Numeric Criteria Development

The information presented below gives a summary of state progress towards the development of numeric criteria. The information comes from EPA’s “State Adoption of Numeric Nutrient Standards (1998-2008)” report, current water quality standards, program activity measures, and nutrient criteria development plans. Links to the Montana’s Nutrient Criteria Plan and state water quality standards are also provided.

• Existing Numeric Criteria
• Links to the Plan and Criteria
• Milestone Information

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Existing Numeric Criteria

Waterbody Type	N	P	Chl-a	Clarity
Lakes & Reservoirs
Rivers & Streams	W	W	W
Estuaries	N ⁄ A	N ⁄ A	N ⁄ A	N ⁄ A
Wetlands

S = Statewide    W = For selected waterbody    N ⁄ A=Not Applicable

Note: See Statewide Criteria and Site-specific Criteria tabs for more information.

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Links to Numeric Nutrient Criteria Plan and Existing Nutrient Criteria

Plan:

• Nutrient Criteria Development Plan for the State of Montana 2002

WQS: Montana Water Quality Standards
Montana DEQ: Water Quality Standards and Classifications Exit

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Milestone Information

Milestone information updated July 2012.

TN: Total Nitrogen; TP: Total Phosphorus

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Statewide Criteria

The information on this tab shows EPA-approved nutrient criteria for Montana’s waterbodies. The language presented below comes directly from state water quality standards and applies to all waterbodies within the state (unless a waterbody type or designated use is noted). Criteria applicable to specific waterbodies within the state can be found on the “Site-specific Criteria” tab. For more information, refer to the Montana water quality standards.

The following information reflects Montana’s water quality standards posted to the Water Quality Standards Repository as of November 2010 (EPA-approved September 2008).

17.30.620 Specific Surface Water Quality Standards—General

17.30.621 A-Closed Classification Standards (1) Waters classified A-Closed are to be maintained suitable for drinking, culinary, and food processing purposes after simple disinfection. Water quality is to be maintained suitable for swimming, recreation, growth, and propagation of fishes and associated aquatic life, although access restrictions to protect public health may limit actual use of A-Closed waters for these uses.

(3) No person may violate the following specific water quality standards for waters classified A-Closed:

(g) No increase in true color is allowed.

17.30.622 A-1 Classification Standards (1) Waters classified A-1 are to be maintained suitable for drinking, culinary and food processing purposes after conventional treatment for removal of naturally present impurities.

(3) No person may violate the following specific water quality standards for waters classified A-1:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards given in department Circular DEQ-7.

(g) True color must not be increased more than two color units above naturally occurring color.

(h) Concentrations of carcinogenic, bioconcentrating, toxic, radioactive, nutrient or harmful parameters may not exceed the applicable standards set forth in department Circular DEQ-7.

17.30.623 B-1 Classification Standards (1) Waters classified B-1 are to be maintained suitable for drinking, culinary, and food processing purposes, after conventional treatment; bathing, swimming, and recreation; growth and propagation of salmonid fishes and associated aquatic life, waterfowl and furbearers; and agricultural and industrial water supply.

(2) No person may violate the following specific water quality standards for waters classified B-1:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards given in department Circular DEQ-7.

(g) True color must not be increased more than five color units above naturally occurring color.

(h) Concentrations of carcinogenic, bioconcentrating, toxic, radioactive, nutrient, or harmful parameters may not exceed the applicable standards set forth in department Circular DEQ-7.

17.30.624 B-2 Classification Standards (1) Waters classified B-2 are to be maintained suitable for drinking, culinary, and food processing purposes, after conventional treatment; bathing, swimming, and recreation; growth and marginal propagation of salmonid fishes and associated aquatic life, waterfowl and furbearers; and agricultural and industrial water supply.

(2) No person may violate the following specific water quality standards for waters classified B-2:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards given in department Circular DEQ-7.

(g) True color must not be increased more than five color units above naturally occurring color.

(h) Concentrations of carcinogenic, bioconcentrating, toxic, radioactive, nutrient, or harmful parameters may not exceed the applicable standards set forth in department Circular DEQ-7.

17.30.625 B-3 Classification Standards (1) Waters classified B-3 are to be maintained suitable for drinking, culinary, and food processing purposes, after conventional treatment; bathing, swimming, and recreation; growth and propagation of non-salmonid fishes and associated aquatic life, waterfowl and furbearers; and agricultural and industrial water supply.

(2) No person may violate the following specific water quality standards for waters classified B-3:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards specified in department Circular DEQ-7.

(g) True color must not be increased more than five color units above naturally occurring color.

(h) Concentrations of carcinogenic, bioconcentrating, toxic, radioactive, nutrient, or harmful parameters may not exceed the applicable standards set forth in department Circular DEQ-7.

17.30.626 C-1 Classification Standards (1) Waters classified C-1 are to be maintained suitable for bathing, swimming, and recreation; growth and propagation of salmonid fishes and associated aquatic life, waterfowl and furbearers; and agricultural and industrial water supply.

(2) No person may violate the following specific water quality standards for waters classified C-1:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards given in department Circular DEQ-7.

(g) True color must not be increased more than five color units above naturally occurring color.

(h) Concentrations of carcinogenic, bioconcentrating, toxic, radioactive, nutrient, or harmful parameters may not exceed the applicable standards specified in department Circular DEQ-7.

17.30.627 C-2 Classification Standards (1) Waters classified C-2 are to be maintained suitable for bathing, swimming, and recreation; growth and marginal propagation of salmonid fishes and associated aquatic life, waterfowl and furbearers; and agricultural and industrial water supply.

(2) No person may violate the following specific water quality standards for waters classified C-2:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards given in department Circular DEQ-7. These levels apply to all waters in the state classified C-2 except for Ashley Creek below the bridge crossing on Airport Road where the dissolved oxygen concentrations may not be reduced below five mg/L from October 1 through June 1, nor below three mg/L from June 2 through September 30.

(g) True color must not be increased more than five color units above naturally occurring color.

(h) Concentrations of carcinogenic, bioconcentrating, toxic, radioactive, nutrient, or harmful parameters may not exceed the applicable standards specified in department Circular WQB-7.

17.30.628 I Classification Standards (1) The goal of the state of Montana is to have these waters fully support the following uses: drinking, culinary, and food processing purposes after conventional treatment; bathing, swimming, and recreation; growth and propagation of fishes and associated aquatic life, waterfowl, and furbearers; and agricultural and industrial water supply. An analysis will be performed for each of these waters during each triennial standards review period to determine the factors preventing or limiting attainment of the designated uses listed herein. Based on these analyses, the specific standards listed below will be adjusted to reflect any improvements which have occurred in water quality as a result of water quality control of nonpoint-source pollution.

(2) No person may violate the following specific water quality standards for waters classified I:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards given in department Circular DEQ-7.

(g) No increase in naturally occurring true color is allowed which will or is likely to create a nuisance or render the waters harmful, detrimental, or injurious to public health, recreation, safety, welfare, livestock, wild animals, birds, fish, or other wildlife.

17.30.629 C-3 Classification Standards (1) Waters classified C-3 are to be maintained suitable for bathing, swimming, and recreation, and growth and propagation of non-salmonid fishes and associated aquatic life, waterfowl, and furbearers. The quality of these waters is naturally marginal for drinking, culinary, and food processing purposes, agriculture, and industrial water supply. Degradation which will impact established beneficial uses will not be allowed.

(2) No person may violate the following specific water quality standards for waters classified C-3:

(b) Dissolved oxygen concentration must not be reduced below the applicable standards specified in department Circular DEQ-7.

(g) True color must not be increased more than five color units above naturally occurring color.

(h) Concentrations of carcinogenic, bioconcentrating, toxic, radioactive, nutrient, or harmful parameters may not exceed the applicable standards set forth in department Circular DEQ-7.

17.30.637 General Prohibitions (1) State surface waters must be free from substances attributable to municipal, industrial, agricultural practices or other discharges that will:

(c) produce odors, colors, or other conditions as to which create a nuisance or render undesirable tastes to fish flesh or make fish inedible;

(e) create conditions which produce undesirable aquatic life.

The following table is from “Circular DEQ-7: Montana Numeric Water Quality Standards” (February, 2008):

Circular DEQ-7, Montana Numeric Water Quality Standards (9)
Except where indicated, values are listed as micro-grams-per-liter (ug/L). A '---' indicates that a Standard has not been adopted or information is currently unavailable. A '( )' indicates that a detailed note of explanation is provided.
Pollutant Element / Chemical Compound or Condition §§ - Primary Synonym § - Other Names	Category (1) (2)	Aquatic Life Standards (16)		Human Health Standards (17) (3)		Trigger Value (22)	Required Reporting Value (19)
		Acute (3)	Chronic (4)	Acute (3)	Chronic (4)
Nitrate (as Nitrogen[N]) §§ NO3	Toxic	(8)	(8)	10,000 MCL	10,000  MCL	10, surface water 5000, ground water, see ARM 17.30.715	10
Nitrate plus nitrite (as Nitrogen[N])    §§ NO3 + NO2	Toxic	(8)	(8)	10,000 MCL	10,000 MCL	10, surface water 5000, ground water, see ARM 17.30. 715	10
Nitrite (as Nitrogen[N]) §§ NO2	Toxic	(8)	(8)	1,000 MCL	1,000 MCL	4	10
Phosphorus (20) §§ --- § Orthophosphorus § phosphorus, Ortho- § reactive phosphorus	Nutrient	(8)	(8)	---	---	1	1

(1) Based on EPA's categories and include parameters determined to be toxic (toxin), carcinogenic (carcinogen), or harmful. Harmful parameters include nutrients, biological agents, and those
parameters which cause taste and/or odor effects or physical effects.

(2) Carcinogens are chemicals classified by EPA as carcinogens for an oral route of exposure in the drinking water regulations and health advisories (EPA 822-B-96-002) and those listed as carcinogens in the EPA priority pollutants list. Carcinogens include those parameters in classifications A (Human Carcinogens), B1 or B2 (Probable Human Carcinogens), and C (Possible Human Carcinogen).

(3) No surface water or ground water sample concentration shall exceed these values.

(4) No surface water or ground water average concentration shall exceed these values based upon a four-day (96-hour) or longer period.

(8) A plant nutrient, excessive amounts of which may cause violations of Administrative Rules of Montana (ARM) 17.30.637 (1)(e).

(9) Approved methods of sample preservation, collection, and analysis for determining compliance with the standards set forth in DEQ-7 are found in the surface water quality standards (ARM17.30.601, et seq.) and the ground water rules (ARM 17.30.1001, et seq.).

Standards for metals (except aluminum) in surface water are based upon the analysis of samples following a "total recoverable" digestion procedure (Section 9.4, "Methods of Analysis of Water and Wastes", 1983, Environmental Monitoring and Support Laboratory, U.S. Environmental Protection Agency, EPA-600/4-79-020, or equivalent). Standards for alpha emitters, beta emitters and gamma emitters in surface waters are based upon the analysis of unfiltered samples and appropriate EPA approved analysis methods.

Standards for metals in ground water are based upon the dissolved portion of the sample (after filtration through a 0.45um membrane filter, as specified in "Methods for Analysis of Water and Wastes" 1983, Environmental Monitoring and Support Laboratory, U.S. Environmental Protection Agency, EPA-600/4-79-020, or equivalent). Standards for alpha emitters, beta emitters and gamma emitters in ground water are based upon the analysis of filtered samples and appropriate EPA approved analysis methods.

Standard for organic parameters in surface water and ground water are based on unfiltered samples.

(17) Source of the criteria used to derive the standard:

PP = priority pollutant criteria
NPP = non-priority pollutant criteria
MCL = Maximum contaminate level from the drinking water regulations
SMCL =secondary maximum contaminate level
HA = health advisory all from EPA's "Drinking Water Standards and Health Advisories" (October 1996)
I = standard derived from data obtained from federal data sources available on the Internet.
NRWQC = National Recommended Water Quality Criteria

(19) The Required Reporting Value (RRV) is the detection level that must be achieved in reporting surface water or ground water monitoring or compliance data to the department unless otherwise specified in a permit, approval or authorization issued by the department. The RRV is the Department’s best determination of a level of analysis that can be achieved by the majority of commercial, university, or governmental laboratories using EPA approved methods or methods approved by the department.

(22) Trigger Values are used to determine if a given increase in the concentration of toxic parameters is significant or non-significant as per the non-degradation rules ARM 17.30.701 et seq.
The acronym "N/A" means "not applicable".

Site-specific Criteria

The information on this tab shows EPA-approved site-specific nutrient criteria for Montana’s waterbodies. Criteria on this page apply only to the waterbodies listed below. Criteria applicable to all waterbodies within the state are found on the “Statewide Criteria” tab. For more information, refer to the Montana water quality standards.

The following information reflects Montana’s water quality standards posted to the Water Quality Standards Repository as of November 2010 (EPA-approved September 2008).

17.30.631 Numeric Algal Biomass and Nutrient Standards

(1) No person may violate the numeric water quality standards identified below.

(2) The numeric nutrient and standing crop of benthic algae water quality standards for the mainstem Clark Fork River from below the Warm Springs Creek confluence (N46º11'17", W112º46'03") to the confluence with the Flathead River (N47º21'45", W114º46'43") are as follows:

(a) In the mainstem Clark Fork River from below the Warm Springs Creek confluence (N46º11'17", W112º46'03") to the confluence with the Blackfoot River (N46º52'19", W113º53'35") the numeric water quality standards for Total Nitrogen, Total Phosphorus, and benthic algal chlorophyll a, applicable from June 21 to September 21, are as follows:

(i)	Parameter	Concentration
	Total Phosphorus as P	20 ug/L
	Total Nitrogen as N	300 ug/L
(ii)	Parameter	Density
	(Summer mean) - Benthic algal chlorophyll a	100 mg/square meter
	(Maximum) - Benthic algal chlorophyll a	150 mg/square meter

(b) In the Clark Fork River from the confluence with the Blackfoot River (N46º52'19", W113º53'35") to the confluence with the Flathead River (N47º21'45", W114º46'43") the numeric water quality standards for Total Nitrogen, Total Phosphorus, and benthic algal chlorophyll a, applicable from June 21 to September 21, are as follows:

(i)	Parameter	Concentration
	Total Phosphorus as P	39 ug/L
	Total Nitrogen as N	300 ug/L
(ii)	Parameter	Density
	(Summer mean) - Benthic algal chlorophyll a	100 mg/square meter
	(Maximum) - Benthic algal chlorophyll a	150 mg/square meter