Arkansas Administrative Code
Agency 118 - DEPARTMENT OF ENERGY AND ENVIRONMENT
Division 01 - Arkansas Pollution Control and Ecology Commission
Rule 118.01.22-002 - Rule 2, Rule Establishing Water Quality Standards for Surface Waters of the State of Arkansas

Rule 2.101 Authority

Pursuant to the Arkansas Water and Air Pollution Control Act, (Ark. Code Ann. § 8-4-101 et seq.), and in compliance with the requirements of the Federal Water Pollution Control Act, 33 U.S.C. § 1251 et seq., (hereinafter "Clean Water Act"), the Arkansas Pollution Control and Ecology Commission (hereinafter "Commission") hereby promulgates this rule establishing water quality standards for all surface waters, interstate and intrastate, of the State of Arkansas.

Rule 2.102 Purpose

The water quality standards herein set forth are based upon present, future and potential uses of the surface waters of the State and criteria developed from statistical evaluations of past water quality conditions and a comprehensive study of least-disturbed, ecoregion reference streams. The standards are designed to enhance the quality, value, and beneficial uses of the water resources of the State of Arkansas, to aid in the prevention, control and abatement of water pollution, to provide for the protection and propagation of fish and wildlife and to provide for recreation in and on the water. In establishing these standards, the Commission has taken into consideration the use and value of the streams for public water supplies, commercial, industrial and agricultural uses, aesthetics, recreational purposes, propagation of fish and wildlife, other beneficial uses, and views expressed at public hearings. The State of Arkansas has an exceptionally large volume of high quality water. With few exceptions the streams and lakes of Arkansas contain waters of a quality suitable for all legitimate uses without the necessity of unreasonable water treatment. Where man-made pollution exists, substantial progress has been made in abatement. It is the purpose of these rules to preserve and protect the quality of this water so that it shall be reasonably available for all beneficial uses and thus promote the social welfare and economic well-being of the people of the State. It is further the purpose of these rules to designate the uses for which the various waters of the State shall be maintained and protected; to prescribe the water quality standards required to sustain the designated uses; and to prescribe rules necessary for implementing, achieving and maintaining the prescribed water quality.

Rule 2.103 Commission Review

The water quality standards herein established will be reviewed by the Commission at least once each three-year period beginning as of October 18, 1972. Revisions may be made to take into account changing technology of waste production, treatment and removal, advances in knowledge of water quality requirements, and other relevant factors.

Rule 2.104 Policy for Compliance

It shall be the policy of the Arkansas Department of Energy and Environment, Division of Environmental Quality (hereinafter "Division") to provide, on a case-by-case basis, a reasonable time for an existing permittee to comply with new or revised water quality based effluent limits. Consequently, compliance schedules may be included in National Pollutant Discharge Elimination System (NPDES) permits at the time of renewal or permit modification initiated by the Division to require compliance with new water quality standards. Compliance must occur at the earliest practicable time, in accordance with 40 C.F.R. § 122.47.

Rule 2.105 Environmental Improvement Projects

The Commission may, after consideration of information provided pursuant to Appendix B and Ark. Code Ann. § 8-5-901 et seq., grant temporary modifications to the General and Specific Standards or establish a subcategory(ies) of use(s) for completion of long-term Environmental Improvement Projects.

Rule 2.106 Definitions

304(a) Guidance: Refers to Section 304(a) of the Clean Water Act, 33 U.S.C. § 1314(a), which requires the United States Environmental Protection Agency to publish and periodically update ambient water quality criteria which will be protective of human health and the environment.

Abatement: The reduction in degree or intensity of pollution.

Acute toxicity: A statistically significant difference (at the 95 percent confidence level) in mortality or immobilization between test organisms and a control measured during a specified period of time which is normally less than 96 hours.

Algae: Simple plants (without roots, stems, or leaves ) that contain chlorophyll and are capable of photosynthesis.

Aquatic biota: All those life forms which inhabit the aquatic environment.

Aquatic life: The designated use of a waterbody determined by the fish community and other associated aquatic biota.

Base flows: That portion of the stream discharge that is derived from natural storage (i.e., outflow from groundwater or swamps), or sources other than recent rainfall that creates surface runoff. Also called sustaining, normal, dry weather, ordinary, or groundwater flow.

Bioaccumulation: The process by which a compound is taken up by an aquatic organism, both from water and through food.

Chronic toxicity: A statistically significant difference (at the 95 percent confidence level) in mortality or immobilization, reduced reproduction or limited growth between test organisms and a control measured during a substantial segment of the life span of the test organism.

Commission: The Arkansas Pollution Control and Ecology Commission.

Conventional pollutants: Pursuant to section 304(a)(4) of the Clean Water Act, 33 U.S.C. § 1314(a)(4), includes biochemical oxygen demand (BOD), total suspended solids (nonfilterable) (TSS), pH, fecal coliform, and oil and grease.

Criterion continuous concentration (CCC): An estimate of the highest concentration of a material in ambient water to which an aquatic community can be exposed indefinitely without resulting in an unacceptable adverse effect. This is the chronic criterion.

Criterion maximum concentration (CMC): An estimate of the highest concentration of a material in ambient water to which an aquatic community can be exposed briefly without resulting in an unacceptable adverse effect. This is the acute criterion.

Critical flows: The flow volume used as background dilution flows in calculating concentrations of pollutants from permitted discharges. These flows may be adjusted for mixing zones. The following critical flows are applicable:

For a seasonal aquatic life - 1 cubic foot per second minus the design flow of any point source discharge (may not be less than zero);

For human health - harmonic mean flow or long term average flow;

* Rule 2.511(A) Site Specific Mineral Criteria listed with an asterisk- 4 cubic feet per second.

* Rule 2.511(C) Domestic Water Supply: Q7-10; and

For metals and conventional pollutants - Q7-10.

Critical season: That period of the year when water temperatures exceed 22°C. This is normally the hot, dry season and after the majority of the fish spawning activities have ceased. This season occurs during a different time frame in different parts of the state, but normally exists from about mid-May to mid-September.

Cumulative: Increasing by successive additions.

Degradation: The act or process of causing any decrease in quality.

Design flow: A facility discharge flow of process wastewater that is authorized in a NPDES permit.

Designated uses: Those uses specified in the water quality standards for each waterbody or stream segment whether or not they are being attained.

Discharge: A discrete point source of waste or wastewater entering into waters of the State.

Dissolved oxygen (DO): A measure of the concentration of oxygen in solution in a liquid.

Division: The Arkansas Department of Energy and Environment, Division of Environmental Quality or its successor.

Ecoregion: A large area of landscape with relatively homogenous physical, chemical and biological characteristics.

Effluent: Water that is not reused after flowing out of any wastewater treatment facility or other works used for the purpose of treating, stabilizing, or holding wastes.

Escherichia coli: A rod shaped gram negative bacillus (0.5 - 3-5 microns) abundant in the large intestines of mammals.

Endemic: Native to and confined to a specific region.

Existing uses: Those uses listed in Section 303(c)(2) of the Clean Water Act, 33 U.S.C. § 1313(c)(2) (i.e., public water supplies, propagation of fish and wildlife, recreational uses, agricultural and industrial water supplies, and navigation), which were actually attained in the waterbody on or after November 28, 1975, whether or not they are included in the water quality standards.

Fecal coliform bacteria: Gram-negative nonspore-forming rods that ferment lactose in 24 ± 2 hours at 44.5 ± 0.2°C with the production of gas in a multiple-tube procedure or produce acidity with blue colonies in a membrane filter procedure. For the purpose of this rule, the genus Klebsiella is not included in this definition.

Fishable/swimmable: Refers to one of the national goals stated in Section 101(a)(2) of the Clean Water Act, 33 U.S.C. § 1251(a)(2),"...provides for the protection and propagation of fish, shellfish and wildlife and provides for recreation in and on the water."

Groundwater: Water below the land surface in a zone of saturation.

Hardness: A measure of the sum of multivalent metallic cations expressed as calcium carbonate (CaCO3).

Harmonic mean flow: The reciprocal of the mean of the reciprocals of daily flow measurements.

Headwater: The upper watershed area where streams generally begin; typically consists of 1st-and 2nd-order streams.

Heavy metals: A general name given to the ions of metallic elements heavier than iron, such as cadmium, lead, mercury, copper, zinc and chromium.

Human health criteria: Levels of toxicants in ambient water which will not manifest adverse health effects in humans.

Hypolimnion: That portion of a thermally stratified lake or reservoir below the zone in which the rate of temperature change is greatest. An area of minimal circulation and mixing.

Impairment: Exceedances of the water quality standards by a frequency and/or magnitude which results in any designated use of a waterbody to fail to be met as a result of physical, chemical or biological conditions.

Indicator species: Species of fish which may not be dominant within a species group and may not be limited to one area of the state, but which, because of their presence, are readily associated with a specific ecoregion. All indicator species need not be present to establish a normal or representative fishery.

Indigenous: Produced, growing or living naturally in a particular region or environment.

Interstate: Of, connecting, or existing between two or more states.

Intrastate: Existing or occurring within a state.

Ionizing radiation: Gamma rays and x-rays; alpha and beta particles, high speed electrons, neutrons, protons and other nuclear particles; but not sound or radio waves, or visible, infrared or ultraviolet light.

Key species: Fishes which are normally the dominant species (except for some ubiquitous species) within the important groups such as fish families or trophic feeding levels. All specified key species need not be present to establish a normal or representative fishery.

Long term average flow: An average annual stream flow based on a period of record which reflects the typical annual variability.

Milligrams per liter (mg/L): The concentration at which one milligram is contained in a volume of one liter; one milligram per liter is equivalent to one part per million (ppm) at unit density.

Mixing zone: An area where an effluent discharge undergoes mixing with the receiving waterbody. For toxic discharges a zone of initial dilution may be allowed within the mixing zone.

Mouth: The point of confluence where a stream enters a larger body of water.

Natural background: Ambient conditions or concentrations of a parameter due to non-anthropogenic sources; natural background does not typically interfere with support of designated uses nor the level of aquatic biota expected to occur naturally at the site.

Naturally occurring excursions: Temporary deviation from natural background due to natural events such as severe storm events, drought, temperature extremes, etc.

Nephelometric turbidity unit (NTU): A measure of turbidity based upon a comparison of the intensity of light scattered by a sample of water under defined conditions with the intensity of light scattered by a standard reference suspension; NTU are considered comparable to the previously reported Jackson Turbidity Units (JTU). May also be reported as Formazin Turbidity Units (FTU) in equivalent units.

Nonpoint source: A contributing factor to water pollution that is not confined to an end-of-the-pipe discharge, i.e., stormwater runoff not regulated under Clean Water Act § 402(p)(1), 33 U.S.C. § 1342(p), agricultural or silvicultural runoff, irrigation return flows, etc.

Nuisance species: Those organisms capable of interfering with the beneficial use of water.

Nutrient: Any substance assimilated by an organism which promotes growth and replacement of cellular constituents. The usual nutrient components of water pollution are nitrogen, phosphorus and carbon.

Objectionable algal densities: Numbers of total algae which would interfere with a beneficial use.

Persistent: Degraded only slowly by the environment.

pH: The negative logarithm of the effective hydrogen-ion concentration in gram equivalents per liter.

Picocurie: One trillionth (10 -13) of a curie which is a unit of quantity of any radioactive nuclide in which 3.7 X 1010 disintegrations occur per second.

Point source: A discharge from a discrete point.

Primary season: That period of the year when water temperatures are 22°C or below. This includes the major part of the year from fall through spring, including the spawning season of most fishes. It normally occurs from about mid-September to mid-May.

Q7-10: A flow volume equal to or less than the lowest mean discharge during 7 consecutive days of a year which, on the average, occurs once every 10 years.

Regulated-flow stream: Those streams restricted by structures which have the ability to control stream flow.

Seasonal aquatic life: The designated aquatic life use that occurs in some waterbodies only during the period when stream flows increase substantially and water temperatures are cooler. This is normally during the months of December through May.

State of Arkansas Continuing Planning Process: A document setting forth the principal procedures of the State's water quality management programs, developed pursuant to Section 303(e) of the Clean Water Act, 33 U.S.C. § 1313(e), and 40 C.F.R. § 130.5. The CPP is not a rule.

Storm flows: Takes into account all flows and data collected throughout the year, including elevated flows due to rainfall events.

Surface water: That water contained on the exterior or upper portion of the earth's surface as opposed to groundwater.

Synergism: Cooperative action of discrete agents such that the total effect is greater than the sum of the effects taken independently.

Total dissolved solids (TDS): The total soluble organic and inorganic material contained in water; includes those materials, both liquid and solid, in solution and otherwise, which pass through a standard glass fiber filter disk and are not volatilized during drying at 180°C.

Trout fishery: Water that is suitable for the growth and survival of trout, usually characterized as high quality water having a maximum summer temperature of 68°F or less.

Use attainability analysis: A structured scientific assessment of the factors affecting the attainment of the fishable/swimmable use which may include physical, chemical, biological and economic factors.

Waterbodies, waterways, waters: In this document, refers to surface waters of the State as described in Act 472.

Water effects ratio (WER): A specific pollutant's acute or chronic value measured from a specific site ambient water, divided by the respective acute or chronic toxicity of the same pollutant in laboratory water.

Zone of initial dilution (ZID): An area within the mixing zone where a toxic effluent discharge initiates mixing in the receiving waterbody. This is an area where acute water quality criteria may be exceeded, but acute toxicity may not occur.

Rule 2.201 Existing Uses

Existing instream water uses and the level of water quality necessary to protect the existing uses shall be maintained and protected.

Rule 2.202 High Quality Waters

Where the quality of the waters exceeds levels necessary to support propagation of fish, shellfish and wildlife and recreation in and on the water, that quality shall be maintained and protected unless the State finds, after full satisfaction of the intergovernmental coordination and public participation provisions of the State of Arkansas's Continuing Planning Process, that allowing lower water quality is necessary to accommodate important economic or social development in the area in which the waters are located. In allowing such degradation or lower water quality, the State shall assure water quality adequate to protect existing uses fully. Further, the State shall assure that (1) there shall be achieved the highest statutory and regulatory requirements for all new and existing point sources and (2) that the provisions of the Arkansas Water Quality Management Plan be implemented with regard to nonpoint sources.

Rule 2.203 Outstanding Resource Waters

Where high quality waters constitute an outstanding state or national resource, such as those waters designated as Extraordinary Resource Waters, Ecologically Sensitive Waterbodies or Natural and Scenic Waterways, those uses and water quality for which the outstanding waterbody was designated shall be protected by (1) water quality controls, (2) maintenance of natural flow regime, (3) protection of instream habitat, and (4) encouragement of land management practices protective of the watershed. It is not the intent of the Extraordinary Resource Waters (ERW) designated use definition to imply that ERW status dictates regulatory authority over private land within the watershed, other than what exists under local, state, or federal law. The Arkansas Natural Resources Commission has responsibility for the regulation of the withdrawal of water from streams and reservoirs, and such withdrawals are not within the jurisdiction of this rule.

Rule 2.204 Thermal Discharges

In those cases where potential water quality impairment associated with a thermal discharge is involved, the antidegradation policy and implementing method shall be consistent with Section 316 of the Clean Water Act, 33 U.S.C. § 1326.

Rule 2.301 Introduction

Substantially all the waters of the State have been designated for specific uses as shown in Appendix A. In those instances where waters are classified for multiple uses and different criteria are specified for each use, the criteria to protect the most sensitive use shall be applicable.

Rule 2.302 Designated Uses

The designated uses are defined as follows:

Rule 2.303 Use Attainability Analysis

Rule 2.304 Physical Alteration of Habitat

Significant physical alterations of the habitat within Extraordinary Resource Waters, Ecologically Sensitive Waterbodies, or Natural and Scenic Waterways are not allowed. In other waters, where significant physical alterations of the habitat are proposed, the Division must be assured that no significant degradation of any existing use or water quality necessary to protect that use will occur. In order to make such determinations, the Division may require an evaluation of all practicable alternatives to the project including: an environmental assessment of the impacts of each alternative, an engineering and economic analysis, and a socio-economic evaluation of the project in the local area.

Rule 2.305 Short Term Activity Authorization

The Director may authorize, with whatever conditions deemed necessary and without public notice, short term activities which might cause a violation of the Arkansas Water Quality Standards. This authorization is subject to the provisions that such activity is essential to the protection or promotion of the public interest and that no permanent or long-term impairment of beneficial uses is likely to result from such activity. Nothing herein shall be intended to supersede existing state and federal permitting processes or requirements.

Activities eligible for authorization include, but are not limited to:

Rule 2.306 Procedures for Removal of Any Designated Use Except Fishable/Swimmable, Extraordinary Resource Water, Ecologically Sensitive Waterbody, or Natural and Scenic Waterway, and Modification of Water Quality Criteria not Related to These Uses

This procedure is applicable in those cases where the Commission chooses to establish less stringent water quality criteria without affecting a fishable/swimmable use or the designated use of Extraordinary Resource Water, Ecologically Sensitive Waterbody, or Natural and Scenic Waterway, or when the Commission chooses to remove a use which is not an existing use other than fishable/swimmable, Extraordinary Resource Water, Ecologically Sensitive Waterbody, or Natural and Scenic Waterway.

The Commission may allow a modification of the water quality criteria or the removal of a use which is not a fishable/swimmable use or designated use of Extraordinary Resource Water, Ecologically Sensitive Waterbody, or Natural and Scenic Waterway to accommodate important economic or social development in a local area, if existing uses are maintained and protected fully and the requirements for public participation in the State of Arkansas Continuing Planning Process are met. As a minimum, the following information shall be submitted to the Director before initiation of the public participation process:

Rule 2.307 Use Subcategories

The Commission may adopt sub-categories of a use and set the appropriate criteria to reflect varying needs of such sub-categories of uses; for instance, to differentiate between cold and warm water fisheries or agricultural and domestic water supply.

Rule 2.308 Site Specific Criteria

In establishing criteria:

Rule 2.309 Water Quality Standards Temporary Variance

A water quality standards temporary variance shall be developed in accordance with and meet the requirements of 40 C.F.R. § 131.14 and must be approved by the Arkansas Pollution Control and Ecology Commission and the United States Environmental Protection Agency.

Rule 2.310 Procedure for the Removal of the Designated Use of Extraordinary Resource Water, or Ecologically Sensitive Waterbody, or Natural and Scenic Waterway for the Purpose of Constructing a Reservoir on a Free Flowing Waterbody to Provide a Domestic Water Supply.

Rule 2.311 Procedure for the Addition of the Designated Use of Extraordinary Resource Water, or Ecologically Sensitive Waterbody, or Natural and Scenic Waterway to a Waterbody or Segment of a Waterbody.

Rule 2.401 Applicability

Unless otherwise indicated in this Chapter or in Appendix A, the general standards outlined below are applicable to all surface waters of the State at all times. They apply specifically with regard to substances attributed to discharges, nonpoint sources, or instream activities as opposed to natural phenomena. Waters may, on occasion, have natural background levels of certain substances outside the limits established by these criteria, in which case these criteria do not apply.

Rule 2.402 Nuisance Species

All waters shall be free from substances attributed to man-caused point or nonpoint source discharges in concentrations that produce undesirable aquatic biota or result in the dominance of nuisance species.

Rule 2.403 Methods

The methods of sample collection, preservation, measurements, and analyses shall be in accordance with the United States Environmental Protection Agency Guidelines Establishing Test Procedures for the Analysis of Pollutants ( 40 C.F.R. § 136) or other proven methods acceptable to the.

Rule 2.404 Mixing Zones

Where mixing zones are allowed, the effects of wastes on the receiving stream shall be determined after the wastes have been thoroughly mixed with the mixing zone volume. Outfall structures should be designed to minimize the extent of mixing zones to ensure rapid and complete mixing.

For aquatic life toxic substances in larger streams (those with Q7-10 flows equal to or greater than 100 cfs), the zone of mixing shall not exceed 1/4 of the cross-sectional area and/or critical flow volume of the stream. The remaining 3/4 of the stream shall be maintained as a zone of passage for swimming and drifting organisms, and shall remain of such quality that stream ecosystems are not significantly affected. In the smaller streams (Q7-10 flows less than 100 cfs) because of varying local physical and chemical conditions and biological phenomena, a sitespecific determination shall be made on the percentage of river width necessary to allow passage of critical free-swimming and drifting organisms so that negligible or no effects are produced on their populations. As a guideline, no more than 2/3 of the cross-sectional area and/or critical flow volume of smaller streams should be devoted to mixing zones thus leaving at least 1/3 of the cross-sectional area free as a zone of passage.

Mixing zones are not allowed for the parameters of bacteria or oil and grease, or where the background flow is less than the critical flow or where the background concentration of a waste parameter exceeds the specific criteria for that waste parameter.

In lakes and reservoirs the size of mixing zones shall be defined by the Division on an individual basis, and the area shall be kept at a minimum.

Mixing zones shall not prevent the free passage of fish or significantly affect aquatic ecosystems.

A mixing zone shall not include any domestic water supply intake.

Rule 2.405 Biological Integrity

For all waters with specific aquatic life use designated in Appendix A, aquatic biota should not be impacted. Aquatic biota should be representative of streams that have the ability to support the designated fishery, taking into consideration the seasonal and natural variability of the aquatic biota community under naturally varying habitat and hydrological conditions; the technical and economic feasibility of the options available to address the relevant conditions; and other factors.

An aquatic biota assessment should compare biota communities that are similar in habitat and hydrologic condition, based upon either an in-stream study including an upstream and downstream comparison, a comparison to a reference water body within the same ecoregion, or a comparison to community characteristics from a composite of reference waters. Such a comparison should consider the seasonal and natural variability of the aquatic biota community. It is the responsibility of the Division to evaluate the data for an aquatic biota assessment to protect aquatic life uses designated in Appendix A. Such data may be used to develop permit effluent limitations or conditions.

Rule 2.406 Color

True color shall not be increased in any waters to the extent that it will interfere with present or projected future uses of these waters.

Rule 2.407 Taste and Odor

Taste and odor producing substances shall be limited in receiving waters to concentrations that will not interfere with the production of potable water by reasonable water treatment processes, impart unpalatable flavor to food or fish, result in offensive odors arising from the waters, or otherwise interfere with the reasonable use of the water.

Rule 2.408 Solids, Floating Material and Deposits

Receiving waters shall have no distinctly visible solids, scum, or foam of a persistent nature, nor shall there be any formation of slime, bottom deposits, or sludge banks.

Rule 2.409 Toxic Substances

Discharges shall not be allowed into any waterbody which, after consideration of the zone of initial dilution, the mixing zone, and critical flow conditions, will cause toxicity to human, animal, plant, or aquatic biota or interfere with normal propagation, growth, and survival of aquatic biota.

Rule 2.410 Oil and Grease

Oil, grease, or petrochemical substances shall not be present in receiving waters to the extent that they produce globules, other residue, or any visible, colored film on the surface; coat the banks and/or bottoms of the waterbody; or adversely affect any of the aquatic biota.

Rule 2.501 Applicability

Unless otherwise indicated in this Chapter or in Appendix A, the following specific standards shall apply to all surface waters of the State at all times except during periods when flows are less than the applicable critical flow. Streams with regulated flow will be addressed on a case-by-case basis to maintain designated instream uses. These standards apply outside the applicable mixing zone. Waters may, on occasion, have natural background levels of certain substances outside the limits established by these criteria, in which case these criteria do not apply to the naturally occurring excursions.

Rule 2.502 Temperature

Heat shall not be added to any waterbody in excess of the amount that will elevate the natural temperature, outside the mixing zone, by more than 5°F (2.8°C) based upon the monthly average of the maximum daily temperatures measured at mid-depth or three feet (whichever is less) in streams, lakes, or reservoirs.

The following criteria are applicable:

Temperature requirements shall not apply to off-stream privately-owned reservoirs constructed primarily for industrial cooling purposes and financed in whole or in part by the entity or successor entity using the lake for cooling purposes.

Rule 2.503 Turbidity

There shall be no distinctly visible increase in turbidity of receiving waters attributable to discharges or instream activities.

The values below should not be exceeded during base flow (June 1 through October 31) in more than 20% of samples. The values below should not be exceeded during storm flows in more than 25% of samples taken in no less than 24 monthly samples.

Rule 2.504 pH

pH between 6.0 and 9.0 standard units are the applicable criteria for rivers, streams, lakes, and reservoirs. As a result of waste discharges, the pH of water in streams or lakes must not fluctuate in excess of 1.0 standard unit over a period of 24 hours.

Rule 2.505 Dissolved Oxygen

Rivers and Streams

The following dissolved oxygen criteria are applicable:

In streams with watersheds of less than 10 mi2, it is assumed that insufficient water exists to support aquatic life during the critical season. During this time, a dissolved oxygen criteria of 2 mg/L will apply to prevent nuisance conditions. However, field verification is required in areas suspected of having significant groundwater flows or enduring pools that may support unique aquatic biota. In such waters the critical season criteria for the next size category of stream shall apply.

All streams with watersheds of less than 10 mi2 are expected to support aquatic life during the primary season when stream flows, including discharges, equal or exceed 1 cubic foot per second (cfs). However, when site verification indicates that aquatic life exists at flows below 1 cfs, such aquatic biota will be protected by the primary standard (refer to the State of Arkansas Continuing Planning Process for field verification requirements).

Also in streams with watersheds of less than 10 mi2, where waste discharges are 1 cfs or more, streams are assumed to provide sufficient water to support aquatic life and, therefore, must meet the dissolved oxygen criteria of the next size category of streams.

For purposes of determining effluent discharge limits, the following conditions shall apply:

Rule 2.506 Radioactivity

The Rules and Regulations for the Control of Sources of Ionizing Radiation of the Division of Radiological Health, Arkansas Department of Health, limits the maximum permissible levels of radiation that may be present in effluents to surface waters in uncontrollable areas. These limits shall apply for the purposes of these standards, except that in no case shall the levels of dissolved radium-226 and strontium-90 exceed 3 and 10 picocuries/liter, respectively, in the receiving water after mixing, nor shall the gross beta concentration exceed 1000 picocuries/liter.

Rule 2.507 Bacteria

For the purposes of this rule, all streams with watersheds less than 10 mi2 shall not be designated for primary contact unless and until site verification indicates that such use is attainable. Secondary contact use is assumed in all watershed sizes. No mixing zones are allowed for discharges of bacteria.

For assessment of ambient waters as impaired by bacteria, the below listed applicable criteria for E. coli shall not be exceeded in more than 25% of individual samples in no less than eight (8) samples taken during the primary contact season or during the secondary contact season.

The following criteria are applicable:

1 May 1 to September 30

2 (RESERVED)

3 For assessment of Individual Sample Criteria- at least eight (8) data points

4 For calculation and assessment of Geometric Mean - calculated on a minimum of five (5) samples spaced evenly and within a thirty (30)-day period.

5 Year-round.

The Arkansas Department of Health has the responsibility of approving or disapproving surface waters for public water supply and of approving or disapproving the suitability of specifically delineated outdoor bathing places for body contact recreation, and it has issued rules pertaining to such uses.

Rule 2.508 Toxic Substances

Toxic substances shall not be present in receiving waters, after mixing, in such quantities as to be toxic to human, animal, plant or aquatic life or to interfere with the normal propagation, growth and survival of the indigenous aquatic biota. Acute toxicity standards apply outside the zone of initial dilution. Within the zone of initial dilution acute toxicity standards may be exceeded but acute toxicity may not occur. Chronic toxicity and chronic numeric toxicity standards apply at, or beyond, the edge of the mixing zone. Permitting of all toxic substances shall be in accordance with the toxic implementation strategy found in the State of Arkansas Continuing Planning Process. For non-permit issues and as a guideline for evaluating toxic substances not listed in the following tables, the Division may consider No Observed Effect Concentrations or other literature values as appropriate. For the substances listed below, the following standards shall apply:

DISSOLVED METALS *

*These values may be adjusted by a site specific Water Effects Ratio (WER) as defined in 40 C.F.R. § 131.36(c).

Rule 2.509 Nutrients

Rule 2.510 Oil and Grease

Oil, grease, or petrochemical substances shall not be present in receiving waters to the extent that they produce globules, other residue, or any visible, colored film on the surface; coat the banks and/or bottoms of the waterbodies; or adversely affect any of the aquatic biota. Oil and grease shall be an average of no more than 10 mg/L or a maximum of no more than 15 mg/L. No mixing zones are allowed for discharges of oil and grease.

Rule 2.511 Mineral Quality

Rule 2.512 Ammonia

The total ammonia nitrogen (N) criteria and the frequency of occurrence are as follows:

RULE 2

APPENDIX A

Designated Uses, Specific Standards, and Maps of Waters of the State by Ecoregions

APPENDIX A: MAP OF ECOREGIONS OF ARKANSAS

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DESIGNATED USES: OZARK HIGHLANDS ECOREGION

(Plates OH-1, OH-2, OH-3, OH-4)

Extraordinary Resource Waters

Current River (OH-4)

Eleven Point River (OH-4)

Strawberry River (OH-3, OH-4)

Little Strawberry River (OH-3)

Spring River, including its tributaries: Field Creek, Big Creek, English Creek, Gut Creek and Myatt Creek (OH-4)

South Fork Spring River (OH-3, OH-4)

North Sylamore Creek (OH-3)

Buffalo River (OH-2, OH-3)

Kings River (OH-2)

Bull Shoals Reservoir (OH-2, OH-3)

Natural and Scenic Waterways

Strawberry River from headwaters to Sharp-Izard County Line (OH-3, OH-4)

Kings River - that segment in Madison County (OH-2)

Buffalo River (OH-2, OH-3)

North Sylamore Creek (OH-3)*

Ecologically Sensitive Waterbodies

Cave Springs Cave, Logan Cave and numerous springs and spring-fed tributaries which support southern cavefish, Ozark cavefish, Arkansas darter, least darter, Oklahoma salamander, cave snails, cave crawfish and unique invertebrates (OH-1, OH-2, OH-3)

Strawberry River - location of Strawberry River darter (OH-3, OH-4)

Little Strawberry River - location of the Strawberry River darter (OH-3)

Spring River - snuffbox and pink mucket mussels; Ozark hellbender (OH-4)

Rock Creek - snuffbox and pink mucket mussels; Ozark hellbender (OH-4)

Eleven Point River - location of Ozark hellbender (OH-4)

Current River - location of flat floater and pink mucket mussels (OH-4)

Illinois River - Neosho mucket (OH-1)

Primary Contact Recreation- all streams with watersheds of greater than 10 mi2 and all lakes/reservoirs**

Secondary Contact Recreation- all waters**

Domestic, Industrial and Agricultural Water Supply- all waters**

Aquatic Life**

Trout Waters

Bull Shoals Reservoir - lower portion (OH-2)

White River from Bull Shoals Dam to Dam #3 (OH-3)

North Fork White River (OH-3)

Spring River from Mammoth Springs to South Fork Spring River (OH-4)

Upper White River from Beaver Dam to Missouri state line (OH-1)

Lakes and Reservoirs - all

Streams

Seasonal Ozark Highlands aquatic life use - all streams with watersheds of less than 10 mi2 except as otherwise provided in Rule 2.505

Perennial Ozark Highlands aquatic life use - all streams with watersheds of 10 mi2 and larger and those waters where discharges equal or exceed 1 cfs

*As designated in the National Wild and Scenic Rivers System

**Except for those waters with designated use variations supported by Use Attainability Analysis or other investigations.

Site Specific Designated Use Variations Supported by Use Attainability Analysis or Other Investigations

SPECIFIC CRITERIA: OZARK HIGHLANDS ECOREGION

(Plates OH-1, OH-2, OH-3, OH-4)

All other criteria (same as statewide)

*Increase over natural temperatures may not be more than 2.8°C (5°F).

**At water temperatures <= 10°C or during March, April and May when stream flows are 15 cfs and greater, the primary season dissolved oxygen standard will be 6.5 mg/L. When water temperatures exceed 22°C, the critical season dissolved oxygen standard may be depressed by 1 mg/L for no more than 8 hours during a 24-hour period.

Site Specific Criteria Variations Supported by Use Attainability Analysis

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DESIGNATED USES: BOSTON MOUNTAINS ECOREGION

(Plates BM-1, BM-2, BM-3)

Extraordinary Resource Waters

Middle and Devils Forks of the Little Red River including Beech Creek, Tomahawk Creek, Turkey Creek, Lick Creek, Raccoon Creek, and Little Raccoon Creek (BM-2, BM-3)

Archey Creek from headwaters to confluence with South Fork Little Red River (BM-2)

Illinois Bayou including North, Middle and East Forks (BM-2)

Big Piney Creek (BM-2)

Hurricane Creek (BM-2)

Mulberry River (BM-1, BM-2)

Lee Creek from state line upstream to headwaters (BM-1)

Salado Creek (BM-3)

Kings River (BM-1)

Richland Creek and Falling Water Creek (BM-2)

Buffalo River (BM-1, BM-2)

Natural and Scenic Waterways

Mulberry River (BM-1, BM-2)

Buffalo River (BM-1, BM-2)

Kings River (BM-1)

Big Piney Creek (BM-2)*

Hurricane Creek (BM-2)*

Richland Creek (BM-2)*

Ecologically Sensitive Waterbodies

Middle, South, and Devils Forks of Little Red River including Beech Creek, Tomahawk Creek, Turkey Creek, Lick Creek, Raccoon Creek, Little Raccoon Creek, and Archey Creek above Greers Ferry Reservoir - location of endemic yellowcheek darter and endangered speckled pocketbook mussel (except Devils Fork) (BM-2, BM-3)

Foshee Cave - location of aquatic cave snail (BM-3)

Upper White River - location of longnose darter (BM-1)

Primary Contact Recreation - all streams with watersheds of greater than 10 mi2 and all lakes/reservoirs**

Secondary Contact Recreation - all waters**

Domestic, Industrial and Agricultural Water Supply - all waters**

Aquatic Life**

Trout Waters

Greers Ferry Reservoir below Narrows (BM-3)

Little Red River below Greers Ferry Dam (BM-3)

Lakes and Reservoirs - all

*As designated in the National Wild and Scenic Rivers System

** Except for those waters with designated use variations supported by Use Attainability Analysis or other investigations.

Streams

Seasonal Boston Mountain aquatic life- all waters with watersheds of less than 10 mi2 except as otherwise provided in Rule 2.505

Perennial Boston Mountain aquatic life- all waters with 10 mi2 watershed or larger and those waters where discharges equal or exceed 1 cfs

Use Variations Supported by Use Attainability Analysis

None

SPECIFIC CRITERIA: BOSTON MOUNTAINS ECOREGION

(Plates BM-1, BM-2, BM-3)

Site Specific Criteria Variations Supported by Use Attainability Analysis

None

*Increase over natural temperatures may not be more than 2.8°C (5°F).

**At water temperatures <= 10°C or during March, April and May when stream flows are 15 cfs and greater, the primary season dissolved oxygen criteria will be 6.5 mg/L. When water temperatures exceed 22°C, the critical season dissolved oxygen criteria may be depressed by 1 mg/l for no more than 8 hours during a 24-hour period.

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DESIGNATED USES: ARKANSAS RIVER VALLEY ECOREGION

(Plates ARV-1, ARV-2, ARV-3)

Extraordinary Resource Waters

Cadron Creek including North Fork and East Fork (ARV-2, ARV-3)

Mulberry River (ARV-1)

Big Creek adjacent to natural areas (ARV-3)

Natural and Scenic Waterway

Mulberry River (ARV-1)

Ecologically Sensitive Waterbodies

None

Primary Contact Recreation- all streams with watersheds of greater than 10 mi2 and all lakes/reservoirs**

Secondary Contact Recreation- all waters**

Domestic, Industrial and Agricultural Water Supply- all waters**

Aquatic Life**

Trout Waters

Little Red River below Greers Ferry Dam to Searcy (ARV-3)

Lakes and Reservoirs - all

Streams

Seasonal Arkansas River Valley aquatic life use - all streams with watersheds of less than 10 mi2 except as otherwise provided in Rule 2.505

Perennial Arkansas River Valley aquatic life - all streams with watersheds of 10 mi2 or larger and those waters where discharges equal or exceed 1 cfs

Site Specific Designated Use Variations Supported by Use Attainability Analysis

**Except for those waters with designated use variations supported by Use Attainability Analysis or other investigations.

SPECIFIC CRITERIA: ARKANSAS RIVER VALLEY ECOREGION

(Plates ARV-1, ARV-2, ARV-3)

Site Specific Criteria Variations Supported by Use Attainability Analysis

*Increase over natural temperatures may not be more than 2.8°C (5°F).

**At water temperatures <= 10°C or during March, April and May when stream flows are 15 cfs and greater, the primary season dissolved oxygen criteria will be 6.5 mg/L. When water temperatures exceed 22°C, the critical season dissolved oxygen criteria may be depressed by 1 mg/L for no more than 8 hours during a 24-hour period.

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DESIGNATED USES: OUACHITA MOUNTAIN ECOREGION

(Plates OM-1, OM-2)

Extraordinary Resource Waters

Lake Ouachita (OM-1, OM-2)

DeGray Reservoir (OM-2)

Saline River - entire segment including North, Alum, Middle and South Forks (OM-2)

Caddo River - above DeGray Reservoir (OM-1, OM-2)

South Fork Caddo River (OM-1)

Cossatot River - above Gillham Reservoir (OM-1)

Caney Creek (OM-1)

Little Missouri River - above Lake Greeson (OM-1)

Mountain Fork River (OM-1)

Big Fork Creek - adjacent to natural area (OM-1)

Natural and Scenic Waterway

Cossatot River above Gillham Reservoir (OM-1)

Little Missouri River above Lake Greeson (OM-1)

Brushy Creek (OM-1)*

Ecologically Sensitive Waterbodies

Ouachita River above Lake Ouachita - location of Caddo madtom, longnose darter, peppered shiner and threatened

Arkansas fatmucket Mussel (OM-1)

South Fork Ouachita River - location of Arkansas fatmucket mussel and Caddo madtom (OM-1)

Caddo River and all tributaries above DeGray Reservoir - location of endemic paleback darter, Caddo madtom and threatened Arkansas fatmucket mussel (OM-1, OM-2)

Mountain Fork River - location of threatened leopard darter (OM-1)

Cossatot River above Gillham Reservoir - location of threatened leopard darter (OM-1)

Saline River including Alum, Middle, North and South Forks, and Ten Mile Creek - location of endemic Ouachita madtom and threatened Arkansas fatmucket mussel (except South fork and Ten Mile Creek) (OM-2)

Little Missouri River above Lake Greeson - location of Caddo madtom

Mayberry Creek (tributary to Hallman's Creek) - location of paleback darter (OM-2)

Robinson Creek - location of threatened leopard darter (OM-1)

Primary Contact Recreation- all streams with watersheds of greater than 10 mi2 and all lakes/reservoirs**

Secondary Contact Recreation- all waters**

Domestic, Industrial and Agricultural Water Supply- all waters**

Aquatic Life**

Trout Waters

Lake Ouachita (lower portion) (OM-2)

Ouachita River from Blakely Mt. Dam to Hwy. 270 bridge (OM-2)

Lakes and Reservoirs - all

*As designated in the National Wild and Scenic Rivers System

**Except for those waters with designated use variations supported by Use Attainability Analysis or other investigations.

Aquatic Life**

Streams

Seasonal Ouachita Mountain Ecoregion aquatic life - all streams with watersheds of less than 10 mi2 except as otherwise provided in Rule 2.505

Perennial Ouachita Mountain Ecoregion aquatic life - all streams with watershed of 10 mi2 or larger and those waters where discharges equal or exceed 1cfs

Site Specific Designated Use Variations Supported by Use Attainability Analysis

**Except for those waters with designated use variations supported by Use Attainability Analysis or other investigations.

SPECIFIC CRITERIA: OUACHITA MOUNTAIN ECOREGION

(Plates OM-1, OM-2)

Site Specific Criteria Variations Supported by Use Attainability Analysis

*Increase over natural temperatures may not be more than 2.8°C (5°F).

**At water temperatures <= 10°C or during March, April and May when stream flows are 15 cfs and greater, the primary season dissolved oxygen criteria will be 6.5 mg/L. When water temperatures exceed 22°C, the critical season dissolved oxygen criteria may be depressed by 1 mg/L for no more than 8 hours during a 24-hour period.

Temporary Variations Supported by Environmental Improvement Project

* These temporary standards variations are effective for 148 months from EPA's approval of the EIP on January 7, 2020.

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DESIGNATED USES: GULF COASTAL ECOREGION

(Plates GC-1, GC-2, GC-3, GC-4)

Extraordinary Resource Waters

Saline River (GC-3, GC-4)

Moro Creek - adjacent to natural area (GC-2)

Natural and Scenic Waterways

Saline River from the Grant-Saline County line to mouth (GC-3)

Ecologically Sensitive Waterbodies

Little River above Millwood Reservoir - location of Ouachita rock pocketbook and pink mucket mussels (GC-1)

Grassy Lake and Yellow Creek below Millwood Reservoir - unique ecosystem and biota (GC-1)

Lower Little Missouri River - location of peppered shiner and longnose darter (GC-2)

Lower Saline River - location of peppered shiner, crystal darter and goldstripe darter (GC-3)

Ouachita River near Arkadelphia - location of flat floater, Ouachita rock pocketbook and pink mucket mussels (GC-4)

Streams with Substantial Springwater Influence

L'Eau Frais (GC-4)

Cypress Creek (GC-4)

East and West Fork Tulip Creeks (GC-4)

Others to be determined

Primary Contact Recreation- all streams with watersheds greater than 10 mi² and all lakes/reservoirs**

Secondary Contact Recreation- all waters**

Domestic, Industrial, and Agricultural Water Supply- all waters**

Aquatic Life**

Trout Waters

Little Missouri River from Narrows Dam to confluence with Muddy Fork (GC-1)

Lakes and Reservoirs - all

Streams

Seasonal Gulf Coastal aquatic life - all streams with watersheds of less than 10 mi2 except as otherwise provided in Rule 2.505

Perennial Gulf Coastal aquatic life - all streams with watersheds of 10 mi2 or larger and those waters where discharges equal or exceed 1 cfs

**Except for those waters with designated use variations supported by Use Attainability Analysis or other investigations.

Site Specific Designated Use Variations Supported by Use Attainability Analysis

SPECIFIC CRITERIA: GULF COASTAL ECOREGION

(Plates GC-1, GC-2, GC-3, GC-4)

*Increase over natural temperatures may not be more than 2.8°C (5°F).

**At water temperatures <= 10°C or during March, April and May when stream flows are 15 cfs and greater, the primary season dissolved oxygen criteria will be 6.5 mg/L. When water temperatures exceed 22°C, the critical season dissolved oxygen criteria may be depressed by 1 mg/L for no more than 8 hours during a 24-hour period

Site Specific Criteria Variations Supported by Use Attainability Analysis

Temporary Variations Supported by Environmental Improvement Project

*These temporary standards variations are effective for 148 months from EPA's approval of the EIP on January 7, 2020.

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DESIGNATED USES: DELTA ECOREGION

(Plates D-1, D-2, D-3, D-4, D-5)

Extraordinary Resource Waters

Second Creek (D-4)

Cache River above Cache Bayou - adjacent to natural areas (D-3)

Arkansas River below Norrell Lock and Dam (Dam #2) (D-5)

Strawberry River (D-1)

Two Prairie Bayou adjacent to natural areas (D-3)

Natural and Scenic Waterways

None

Ecologically Sensitive Waterbodies

Lower St. Francis River and lower 10 miles of Straight Slough - location of fat pocketbook mussel (D-2, D-4)

Right Hand Chute at confluence with St. Francis River - location of fat pocketbook mussel (D-2)

Departee Creek - location of flat floater mussel (D-1)

Black River at mouth of Spring River - location of pink mucket mussel (D-1)

Channel-altered Delta Ecoregion Streams - These include the majority of the streams in this ecoregion and are characterized by substantial alteration of the morphology of their main-stream channel as well as their tributary streams. Such alteration of the tributaries of these streams significantly affects the water quality and hydrology of the streams and their watersheds. Most of the upper segments of these waters have been dredged and straightened into ditches. Additionally most of the tributaries of these streams have been straightened, ditched and, in some cases, rerouted to quickly move water off the agriculture fields and into the major streams. In the lower segments of these waters, channel realignment is less expansive but most of these channels have been "snagged" to remove any instream obstructions (brush, logs, and other debris) and the stream channel and banks have been dredged to uniform depths and cleared of any obstructions. These include cache river, bayou deview, village creek, blackfish Bayou and others to be determined by the Division on a case by case basis.

Primary Contact Recreation - all streams with watersheds of greater than 10 mi2 and all lakes/reservoirs**

Secondary Contact Recreation - all waters**

Domestic, Industrial and Agricultural Water Supply - all waters**

Aquatic Life**

Trout Waters - none

Lakes and Reservoirs - all

Streams

Seasonal Delta aquatic life - all streams with watersheds of less than 10 mi2 except as otherwise provided in Rule 2.505

Perennial Delta aquatic life - all streams with watersheds 10 mi2 or larger and those waters where discharges equal or exceed 1cfs

**Except for those waters with designated use variations supported by Use Attainability Analysis or other investigations.

Site Specific Designated Use Variation Supported by Use Attainability Analysis

SPECIFIC CRITERIA: DELTA ECOREGION

(Plates D-1, D-2, D-3, D-4, D-5)

*Increase over natural temperatures may not be more than 2.8°C (5°F).

**When water temperatures exceed 22°C, the critical season dissolved oxygen criteria may be depressed by 1 mg/L for no more than 8 hours during a 24-hour period.

Site Specific Criteria Variations Supported by Use Attainability Analysis

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RULE 2

APPENDIX B: ENVIRONMENTAL IMPROVEMENT PROJECT

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For An Act To Be Entitled

"AN ACT TO ENCOURAGE LONG-TERM ENVIRONMENTAL PROJECTS; AND FOR OTHER PURPOSES."

Subtitle

"AN ACT TO ENCOURAGE LONG-TERM ENVIRONMENTAL PROJECTS."

BE IT ENACTED BY THE GENERAL ASSEMBLY OF THE STATE OF ARKANSAS:

RULE 2

APPENDIX C: SCIENTIFIC NAMES OF AQUATIC BIOTA