confluence with Naked Creek at Route 759 upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Fultz Run from the Park boundary (river mile 1.8) upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Gooney Run ~~(in~~ (Warren County) from 6.6 miles above its confluence with the South Fork Shenandoah River 3.9 miles upstream.
	ii	pH-6.5-9.5	Hawksbill Creek in the vicinity of Pine Grove at Route 624 (river mile 17.7) 1.5 miles upstream.
	ii	pH-6.5-9.5	Jeremys Run from the Shenandoah National Park boundary upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Lands Run from its confluence with Gooney Run upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Little Creek (Page County) from its confluence with Big Creek upstream including all named and unnamed tributaries.
	i	pH-6.5-9.5	Little Hawksbill Creek from Route 626 upstream including all named and unnamed tributaries.
	ii		Morgan Run (Page County) from its confluence with Cub Run upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Overall Run from its confluence with the South Fork Shenandoah River 4.8 miles upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Pass Run (Page County) from its confluence with Hawksbill Creek upstream including all named and unnamed tributaries.
	ii		Pitt Spring Run from its confluence with Cub Run upstream including all named and unnamed tributaries.
	ii		Roaring Run from its confluence with Cub Run upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	South Branch Naked Creek from 1.7 miles above its confluence with Naked Creek (in the vicinity of Route 607) upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Stony Run (Page County) from 1.6 miles above its confluence with Naked Creek upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	West Branch Naked Creek from 2.1 miles above its confluence with Naked Creek upstream including all named and unnamed tributaries.
2a	IV	PWS, pH-6.5-9.5	Happy Creek and Sloan Creek from Front Royal's raw water intake to its headwaters.
2b	IV	PWS	The South Fork Shenandoah River and its tributaries from the Town of Front Royal's raw water intake (at the State Route 619 bridge at Front Royal) to points 5 miles upstream.
2c			(Deleted)
2d			(Deleted)
	V		Stockable Trout Waters in Section 2d
	VI		Natural Trout Waters in Section 2d
3	IV	pH-6.5-9.5, ESW-16	South Fork Shenandoah River from 5 miles above the Town of Shenandoah's raw water intake to its confluence with the North and South Rivers and its tributaries to their headwaters in this section, and the South River and its tributaries from its confluence with the South Fork Shenandoah River to their headwaters, unless otherwise designated in this chapter.
	V		Stockable Trout Waters in Section 3
	vi	pH-6.5-9.5	Hawksbill Creek (Rockingham County) from 0.8 mile above its confluence with the South Fork Shenandoah River 6.6 miles upstream.
	vi	pH-6.5-9.5	Mills Creek (Augusta County) from 1.8 miles above its confluence with Back Creek 2 miles upstream.
	vi	pH-6.5-9.5	North Fork Back Creek (Augusta County) from its confluence with Back Creek 2.6 miles upstream, unless otherwise designated in this chapter.
	VI		Natural Trout Waters in Section 3
	i	pH-6.5-9.5	Bearwallow Run from its confluence with Onemile Run upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Big Run (Rockingham County) from 3.3 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	iii	pH-6.5-9.5	Cold Spring Branch (Augusta County) from Sengers Mountain Lake (Rhema Lake) upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Cool Springs Hollow (Augusta County) from Route 612 upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Deep Run (Rockingham County) from 1.8 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	East Fork Back Creek from its confluence with the South Fork Back Creek upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Gap Run from 1.7 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	iii		Inch Branch (Augusta County) from the dam upstream including all named and unnamed tributaries.
	ii		Johns Run (Augusta County) from its confluence with the South River upstream including all named and unnamed tributaries.
	iv		Jones Hollow (Augusta County) from 1.1 miles above its confluence with the South River upstream including all named and unnamed tributaries.
	ii		Kennedy Creek from its confluence with the South River upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Lee Run from 0.6 mile above its confluence with Elk Run 3.3 miles upstream.
	iii	pH-6.5-9.5	Loves Run (Augusta County) from 2.7 miles above its confluence with the South River upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Lower Lewis Run (Rockingham County) from 1.7 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Madison Run (Rockingham County) from 2.9 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Meadow Run (Augusta County) from its confluence with the South River upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	North Fork Back Creek (Augusta County) from river mile 2.6 (in the vicinity of its confluence with Williams Creek) upstream including all named and unnamed tributaries.
	i	pH-6.5-9.5	Onemile Run (Rockingham County) from 1.5 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	iv		Orebank Creek from its confluence with Back Creek upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Paine Run (Augusta County) from 1.7 miles above its confluence with the South River upstream including all named and unnamed tributaries.
	ii		Robinson Hollow (Augusta County) from the dam upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Rocky Mountain Run from its confluence with Big Run upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Sawmill Run from 2.5 miles above its confluence with the South River upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	South Fork Back Creek from its confluence with Back Creek at Route 814 (river mile 2.1) upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Stony Run (Augusta County) from 3.5 miles above its confluence with the South River upstream including all named and unnamed tributaries.
	iii	pH-6.5-9.5	Stony Run (Rockingham County) from 4.1 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	iii		Toms Branch (Augusta County) from 1.1 miles above its confluence with Back Creek upstream including all named and unnamed tributaries.
	i	pH-6.5-9.5	Twomile Run from 1.4 miles above its confluence with the South Fork Shenandoah River upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Upper Lewis Run from 0.5 mile above its confluence with Lower Lewis Run upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	West Swift Run (Rockingham County) from the Route 33 crossing upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Whiteoak Run from its confluence with Madison Run upstream including all named and unnamed tributaries.
3a	IV	pH-6.5-9.5	South River from the dam above Waynesboro (all waters of the impoundment).
3b	IV	PWS	Coles Run and Mills Creek from South River Sanitary District's raw water intake to their headwaters.
	VI	PWS	Natural Trout Waters in Section 3b
	ii		Coles Run (Augusta County) from 3.9 miles above its confluence with the South River Sanitary District's raw water intake (Coles Run Dam) upstream including all named and unnamed tributaries.
	ii		Mills Creek (Augusta County) from the South River Sanitary District's raw water intake (river mile 3.8) upstream including all named and unnamed tributaries.
3c	IV	PWS pH-6.5-9.5	A tributary to Coles Run from Stuarts Draft raw water intake approximately ~~one-half~~ 0.5 mile south of Stuarts Draft and just off Route 610, to its headwaters.
4	IV	pH-6.5-9.5	Middle River and its tributaries from the confluence with the North River upstream to its headwaters, unless otherwise designated in this chapter.
	V		Stockable Trout Waters in Section 4
	v	pH-6.5-9.5	Barterbrook Branch from its confluence with Christians Creek 2.8 miles upstream.
	***	pH-6.5-9.5	East Dry Branch from its confluence with the Buffalo Branch to its confluence with Mountain Run.
	vi	pH-6.5-9.5	Folly Mills Creek from 2.4 miles above its confluence with Christians Creek (in the vicinity of Route 81) 4.5 miles upstream.
	VI		Natural Trout Waters in Section 4
	iv		Buffalo Branch from Route 703 upstream including all named and unnamed tributaries.
	ii		Cabin Mill Run (Augusta County) from the Camp Shenandoah Boy Scout Lake upstream including all named and unnamed tributaries.
	iv		East Dry Branch (Augusta County) from the confluence of Mountain Run upstream including all named and unnamed tributaries.
	iv		Jennings Branch (Augusta County) from the confluence of White Oak Draft upstream including all named and unnamed tributaries.
4a	IV	PWS pH-6.5-9.5	Middle River and its tributaries from Staunton's raw water intake at Gardner Spring to points 5 miles upstream.
5	IV	pH-6.5-9.5	North River and its tributaries from its confluence with the South River upstream to its headwaters, unless otherwise designated in this chapter.
	V		Stockable Trout Waters in Section 5
	v	pH-6.5-9.5	Beaver Creek (Rockingham County) from its confluence with Briery Branch to the spring at a point 2.75 miles upstream.
	v	pH-6.5-9.5	Naked Creek (Augusta County) from 3.7 miles above its confluence with the North River at Route 696, 2 miles upstream.
	VI		Natural Trout Waters in Section 5
	iv		Big Run (Augusta County) from 0.9 mile above its confluence with Little River upstream including all named and unnamed tributaries.
	ii		Black Run (Rockingham County) from its mouth upstream including all named and unnamed tributaries.
	iii		Briery Branch (Rockingham County) from river mile 6.9 upstream including all named and unnamed tributaries.
	iv		Gum Run from its mouth upstream including all named and unnamed tributaries.
	iii		Hone Quarry Run from its confluence with Briery Branch upstream including all named and unnamed tributaries.
	iv		Little River from its confluence with the North River at Route 718 upstream including all named and unnamed tributaries.
	iv		Maple Spring Run from its mouth upstream including all named and unnamed tributaries.
	iv		Mines Run from its confluence with Briery Branch upstream including all named and unnamed tributaries.
	iv		Rocky Run (which is tributary to Briery Branch in Rockingham County) from its mouth upstream including all named and unnamed tributaries.
	iii		Rocky Run (which is tributary to Dry River in Rockingham County) from its mouth upstream including all named and unnamed tributaries.
	ii		Union Springs Run from 3 miles above its confluence with Beaver Creek upstream including all named and unnamed tributaries.
	iv		Wolf Run (Augusta County) from its confluence with Briery Branch upstream including all named and unnamed tributaries.
5a	IV	PWS pH-6.5-9.5	Silver Lake
5b	IV	PWS pH-6.5-9.5	North River and its tributaries from Harrisonburg's raw water intake at Bridgewater to points 5 miles above Bridgewater's raw water intake to include Dry River and Muddy Creek.
	V	PWS	Stockable Trout Waters in Section 5b
	v	pH-6.5-9.5	Mossy Creek from its confluence with the North River 7.1 miles upstream.
	v	pH-6.5-9.5	Spring Creek (Rockingham County) from its confluence with the North River 2 miles upstream.
5c	IV	PWS	Dry River in (Rockingham County) from Harrisonburg's raw water intake (approximately 11.7 miles above its confluence with the North River) to a point 5 miles upstream, unless otherwise designated in this chapter.
	V	PWS	Stockable Trout Waters in Section 5c
	viii		Raccoon Run (Rockingham County) from its confluence with Dry River to its headwaters.
	VI	PWS	Natural Trout Waters in Section 5c
	iv		Dry River (Rockingham County) from Harrisonburg's raw water intake (approximately 11.7 miles above its confluence with the North River) to a point 5 miles upstream.
	iv		Dry Run (Rockingham County) from its confluence with Dry River upstream including all named and unnamed tributaries.
	iv		Hopkins Hollow from its confluence with Peach Run upstream including all named and unnamed tributaries.
	iv		Kephart Run from its confluence with Dry River upstream including all named and unnamed tributaries.
5d	VI		Dry River and its tributaries from 5 miles above Harrisonburg's raw water intake to its headwaters.
	VI		Natural Trout Waters in Section 5d
	iv		Dry River (Rockingham County) from 5 miles above Harrisonburg's raw water intake upstream including all named and unnamed tributaries.
	ii		Laurel Run (Rockingham County) from its confluence with Dry River upstream including all named and unnamed tributaries.
	ii		Little Laurel Run from its confluence with Dry River upstream including all named and unnamed tributaries.
	ii		Low Place Run from its confluence with Dry River upstream including all named and unnamed tributaries.
	iv		Miller Spring Run from its confluence with Dry River upstream including all named and unnamed tributaries.
	iii		Sand Run from its confluence with Dry River upstream including all named and unnamed tributaries.
	iv		Skidmore Fork from its confluence with Dry River upstream including all named and unnamed tributaries.
5e	VI	PWS	North River and its tributaries from Staunton Dam to their headwaters.
	VI		Natural Trout Waters in Section 5e
	iv		North River from Elkhorn Dam upstream including all named and unnamed tributaries.
6	IV	pH-6.5-9.5	North Fork Shenandoah River from its confluence with the Shenandoah River to its headwaters, unless otherwise designated in this chapter.
	V		Stockable Trout Waters in Section 6
	vi	pH-6.5-9.5	Bear Run from its confluence with Foltz Creek to its headwaters.
	vi	pH-6.5-9.5	Bull Run (Shenandoah County) from its confluence with Foltz Creek to its headwaters.
	vi	pH-6.5-9.5	Falls Run from its confluence with Stony Creek to its headwaters.
	vi	pH-6.5-9.5	Foltz Creek from its confluence with Stony Creek to its headwaters.
	vi	pH-6.5-9.5	Little Passage Creek from its confluence with Passage Creek to the Strasburg Reservoir Dam.
	***	pH-6.5-9.5, hh	Mill Creek from Mount Jackson to Route 720 - 3.5 miles.
	vi	pH-6.5-9.5	Mountain Run from its mouth at Passage Creek to its headwaters.
	***	pH-6.5-9.5	Passage Creek from the U.S. Forest Service line (in the vicinity of Blue Hole and Buzzard Rock) 4 miles upstream.
	vi	pH-6.5-9.5	Passage Creek from 29.6 miles above its confluence with the North Fork Shenandoah River to its headwaters.
	vi	pH-6.5-9.5	Peters Mill Run from the mouth to its headwaters.
	***	pH-6.5-9.5	Shoemaker River from 612 at Hebron Church to its junction with Route 817 at ~~the Shoemaker's~~ its confluence with Slate Lick Branch.
	v	pH-6.5-9.5	Stony Creek from its confluence with the North Fork Shenandoah River to Route 682.
	***	pH-6.5-9.5	Stony Creek from Route 682 above Edinburg upstream to Basye.
	VI		Natural Trout Waters in Section 6
	ii	pH-6.5-9.5	Anderson Run (Shenandoah County) from 1.1 miles above its confluence with Stony Creek upstream including all named and unnamed tributaries.
	iv		Beech Lick Run from its confluence with the German River upstream including all named and unnamed tributaries.
	iii		Bible Run from its confluence with Little Dry River upstream including all named and unnamed tributaries.
	ii		Camp Rader Run from its confluence with the German River upstream including all named and unnamed tributaries.
	iv		Carr Run from its confluence with Little Dry River upstream including all named and unnamed tributaries.
	iv		Clay Lick Hollow from its confluence with Carr Run upstream including all named and unnamed tributaries.
	iv		Gate Run from its confluence with Little Dry River upstream including all named and unnamed tributaries.
	iv		German River (Rockingham County) from its confluence with the North Fork Shenandoah River (at Route 820) upstream including all named and unnamed tributaries.
	ii		Laurel Run (Shenandoah County) from its confluence with Stony Creek upstream including all named and unnamed tributaries.
	ii		Little Stony Creek from its confluence with Stony Creek upstream including all named and unnamed tributaries.
	iv		Marshall Run (Rockingham County) from 1.2 miles above its confluence with the North Fork Shenandoah River upstream including all named and unnamed tributaries.
	iii	pH-6.5-9.5	Mine Run (Shenandoah County) from its confluence with Passage Creek upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Poplar Run (Shenandoah County) from its confluence with Little Stony Creek upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Rattlesnake Run (Rockingham County) from its confluence with Spruce Run upstream including all named and unnamed tributaries.
	iv		Root Run from its confluence with Marshall Run upstream including all named and unnamed tributaries.
	iv		Seventy Buck Lick Run from its confluence with Carr Run upstream including all named and unnamed tributaries.
	iv		Sirks Run (Spring Run) from 1.3 miles above its confluence with Crab Run upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Spruce Run (Rockingham County) from its confluence with Capon Run upstream including all named and unnamed tributaries.
	iv	pH-6.5-9.5	Sumac Run from its confluence with the German River upstream including all named and unnamed tributaries.
6a	IV	PWS pH-6.5-9.5	Little Passage Creek from the Strasburg Reservoir Dam upstream to its headwaters, unless otherwise designated in this chapter.
	V	PWS	Stockable Trout Waters in Section 6a
	vi	pH-6.5-9.5	Little Passage Creek from the Strasburg Reservoir Dam upstream to its headwaters.
6b	IV	PWS pH-6.5-9.5	North Fork Shenandoah River and its tributaries from the Winchester raw water intake to points 5 miles upstream (to include Cedar Creek and its tributaries to their headwaters).
	V	PWS	Stockable Trout Waters in Section 6b
	***	pH-6.5-9.5	Cedar Creek (Shenandoah County) from Route 55 (river mile 23.56) to the U.S. Forest Service Boundary (river mile 32.0) - approximately 7 miles.
	v	PWS pH-6.5-9.5	Meadow Brook (Frederick County) from its confluence with Cedar Creek 5 miles upstream.
	VI	PWS	Natural Trout Waters in Section 6b
	iii	pH-6.5-9.5	Cedar Creek (Shenandoah County) from the U.S. Forest Service boundary (river mile 32.0) near Route 600 upstream including all named and unnamed tributaries.
	ii	pH-6.5-9.5	Duck Run from its confluence with Cedar Creek upstream including all named and unnamed tributaries.
			Paddy Run (Frederick County) from the mouth upstream including all named and unnamed tributaries.
	***		(Paddy Run (Frederick County) from its mouth (0.0) to river mile 1.8.)
	vi**		(Paddy Run (Frederick County) from river mile 1.8 to river mile 8.1 - 6.3 miles.)
	iii	pH-6.5-9.5	Sulphur Springs Gap (Shenandoah County) from its confluence with Cedar Creek 1.9 miles upstream.
6c	IV	PWS pH-6.5-9.5	North Fork Shenandoah River and its tributaries from Strasburg's raw water intake to points 5 miles upstream.
6d	IV	PWS pH-6.5-9.5	North Fork Shenandoah River and its tributaries from Woodstock's raw water intake (approximately ~~1/4~~ 0.25 mile upstream of State Route 609 bridge near Woodstock) to points 5 miles upstream.
6e	IV	PWS pH-6.5-9.5	Smith Creek and its tributaries from New Market's raw water intake to their headwaters.
			Natural Trout Waters in Section 6e
	iv	pH-6.5-9.5	Mountain Run (Fridley Branch, Rockingham County) from Route 722 upstream including all named and unnamed tributaries.
6f	IV	PWS pH-6.5-9.5	North Fork Shenandoah River and its tributaries from the Food Processors Water Coop, Inc. dam at Timberville and the Town of Broadway's intakes on Linville Creek and the North Fork Shenandoah to points 5 miles upstream.
6g	IV		Shoemaker River and its tributaries from Slate Lick Run, and including Slate Lick Run, to its headwaters.
	V		Stockable Trout Waters in Section 6g
	***		Slate Lick Run from its confluence with the Shoemaker River upstream to the 1500 foot elevation.
	VI		Natural Trout Waters in Section 6g
	iv		Long Run (Rockingham County) from its confluence with the Shoemaker River upstream including all named and unnamed tributaries.
	iv		Slate Lick Run from the 1500 foot elevation upstream including all named and unnamed tributaries.
6h	IV	PWS pH-6.5-9.5	Unnamed tributary of North Fork Shenandoah River (on the western slope of Short Mountain opposite Mt. Jackson) from the Town of Mt. Jackson's (inactive mid-1992) raw water intake (north and east dams) to its headwaters.
6i	IV	PWS pH-6.5-9.5	Little Sulfur Creek, Dan's Hollow and Horns Gully (tributaries of the North Fork Shenandoah River on the western slope of Short Mountain opposite Mt. Jackson) which served as a water supply for the Town of Edinburg until March 31, 1992, from the Edinburg intakes upstream to their headwaters.

9VAC25-260-410. James River Basin (Lower).

SEC.	CLASS	SP. STDS.	SECTION DESCRIPTION
1	II	a,z, bb, ESW-11	James River and its tidal tributaries from Old Point Comfort ‑ Fort Wool to the end of tidal waters (fall line, Mayo's Bridge, 14th Street, Richmond), except prohibited or spoil areas, unless otherwise designated in this chapter.
1a	III		Free flowing or nontidal portions of streams in Section 1, unless otherwise designated in this chapter.
	VII		Swamp waters in Section 1a
			Gunns Run and its tributaries from the head of tide at river mile 2.64 to its headwaters.
1b	II	a,z	Eastern and Western Branches of the Elizabeth River and tidal portions of their tributaries from their confluence with the Elizabeth River to the end of tidal waters.
1c	III		Free flowing portions of the Eastern Branch of the Elizabeth River and its tributaries. Includes Salem Canal up to its intersection with Timberlake Road at N36°48'35.67"/W76°08'31.70".
1d	II	a,z	Southern Branch of the Elizabeth River from its confluence with the Elizabeth River to the lock at Great Bridge.
1e	III		Free flowing portions of the Western Branch of the Elizabeth River and of the Southern Branch of the Elizabeth River from their confluence with the Elizabeth River to the lock at Great Bridge.
1f	II	a	Nansemond River and its tributaries from its confluence with the James River to Suffolk (dam at Lake Meade), unless otherwise designated in this chapter.
1g	III		Shingle Creek from its confluence with the Nansemond River to its headwaters in the Dismal Swamp.
	VII		Swamp waters in Section 1g Shingle Creek and its tributaries from the head of tide (approximately 500 feet downstream of Route 13/337) to their headwaters.
1h	III	PWS	Lake Prince, Lake Burnt Mills and Western Branch impoundments for Norfolk raw water supply and Lake Kilby ‑ Cahoon Pond, Lake Meade and Lake Speight impoundments for Portsmouth raw water supply and including all tributaries to these impoundments.
	VII		Swamp waters in Section 1h
			Eley Swamp and its tributaries from Route 736 upstream to their headwaters.
1i	III		Free flowing portions of the Pagan River and its free flowing tributaries.
1j			(Deleted)
1k	III	PWS	Skiffes Creek Reservoir (Newport News water impoundment).
1l	III	PWS	The Lone Star lakes and impoundments in the City of Suffolk, Chuckatuck Creek watershed which serve as a water source for the City of Suffolk.
1m	III	PWS	The Lee Hall Reservoir system, near Skiffes Creek and the Warwick River, in the City of Newport News.
1n	III	PWS	Chuckatuck Creek and its tributaries from Suffolk's raw water intake (at Godwin's Millpond) to a point 5 miles upstream.
1o	II	PWS, bb	James River from City Point (Hopewell) to a point 5 miles ~~above American Tobacco Company's raw water intake~~ upstream.
1p	III	PWS,	Free flowing tributaries to section 1o.
2	III		Free flowing tributaries of the ~~James River from Buoy 64 to Brandon and free flowing tributaries of the~~ Chickahominy River to Walkers Dam, unless otherwise designated in this chapter.
	VII		Swamp waters in Section 2
			Morris Creek and its tributaries from the head of tide at river mile 5.97 upstream to its headwaters.
2a	III	PWS	Diascund Creek and its tributaries from Newport ~~News'~~ News's raw water intake dam to its headwaters.
2b	III	PWS	Little Creek Reservoir and its tributaries from the City of Newport News impoundment dam to 5 miles upstream of the raw water intake.
3	III	m	Chickahominy River and its tributaries from Walkers Dam to Bottoms Bridge (Route 60 bridge), unless otherwise designated in this chapter.
	VII		Swamp waters in Section 3
		m	Chickahominy River from its confluence with Toe Ink Swamp at ~~river mile~~ river mile 43.07 upstream to Bottoms Bridge (Route 60).
		m	Rumley Marsh and tributaries from the confluence of an unnamed tributary at river mile 2.61, upstream to the confluence with Beus Swamp. Beus Swamp, Piney Branch, and Pelham Swamp above the confluence of Beus Swamp are excluded.
		m	White Oak Swamp and its tributaries from its confluence with the Chickahominy River to their headwaters.
3a	III	PWS,m	Chickahominy River and its tributaries from Walkers Dam to points 5 miles upstream.
4	III	m	Chickahominy River and its tributaries, unless otherwise designated in this chapter, from Bottoms Bridge (Route 60 bridge) to its headwaters.
	VII		Swamp waters in Section 4
		m	Chickahominy River from Bottoms Bridge (Route 60) upstream to its confluence with Stony Run at rivermile 71.03.
		m	Stony Run and tributaries from the confluence with Chickahominy River to their headwaters.
4a	III		Free flowing tributaries to the James River from Brandon to the fall line at Richmond, unless otherwise designated in this chapter.
	VII		Swamp waters in Section 4a
			Fourmile Creek and its tributaries to their headwaters.

9VAC25-260-415. James River Basin (Lower) (Appomattox River Subbasin).

SEC.	CLASS	SP. STDS.	SECTION DESCRIPTION
5	II		Appomattox River and its tidal tributaries from its confluence with the James River to the end of tidal waters.
5a	II	PWS	Appomattox River and its tidal tributaries from its mouth to 5 miles upstream of the Virginia-American Water Company's raw water intake.
5b	III	PWS	Free flowing tributaries to ~~section~~ Section 5a.
5c	III		Appomattox River from the head of tidal waters, and free flowing tributaries to the Appomattox River, to their headwaters, unless otherwise designated in this chapter.
	VII		Swamp waters in Section 5c
			Skinquarter Creek from its confluence with the Appomattox River upstream to river mile 5.27.
			Deep Creek from the confluence with Winningham Creek downstream to the confluence of Little Creek, a distance ~~of.54~~ of 5.4 river miles. Winticomack Creek from its confluence with the Appomattox River to its headwaters including unnamed tributaries at river miles 1.92, 3.15, 8.77, and 11.16.
5d	III		Swift Creek and its tributaries from the dam at Pocahontas State Park upstream to Chesterfield County's raw water impoundment dam.
5e	III	PWS	Swift Creek and its tributaries from Chesterfield County's raw water impoundment dam to points 5 miles upstream.
5f	III	PWS	Appomattox River and its tributaries from Appomattox River Water Authority's raw water intake located at the dam at Lake Chesdin to the headwaters of the lake.
	VII		Swamp waters in Section 5f
			~~Winticomack Creek from its confluence with the Appomattox River to its headwaters including unnamed tributaries at river miles 1.92, 3.15, 8.77, and 11.16.~~
			Winterpock Creek and its tributaries (excluding Surline Branch) from its confluence with Lake Chesdin upstream to river mile 8.47.
5g	III	PWS	The Appomattox River and its tributaries from Farmville's raw water intake (approximately 2.5 miles above the Route 15/45 bridge) to points 5 miles upstream.

9VAC25-260-440. Rappahannock River Basin.

SEC.	CLASS	SP. STDS.	SECTION DESCRIPTION
1	II	a	Rappahannock River and the tidal portions of its tributaries from Stingray and Windmill Points to Route 1 Alternate Bridge at Fredericksburg.
1a	II		Hoskins Creek from the confluence with the Rappahannock River to its tidal headwaters.
2	III		Free flowing tributaries of the Rappahannock from Stingray and Windmill Points upstream to Blandfield Point, unless otherwise designated in this chapter.
	VII		Swamp waters in Section 2
			Cat Point Creek and its tributaries, from their headwaters to the head of tide at river mile 10.54.
			Hoskins Creek and its nontidal tributaries from the head of tidal waters to their headwaters. Mason Mill Swamp and its tributaries from the head of tidal waters to their headwaters. Mount Landing Creek and its tributaries from the end of tidal waters at river mile 4.4 to their headwaters.
			Piscataway Creek and its tributaries from the confluence of Sturgeon Swamp to their headwaters.
3	III		The Rappahannock River from the Route 1 Alternate Bridge at Fredericksburg upstream to the low dam water intake at Waterloo (Fauquier County).
3a	III	PWS	The Rappahannock River and its tributaries from Spotsylvania County's raw water intake near Golin Run to points 5 miles upstream (excluding Motts Run and tributaries, which is in ~~section~~ Section 4c).
3b	III	PWS	The Rappahannock River and its tributaries from the low dam water intake at Waterloo, (Fauquier County,) to points 5 miles upstream.
4	III	ESW 17,18	Free flowing tributaries of the Rappahannock from Blandfield Point to its headwaters, unless otherwise designated in this chapter.
	VII		Swamp waters in Section 4 Goldenvale Creek from the head of tidal waters near the confluence with the Rappahannock River to its headwaters.
			Occupacia Creek and its tributaries from the end of tidal waters at river mile 8.89 on Occupacia Creek to their headwaters.
	V		Stockable Trout Waters in Section 4
	***		Hughes River (Madison County) from Route 231 upstream to the upper crossing of Route 707 near the confluence of Rocky Run.
	***		Robinson River from Route 231 to river mile 26.7.
	***		Rose River from its confluence with the Robinson River 2.6 miles upstream.
	***		South River from 5 miles above its confluence with the Rapidan River 3.9 miles upstream.
	VI		Natural Trout Waters in Section 4
	ii		Berry Hollow from its confluence with the Robinson River upstream including all named and unnamed tributaries.
	Ii ii		Bolton Branch from 1.7 miles above its confluence with Hittles Mill Stream upstream including all named and unnamed tributaries.
	Ii ii		Broad Hollow Run from its confluence with Hazel River upstream including all named and unnamed tributaries.
	I i		Brokenback Run from its confluence with the Hughes River upstream including all named and unnamed tributaries.
	I i		Bush Mountain Stream from its confluence with the Conway River upstream including all named and unnamed tributaries.
	I i		Cedar Run (Madison County) from 0.8 mile above its confluence with the Robinson River upstream including all named and unnamed tributaries.
	I i		Conway River (Greene County) from the Town of Fletcher upstream including all named and unnamed tributaries.
	Ii ii		Dark Hollow from its confluence with the Rose River upstream including all named and unnamed tributaries.
	I i		Devils Ditch from its confluence with the Conway River upstream including all named and unnamed tributaries.
	iii		Entry Run from its confluence with the South River upstream including all named and unnamed tributaries.
	iii		Garth Run from 1.9 miles above its confluence with the Rapidan River at the Route 665 crossing upstream including all named and unnamed tributaries.
	ii		Hannah Run from its confluence with the Hughes River upstream including all named and unnamed tributaries.
	ii		Hazel River (Rappahannock County) from the Route 707 bridge upstream including all named and unnamed tributaries.
	ii		Hogcamp Branch from its confluence with the Rose River upstream including all named and unnamed tributaries.
	i		Hughes River (Madison County) from the upper crossing of Route 707 near the confluence of Rocky Run upstream including all named and unnamed tributaries.

REGULATIONSVol. 31 Iss. 22 - June 29, 2015

REGULATIONS
Vol. 31 Iss. 22 - June 29, 2015