NEVADA ADMINISTRATIVE CODE: WATER CONTROLS

CHAPTER 445A - WATER CONTROLS

Standards for Water Quality

445A.119 Criteria for water quality for designated beneficial uses.

445A.120 Applicability.

445A.121 Standards applicable to all surface waters.

445A.122 Standards applicable to beneficial uses.

445A.123 Classification and reclassification of waters.

445A.124 Class A waters: Description; beneficial uses; quality standards.

445A.125 Class B waters: Description; beneficial uses; quality standards.

445A.126 Class C waters: Description; beneficial uses; quality standards.

445A.127 Class D waters: Description; beneficial uses; quality standards.

445A.128 Definitions.

445A.129 “A‑Avg.” or “A.A.” defined.

445A.130 “D” defined.

445A.131 “D pH” defined.

445A.132 “D T” defined.

445A.133 “Geometric mean” defined.

445A.134 “mg/l” defined.

445A.135 “No./100ml” defined.

445A.136 “NTU” defined.

445A.137 “PCU” defined.

445A.138 “pH unit” defined.

445A.139 “SAR” defined.

445A.140 “S.V.” defined.

445A.141 “³” defined.

445A.142 “£” defined.

445A.143 Cooperation regarding Colorado River; salinity standards.

445A.144 Standards for toxic materials applicable to designated waters.

445A.145 Control points: Prescription and applicability of numerical standards for water quality; designation of beneficial uses.

445A.146 Beneficial uses for Carson River.

445A.147 Carson River: West Fork at the state line.

445A.148 Carson River: Bryant Creek near the state line.

445A.149 Carson River: East Fork at the state line.

445A.150 Carson River: East Fork at Highway 395, south of Gardnerville.

445A.151 Carson River: East Fork at Muller Lane.

445A.152 Carson River at Genoa Lane.

445A.153 Carson River at Cradlebaugh Bridge.

445A.154 Carson River at Mexican Ditch Gage.

445A.155 Carson River near New Empire.

445A.156 Carson River at Dayton Bridge.

445A.157 Carson River at Weeks.

445A.158 Carson River at Lahontan Dam.

445A.159 Beneficial uses for Walker River.

445A.160 West Walker River at the state line.

445A.161 Topaz Lake.

445A.162 West Walker River near Wellington.

445A.163 West Walker River above confluence with East Walker River at Nordyke Road.

445A.164 Sweetwater Creek.

445A.165 East Walker River at the state line.

445A.166 East Walker River south of Yerington.

445A.167 Walker River at inlet to Weber Reservoir.

445A.168 Walker River at Schurz Bridge.

445A.169 Desert Creek.

445A.170 Beneficial uses for part of Colorado River, Beaver Dam Wash and certain creeks.

445A.171 Chiatovich Creek.

445A.172 Indian Creek.

445A.173 Leidy Creek.

445A.174 Beneficial uses for Virgin River, Meadow Valley Wash and part of Muddy River.

445A.175 Virgin River at Mesquite.

445A.176 Virgin River at the state line near Littlefield.

445A.177 Virgin River at Riverside.

445A.178 Beaver Dam Wash.

445A.179 Snake Creek.

445A.180 Smoke Creek.

445A.181 Bronco Creek.

445A.182 Gray Creek.

445A.183 Beneficial uses for Truckee River from Pyramid Lake to the state line.

445A.184 Truckee River at the state line.

445A.185 Truckee River at Idlewild.

445A.186 Truckee River at East McCarran.

445A.187 Truckee River at Lockwood Bridge.

445A.188 Truckee River at Derby Dam.

445A.189 Truckee River at Wadsworth Gage.

445A.190 Truckee River at Pyramid Lake.

445A.1905 Beneficial uses for Lake Tahoe.

445A.191 Lake Tahoe.

445A.1912 Beneficial uses for tributaries to Lake Tahoe.

445A.1915 Tributaries to Lake Tahoe.

445A.1917 Standards to maintain higher quality waters within tributaries to Lake Tahoe.

445A.192 Colorado River below Davis Dam.

445A.193 Colorado River below Hoover Dam.

445A.194 Requirements to maintain existing higher quality for area of Lake Mead; standards for beneficial uses for area not covered by NAC 445A.196.

445A.195 Lake Mead excluding area covered by NAC 445A.197.

445A.196 Requirements to maintain existing higher quality for area of Lake Mead from western boundary of Las Vegas Bay Campground to confluence of Las Vegas Wash; standards for beneficial uses; goal of requirements and standards.

445A.197 Lake Mead from western boundary of Las Vegas Bay Campground to confluence of Las Vegas Wash.

445A.198 Requirements to maintain existing higher quality for area of Las Vegas Wash from Telephone Line Road to confluence of discharges from Clark County and City of Las Vegas wastewater treatment plants; standards for beneficial uses; goal of requirements and standards.

445A.199 Las Vegas Wash from Telephone Line Road to confluence of discharges from City of Las Vegas and Clark County wastewater treatment plants.

445A.200 Requirements to maintain existing higher quality for area from confluence of Las Vegas Wash with Lake Mead to Telephone Line Road; standards for beneficial uses; goal of requirements and standards.

445A.201 Confluence of Las Vegas Wash with Lake Mead to Telephone Line Road.

445A.202 Beneficial uses for Humboldt River.

445A.203 Humboldt River near Osino.

445A.204 Humboldt River at Palisade Gage.

445A.205 Humboldt River at Battle Mountain Gage.

445A.206 Humboldt River at crossing of state highway 789.

445A.207 Humboldt River at Imlay.

445A.208 Humboldt River at Woolsey.

445A.209 Beneficial uses for Muddy River at Glendale Bridge.

445A.210 Muddy River at Glendale Bridge.

445A.211 Muddy River at Overton.

445A.212 Meadow Valley Wash.

445A.214 Beneficial uses for areas in Snake River Basin.

445A.215 Big Goose Creek.

445A.216 Salmon Falls Creek.

445A.217 Shoshone Creek.

445A.218 Jarbidge River: East Fork.

445A.219 Jarbidge River upstream from Jarbidge.

445A.220 Jarbidge River downstream from Jarbidge.

445A.221 Bruneau River: West Fork.

445A.222 Owyhee River: East Fork above Mill Creek.

445A.223 Owyhee River: East Fork south of Owyhee.

445A.224 Owyhee River: East Fork, Nevada‑Idaho state line.

445A.225 Owyhee River: South Fork.

Standards for Water Quality

NAC 445A.119 Criteria for water quality for designated beneficial uses. The water quality criteria for designated beneficial uses for the various waters of the state are in the following table. The criteria are water quality characteristics based upon available scientific and technical information and are to be used as guidelines in establishing water quality standards.

WATER QUALITY CRITERIA FOR

DESIGNATED BENEFICIAL USES²

Beneficial Uses		Agricultural Use	Aquatic Life Cold Warm Water Water
Temperature °C		x	x	<----- Site Specific Determination ^a,b --->	15-34^a	x	x	x	x
pH Units Single Value Dissolved Oxygen Single Value-mg/l Chlorides Single Value-mg/l	> <	4.5-9.0^a,b x y^a	5.0-9.0^b Aerobic^b 1500^f	6.5-9.0^b 5.0^b x	6.5-9.0^b 5.0^b x	6.5-9.0^b 5.0 ^b x	6.5-9.0^b 5.0 ^b x	6.5-8.3^a Aerobic^b x	x Aerobic^b x	5.0-9.0 Aerobic^b 250/400^c	3.0-11.7^b x --	7.0-9.2^a Aerobic^b 1500^f
Total Phosphates as P Single Value-mg/l		x	x	<----------------------------- Site Specific Determination^b,e -------------------------------->	x	x
Nitrates as N Single Value-mg/l Nitrites as N Single Value-mg/l	< <	x x	100^a 10^a	y^b 0.06^b	x x	90^b x	90^b x	x x	x x	10^b,c 1.0^a,b	x x	100^a 10^a
Total Nitrogen as N Single Value-mg/l		x	x	<----------------------------- Site Specific Determination^b,e -------------------------------->	x	x
Un-ionized Ammonia as NH₃ Single Value-mg/l	<	x	x	0.02^b,e	<Site Specific Determination>	x	x	0.5 (Total NH₃-N)^b	x	x
Total Dissolved Solids Single Value-mg/l Color (PT-CO), Single Value Turbidity, Single Value-NTU Fecal Coliform (MF/100ml) Geometric Mean	< < < <	x x x 1000^a	3000^a x x 1000^a	x x 10^d x	x x 10^d x	x x 50^d x	x x 50^d x	x x x 200/400^b See Footnote₁	x x x 1000/2000^d	500/1000^c 75^b y^b 2000^a	x x x x	x x x 1000^a
Alkalinity as C_aCO₃ Single Value-mg/l		x	x	Less than 25% change from natural conditions^a,e	x	x	x	x	30-130^a
Suspended Solids Single Value-mg/l Sulfate Single Value-mg/l	< <	x x	x x	25-80^a x	25-80^a x	25-80^a x	25-80^a x	x x	x x	x 250^b,c/500^c	x x	x x

Beneficial Uses

Agricultural

Use

Aquatic Life

Cold Warm

Water Water

Parameter

Irrigation

Watering of Livestock

Propa-

gation

Put & Take

Propa-

gation

Put &

Take

Water Contact Recreation

Non-Contact Recreation

Municipal or

Domestic Supply

Industrial Supply Supply

Propa-gation of Wildlife

Temperature °C

<----- Site Specific Determination ^a,b --->

15-34^a

pH Units

Single Value

Dissolved
Oxygen Single Value-mg/l

Chlorides Single Value-mg/l

4.5-9.0^a,b

y^a

5.0-9.0^b

Aerobic^b

1500^f

6.5-9.0^b

5.0^b

6.5-9.0^b

5.0^b

6.5-9.0^b

5.0 ^b

6.5-9.0^b

5.0 ^b

6.5-8.3^a

Aerobic^b

5.0-9.0

Aerobic^b

250/400^c

3.0-11.7^b

7.0-9.2^a

Aerobic^b

1500^f

Total Phosphates as P Single Value-mg/l

<----------------------------- Site Specific Determination^b,e -------------------------------->

Nitrates as N

Single Value-mg/l

Nitrites as N

Single Value-mg/l

100^a

10^a

y^b

0.06^b

90^b

10^b,c

1.0^a,b

100^a

10^a

Total Nitrogen as N Single Value-mg/l

<----------------------------- Site Specific Determination^b,e -------------------------------->

Un-ionized Ammonia

as NH₃

Single Value-mg/l

0.02^b,e

0.5

(Total NH₃-N)^b

Total Dissolved Solids Single Value-mg/l

Color (PT-CO),

Single Value

Turbidity,

Single Value-NTU

Fecal Coliform

(MF/100ml)

Geometric Mean

1000^a

3000^a

1000^a

10^d

50^d

200/400^b See Footnote₁

1000/2000^d

500/1000^c

75^b

y^b

2000^a

1000^a

Alkalinity as C_aCO₃

Single Value-mg/l

Less than 25% change from
natural conditions^a,e

30-130^a

Suspended Solids

Single Value-mg/l

Sulfate

Single Value-mg/l

25-80^a

250^b,c/500^c

FOOTNOTES AND REFERENCES

< means less than

> means greater than

x means a specific recommendation has not been developed.

y means the cited reference recommended no value be established.

(1) Based on a minimum of five samples taken over a 30‑day period, the fecal coliform bacterial level must not exceed a log mean of 200 per 100 ml nor may more than 10 percent of the total samples taken during any 30‑day period exceed 400 per 100 ml.

(2) The table is not all‑inclusive. As the need arises and data becomes available, appropriate revisions and additions will be made.

a. National Academy of Sciences, Water Quality Criteria (Blue Book) (1972).

b. U.S. Environmental Protection Agency, Pub. No. EPA 440/9‑76‑023, Quality Criteria for Water (1976). Office of Water and Hazardous Materials, Washington, D.C.

c. Nevada Division of Health, Water Supply Regulation, Part I, Water Quality Standards, Monitoring, Record Keeping and Reporting (1977). State Board of Health, Carson City, Nevada.

d. Report of the Commission on Water Quality Criteria (FWPCA) (Green Book) (1968).

e. American Fisheries Society, Water Quality Section, A Review of the EPA Red Book; Quality Criteria for Water (1979).

f. McKee and Wolf, California State Water Resources Control Board, Water Quality Criteria (1963).

[Environmental Comm’n, Water Pollution Control Reg. § 4.1.4, eff. 9‑15‑80]—(NAC A 7‑27‑82; 12‑3‑84; 9‑25‑90)—(Substituted in revision for NAC 445.117)

NAC 445A.120 Applicability. (NRS 445A.425, 445A.520)

1. NAC 445A.120 to 445A.225, inclusive, apply to all natural streams and lakes, reservoirs or impoundments on natural streams and other specified waterways, unless excepted on the basis of existing irreparable conditions which preclude such use. Man‑made waterways, unless otherwise specified, must be protected for public health and the use for which the waterways were developed.

2. The quality of any waters receiving waste discharges must be such that no impairment of the beneficial usage of water occurs as the result of the discharge. Natural water conditions may, on occasion, be outside the limits established by standards. The standards adopted in NAC 445A.120 to 445A.225, inclusive, relate to the condition of waters as affected by discharges relating to the activities of man.

[Environmental Comm’n, Water Pollution Control Reg. § 4.1, eff. 5‑2‑78]—(NAC A 12‑3‑84; R017‑99, 9‑27‑99)

NAC 445A.121 Standards applicable to all surface waters. (NRS 445A.425, 445A.520)The following standards are applicable to all surface waters of the state:

1. Waters must be free from substances attributable to domestic or industrial waste or other controllable sources that will settle to form sludge or bottom deposits in amounts sufficient to be unsightly, putrescent or odorous or in amounts sufficient to interfere with any beneficial use of the water.

2. Waters must be free from floating debris, oil, grease, scum and other floating materials attributable to domestic or industrial waste or other controllable sources in amounts sufficient to be unsightly or in amounts sufficient to interfere with any beneficial use of the water.

3. Waters must be free from materials attributable to domestic or industrial waste or other controllable sources in amounts sufficient to produce taste or odor in the water or detectable off‑flavor in the flesh of fish or in amounts sufficient to change the existing color, turbidity or other conditions in the receiving stream to such a degree as to create a public nuisance or in amounts sufficient to interfere with any beneficial use of the water.

4. Waters must be free from high temperature, biocides, organisms pathogenic to human beings, toxic, corrosive or other deleterious substances attributable to domestic or industrial waste or other controllable sources at levels or combinations sufficient to be toxic to human, animal, plant or aquatic life or in amounts sufficient to interfere with any beneficial use of the water. Compliance with the provisions of this subsection may be determined in accordance with methods of testing prescribed by the department. If used as an indicator, survival of test organisms must not be significantly less in test water than in control water.

5. If toxic materials are known or suspected by the department to be present in a water, testing for toxicity may be required to determine compliance with the provisions of this section and effluent limitations. The department may specify the method of testing to be used. The failure to determine the presence of toxic materials by testing does not preclude a determination by the department, on the basis of other criteria or methods, that excessive levels of toxic materials are present.

6. Radioactive materials attributable to municipal, industrial or other controllable sources must be the minimum concentrations that are physically and economically feasible to achieve. In no case must materials exceed the limits established in the 1962 Public Health Service Drinking Water Standards (or later amendments) or 1/30th of the MPC values given for continuous occupational exposure in the “National Bureau of Standards Handbook No. 69.” The concentrations in water must not result in accumulation of radioactivity in plants or animals that result in a hazard to humans or harm to aquatic life.

7. Wastes from municipal, industrial or other controllable sources containing arsenic, barium, boron, cadmium, chromium, cyanide, fluoride, lead, selenium, silver, copper and zinc that are reasonably amenable to treatment or control must not be discharged untreated or uncontrolled into the waters of Nevada. In addition, the limits for concentrations of the chemical constituents must provide water quality consistent with the mandatory requirements of the 1962 Public Health Service Drinking Water Standards.

8. The specified standards are not considered violated when the natural conditions of the receiving water are outside the established limits, including periods of extreme high or low flow. Where effluents are discharged to such waters, the discharges are not considered a contributor to substandard conditions provided maximum treatment in compliance with permit requirements is maintained.

[Environmental Comm’n, Water Pollution Control Reg. § 4.1.2 subsecs. a‑g, eff. 5‑2‑78]—(NAC A 9‑26‑90; R017‑99, 9‑27‑99)

NAC 445A.122 Standards applicable to beneficial uses.

1. The following standards are intended to protect both existing and designated beneficial uses and must not be used to prohibit the use of the water as authorized under Title 48 of NRS:

(a) Watering of livestock. The water must be suitable for the watering of livestock without treatment.

(b) Irrigation. The water must be suitable for irrigation without treatment.

(c) Aquatic life. The water must be suitable as a habitat for fish and other aquatic life existing in a body of water. This does not preclude the reestablishment of other fish or aquatic life.

(d) Recreation involving contact with the water. There must be no evidence of manmade pollution, floating debris, sludge accumulation or similar pollutants.

(e) Recreation not involving contact with the water. The water must be free from:

(1) Visible floating, suspended or settled solids arising from man’s activities;

(2) Sludge banks;

(3) Slime infestation;

(4) Heavy growth of attached plants, blooms or high concentrations of plankton, discoloration or excessive acidity or alkalinity that leads to corrosion of boats and docks;

(5) Surfactants that foam when the water is agitated or aerated; and

(6) Excessive water temperatures.

(f) Municipal or domestic supply. The water must be capable of being treated by conventional methods of water treatment in order to comply with Nevada’s drinking water standards.

(g) Industrial supply. The water must be treatable to provide a quality of water which is suitable for the intended use.

(h) Propagation of wildlife. The water must be suitable for the propagation of wildlife and waterfowl without treatment.

(i) Waters of extraordinary ecological or aesthetic value. The unique ecological or aesthetic value of the water must be maintained.

(j) Enhancement of water quality. The water must support natural enhancement or improvement of water quality in any water which is downstream.

2. This section does not entitle an appropriator to require that the source meet his particular requirements for water quality.

[Environmental Comm’n, Water Pollution Control Reg. § 4.1.1, eff. 5‑2‑78]—(NAC A 11‑22‑82; 12‑3‑84; 11‑9‑95)

NAC 445A.123 Classification and reclassification of waters.

1. Stream standards and classifications in NAC 445A.123 to 445A.127, inclusive, do not preclude the commission from establishing standards and classifications for additional public waters nor reclassifying the waters covered by those sections.

2. The commission will consider classification of a body of public water not contained in the tables in NAC 445A.123 to 445A.127, inclusive, upon a request for a permit to discharge into that body of water.

[Environmental Comm’n, Water Pollution Control Reg. § 4.2, eff. 5‑2‑78]—(NAC A 12‑3‑84)—(Substituted in revision for NAC 445.121)

NAC 445A.124 Class A waters: Description; beneficial uses; quality standards.

1. Class A waters include waters or portions of waters located in areas of little human habitation, no industrial development or intensive agriculture and where the watershed is relatively undisturbed by man’s activity.

2. The beneficial uses of class A waters are municipal or domestic supply, or both, with treatment by disinfection only, aquatic life, propagation of wildlife, irrigation, watering of livestock, recreation including contact with the water and recreation not involving contact with the water.

3. The quality standards for class A waters are:

Item		Specifications
(a) Floating solids, sludge deposits, tastes or odor-producing substances.		None attributable to man’s activities.
(b) Sewage, industrial wastes or other wastes.		None.
(c) Toxic materials, oils, deleterious substances, colored or other wastes.		None.
(d) Settleable solids.		Only amounts attributable to man’s activities which will not make the waters unsafe or unsuitable as a drinking water source or which will not be detrimental to aquatic life or for any other beneficial use established for this class.
(e) pH.		Range between 6.5 to 8.5.
(f) Dissolved oxygen.		Must not be less than 6.0 milligrams/liter.
(g) Temperature.		Must not exceed 20°C. Allowable temperature increase above natural receiving water temperature: None.
(h) Fecal coliform.		The fecal coliform concentration, based on a minimum of 5 samples during any 30‑day period, must not exceed a geometric mean of 200 per 100 milliliters nor may more than 10 percent of total samples during any 30‑day period exceed 400 per 100 milliliters.
(i) Total phosphate.		Must not exceed 0.15 mg/l in any stream at the point where it enters any reservoir or lake, nor 0.075 mg/l in any reservoir or lake, nor 0.30 mg/l in streams and other flowing waters.
(j) Total dissolved solids.		Must not exceed 500 mg/l or one-third above that characteristic of natural conditions (whichever is less).
4. The waters classified as class A are:

TABLE A

Class A Waters

HR-Hydrographic region

HA-Hydrographic area

CARSON CITY

Water	HR	HA	Description of Area Classified
Ash Canyon	8	104	From its origin to the first point of diversion of the Carson City water department.
Clear Creek	8	104	From its origin to gaging station number 10‑3105 located in NE 1/4 NE 1/4, section 1, T. 14 N., R. 19E., M.D.B. & M.
Kings Canyon	8	104	From its origin to the point of the diversion of the Carson City water department.

DOUGLAS COUNTY

Water	HR	HA	Description of Area Classified
Daggett Creek	8	105	From its origin to the Carson River.
Genoa Creek	8	105	From its origin to the first diversion box at the mouth of the canyon.
Sierra Canyon Creek	8	105	From its origin to the first diversion structure at the mouth of the canyon.

ELKO COUNTY

Water	HR	HA	Description of Area Classified
Angel Lake	10	177	The entire lake.
Bear Creek	3	39	From its origin to the point of diversion for the Jarbidge municipal water supply.
Brown’s Gulch	3	37	From its origin to the point of diversion for the Mountain City municipal water supply.
Camp Creek	3	40	From its origin to the national forest boundary.
Canyon Creek	3	40	From its origin to the national forest boundary.
Cottonwood Creek	3	40	From its origin to the national forest boundary.
Deep Creek	3	37	From its origin to the Wildhorse Reservoir.
Green Mountain Creek	4	47	From its origin to the national forest boundary.
Hendricks Creek	3	37	From its origin to Wildhorse Reservoir.
Humboldt River (N. Fork) and tributaries in Indepen-dence Mountain Range	4	44	From its origin to the national forest boundary.
Humboldt River (S. Fork) and tributaries	4	46	From its origin to Lee.
Jack Creek	3	37	From its origin to the north line of T. 41 N., R. 52 E., M.D.B. & M.
Lamoille Creek	4	45	From its origin to gaging station number 10‑316500 located in the NE 1/4, section 6, T. 32 N., R. 58 E., M.D.B. & M.
Maggie Creek tributaries	4	51	From their origin to the point where they become Maggie Creek or the point where they reach Maggie Creek.
Mary’s River	4	42	From its origin to the point where the river crosses the east line of T. 42 N., R. 59 E., M.D.B. & M.
Owyhee River (E. Fork) above Wildhorse	3	37	From its origin to Wildhorse Reservoir.
Penrod Creek	3	37	From its origin including tributaries to Wildhorse Reservoir.
Pole Canyon Creek	3	37	From its origin to where it be comes Franklin River.
Secret Creek	4	43	From its origin to the national forest boundary.
Starr Creek	4	43	From its origin to the national forest boundary.
Tabor Creek	4	42	From its origin to the east line of T. 40 N., R. 60 E., M.D.B. & M.
Toyn Creek	4	47	From its origin to the national forest boundary.
Willow Creek	4	63	From its origin to Willow Creek Reservoir.

EUREKA COUNTY

Water	HR	HA	Description of Area Classified
Denay Creek	4	53	From its origin to Tonkin Reservoir.
Roberts Creek	10	139	From its origin to Roberts Creek Reservoir.
Tonkin Reservoir	4	53	The entire reservoir.

HUMBOLDT COUNTY

Water	HR	HA	Description of Area Classified
Bilk Creek	2	29	From its origin to its intersection with the south line of section 35, T. 45 N., R. 32 E., M.D.B. & M.
Blue Lakes	1	2	Entire area.
Bottle Creek	2	31	From its origin to the first point of diversion.
Dutch John Creek	4	68	The entire length.
Leonard Creek	2	28	From its origin to the first point of diversion.
Little Humboldt River (N. Fork)	4	67	From its origin to the national forest boundary.
Little Humboldt River (S. Fork)	4	67	From its origin to Elko‑Humboldt county line.
Mahogany Creek	2	27	From its origin to Summit Lake.
Martin Creek	4	68, 69	From its origin to the national forest boundary.
Pole Creek	4	70	From its origin to the point of diversion of the Golconda water supply.
Quinn River	2	28, 29, 30, 33	From its origin to the confluence of the east fork and south fork.
Water Canyon Creek	4	71	From its origin to the point of diversion of the Winnemucca municipal water supply.

LANDER COUNTY

Water	HR	HA	Description of Area Classified
Big Creek	4	56	From its origin to the east boundary of United States Forest Service Big Creek Campground.
Birch Creek	10	137	From its origin to the national forest boundary.
Kingston Creek	10	137	From its origin to Groves Reservoir.
Lewis Creek	4	59	From its origin to the first point of diversion.
Mill Creek	4	59	From its origin to the first point of diversion.
Rock Creek	4	61, 62, 63	From its origin to Squaw Valley Ranch.
Skull Creek	10	138	From its origin to the first point of diversion.
Steiner Creek	10	138	From its origin to the first point of diversion.

MINERAL COUNTY

Water	HR	HA	Description of Area Classified
Corey Creek	9	110C	From its origin to the point of diversion of the town of Hawthorne.
Cottonwood Creek	9	110B	From its origin to the point of diversion of the Hawthorne Naval Ammunition Depot.
Rose Creek	9	110B	From its origin to the point of diversion of the Hawthorne Naval Ammunition Depot.
Squaw Creek	9	110B	From its origin to the point of diversion of the Hawthorne Naval Ammunition Depot.

NYE COUNTY

Water	HR	HA	Description of Area Classified
Barley Creek	10	140	From its origin to the first point of diversion.
Currant Creek	10	173	From its origin to the national forest boundary.
Jett Creek	10	137	From its origin to the national forest boundary.
Mosquito Creek	10	140	From its origin to the national forest boundary.
Peavine Creek	10	137	From its origin to the first point of diversion.
Pine Creek	10	140	From its origin to the national forest boundary.
Reese Creek	4	56	From its origin to its confluence with Indian Creek.
San Juan Creek	4	56	From its origin to the national forest boundary.
Stoneberger Creek	10	140	From its origin to the national forest boundary.
Twin River (N. Fork)	10	137	From its origin to the first point of diversion.
Twin River (S. Fork)	10	137	From its origin to the first point of diversion.

PERSHING COUNTY

Water		HR		HA		Description of Area Classified
Star Creek		10		129		From its origin to the first point of diversion.

Water

Description of Area Classified

Star Creek

129

From its origin to the first point of diversion.

WASHOE COUNTY

Water	HR	HA	Description of Area Classified
Boulder Reservoir	1	9	The entire reservoir.
Catnip Reservoir	1	6	The entire reservoir.
Franktown Creek	6	89	From its origin to the first irrigation diversion.
Galena Creek	6	88	From its origin to the east line of section 18, T. 17 N., R. 19 E., M.D.B. & M.
Hunter Creek	6	91	From its origin to Hunter Lake.
Hunter Lake	6	87	The entire lake.
Nigger Creek	2	24	From its origin to the first irrigation diversion.
Ophir Creek	6	89	From its origin to old U.S. Highway 395.
Price’s Lakes	6	89	The entire lake.
White’s Creek	6	87	From its origin to the east line of section 33, T. 18 N., R. 19 E., M.D.B. & M.

WHITE PINE COUNTY

Water	HR	HA	Description of Area Classified
Baker Creek	11	195	From its origin to the national forest boundary.
Berry Creek	10	179	From its origin to pipeline intake.
Bird Creek	10	179	From its origin to pipeline intake.
Cave Creek	10	179	Its entire length.
Cleve Creek	10	184	From its origin to the national forest boundary.
Current Creek	10	173	From its origin to the national forest boundary.
Duck Creek	10	179	From its origin to pipeline intake.
East Creek	10	179	From its origin to pipeline intake.
Goshute Creek	10	179	From its origin to the first point of diversion.
Hendry’s Creek	11	195	From its origin to the national forest boundary.
Huntington Creek	4	47	From its origin to the White Pine-Elko county line.
Lehman Creek	11	195	From its origin to the national forest boundary.
North Creek	10	179	From its origin to pipeline intake.
Pine Creek	10	184	From its origin to the first point of diversion.
Ridge Creek	10	184	From its origin to the first point of diversion.
Silver Creek	11	195	From its origin to the national forest boundary.
Timber Creek	10	179	From its origin to pipeline intake.
White River	13	207	From its origin to the national forest boundary.

[Environmental Comm’n, Water Pollution Control Reg. §§ 4.2.1‑4.2.1.3, eff. 5‑2‑78]—(NAC A 12‑3‑84)—(Substituted in revision for NAC 445.122)

NAC 445A.125 Class B waters: Description; beneficial uses; quality standards.

1. Class B waters include waters or portions of waters which are located in areas of light or moderate human habitation, little industrial development, light-to-moderate agricultural development and where the watershed is only moderately influenced by man’s activity.

2. The beneficial uses of class B water are municipal or domestic supply, or both, with treatment by disinfection and filtration only, irrigation, watering of livestock, aquatic life and propagation of wildlife, recreation involving contact with the water, recreation not involving contact with the water, and industrial supply.

3. The quality standards for class B waters are:

Item		Specifications
(a) Floating solids, settleable solids or sludge deposits.		Only such amounts attributable to man’s activities which will not make the waters unsafe or unsuitable as a drinking water source, injurious to fish or wildlife or impair the waters for any other beneficial use established for this class.
(b) Sewage, industrial wastes or other wastes.		None which are not effectively treated to the satisfaction of the department.
(c) Odor-producing substances.		Only such amounts which will not impair the palatability of drinking water or fish or have a deleterious effect upon fish, wildlife or any beneficial uses established for waters of this class.
(d) Toxic materials, oil, deleterious substances, colored or other wastes, or heated or cooled liquids.		Only such amounts as will not render the receiving waters injurious to fish or wildlife or impair the receiving waters for any beneficial uses established for this class.
(e) pH.		Range between 6.5 to 8.5.
(f) Dissolved oxygen.		For trout waters, not less than 6.0 milligrams/liter; for nontrout waters, not less than 5.0 milligrams/liter.
(g) Temperature.		Must not exceed 20°C for trout waters or 24°C for nontrout waters. Allowable temperature increase above natural receiving water temperatures: None.
(h) Fecal coliform.		The fecal coliform concentration, based on a minimum of 5 samples during any 30‑day period, must not exceed a geometric mean of 200 per 100 milliliters, nor may more than 10 percent of total samples during any 30‑day period exceed 400 per 100 milliliters.
(i) Total phosphates.		Must not exceed 0.3 mg/l.
(j) Total dissolved solids.		Must not exceed 500 mg/l or one-third above that characteristic of natural conditions (whichever is less).

4. The waters classified as class B are:

TABLE B

Class B Waters

HR‑Hydrographic region

HA‑Hydrographic area

CARSON CITY

Water		HR		HA		Description of Area Classified
Clear Creek		8		104		From gaging station number 10‑3105 located in the NE 1/4 NW 1/4, section 1, T. 14 N., R. 19 E., M.D.B. & M. to the Carson River.

Water

Description of Area Classified

Clear Creek

104

From gaging station number 10‑3105 located in the NE 1/4 NW 1/4, section 1, T. 14 N., R. 19 E., M.D.B. & M. to the Carson River.

ELKO COUNTY

Water	HR	HA	Description of Area Classified
Bull Run Reservoir	3	35	The entire reservoir.
Camp Creek	3	40	From the national forest boundary to its confluence with the south fork of Salmon Falls Creek.
Canyon Creek	3	40	From the national forest boundary to its confluence with the south fork of Salmon Falls Creek.
Cottonwood Creek	3	40	From the national forest boundary to its confluence with the south fork of Salmon Falls Creek.
Green Mountain Creek	4	47	From the national forest boundary to its confluence with Corral Creek.
Humboldt River (N. Fork)	4	44	From the national forest boundary to its confluence with the Humboldt River.
Humboldt River (S. Fork)	4	46	From Lee to its confluence with the Humboldt River.
Huntington Creek	4	47	From White Pine county line to confluence with South Fork Humboldt River.
Jack Creek	3	36	From the north line of T. 41 N., R. 52 E., M.D.B. & M. to South Fork Owyhee River.
Lamoille Creek	4	45	From gaging station number 10‑316500 located in the NE 1/4, section 6, T. 32 N., R. 58 E., M.D.B. & M. to its confluence with the Humboldt River.
Maggie Creek	4	51	From where it is formed by tributaries to its confluence with Jack Creek.
Mary’s River	4	42	From the east line of T. 42 N., R. 59 E., M.D.B. & M. to its confluence with the Humboldt River.
Ruby Marsh	10	176	The entire area.
Salmon Falls Creek (N. Fork)	3	40	From the national forest boundary to its confluence with the south fork of Salmon Falls Creek.
Salmon Falls Creek (S. Fork)	3	40	From the national forest boundary to its confluence with the north fork of Salmon Falls Creek.
76 Creek	3	38	Its entire length.
Secret Creek	4	43	From the national forest boundary to the Humboldt River.
Starr Creek	4	43	From the national forest boundary to the Humboldt River.
Wildhorse Reservoir	3	37	The entire reservoir.
Willow Creek Reservoir	4	63	The entire reservoir.
Wilson Reservoir	3	35	The entire reservoir.

EUREKA COUNTY

Water	HR	HA	Description of Area Classified
Denay Creek	4	53	Below Tonkin Reservoir.
Fish Springs Pond	10	155	The entire pond.
Roberts Creek	10	139	Below Roberts Creek Reservoir.

HUMBOLDT COUNTY

Water	HR	HA	Description of Area Classified
Bilk Creek	2	29	From its intersection with the south line of section 35, T. 45 N., R. 32 E., M.D.B. & M. to Bilk Creek Reservoir.
Bilk Creek Reservoir	2	29	The entire reservoir.
Knott Creek Reservoir	1	3	The entire reservoir.
Little Humboldt River (N. Fork)	4	67	From the national forest boundary to its confluence with the south fork of the Little Humboldt River.
Little Humboldt River (S. Fork)	4	67	From the Elko-Humboldt county line to its confluence with the north fork of the Little Humboldt River.
Martin Creek	4	68, 69	From the national forest boundary downstream to the first diversion in T. 42 N., R. 40 E., M.D.B. & M.
Onion Valley Reservoir	1	2	The entire reservoir.
Quinn River	2	28, 29, 30, 33	From the point of confluence of the east fork and south fork to the Ft. McDermitt Indian Reservation diversion dam.
Summit Lake	2	27	The entire lake.

LANDER COUNTY

Water	HR	HA	Description of Area Classified
Big Creek	4	56	From the east boundary of the United States Forest Service Big Creek Campground to the first diversion dam.
Birch Creek	10	137	From the national forest boundary to the first diversion dam.
Groves Lake	10	137	The entire lake.
Iowa Canyon Reservoir	4	55	The entire reservoir.
Kingston Creek	10	137	Below Groves Lake.
Reese River	4	56, 58, 59	From its confluence with Indian Creek to old U.S. Highway 50.
Willow Creek Reservoir	10	131	The entire reservoir.

LINCOLN COUNTY

Water	HR	HA	Description of Area Classified
Clover Creek	13	204	From its origin to the point where it crosses the east range line of T. 4 S., R. 67 E., M.D.B. & M.
Eagle Valley Creek	13	200, 201	From its headwaters to Eagle Valley Reservoir.
Eagle Valley Reservoir	13	201	The entire reservoir.

NYE COUNTY

Water	HR	HA	Description of Area Classified
Adams McGill Reservoir	13	207	The entire reservoir.
Currant Creek	10	173	From the national forest boundary to Currant.
Dacey Reservoir	13	207	The entire reservoir.
Hay Meadow Reservoir	13	207	The entire reservoir.
Reese River	4	56	From its confluence with Indian Creek to old U.S. Highway 50.
Sunnyside Creek	13	207	From its origin to the Adams McGill Reservoir.

WASHOE COUNTY

Water	HR	HA	Description of Area Classified
Davis Lake	6	89	The entire lake.
Franktown Creek	4	89	From the first irrigation diversion to Washoe Lake.
Galena Creek	6	88	From the east line of section 18, T. 17 N., R. 19 E., M.D.B. & M. to gaging station number 10‑348900 located in the SW 1/4 SW 1/4, section 2, T. 17 N., R. 19 E., M.D.B. & M.
Hobart Reservoir and tributaries	6	89	The entire system.
Hunter Creek	6	91	From Hunter Lake to its confluence with the Truckee River.
Ophir Creek	6	89	From old U.S. Highway 395 to Washoe Lake.
Squaw Creek Reservoir	2	21	The entire reservoir.
Wall Canyon Reservoir	1	16	The entire reservoir.
White’s Creek	6	87	Below the east line of section 33, T. 18 N., R. 19 E., M.D.B. & M.

WHITE PINE COUNTY

Water	HR	HA	Description of Area Classified
Cave Lake	10	179	The entire lake.
Illipah Reservoir	10	174	The entire reservoir.
Silver Creek Reservoir	11	195	The entire reservoir.
White River	13	207	From the national forest boundary to its confluence with Ellison Creek.

[Environmental Comm’n, Water Pollution Control Reg. §§ 4.2.2‑4.2.2.3, eff. 5‑2‑78]—(NAC A 12‑3‑84)—(Substituted in revision for NAC 445.123)

NAC 445A.126 Class C waters: Description; beneficial uses; quality standards.

1. Class C waters include waters or portions of waters which are located in areas of moderate-to-urban human habitation, where industrial development is present in moderate amounts, agricultural practices are intensive and where the watershed is considerably altered by man’s activity.

2. The beneficial uses of class C water are municipal or domestic supply, or both, following complete treatment, irrigation, watering of livestock, aquatic life, propagation of wildlife, recreation involving contact with the water, recreation not involving contact with the water, and industrial supply.

3. The quality standards for class C waters are:

Item		Specifications
(a) Floating solids, solids that will settle or sludge deposits.		Only those amounts attributable to the activities of man which will not make the receiving waters injurious to fish or wildlife or impair the waters for any beneficial use established for this class.
(b) Sewage, industrial wastes or other wastes.		None which are not effectively treated to the satisfaction of the department.
(c) Toxic materials, oils, deleterious substances, colored or other wastes or heated or cooled liquids.		Only such amounts as will not render the receiving waters injurious to fish and wildlife or impair the waters for any beneficial use established for this class.
(d) pH.		Range between 6.5 to 8.5.
(e) Dissolved oxygen.		For waters with trout, not less than 6.0 mg/l; for waters without trout, not less than 5.0 mg/l.
(f) Temperature.		Must not exceed 20°C for waters with trout or 34°C for waters without trout. Allowable temperature increase above normal receiving water temperature: 3°C.
(g) Fecal coliform.		The more stringent of the following apply:

(1) The fecal coliform concentration must not exceed a geometric mean of 1000 per 100 milliliters nor may more than 20 percent of total samples exceed 2400 per 100 milliliters.

(2) The annual geometric mean of fecal coliform concentration must not exceed that characteristic of natural conditions by more than 200 per 100 milliliters nor may the number of fecal coliform in a single sample exceed that characteristic of natural conditions by more than 400 per 100 milliliters.

(3) The fecal coliform concentration, based on a minimum of 5 samples during any 30‑day period, must not exceed a geometric mean of 200 per 100 milliliters, nor may more than 10 percent of total samples during any 30‑day period exceed 400 per 100 milliliters. This is applicable only to those waters used for primary contact recreation.

(h) Total phosphates.		Must not exceed 1.0 mg/l.
(i) Total dissolved solids.		Must not exceed 500 mg/l or one-third above that characteristic of natural conditions (whichever is less).

4. The waters classified as class C waters are:

TABLE C

Class C Waters

HR‑Hydrographic region

HA‑Hydrographic area

CHURCHILL COUNTY

Water	HR	HA	Description of Area Classified
Diagonal Drain	8	101	Its entire length.
Harmon Reservoir	8	101	The entire reservoir.
Indian Lakes	8	101	All the lakes, including Upper Lake, Likes Lake, Papoose Lake, Big Indian Lake, Little Cottonwood Lake, Big Cottonwood Lake and East Lake.
Lower Carson River	8	101	From Lahontan Reservoir to Carson Sink (the natural channel).
Rattlesnake Reservoir	8	101	Also known as S‑Line Reservoir, the entire reservoir.
South Carson Lake	8	101	Also known as Government Pasture or the Greenhead Gun Club, the entire lake.
Stillwater Marsh	8	101	All that area of Stillwater Marsh east of Westside Road and north of the community of Stillwater.
V‑Line Canal	8	101	From the Carson diversion dam to its division into the S & L Canals.

CLARK COUNTY

Water

Description of Area Classified

Bowman Reservoir

220

The entire reservoir.

Muddy (Moapa) River

219

From its origin (but not including source springs) to its confluence with Lake Mead.

ELKO COUNTY

Water

Description of Area Classified

Maggie Creek

From its confluence with Jack Creek to the Humboldt River.

ESMERALDA COUNTY

Water

Description of Area Classified

Fish Lake

117

The entire lake.

EUREKA COUNTY

Water

Description of Area Classified

J.D. Ponds

The entire area.

HUMBOLDT COUNTY

Water

Description of Area Classified

Little Humboldt River

Its entire length.

LANDER COUNTY

Water

Description of Area Classified

Reese River

56, 58,

North of old U.S. Highway 50.

Rock Creek

61, 62,

Below Squaw Valley Ranch.

LINCOLN COUNTY

Water	HR	HA	Description of Area Classified
Echo Canyon Reservoir	13	199	The entire reservoir.
Nesbitt Lake	13	209	The entire lake.
Pahranagat Reservoir	13	209	The entire reservoir.
Schroeder Reservoir	13	222	The entire reservoir.

LYON COUNTY

Water

Description of Area Classified

Mason Wildlife Area

109

All surface water impoundments.

MINERAL COUNTY

Water

Description of Area Classified

Weber Reservoir

110

Entire reservoir.

PERSHING COUNTY

Water

Description of Area Classified

Humboldt River

From Woolsey to Rodgers Dam.

STOREY COUNTY

Water

Description of Area Classified

Tracy Pond

The entire area.

WASHOE COUNTY

Water	HR	HA	Description of Area Classified
Galena Creek	6	88	From gaging station number 10‑348900 located in the SW 1/4, SW 1/4, sec-tion 2, T. 17 N., R. 19 E., M.D.B. & M., to its confluence with Steamboat Creek.
Steamboat Creek	6	87, 88, 89	From Little Washoe Lake to gaging station number 10‑349300 located in the S 1/2, section 33, T. 18 N., R. 20 E., M.D.B. & M.
Washoe Lakes	6	89	The entire lakes.

WHITE PINE COUNTY

Water	HR	HA	Description of Area Classified
Comins Reservoir	10	179	The entire reservoir.
Gleason Creek	10	179	From its origin to State Highway 44.
Snake Creek	11	195	From control point above fish hatchery to the Nevada-Utah state line.
Willow Reservoir	10	179	The entire reservoir.

[Environmental Comm’n, Water Pollution Control Reg. §§ 4.2.3‑4.2.3.2, eff. 5‑2‑78; § 4.2.3.3, eff. 5‑2‑78; A 1‑25‑79]—(NAC A 12‑3‑84; 9‑13‑85; 5‑27‑93)—(Substituted in revision for NAC 445.124)

NAC 445A.127 Class D waters: Description; beneficial uses; quality standards.

1. Class D waters include waters or portions of waters located in areas of urban development, highly industrialized or intensively used for agriculture or a combination of all the above and where effluent sources include a multiplicity of waste discharges from the highly altered watershed.

2. The beneficial uses of class D waters are recreation not involving contact with the water, aquatic life, propagation of wildlife, irrigation, watering of livestock, and industrial supply except for food processing purposes.

3. The quality standards for class D waters are:

Item		Specifications
(a) Floating solids, settleable solids or sludge deposits.		Only such amounts attributable to the activities of man which will not impair the receiving waters for any beneficial use established for this class.
(b) Sewage, industrial wastes or other wastes.		None which are not effectively treated to the satisfaction of the department.
(c) Toxic materials, oils, deleterious substances, colored or other wastes or heated or cooled liquid.		Only such amounts as will not impair the receiving waters for any beneficial use established for this class.
(d) pH.		Range between 6.0 and 9.0.
(e) Dissolved oxygen.		Not less than 3.0.

4. The waters classified as class D waters are:

TABLE D

Class D Waters

HR‑Hydrographic region

HA‑Hydrographic area

CHURCHILL COUNTY

Water

Description of Area Classified

Stillwater Marsh

101

All that area of Stillwater Marsh not designated as class C.

HUMBOLDT COUNTY

Water

Description of Area Classified

Quinn River

From the Idaho‑Nevada state line in section 31, T. 48 N., R. 38 E., to the confluence with the main tributary of the Quinn River at the south section line of section 17, T. 47 N., R. 38 E.

PERSHING COUNTY

Water

Description of Area Classified

Humboldt River

Rodgers Dam to and including Humboldt Sink.

STOREY COUNTY

Water

Description of Area Classified

Lagomarsino Creek

The entire length.

WASHOE COUNTY

Water

Description of Area Classified

Steamboat Creek

From gaging station number 10‑349300 located in S 1/2, section 33, T. 18 N., R. 20 E., M.D.B. & M. to its confluence with the Truckee River.

WHITE PINE COUNTY

Water

Description of Area Classified

Gleason Creek

179

From State Highway 44 to its con-fluence with Murray Creek.

Murray Creek

179

From its confluence with Gleason Creek to the south line of section 35, T. 17 N., R. 63 E., M.D.B. & M.

[Environmental Comm’n, Water Pollution Control Reg. §§ 4.2.4, 4.2.4.2 & 4.2.4.3, eff. 5‑2‑78; § 4.2.4.1, eff. 5‑2‑78; A 11‑21‑79]—(NAC A 12‑3‑84)—(Substituted in revision for NAC 445.125)

NAC 445A.128 Definitions. As used in NAC 445A.143 to 445A.225, inclusive, the terms and symbols defined in NAC 445A.129 to 445A.142, inclusive, have the meanings ascribed to them in those sections.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84; A 11‑9‑95)

NAC 445A.129 “A‑Avg.” or “A.A.” defined. “A‑Avg.” or “A.A.” means annual average.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1282)

NAC 445A.130 “D” defined. “D” means the difference between two points.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1284)

NAC 445A.131 “D pH” defined. “D pH” means the change in pH.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1286)

NAC 445A.132 “D T” defined. “D T” means the change in temperature.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1288)

NAC 445A.133 “Geometric mean” defined. “Geometric mean” means the mean of n positive numbers obtained by taking the nth root of the product of the numbers.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.129)

NAC 445A.134 “mg/l” defined. “mg/l” means the concentration of a substance, in milligrams, present in one liter of the water.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1292)

NAC 445A.135 “No./100ml” defined. “No./100ml” means the number of organisms present in 100 milliliters of the water.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1294)

NAC 445A.136 “NTU” defined. “NTU” means nephelometric turbidity units, a measure of turbidity.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1296)

NAC 445A.137 “PCU” defined. “PCU” means platinum cobalt unit, a measure of color.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1298)

NAC 445A.138 “pH unit” defined. “pH unit” means the negative log of the hydrogen ion concentration.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.130)

NAC 445A.139 “SAR” defined. “SAR” means sodium adsorption ratio.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1302)

NAC 445A.140 “S.V.” defined. “S.V.” means single value.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1304)

NAC 445A.141 “³” defined. “³” means greater than or equal to.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1306)

NAC 445A.142 “£” defined. “£” means less than or equal to.

(Added to NAC by Environmental Comm’n, eff. 6‑29‑84)—(Substituted in revision for NAC 445.1308)

NAC 445A.143 Cooperation regarding Colorado River; salinity standards. (NRS 445A.425, 445A.520)

1. The State of Nevada will cooperate with the other Colorado River Basin states and the Federal Government to support and carry out the conclusions and recommendations adopted April 27, 1972, by the reconvened 7th session of the conference in the matter of pollution of interstate waters of the Colorado River and its tributaries.

2. Pursuant to subsection 1, the flow weighted annual average concentrations for total dissolved solids in mg/l at the three lower main stem stations of the Colorado River are as follows:

Below Hoover Dam....................................................................... 723

Below Parker Dam........................................................................ 747

Imperial Dam................................................................................. 879

[Environmental Comm’n, Water Pollution Control Reg. Appendix B, eff. 5‑2‑78]—(NAC A 12‑3‑84; R017‑99, 9‑27‑99)

NAC 445A.144 Standards for toxic materials applicable to designated waters. Except as otherwise provided in this section, the following standards for toxic materials are applicable to the waters specified in NAC 445A.123 to 445A.127, inclusive, and 445A.145 to 445A.225, inclusive. If the standards are exceeded at a site and are not economically controllable, the commission will review and adjust the standards for the site.

	Municipal or			Watering of
Chemical	Domestic Supply	Aquatic Life	Irrigation	Livestock
	(mg/l)	(mg/l)	(mg/l)	(mg/l)

Antimony	146^a	‑	‑	‑
Arsenic	50^b	‑	100^c	200^d
Arsenic (III)	‑	‑	‑	‑
1‑hour average	‑	342^a,g	‑	‑
96‑hour average	‑	180^a,g	‑	‑
Barium	2,000^b	‑	‑	‑
Beryllium	0^a	‑	100^c	‑
hardness <75 mg/l	‑	‑	‑	‑
hardness >= 75 mg/l	‑	‑	‑	‑
Boron	‑	‑	750^a	5,000^d
Cadmium	5^b	‑	10^d	50^d
1‑hour average	‑	0.85exp{1.128 ln(H)‑3.828}^a,g	‑	‑
96‑hour average	‑	0.85exp{0.7852 ln(H)‑3.490}^a,g	‑	‑
Chromium (total)	100^b	‑	100^d	1,000^d
Chromium (VI)	‑	‑	‑	‑
1‑hour average	‑	15^a,g	‑	‑
96‑hour average	‑