The numeric levels for parameters listed in Tables I, II, III shall be considered and applied as appropriate by the Commission in establishing site-specific numeric standards, in accordance with section 31.7.
For the purposes of integrating these parameters into NPDES discharge permits, the duration of the averaging period for the numeric level is designated in the tables. Chronic levels and 30-day levels are to be averaged as defined in section 31.5 . Acute levels and 1-day levels are to be averaged as defined in section 31.5(2).
Certain toxic metals for Aquatic Life have different numeric levels for different levels of water hardness. Water hardness is being used here as an indication of differences in the complexing capacity of natural waters and the corresponding variation of metal toxicity. Other factors such as organic and inorganic ligands, pH, and other factors affecting the complexing capacity of the waters may be considered in setting site-specific numeric standards in accordance with section 31.7 . Metals listed in Table III for aquatic life uses are stated in the dissolved form unless otherwise indicated.
Various testing procedures to determine that numeric values for water quality parameters may be appropriate to present to the Water Quality Control Commission at stream classification hearings. (See section 31.6(3)). These include:
Other procedures may be deemed appropriate by either the Water Quality Control Commission and/or the Water Quality Control Division.
Capital letters following levels in the tables indicate the sources of the level; they are referenced below.
TABLE I - PHYSICAL AND BIOLOGICAL PARAMETERS
TABLE I PHYSICAL AND BIOLOGICAL PARAMETERS | ||||||||
Parameter | Recreation | Aquatic Life | Agriculture | Domestic Water Supply | ||||
CLASS E (Existing Primary Contact) and CLASS U (Undetermined Use) | CLASS P (Potential Primary Contact Use) | CLASS N (Not Primary Contact Use) | CLASS 1 COLD WATER BIOTA | CLASS 1 WARM WATER BIOTA | CLASS 2 | |||
PHYSICAL | ||||||||
D.O. (mg/L)(1)(9) | 3.0(A) | 3.0(A) | 3.0(A) | 6.0(2)(G) 7.0 (spawning) | 5.0(2)(G) | 5.0(A) | 3.0(A) | 3.0(A) |
pH (Std. Units)(3) | 6.5-9.0(B,M) | 6.5-9.0(B,M) | 6.5-9.0(B,M) | 6.5-9.0(A) | 6.5-9.0(A) | 6.5-9.0(A) | 5.0-9.0(A) | |
Suspended Solids(4) | ||||||||
Temperature (°C)(5) | Rivers & Streams: Tier Ia,g: June-Sept = 17.0 (ch), 21.7 (ac) Oct -May = 9.0 (ch), 13.0 (ac) Tier IIb,g: Apr-Oct = 18.3 (ch), 24.3 (ac) Nov-Mar = 9.0 (ch), 13.0 (ac) Lakes & Resh: Apr-Dec = 17.0 (ch), 21.2 (ac) Jan-Mar = 9.0 (ch), 13.0 (ac) Large Lakes & Resc,h: Apr-Dec = 18.3 (ch), 24.2 (ac) Jan-Mar = 9.0 (ch), 13.0 (ac) | Rivers & Streams: Tier Id: Mar-Nov = 24.2 (ch), 29.0 (ac) Dec-Feb = 12.1 (ch), 24.6 (ac) Tier IIe: Mar-Nov = 27.5 (ch), 28.6 (ac) Dec-Feb = 13.8 (ch), 25.2 (ac) Tier IIIf: Mar-Nov = 28.7 (ch), 31.8 (ac) Dec-Feb = 14.3 (ch), 24.9 (ac) Lakes & Res: Apr-Dec = 26.2 (ch), 29.3 (ac) Jan-Mar = 13.1 (ch), 24.1 (ac) | Same as Class 1 | |||||
BIOLOGICAL: | ||||||||
E. coli per 100 ml | 126(7) | 205(7) | 630(7) | 630 | ||||
Note: Capital letters In parentheses refer to references listed in section 31.16 ; numbers in parentheses refer to Table I footnotes. | ||||||||
Temperature Definitions a Cold Stream Tier I temperature criteria apply where cutthroat trout and brook trout are expected to occur. b Cold Stream Tier II temperature criteria apply where cold-water aquatic species, excluding cutthroat trout or brook trout, are expected to occur. c Large Cold Lakes temperature criteria apply to lakes and reservoirs with a surface area equal to or greater than 100 acres surface area. d Warm Stream Tier I temperature criteria apply where common shiner, johnny darter, or orangethroat darter, or stonecat are expected to occur. e Warm Stream Tier II temperature criteria apply where brook stickleback, central stoneroller, creek chub, finescale dace, longnose dace, mountain sucker, northern redbelly dace, razorback sucker, or white sucker are expected occur, and none of the more thermally sensitive species in Tier I are expected to occur. f Warm Stream Tier III temperature criteria apply where warm-water aquatic species are expected to occur, and none of the more thermally sensitive species in Tiers I and II are expected to occur. g Mountain whitefish-based summer temperature criteria [16.9 (ch), 21.2 (ac)] apply when and where spawning and sensitive early life stages of this species are known to occur. h Lake trout-based summer temperature criteria [16.6 (ch), 22.4 (ac)] apply where appropriate and necessary to protect lake trout from thermal impacts. |
Table I - Footnotes
TABLE II - INORGANIC PARAMETERS
TABLE II INORGANIC PARAMETERS | ||||||||
Parameter | Aquatic Life | Agriculture | Domestic Water Supply | |||||
CLASS 1 COLD WATER BIOTA | CLASS 1 WARM WATER BIOTA | CLASS 2 | ||||||
Ammonia (mg/L as N) Total | chronic = elsp or elsa(1) acute = sp(1)(N) | chronic = Apr 1-Aug 31 = elsp(1) Sept 1-Mar 29 = elsa(1) acute = sa(1)(N) | Class 2 Cold/Warm have the same standards as Class 1 Cold/Warm(N) | |||||
Total residual Chlorine (mg/L) | 0.019(L) (acute) | 0.011(L) (chronic) | 0.019(L) (acute) | 0.011(L) (chronic) | 0.019(L) (acute) | 0.011(L) (chronic) | ||
Cyanide - Free (mg/L) | 0.005(H) (acute) | 0.005(H) (acute) | 0.005(H) (acute) | 0.2(G) (acute) | 0.2(B,D,M) (acute) | |||
Fluoride(6) (mg/L) | 2.0 (E) (acute) | |||||||
Nitrate (mg/L as N) | 100(2)(B) (acute) | 10(4)(K) (acute) | ||||||
Nitrite (mg/L as N) | TO BE ESTABLISHED ON A CASE BY CASE BASIS(3) | A CASE BY CASE BASIS(3) | 10(2)(B) (acute) | 1.0(2)(4)(K) (acute) | ||||
Sulfide as H2S (mg/L) | 0.002 undissociated(A) (chronic) | 0.002 undissociated(A) (chronic) | 0.002 undissociated(A) (chronic) | 0.05(F) (chronic) | ||||
Boron (mg/L) | 0.75(A,B) (chronic) | |||||||
Chloride (mg/L) | 250(F) (chronic) | |||||||
Sulfate, dissolved(7) (mg/L) | 250(F) (chronic) | |||||||
Asbestos(6) fibers/L | 7,000,000 (5) (chronic) | |||||||
Note: Capital letters in parentheses refer to references listed in 31.16(3); numbers in parentheses refer to Table II footnotes. |
Table II - Footnotes
Acute= 0.10 (0.59 * [Cl-]+3.90) mg/L NO2-N Chronic= 0.10 (0.29 * [Cl-]+0.53) mg/L NO2-N
[Cl-] = Chloride ion concentration; upper limit for Cl- = 40 mg/L Salmonids and other sensitive fish species* absent: Acute= 0.20 (2.00 * [Cl-]+0.73) mg/L NO2-N Chronic=0.10 (2.00 *[Cl-]+0.73) mg/L NO2-N
[Cl-] = Chloride ion concentration; upper limit for Cl- = 22 mg/L
*Sensitive fish species include salmonids, channel catfish, logperch and brook stickleback. Either total or dissolved chloride data may be used in these equations.
TABLE III - METAL PARAMETERS
TABLE III METAL PARAMETERS (concentration in µg/L) | ||||||
Metal(1) | Aquatic Life(1)(3)(4)(J) | Agriculture(2) | Domestic Water Supply(2) | Water + Fish(7) | Fish Ingestion(10) | |
ACUTE | CHRONIC | CHRONIC | CHRONIC | CHRONIC | ||
Aluminum | e(1.3695*In(hardness)+1.8308) (total recoverable) | 87 or e(1.3695*In(hardness)-0.1158) (total recoverable)(11) | --- | --- | ||
Antimony(18) | 6.0 (chronic) | 5.6 | 640 | |||
Arsenic | 340 | 150 | 100(A) | 0.02 - 10(13) (chronic) | 0.02 | 7.6 |
Barium(18) | 1,000(E) (acute) 490 (chronic) | --- | --- | |||
Beryllium(18) | 100(A,B) | 4.0 (chronic) | --- | --- | ||
Cadmium | Warm(17) = (1.136672-(ln(hardness)* 0.041838))* e(0.9789*ln(hardness)-3.443) Cold(17) = (1.136672-(ln(hardness)* 0.041838))* e(0.9789*ln(hardness)-3.866) | (1.101672-(ln(hardness)*0.041838))* e(0.7977*ln(hardness)-3.909) | 10(B) | 5.0(E) (acute) | --- | --- |
Chromium III(5) | e(0.819*ln(hardness)+2.5736) | e(0.819*ln(hardness)+0.5340) | 100(B) | 50(E) (acute) | --- | --- |
Chromium VI(5) | 16 | 11 | 100(B) | 50(E) (acute) | 100 | --- |
Copper | e(0.9422*ln(hardness)-1.7408) | e(0.8545*ln(hardness)-1.7428) | 200(B) | 1,000(F) (chronic) | 1,300 | --- |
Iron | 1,000 (total recoverable)(A,C) | 300 (dissolved)(F) (chronic) | --- | --- | ||
Lead | (1.46203-(ln(hardness)* 0.145712))* e(1.273*ln(hardness)-1.46) | (1.46203-(ln(hardness)* 0.145712))*e(1.273*ln(hardness)-4.705) | 100(B) | 50(E) (acute) | - | --- |
Manganese | e(0.3331*ln(hardness)+6.4676) | e(0.3331*ln(hardness)+5.8743) | 200(B)(12) | 50 (dissolved)(F) (chronic) | - | --- |
Mercury | FRV(fish)(6) = 0.01 (total recoverable) | 2.0(E) (acute) | - | --- | ||
Molybdenum | 300(O)(15) | 210 (chronic) | ||||
Nickel | e(0.846*ln(hardness)+2.253) | e(0.846*ln(hardness)+0.0554) | 200(B) | 100(E) (chronic) | 610 | 4,600 |
Selenium(9) | 18.4 | 4.6 | 20(B,D) | 50(E) (chronic) | 170 | 4,200 |
Silver | 0.5*e(1.72*ln(hardness)-6.52) | e(1.72*ln(hardness)-9.06) Trout(19) = e(1.72*ln(hardness)-10.51) | 100(F) (acute) | - | --- | |
Thallium(18) | 15(C) | 0.5 (chronic) | 0.24 | 0.47 | ||
Uranium(16) | e(1.1021*ln(hardness)+2.7088) | e(1.1021*ln(hardness)+2.2382) | 16.8 - 30(13) (chronic) | --- | --- | |
Zinc | 0.978*e(0.9094*ln(hardness)+0.9095) | 0.986*e(0.9094*ln(hardness)+0.6235) Sculpin(14) = e(2.140*ln(hardness)-5.084) | 2000(B) | 5,000(F) (chronic) | 7,400 | 26,000 |
Note: Capital letters in parentheses refer to references listed in section 31.16 ; numbers in parentheses refer to Table III footnotes. |
Table III - Footnotes
Where the hardness-based equations in Table III are applied as table value water quality standards for individual water segments, those equations define the applicable numerical standards. As an aid to persons using this regulation, Table IV provides illustrative examples of approximate metals values associated with a range of hardness levels. This table is provided for informational purposes only.
Many forms of mercury are readily converted to toxic forms under natural conditions. The FRV of 0.01 µg/liter is the maximum allowed concentration of total mercury in the water. This value is estimated to prevent bioaccumulation of methylmercury in edible fish or shellfish tissue above the fish tissue standard for methylmercury of 0.3 mg/kg.
In waters supporting populations of fish or shellfish with a potential for human consumption, the Commission can adopt the FRV as the stream standard to be applied as a 30-day average. Alternatively, the Commission can adopt site-specific ambient-based standards for mercury in accordance with section 31.7 . Site-specific water-column standards shall be calculated from the site-specific bioaccumulation factor, using measured water column concentrations of total mercury and measured fish tissue concentrations of methylmercury. Fish tissue data shall be collected from species of the highest trophic level present in the waterbody. Fish tissue samples should include older, larger individuals present in the waterbody. A bioaccumulation factor should be calculated separately for each species sampled, and the highest bioaccumulation factor should be used to calculate the site-specific water column standard in order to prevent the average fish tissue concentrations from exceeding 0.3 mg/kg for all species.
TABLE IV - AQUATIC LIFE TABLE VALUE STANDARDS FOR SELECTED HARDNESS CONCENTRATIONS
TABLE IV AQUATIC LIFE TABLE VALUE STANDARDS FOR SELECTED HARDNESS CONCENTRATIONS (µg/L) | |||||||||||
Mean Hardness in mg/L Calcium Carbonate | |||||||||||
25 | 50 | 75 | 100 | 150 | 200 | 250 | 300 | 350 | 400 | ||
Aluminum | Acute | 512 | 1324 | 2307 | 3421 | 5960 | 8838 | 10071 | 10071 | 10071 | 10071 |
Chronic | 73 | 189 | 329 | 488 | 851 | 1262 | 1438 | 1438 | 1438 | 1438 | |
Cadmium | Acute(cold) | 0.49 | 0.94 | 1.4 | 1.8 | 2.6 | 3.4 | 4.2 | 5.0 | 5.8 | 6.5 |
Acute(warm) | 0.75 | 1.4 | 2.1 | 2.7 | 4.0 | 5.2 | 6.4 | 7.6 | 8.8 | 10 | |
Chronic | 0.25 | 0.43 | 0.58 | 0.72 | 0.97 | 1.2 | 1.4 | 1.6 | 1.8 | 2.0 | |
Chromium III | Acute | 183 | 323 | 450 | 570 | 794 | 1005 | 1207 | 1401 | 1590 | 1773 |
Chronic | 24 | 42 | 59 | 74 | 103 | 131 | 157 | 182 | 207 | 231 | |
Copper | Acute | 3.6 | 7.0 | 10 | 13 | 20 | 26 | 32 | 38 | 44 | 50 |
Chronic | 2.7 | 5.0 | 7.0 | 9.0 | 13 | 16 | 20 | 23 | 26 | 29 | |
Lead | Acute | 14 | 30 | 47 | 65 | 100 | 136 | 172 | 209 | 245 | 281 |
Chronic | 0.5 | 1.2 | 1.8 | 2.5 | 3.9 | 5.3 | 6.7 | 8.1 | 9.5 | 11 | |
Manganese | Acute | 1881 | 2370 | 2713 | 2986 | 3417 | 3761 | 4051 | 4305 | 4532 | 4738 |
Chronic | 1040 | 1310 | 1499 | 1650 | 1888 | 2078 | 2238 | 2379 | 2504 | 2618 | |
Nickel | Acute | 145 | 260 | 367 | 468 | 660 | 842 | 1017 | 1186 | 1351 | 1513 |
Chronic | 16 | 29 | 41 | 52 | 72 | 94 | 113 | 132 | 150 | 168 | |
Silver | Acute | 0.19 | 0.62 | 1.2 | 2.0 | 4.1 | 6.7 | 9.8 | 13 | 18 | 22 |
Chronic(trout) | 0.01 | 0.02 | 0.05 | 0.08 | 0.15 | 0.25 | 0.36 | 0.50 | 0.65 | 0.81 | |
Chronic | 0.03 | 0.10 | 0.20 | 0.32 | 0.64 | 1.0 | 1.6 | 2.1 | 2.8 | 3.5 | |
Uranium | Acute | 521 | 1119 | 1750 | 2402 | 3756 | 5157 | 6595 | 8062 | 9555 | 11070 |
Chronic | 326 | 699 | 1093 | 1501 | 2346 | 3221 | 4119 | 5036 | 5968 | 6915 | |
Zinc | Acute | 45 | 85 | 123 | 160 | 231 | 301 | 368 | 435 | 500 | 565 |
Chronic(sculpin) | 6.1 | 27 | 64 | 118 | N/A | N/A | N/A | N/A | N/A | N/A | |
Chronic | 34 | 65 | 93 | 121 | 175 | 228 | 279 | 329 | 379 | 428 | |
Shading indicates the aquatic life standards exceed drinking water supply standards. |
APPENDIX A. Calculation of a Biologically-Based Low Flow
The biologically-based flow calculation method is an iterative convergence procedure consisting of five parts. In Part I, Z (the allowed number of excursions) is calculated. In Part II, the set of X-day running averages is calculated from the daily flows for the period of record being considered. Because the ambient (instream) concentration of a pollutant can be considered to be inversely proportional to stream flow, the appropriate "running averages" of stream flow are actually "running harmonic means." (The harmonic mean of a set of numbers is the reciprocal of the arithmetic mean of the reciprocals of the numbers.) Thus, "X-day running averages" should be calculated as , not as , where F is the flow for an individual day. Throughout this Appendix A, the term "running average" will mean "running harmonic mean."
Part III describes the calculation of N (the total number of excursions of a specified flow for the period of record being considered). The calculations described in Part III will be performed for a number of different flows that are specified in Parts IV and V. In Part IV, initial lower and upper limits on the flow are calculated, the number of excursions at each limit are calculated using Part III, and an initial trial flow is calculated by interpolation between the lower and upper limits. In Part V, successive iterations are performed to calculate the flow as the highest flow that results in no more than the number of allowed excursions calculated in Part I.
Part I. Calculation of allowed number of excursions.
I-1. Calculate Z = D/[(Y)(365.25 days/year])
where D = the number of days in the flow record;
Y = the average number of years specified in the frequency; and
Z = the allowed number of excursions based on a 1-in-3-year recurrence interval.
Part II. Calculation of X-day running averages, i.e., X-day running harmonic means.
II-1. Where X = the specified duration (in days) of the averaging period, calculate the set of X-day running averages for the entire period of record being considered, i.e., calculate an X-day average starting with day 1, day 2, day 3, etc. Each average will have X-1 days in common with the next average, and the number of X-day averages calculated from the period of record being considered will be (D+1-X).
Part III. Determination of the number of excursions of a specified flow in a set of running averages, i.e., running harmonic means.
III-1. Select a specified trial low flow by method outlined in Part IV or an equivalent method.
III-2. In the set of X-day running averages for the period of record being considered, record the date for which the first average is below the specified trial low flow and record the number of consecutive days that are part of at least one or more of the X-day averages that are below the specified flow. (Note that whether a day is counted as an excursion day does not depend exclusively on whether the X-day average for that day is below the specified trial low flow. Instead, it depends entirely on whether that day is part of any X-day average that is below the specified trial low flow. Table A-1 provides examples of the counting of excursion days. For ease in discussion, it is based on a 4-day flow period, rather than a 30-day flow period. When calculating a low flow pursuant to Section 31.9 , a 30-day period should be used.)
Thus the starting date and the duration (in days) of the first excursion period will be recorded. By definition, the minimum duration is X days.
III-3. Determine the starting dates of, and number of days in, each succeeding excursion period in the period of record being considered.
III-4. Identify all of the excursion periods that begin within 120 days after the beginning of the first excursion period. (Although the first excursion period is often the only one in the 120-day period, two or three sometimes occur within the 120 days. Rarely do any excursion periods occur during days 121 to 240.) All of these excursion periods are considered to be in the first low flow period. Add up the total number of excursion days in the first low flow period and divide the sum by X to obtain the number of excursions in the first low flow period. If the number of excursions is calculated to be greater than 5.0, set it equal to 5.0.
III-5. Identify the first excursion period that begins after the end of the first low flow period, and start the beginning of the second 120-day low flow period on the first day of this excursion period. Determine the number of excursion days and excursions in the second low flow period.
III-6. Determine the starting dates of, and the number of excursions in, each succeeding 120-day low flow period.
III-7. Sum the number of excursions in all the low-flow periods to determine S = the total number of excursions of the specified trial low flow.
Part IV. Calculation of initial limits of the low flow and initial trial flow.
IV-1. Use L = 0 as the initial lower limit.
IV-2. Use U = the XQY low flow as the initial upper limit.
IV-3. Use N L = 0 as the number of excursions (see Part III) of the initial lower limit.
IV-4. Calculate N U = the number of excursions (see Part III) of the initial upper limit.
IV-6. Calculation of initial limits of the low flow and initial trial flow may be accomplished using equivalent methods.
Part V. Iterative convergence to the low flow.
V-1. Calculate N T = the number of excursions for the trial low flow.
If -0.005 < (NT - Z) /Z)< +.005
If NT >Z, set U = Tand NU=NT.
V-2 if NT <Z set L = T and NL= NT. , use T as the low flow and stop.
V-3. If ((U-L)/U) < 0.005, use L as the low flow and stop.
APPENDIX A TABLE A-1 - COUNTING EXCURSION DAYS FOR A SPECIFIED FLOW OF 100 FT3/SEC USING 4-DAY AVERAGES.
TABLE A-1. COUNTING EXCURSION DAYS FOR A SPECIFIED FLOW OF 100 FT3/SEC USING 4-DAY AVERAGES. | |||||||||
Date | Daily flow | 4-day avg. flow | Is the 4-day average below 100? | Is this date part of any 4-day average that is below 100? | Date of start of excursion period | Number of days in excursion period | Date of start of low flow period | Number of excursion days in low flow period | Number or excursions in low flow period |
1 | 130 | 112.5 | No | No | |||||
2 | 120 | 102.5 | No | No | |||||
3 | 110 | 97.5 | Yes | Yes | 3 | 4 | 3 | 12 | 3 |
4 | 90 | 102.5 | No | Yes | |||||
5 | 90 | 117.5 | No | Yes | |||||
6 | 100 | 112.5 | No | Yes | |||||
7 | 130 | 102.5 | No | No | |||||
8 | 150 | 102.5 | No | No | |||||
9 | 70 | 87.5 | Yes | Yes | 9 | 8 | |||
10 | 60 | 90.0 | Yes | Yes | |||||
11 | 130 | 102.5 | No | Yes | |||||
12 | 90 | 95.0 | Yes | Yes | |||||
13 | 80 | 97.5 | Yes | Yes | |||||
14 | 110 | 127.5 | No | Yes | |||||
15 | 100 | 225.0 | No | Yes | |||||
16 | 100 | >100 | No | Yes | |||||
17 | 200 | >100 | No | No | |||||
18 | 500 | >100 | No | No | |||||
The daily flows and four-day average flows for days 19 to 200 are all above 100 ft3/sec. |
5 CCR 1002-31.16