Section 327IAC2-1.5-8. Minimum surface water quality criteria

   (a) All surface water quality criteria in this section, except those provided in subsection (b)(1), will cease to be applicable when the stream flows are less than the applicable stream design flow for the particular criterion as determined under 327 IAC 5-2-11.4.

  (b) The following are minimum surface water quality conditions:

(1) All surface waters within the Great Lakes system at all times and at all places, including waters within the mixing zone, shall meet the minimum conditions of being free from substances, materials, floating debris, oil, or scum attributable to municipal, industrial, agricultural, and other land use practices, or other discharges that do any of the following:

(A) Will settle to form putrescent or otherwise objectionable deposits.

(B) Are in amounts sufficient to be unsightly or deleterious.

(C) Produce:

(i) color;

(ii) visible oil sheen;

(iii) odor; or

(iv) other conditions;

in such degree as to create a nuisance.

(D) Are in concentrations or combinations that will cause or contribute to the growth of aquatic plants or algae to such degree as to:

(i) create a nuisance;

(ii) be unsightly; or

(iii) otherwise impair the designated uses.

(E) Are in amounts sufficient to be acutely toxic to, or to otherwise severely injure or kill, aquatic life, other animals, plants, or humans. To assure protection of aquatic life, the waters shall meet the following requirements:

(i) Concentrations of toxic substances shall not exceed the CMC or SMC outside the zone of initial dilution or the final acute value (FAV = 2 (CMC) or 2 (SMC)) in the undiluted discharge unless, for a discharge to a receiving stream or Lake Michigan, an alternate mixing zone demonstration is conducted and approved in accordance with 327 IAC 5-2-11.4(b)(4), in which case, the CMC or SMC shall be met outside the applicable alternate mixing zone:

(AA) for certain substances, a CMC is established and set forth in subdivision (3), Table 8-1 (which table incorporates subdivision (4), Table 8-2), and subdivision (5);

(BB) for substances for which a CMC is not specified in subdivision (3), Table 8-1, or subdivision (5), a CMC shall be calculated by the commissioner using the procedures in section 11 of this rule, or, if the minimum data requirements to calculate a CMC are not met, an SMC shall be calculated using the procedures in section 12 of this rule; and

(CC) the CMC or SMC determined under subitem (AA) or (BB) may be modified on a site-specific basis to reflect local conditions in accordance with section 16 of this rule.

(ii) A discharge shall not cause acute toxicity, as measured by whole effluent toxicity tests, at any point in the waterbody. Compliance with this criterion shall be demonstrated if a discharge does not exceed one and zero-tenths (1.0) TU_a in the undiluted discharge. For a discharge into a receiving stream or Lake Michigan, for which an alternate mixing zone demonstration is conducted and approved in accordance with 327 IAC 5-2-11.4(b)(4), compliance with this criterion shall be demonstrated if three-tenths (0.3) TU_a is not exceeded outside the applicable alternate mixing zone.

This clause shall not apply to the chemical control of plants and animals when that control is performed in compliance with approval conditions specified by the Indiana department of natural resources as provided by IC 14-22-9.

(2) At all times, all surface waters outside of the applicable mixing zones determined in accordance with section 7 of this rule shall be free of substances in concentrations that, on the basis of available scientific data, are believed to be sufficient to injure, be chronically toxic to, or be carcinogenic, mutagenic, or teratogenic to humans, animals, aquatic life, or plants. To assure protection against the adverse effects identified in this subdivision, a toxic substance or pollutant shall not be present in such waters in concentrations that exceed the most stringent of the following:

(A) A CCC or an SCC to protect aquatic life from chronic toxic effects as follows:

(i) For certain substances, a CCC is established and set forth in subdivision (3), Table 8-1 (which table incorporates subdivision (4), Table 8-2), and subdivision (5).

(ii) For substances for which a CCC is not specified in subdivision (3), Table 8-1, or subdivision (5), a CCC shall be calculated by the commissioner using the procedures in section 11 of this rule, or, if the minimum data requirements to calculate a CCC are not met, an SCC shall be calculated using the procedures in section 12 of this rule.

(iii) The CCC or SCC determined under item (i) or (ii) may be modified on a site-specific basis to reflect local conditions in accordance with section 16 of this rule.

(iv) To assure protection of aquatic life, a discharge shall not cause chronic toxicity, as measured by whole effluent toxicity tests, outside of the applicable mixing zone. Compliance with this criterion shall be demonstrated if the waterbody does not exceed one and zero-tenths (1.0) TU_c at the edge of the mixing zone.

(B) An HNC or HNV to protect human health from adverse noncancer effects that may result from the consumption of aquatic organisms or drinking water from the waterbody determined as follows:

(i) For certain substances, an HNC is established and set forth in subdivision (6), Table 8-3.

(ii) For substances for which an HNC is not specified in subdivision (6), Table 8-3, an HNC shall be calculated by the commissioner using the procedures in section 14 of this rule, or, if the minimum data requirements to calculate an HNC are not met, an HNV shall be calculated using the procedures in section 14 of this rule.

(iii) The HNC or HNV determined under item (i) or (ii) may be modified on a site-specific basis to reflect local conditions in accordance with section 16 of this rule.

(iv) The HNC-nondrinking or HNV-nondrinking for a substance shall apply to all surface waters outside the applicable mixing zone for a discharge of that substance. The HNC-drinking or HNV-drinking shall apply at the point of the public water system intake.

(C) For carcinogenic substances, an HCC or HCV to protect human health from unacceptable cancer risk of greater than one (1) additional occurrence of cancer per one hundred thousand (100,000) population as follows:

(i) For certain substances, an HCC is established and set forth in subdivision (6), Table 8-3.

(ii) For substances for which an HCC is not specified in subdivision (6), Table 8-3, an HCC shall be calculated by the commissioner using the procedures in section 14 of this rule or, if the minimum data requirements to calculate an HCC are not met, an HCV shall be calculated using the procedures in section 14 of this rule.

(iii) The HCC or HCV determined under item (i) or (ii) may be modified on a site-specific basis to reflect local conditions in accordance with section 16 of this rule.

(iv) The HCC-nondrinking or HCV-nondrinking for a substance shall apply to all surface waters outside the applicable mixing zone for a discharge of that substance. The HCC-drinking or HCV-drinking shall apply at the point of the public water system intake.

(D) A WC to protect avian and mammalian wildlife populations from adverse effects that may result from the consumption of aquatic organisms or water from the waterbody as follows:

(i) For certain substances, a WC is established and set forth in subdivision (7), Table 8-4.

(ii) For substances for which a WC is not specified in subdivision (7), Table 8-4, a WC shall be calculated by the commissioner using the procedures in section 15 of this rule or, if the minimum data requirements to calculate a WC are not met, a WV may be calculated using the procedures in section 15 of this rule.

(iii) The WC or WV determined under item (i) or (ii) may be modified on a site-specific basis to reflect local conditions in accordance with section 16 of this rule.

(3) The following establishes surface water quality criteria for protection of aquatic life:

Table 8-1
Surface Water Quality Criteria for Protection of Aquatic Life[1]
CAS Number	Substances		CMC (Maximum) (μg/l)	CMC Conversion Factors	CCC (4-Day Average) (μg/l)	CCC Conversion Factors
	Metals (dissolved)[2]
7440382		Arsenic (III)	WER[3](339.8)	1.000	WER[3](147.9)	1.000
7440439		Cadmium	WER[3](e(1.128 [ln(hardness)]-3.6867))	1.136672-[(ln hardness) (0.041838)]	WER[3](e(0.7852 [ln(hardness)]-2.715))	1.101672-[(ln hardness) (0.041838)]
7440473		Chromium (III)	WER[3](e(0.819 [ln(hardness)]+3.7256))	0.316	WER[3](e(0.819 [ln(hardness)]+0.6848))	0.860
7440473		Chromium (VI)	WER[3](16.02)	0.982	WER[3](10.98)	0.962
7440508		Copper	WER[3](e(0.9422 [ln(hardness)]-1.700))	0.960	WER[3](e(0.8545 [ln(hardness)]-1.702))	0.960
7439976		Mercury	WER[3](1.694)	0.85	WER[3](0.9081)	0.85
7440020		Nickel	WER[3](e(0.846 [ln(hardness)]+2.255))	0.998	WER[3](e(0.846 [ln(hardness)]+0.0584))	0.997
7782492		Selenium			5	0.922
7440666		Zinc	WER[3](e(0.8473 [ln(hardness)]+0.884))	0.978	WER[3](e(0.8473 [ln(hardness)]+0.884))	0.986
	Organics (total)
60571		Dieldrin	0.24	NA	0.056	NA
72208		Endrin	0.086	NA	0.036	NA
56382		Parathion	0.065	NA	0.013	NA
87865		Pentachlorophenol [4]	e(1.005[pH]-4.869)	NA	e(1.005[pH]-5.134)	NA
	Other Substances
		Chloride	[6]	NA	[6]	NA
		Chlorine (total residual)	19	NA	11	NA
		Chlorine (intermittent, total residual) [5]	200	NA		NA
57125		Cyanide (free)	22	NA	5.2	NA
[1] Aquatic organisms should not be affected unacceptably if the four (4) day average concentration of any substance in this table does not exceed the CCC more than once every three (3) years on the average and if the one (1) hour average concentration does not exceed the CMC more than once every three (3) years on the average, except possibly where a commercially or recreationally important species is very sensitive.
[2] The CMC and CCC columns of this table contain total recoverable metals criteria (numeric and hardness-based). The criterion for the dissolved metal is calculated by multiplying the appropriate conversion factor by the CMC or CCC. This dissolved CMC or CCC shall be rounded to two (2) significant digits, except when the criteria are used as intermediate values in a calculation, such as in the calculation of water quality-based effluent limitations (WQBELs).
[3] A value of one (1) shall be used for the WER unless an alternate value is established under section 16 of this rule.
[4] A CMC and CCC calculated for pentachlorophenol using the equation in this table shall be rounded to two (2) significant digits, except when the criteria are used as intermediate values in a calculation, such as in the calculation of WQBELs.
[5] To be considered an intermittent discharge, total residual chlorine shall not be detected in the discharge for a period of more than forty (40) minutes in duration, and such periods shall be separated by at least five (5) hours.
[6] The CMC and CCC for this substance are established in subdivision (5).

(4) The following establishes dissolved CMCs and CCCs for certain metals at selected hardness values calculated from the equations and conversion factors in subdivision (3), Table 8-1 and using a value of one (1) for the WER, where applicable:

Table 8-2
Metals Concentrations in Micrograms Per Liter; Hardness in Milligrams Per Liter CaCO31
	Arsenic (III)		Cadmium		Chromium (III)		Chromium (VI)		Copper		Mercury		Nickel		Selenium		Zinc
Hardness	CMC	CCC	CMC	CCC	CMC	CCC	CMC	CCC	CMC	CCC	CMC	CCC	CMC	CCC	CMC	CCC	CMC	CCC
50	340	150	2.0	1.3	320	42	16	11	7.0	5.0	1.4	0.77	260	29	─	4.6	65	66
100	340	150	4.3	2.2	570	74	16	11	13	9.0	1.4	0.77	470	52	─	4.6	120	120
150	340	150	6.6	3.0	790	100	16	11	20	13	1.4	0.77	660	73	─	4.6	170	170
200	340	150	9.0	3.7	1,000	130	16	11	26	16	1.4	0.77	840	93	─	4.6	210	210
250	340	150	12	4.4	1,200	160	16	11	32	20	1.4	0.77	1,000	110	─	4.6	250	260
300	340	150	14	5.0	1,400	180	16	11	38	23	1.4	0.77	1,200	130	─	4.6	300	300
350	340	150	17	5.6	1,600	210	16	11	44	26	1.4	0.77	1,400	150	─	4.6	340	340
400	340	150	19	6.2	1,800	230	16	11	50	29	1.4	0.77	1,500	170	─	4.6	380	380
450	340	150	22	6.8	2,000	250	16	11	55	32	1.4	0.77	1,700	190	─	4.6	420	420
500	340	150	24	7.3	2,100	280	16	11	61	35	1.4	0.77	1,800	200	─	4.6	460	460
[1] The dissolved metals criteria in this table have been rounded to two (2) significant digits in accordance with subdivision (3), Table 8-1. The equations and conversion factors in subdivision (3), Table 8-1 shall be used instead of the criteria in this table when dissolved metals criteria are used as intermediate values in a calculation, such as in the calculation of WQBELs.

(5) The following establishes surface water quality criteria for chloride for protection of aquatic life:

(A) The following provides the CMC for chloride as a function of hardness (in mg/l as CaCO₃) and sulfate (in mg/l) in surface waters:

C = 287.8 (hardness)^0.205797 (sulfate)^-0.07452

Where: C = chloride CMC (maximum) in mg/l.

(B) The following provides the CCC for chloride as a function of hardness (in mg/l as CaCO₃) and sulfate (in mg/l) in surface waters:

C = 177.87 (hardness)^0.205797 (sulfate)^-0.07452

Where: C = chloride CCC (4-Day Average) in mg/l.

(C) The CMC and CCC for chloride calculated from the equations in this subdivision shall be rounded to the nearest whole numbers, except when the criteria are used as intermediate values in a calculation, such as in the calculation of WQBELs.

(D) The following establishes the CMC for chloride in mg/l at selected concentrations of hardness and sulfate, with the understanding that the equation in clause (A) shall be used instead of the criteria in this clause when chloride criteria are used as intermediate values in a calculation, such as in the calculation of WQBELs:

Table 8-2a

Hardness (mg/l)

Sulfate (mg/l)	50	100	150	200	250	300	350	400	450	500
15	526	607	660	700	733	761	785	807	827	845
20	515	594	646	685	717	745	769	790	809	827
25	506	584	635	674	705	732	756	777	796	813
50	481	555	603	640	670	695	718	738	756	773
100	457	527	573	608	636	660	682	701	718	734
150	443	511	556	589	617	641	661	680	697	712
200	434	500	544	577	604	627	647	665	682	697
250	427	492	535	567	594	617	637	654	671	685
300	421	485	528	560	586	609	628	646	661	676
350	416	480	522	553	579	602	621	638	654	668
400	412	475	516	548	574	596	615	632	647	662
450	408	471	512	543	569	590	609	626	642	656
500	405	467	508	539	564	586	605	622	637	651

(E) The following establishes the CCC for chloride in mg/l at selected concentrations of hardness and sulfate, with the understanding that the equation in clause (B) shall be used instead of the criteria in this clause when chloride criteria are used as intermediate values in a calculation, such as in the calculation of WQBELs:

Table 8-2b

Hardness (mg/l)

Sulfate (mg/l)	50	100	150	200	250	300	350	400	450	500
15	325	375	408	433	453	470	485	499	511	522
20	318	367	399	423	443	460	475	488	500	511
25	313	361	392	416	436	453	467	480	492	503
50	297	343	373	395	414	430	444	456	467	477
100	282	326	354	375	393	408	421	433	444	453
150	274	316	343	364	381	396	409	420	430	440
200	268	309	336	357	373	388	400	411	421	431
250	264	304	331	351	367	381	394	404	414	423
300	260	300	326	346	362	376	388	399	409	418
350	257	297	322	342	358	372	384	394	404	413
400	255	294	319	339	355	368	380	391	400	409
450	252	291	316	336	351	365	377	387	397	405
500	250	289	314	333	349	362	374	384	394	402

(6) The following establishes surface water quality criteria for protection of human health:

Table 8-3
Surface Water Quality Criteria for Protection of Human Health[1]
			Human Noncancer Criteria (HNC)		Human Cancer Criteria (HCC)
CAS Number	Substances		Drinking (μg/l)	Nondrinking (μg/l)	Drinking (μg/l)	Nondrinking (μg/l)
	Metals (total recoverable)
7439976		Mercury (including methylmercury)	0.0018	0.0018
	Organics (total)
71432		Benzene	19	510	12	310
57749		Chlordane	0.0014	0.0014	0.00025	0.00025
108907		Chlorobenzene	470	3,200
50293		DDT	0.002	0.002	0.00015	0.00015
60571		Dieldrin	0.00041	0.00041	6.5 × 10-6	6.5 × 10-6
105679		2,4-dimethylphenol	450	8,700
51285		2,4-dinitrophenol	55	2,800
118741		Hexachlorobenzene	0.046	0.046	0.00045	0.00045
67721		Hexachloroethane	6	7.6	5.3	6.7
58899		Lindane	0.47	0.5
75092		Methylene chloride	1,600	90,000	47	2600
1336363		PCBs (class)			6.8 × 10-6	6.8 × 10-6
1746016		2,3,7,8-TCDD (dioxin)	6.7 × 10-8	6.7 × 10-8	8.6 × 10-9	8.6 × 10-9
108883		Toluene	5,600	51,000
8001352		Toxaphene			6.8 × 10-5	6.8 × 10-5
79016		Trichloroethylene			29	370
	Other Substances
57125		Cyanide (total)	600	48,000
[1]The HNC and HCC are thirty (30) day average criteria.

(7) The following establishes surface water quality criteria for protection of wildlife:

Table 8-4
Surface Water Quality Criteria for Protection of Wildlife[1]
CAS Number	Substances		Wildlife Criteria (μg/l)
	Metals (total recoverable)
7439976		Mercury (including methylmercury)	0.0013
	Organics (total)
50293		DDT and metabolites	1.1 × 10-5
1336363		PCBs (class)	1.2 × 10-4
1746016		2, 3, 7, 8-TCDD (dioxin)	3.1 × 10-9
[1]The WC are thirty (30) day average criteria.

  (c) This subsection establishes minimum surface water quality criteria for aquatic life. In addition to the criteria in subsection (b), this subsection ensures conditions necessary for the maintenance of a well-balanced aquatic community. The following conditions are applicable at any point in the waters outside of the applicable mixing zone, as determined in accordance with section 7 of this rule:

(1) There shall be no substances that:

(A) impart unpalatable flavor to food fish; or

(B) result in offensive odors in the vicinity of the water.

(2) No pH values below six (6.0) or above nine (9.0), except daily fluctuations that:

(A) exceed pH nine (9.0); and

(B) are correlated with photosynthetic activity;

shall be permitted.

(3) Concentrations of dissolved oxygen shall:

(A) average at least five (5.0) milligrams per liter per calendar day; and

(B) not be less than four (4.0) milligrams per liter at any time.

(4) The following are conditions for temperature:

(A) There shall be no abnormal temperature changes that may adversely affect aquatic life unless caused by natural conditions.

(B) The normal daily and seasonal temperature fluctuations that existed before the addition of heat due to other than natural causes shall be maintained.

(C) Water temperatures shall not exceed the maximum limits in the following table during more than one percent (1%) of the hours in the twelve (12) month period ending with any month. At no time shall the water temperature at such locations exceed the maximum limits in the following table by more than three (3) degrees Fahrenheit (one and seven-tenths (1.7) degrees Celsius):

Table 8-5
Maximum Instream Water Temperatures
Month	St. Joseph River Tributary to Lake Michigan Upstream of the Twin Branch Dam °F(°C)	All Other Indiana Streams in the Great Lakes System °F(°C)
January	50 (10)	50 (10)
February	50 (10)	50 (10)
March	55 (12.8)	60 (15.6)
April	65 (18.3)	70 (21.1)
May	75 (23.9)	80 (26.7)
June	85 (29.4)	90 (32.2)
July	85 (29.4)	90 (32.2)
August	85 (29.4)	90 (32.2)
September	84 (29.4)	90 (32.2)
October	70 (21.1)	78 (25.5)
November	60 (15.6)	70 (21.1)
December	50 (10)	57 (14.0)

(D) The following temperature criteria shall apply to Lake Michigan:

(i) In all receiving waters, the points of measurement normally shall be in the first meter below the surface at such depths necessary to avoid thin layer surface warming due to extreme ambient air temperatures, but, where required to determine the true distribution of heated wastes and natural variations in water temperatures, measurements shall be at a greater depth and at several depths as a thermal profile.

(ii) There shall be no abnormal temperature changes so as to be injurious to fish, wildlife, or other aquatic life, or the growth or propagation thereof. In addition, plume interaction with the bottom shall:

(AA) be minimized; and

(BB) not injuriously affect fish, shellfish, and wildlife spawning or nursery areas.

(iii) The normal daily and seasonal temperature fluctuations that existed before the addition of heat shall be maintained.

(iv) At any time and at a maximum distance of a one thousand (1,000) foot arc inscribed from a fixed point adjacent to the discharge or as agreed upon by the commissioner and federal regulatory agencies, the following shall apply:

(AA) The receiving water temperature shall not be more than three (3) degrees Fahrenheit (one and seven-tenths (1.7) degrees Celsius) above the existing natural water temperature.

(BB) Thermal discharges to Lake Michigan shall comply with the following maximum temperature requirements:

(aa) Thermal discharges to Lake Michigan shall not raise the maximum temperature in the receiving water above those listed in the following table, except to the extent the permittee adequately demonstrates that the exceedance is caused by the water temperature of the intake water:

	Table 8-6
	Maximum Water Temperatures
	Month	°F(°C)
	January	45 (7)
	February	45 (7)
	March	45 (7)
	April	55 (13)
	May	60 (16)
	June	70 (21)
	July	80 (27)
	August	80 (27)
	September	80 (27)
	October	65 (18)
	November	60 (16)
	December	50 (10)

(bb) If the permittee demonstrates that the intake water temperature is within three (3) degrees Fahrenheit below an applicable maximum temperature under subitem (aa), Table 8-6, then not more than a three (3) degree Fahrenheit exceedance of the maximum water temperature shall be permitted.

(v) The facilities described as follows that discharge into the open waters of Lake Michigan shall be limited to the amount essential for blowdown in the operation of a closed cycle cooling facility:

(AA) All facilities that have new waste heat discharges exceeding a daily average of five-tenths (0.5) billion British thermal units per hour. As used in this item, "new waste heat discharge" means a discharge that had not begun operations as of February 11, 1972.

(BB) All facilities with existing waste heat discharges that increase the quantity of waste heat discharged by more than a daily average of five-tenths (0.5) billion British thermal units per hour.

(vi) Water intakes shall be designed and located to minimize entrainment and damage to desirable organisms. Requirements may vary depending upon local conditions, but, in general, intakes shall:

(AA) have minimum water velocity; and

(BB) not be located in spawning or nursery areas of important fishes.

Water velocity at screens and other exclusion devices shall also be at a minimum.

(vii) Discharges other than those now in existence shall be such that the thermal plumes do not overlap or intersect.

(viii) Facilities discharging more than a daily average of five-tenths (0.5) billion British thermal units of waste heat shall:

(AA) continuously record intake and discharge temperature and flow; and

(BB) make those records available to the public or regulatory agencies upon request.

(5) The following criteria shall be used to regulate ammonia:

(A) Concentrations of total ammonia (as N) shall not exceed the CMC outside the zone of initial dilution or the final acute value (FAV = 2 (CMC)) in the undiluted discharge unless, for a discharge to a receiving stream or Lake Michigan, an alternate mixing zone demonstration is conducted and approved in accordance with 327 IAC 5-2-11.4(b)(4), in which case, the CMC shall be met outside the applicable alternate mixing zone. The CMC of total ammonia (as N) is determined using the following equation:

Where:	FT	=	100.03(20-T)
	FPH	=	1; when: 8 ≤ pH ≤ 9; or
			; when: 6.5 ≤ pH ≤ 8
	pKa	=
	T	=	Temperature in °C

(B) The CCC of total ammonia (as N) is determined using the following equation:

Where:	FT	=	100.03(20-T)
	FPH	=	1; when: 8 ≤ pH ≤ 9; or
			; when: 6.5 ≤ pH ≤ 8
	RATIO	=	13.5; when: 7.7 ≤ pH ≤ 9; or
			; when: 6.5 ≤ pH ≤ 7.7
	pKa	=
	T	=	Temperature in °C

(C) The use of the equations in clause (A) results in the following CMCs for total ammonia (as N) at different temperatures and pHs:

Table 8-7
Criterion Maximum Concentrations for Total Ammonia (as N) Temperature (°C)
pH	0	5	10	15	20	25	30
6.5	28.48	26.61	25.23	24.26	23.64	23.32	23.29
6.6	27.68	25.87	24.53	23.59	22.98	22.68	22.65
6.7	26.74	24.99	23.69	22.78	22.20	21.92	21.90
6.8	25.64	23.96	22.72	21.85	21.30	21.03	21.01
6.9	24.37	22.78	21.60	20.78	20.26	20.01	20.00
7.0	22.95	21.45	20.35	19.58	19.09	18.86	18.86
7.1	21.38	19.98	18.96	18.24	17.80	17.59	17.60
7.2	19.68	18.40	17.46	16.81	16.40	16.22	16.24
7.3	17.90	16.73	15.88	15.29	14.93	14.78	14.81
7.4	16.06	15.02	14.26	13.74	13.42	13.30	13.35
7.5	14.23	13.31	12.64	12.19	11.92	11.81	11.88
7.6	12.44	11.65	11.07	10.67	10.45	10.37	10.45
7.7	10.75	10.06	9.569	9.238	9.052	9.003	9.088
7.8	9.177	8.597	8.181	7.907	7.760	7.734	7.830
7.9	7.753	7.268	6.924	6.701	6.589	6.584	6.689
8.0	6.496	6.095	5.813	5.636	5.555	5.569	5.683
8.1	5.171	4.857	4.639	4.508	4.457	4.486	4.602
8.2	4.119	3.873	3.707	3.612	3.584	3.625	3.743
8.3	3.283	3.092	2.967	2.900	2.891	2.942	3.061
8.4	2.618	2.472	2.379	2.335	2.340	2.399	2.519
8.5	2.091	1.979	1.911	1.886	1.903	1.968	2.089
8.6	1.672	1.588	1.540	1.529	1.555	1.625	1.747
8.7	1.339	1.277	1.246	1.246	1.279	1.353	1.475
8.8	1.075	1.030	1.011	1.021	1.060	1.137	1.260
8.9	0.8647	0.8336	0.8254	0.8418	0.8862	0.9650	1.088
9.0	0.6979	0.6777	0.6777	0.6998	0.7479	0.8286	0.9521

(D) The use of the equations in clause (B) results in the following CCCs for total ammonia (as N) at different temperatures and pHs:

Table 8-8
Criterion Continuous Concentrations for Total Ammonia (as N) Temperature (°C)
pH	0	5	10	15	20	25	30
6.5	2.473	2.310	2.191	2.106	2.052	2.025	2.022
6.6	2.473	2.311	2.191	2.107	2.053	2.026	2.023
6.7	2.473	2.311	2.191	2.107	2.054	2.027	2.025
6.8	2.473	2.311	2.192	2.108	2.055	2.028	2.027
6.9	2.474	2.312	2.193	2.109	2.056	2.030	2.030
7.0	2.474	2.312	2.193	2.110	2.058	2.033	2.033
7.1	2.475	2.313	2.195	2.112	2.060	2.036	2.037
7.2	2.475	2.314	2.196	2.114	2.063	2.040	2.043
7.3	2.476	2.315	2.198	2.116	2.066	2.044	2.050
7.4	2.477	2.317	2.200	2.119	2.070	2.050	2.058
7.5	2.478	2.319	2.202	2.123	2.075	2.058	2.069
7.6	2.480	2.321	2.206	2.128	2.082	2.067	2.082
7.7	2.450	2.294	2.181	2.106	2.063	2.052	2.071
7.8	2.092	1.959	1.865	1.802	1.769	1.763	1.785
7.9	1.767	1.657	1.578	1.527	1.502	1.501	1.525
8.0	1.481	1.389	1.325	1.285	1.266	1.269	1.295
8.1	1.179	1.107	1.057	1.027	1.016	1.022	1.049
8.2	0.9387	0.8828	0.8450	0.8232	0.8169	0.8263	0.8531
8.3	0.7481	0.7048	0.6762	0.6610	0.6589	0.6705	0.6976
8.4	0.5968	0.5634	0.5421	0.5321	0.5334	0.5468	0.5741
8.5	0.4766	0.4511	0.4357	0.4298	0.4337	0.4485	0.4760
8.6	0.3811	0.3619	0.3511	0.3485	0.3545	0.3704	0.3981
8.7	0.3052	0.2910	0.2839	0.2839	0.2916	0.3083	0.3362
8.8	0.2450	0.2347	0.2305	0.2326	0.2417	0.2591	0.2871
8.9	0.1971	0.1900	0.1881	0.1919	0.2020	0.2199	0.2480
9.0	0.1591	0.1545	0.1545	0.1595	0.1705	0.1889	0.2170

  (d) This subsection establishes surface water quality for cold-water fish. The waters listed in section 5(a)(3) of this rule are designated as salmonid waters and shall be protected for cold-water fish. In addition to subsections (b) and (c), the following criteria are established to ensure conditions necessary for the maintenance of a well-balanced, cold-water fish community and are applicable at any point in the waters outside of the applicable mixing zone:

(1) Dissolved oxygen concentrations shall not be less than:

(A) six (6.0) milligrams per liter at any time; and

(B) seven (7.0) milligrams per liter in areas where spawning occurs during the spawning season and in areas used for imprinting during the time salmonids are being imprinted.

Dissolved oxygen concentrations in the open waters of Lake Michigan shall not be less than seven (7.0) milligrams per liter at any time.

(2) The maximum temperature rise above natural shall not exceed two (2) degrees Fahrenheit (one and one-tenth (1.1) degrees Celsius) at any time or place and, unless due to natural causes, the temperature shall not exceed the following:

(A) Seventy (70) degrees Fahrenheit (twenty-one and one-tenth (21.1) degrees Celsius) at any time.

(B) Sixty-five (65) degrees Fahrenheit (eighteen and three-tenths (18.3) degrees Celsius) during spawning or imprinting periods.

  (e) This subsection establishes bacteriological quality for recreational uses during the recreational season as follows:

(1) The recreational season is defined as the months of April through October, inclusive.

(2) In addition to subsection (b), the criteria in this subsection shall be used to do the following:

(A) Evaluate waters for full body contact recreational uses.

(B) Establish wastewater treatment requirements.

(C) Establish effluent limits during the recreational season.

(3) For full body contact recreational uses, E. coli bacteria shall not exceed the following:

(A) One hundred twenty-five (125) per one hundred (100) milliliters as a geometric mean based on not less than five (5) samples equally spaced over a thirty (30) day period.

(B) Two hundred thirty-five (235) per one hundred (100) milliliters in any one (1) sample in a thirty (30) day period, except that in cases where there are at least ten (10) samples at a given site, up to ten percent (10%) of the samples may exceed two hundred thirty-five (235) cfu or MPN per one hundred (100) milliliters where:

(i) the E. coli exceedances are incidental and attributable solely to E. coli resulting from the discharge of treated wastewater from a wastewater treatment plant as defined at IC 13-11-2-258; and

(ii) the criterion in clause (A) is met.

However, a single sample shall be used for making beach notification and closure decisions.

If a geometric mean cannot be calculated because five (5) equally spaced samples are not available, then the criterion stated in clause (B) must be met.

(4) For demonstrating compliance with wastewater treatment requirements, sanitary wastewater dischargers shall ensure the following:

(A) The concentration of E. coli in the undiluted discharge does not exceed one hundred twenty-five (125) cfu or MPN per one hundred (100) milliliters as a geometric mean of the effluent samples taken in a calendar month.

(B) Not more than ten percent (10%) of all samples when not less than ten (10) samples are taken and analyzed for E. coli in a calendar month exceed two hundred thirty-five (235) cfu or MPN per one hundred (100) milliliters as a daily maximum. Under this clause, the calculation of ten percent (10%) of the samples taken shall be limited to the lowest whole number result.

(5) Effluent limits to implement the criteria in subdivision (3) during the recreational season shall be established in NPDES permits by incorporating the following that are to be applied to the undiluted discharge:

(A) The concentration of E. coli in the undiluted discharge shall not exceed one hundred twenty-five (125) cfu or MPN per one hundred (100) milliliters as a geometric mean of the effluent samples taken in a calendar month.

(B) Not more than ten percent (10%) of all samples in a calendar month exceed two hundred thirty-five (235) cfu or MPN per one hundred (100) milliliters as a daily maximum. Under this clause, the calculation of ten percent (10%) of the samples taken shall be limited to the lowest whole number result.

  (f) This subsection establishes surface water quality for public water supply. In addition to subsection (b), the following criteria are established to protect the surface water quality at the point at which water is withdrawn for treatment for public supply:

(1) The coliform bacteria group shall not exceed the following:

(A) Five thousand (5,000) per one hundred (100) milliliters as a monthly average value (either MPN or MF count).

(B) Five thousand (5,000) per one hundred (100) milliliters in more than twenty percent (20%) of the samples examined during any month.

(C) Twenty thousand (20,000) per one hundred (100) milliliters in more than five percent (5%) of the samples examined during any month.

(2) Taste and odor producing substances, other than those naturally occurring, shall not interfere with the production of a finished water by conventional treatment consisting of the following:

(A) Coagulation.

(B) Sedimentation.

(C) Filtration.

(D) Disinfection.

(3) The concentrations of either chloride or sulfate shall not exceed two hundred fifty (250) milligrams per liter unless due to naturally occurring sources.

(4) The concentration of dissolved solids shall not exceed seven hundred fifty (750) milligrams per liter unless due to naturally occurring sources. A specific conductance of one thousand two hundred (1,200) micromhos per centimeter (at twenty-five (25) degrees Celsius) may be considered equivalent to a dissolved solids concentration of seven hundred fifty (750) milligrams per liter.

(5) Surface waters shall be considered acceptable for public water supply if radium-226 and strontium-90 are present in amounts not exceeding three (3) and ten (10) picocuries per liter, respectively. In the known absence of strontium-90 and alpha emitters, the water supply is acceptable when the gross beta concentrations do not exceed one thousand (1,000) picocuries per liter.

(6) The:

(A) combined concentration of nitrate-N and nitrite-N shall not exceed ten (10) milligrams per liter; and

(B) concentration of nitrite-N shall not exceed one (1) milligram per liter.

(7) Chemical constituents in the waters shall not be present in such levels as to prevent, after conventional treatment, meeting the drinking water standards contained in 327 IAC 8-2, due to other than natural causes.

  (g) This subsection establishes surface water quality for industrial water supply. In addition to subsection (b), the criterion to ensure protection of water quality at the point at which water is withdrawn for use (either with or without treatment) for industrial cooling and processing is that, other than from naturally occurring sources, the dissolved solids shall not exceed seven hundred fifty (750) milligrams per liter at any time. A specific conductance of one thousand two hundred (1,200) micromhos per centimeter (at twenty-five (25) degrees Celsius) may be considered equivalent to a dissolved solids concentration of seven hundred fifty (750) milligrams per liter.

  (h) This subsection establishes surface water quality for agricultural uses. The criteria to ensure water quality conditions necessary for agricultural use are the same as those in subsection (b).

  (i) This subsection establishes surface water quality for limited uses. The quality of waters designated for limited uses under section 19(a) of this rule shall, at a minimum, meet the following criteria:

(1) The criteria contained in subsection (b).

(2) The criteria contained in subsection (e).

(3) The criteria contained in subsection (g).

(4) The waters must be aerobic at all times.

(5) Notwithstanding subdivisions (1) through (4), the quality of a limited use stream at the point where it becomes physically or chemically capable of supporting a higher use or at its interface with a higher use water segment shall meet the criteria that are applicable to the higher use water.

  (j) Additional requirements for the open waters of Lake Michigan are as follows:

(1) In addition to complying with all other applicable subsections, open waters in Lake Michigan shall meet the following criteria:

Table 8-9
Additional Criteria for Lake Michigan
Parameters	Criteria
Dissolved oxygen	Dissolved oxygen concentrations shall not be less than seven (7.0) milligrams per liter at any time at all places outside the applicable mixing zone.
pH	No pH values below six (6.0) or above nine (9.0), except daily fluctuations that exceed pH 9.0 and are correlated with photosynthetic activity, shall be permitted.
Chloride	250 mg/l[1]
Phenols	See subsection (c)(1)
Sulfate	250 mg/l[1]
Total phosphorus	See 327 IAC 5-10-2
Total dissolved solids	750 mg/l[1]
Fluoride	1.0 mg/l[1]
Dissolved iron	300 μg/l[1]
[1] This criterion is established to minimize or prevent increased levels of this substance in Lake Michigan. For the purposes of establishing water quality-based effluent limitations based on this criterion, it shall be treated as a four (4) day average criterion.

(2) During each triennial review of the water quality standards, prior to preliminary adoption of revised rules, the department shall prepare a report for the water pollution control board on the monitoring data for the constituents in the following table (Table 8-10), as measured at the drinking water intakes in Lake Michigan. If these data indicate that the levels of the constituents are either increasing or exceed the levels in the table, the report shall provide available information on the known and potential causes of the increased levels of these parameters, the known and potential impacts on aquatic life, wildlife, and human health, and any recommended revisions of the criteria.

	Table 8-10
	Parameters		Levels
	pH		7.5-8.5 s.u.
	Chloride
		Monthly average	15 mg/l
		Daily maximum	20 mg/l
	Sulfate
		Monthly average	26 mg/l
		Daily maximum	50 mg/l
	Total phosphorus
		Monthly average	0.03 mg/l
		Daily maximum	0.04 mg/l
	Total dissolved solids
		Monthly average	172 mg/l
		Daily maximum	200 mg/l

(Water Pollution Control Division; 327 IAC 2-1.5-8; filed Jan 14, 1997, 12:00 p.m.: 20 IR 1370; errata filed Aug 11, 1997, 4:15 p.m.: 20 IR 3376; filed Feb 14, 2005, 10:05 a.m.: 28 IR 2074; errata filed Apr 6, 2006, 2:48 p.m.: 29 IR 2546; filed Mar 18, 2008, 2:26 p.m.: 20080416-IR-327060573FRA; filed Jul 9, 2012, 2:54 p.m.: 20120808-IR-327110320FRA)