Pennsylvania Code › Title 25 - ENVIRONMENTAL PROTECTION › Part I - Department of Environmental Protection › Subpart C - Protection of Natural Resources › Article II - Water Resources › Chapter 93 - WATER QUALITY STANDARDS › WATER QUALITY CRITERIA › Section 93.7 - Specific water quality criteria

Current through Register Vol. 54, No. 28, July 13, 2024
(a)
						Table 3 displays specific water quality criteria and associated critical uses.
						The criteria associated with the Statewide water uses listed in §
												93.4, Table 2 apply to all surface
						waters, unless a specific exception is indicated in §§
												93.9a-93.9z. These exceptions will be
						indicated on a stream-by-stream or segment-by-segment basis by the words "Add"
						or "Delete" followed by the appropriate symbols described elsewhere in this
						chapter. Other specific water quality criteria apply to surface waters as
						specified in §§
												93.9a-93.9z. All applicable criteria
						shall be applied in accordance with this chapter, Chapter 96 (relating to water
						quality standards implementation) and other applicable State and Federal laws
						and regulations.
TABLE 3
Parameter
Symbol
Criteria
Critical Use*
Alkalinity
Alk
Minimum 20
									 mg/l as CaCO3, except where natural conditions are less.
									 Where discharges are to waters with 20 mg/l or less alkalinity, the discharge
									 should not further reduce the alkalinity of the receiving waters.
CWF,
									 WWF, TSF, MF
Ammonia Nitrogen
Am
In
									 freshwater, the concentration of total ammonia nitrogen (TAN) shall not exceed
									 (more than once in three years on average), the concentration calculated (in
									 milligrams of TAN per liter) by the following: 1-hour average Criteria Maximum
									 Concentration (CMC) acute criterion equation:
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										image
30-day rolling average Criteria Continuous Concentration
									 (CCC) chronic criterion equation:
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										image
The highest 4-day average within the 30-day averaging
									 period should not be more than 2.5 times the CCC (e.g. 2.5 x 0.2 mg TAN/L at pH
									 9 and 20°C or 0.5 mg TAN/L) more than once in 3 years on average.
CWF, WWF, TSF, MF
The pH and temperature used to derive the
									 appropriate ammonia criteria shall be determined by instream measurements or
									 best estimates, based on reference waters that are representative of the median
									 pH and temperature of the receiving water. Instream measurements for pH and
									 temperature will be gathered using department data collection protocols.
Bacteria
Bac1
(Escherichia coli colony forming units per 100 milliliters (CFU per
									 100 ml)) During the swimming season (May 1 through September 30), the maximum
									 E. coli level shall be a geometric mean of 126 CFU per 100 ml. The geometric
									 mean for the samples collected in the waterbody should not be greater than 126
									 CFU per 100 ml in any 30-day interval. There should not be greater than a 10%
									 excursion frequency of 410 CFU per 100 ml for the samples collected in the same
									 30-day duration interval. (Fecal coliforms/100 ml) For the remainder of the
									 year, the maximum fecal coliform level shall be a geometric mean of 2,000 CFU
									 per 100 ml based on a minimum of five consecutive samples collected on
									 different days during a 30-day period.
WC
Chloride
Ch
Maximum 250 mg/l.
PWS
Color
Col
Maximum 75 units on
									 the platinum-cobalt scale; no other colors perceptible to the human
									 eye.
PWS
Dissolved Oxygen
The following
									 specific dissolved oxygen criteria recognize the natural process of
									 stratification in lakes, ponds and impoundments. These criteria apply to
									 flowing freshwater and to the epilimnion of a naturally stratified lake, pond
									 or impoundment. The hypolimnion in a naturally stratified lake, pond or
									 impoundment is protected by the narrative water quality criteria in §
																	93.6 (relating to general water
									 quality criteria). For nonstratified lakes, ponds or impoundments, the
									 dissolved oxygen criteria apply throughout the lake, pond or impoundment to
									 protect the critical uses.
DO1
For flowing
									 waters, 7-day average 6.0 mg/l; minimum 5.0 mg/l. For naturally reproducing
									 salmonid early life stages, applied in accordance with subsection (b), 7-day
									 average 9.0 mg/l; minimum 8.0 mg/l. For lakes, ponds and impoundments, minimum
									 5.0 mg/l.
CWF
DO2
7-day
									 average 5.5 mg/l; minimum 5.0 mg/l.
WWF
DO3
For the
									 period February 15 to July 31 of any year, 7-day average 6.0 mg/l; minimum 5.0
									 mg/l. For the remainder of the year, 7-day average 5.5 mg/l; minimum 5.0 mg/l.
TSF
Fluoride
F
Daily average 2.0
									 mg/l.
PWS
Iron
Fe1
30-day average 1.5 mg/l as total recoverable.
CWF, WWF, TSF,
									 MF
Fe2
Maximum 0.3
									 mg/l as dissolved.
PWS
Manganese
Mn
Maximum 1.0
									 mg/l, as total recoverable.
PWS
Nitrite plus Nitrate
N
Maximum 10 mg/l as nitrogen.
PWS
Osmotic Pressure
OP
Maximum
									 50 milliosmoles per kilogram.
CWF, WWF, TSF, MF
pH
pH
From 6.0 to 9.0
									 inclusive.
CWF, WWF, TSF, MF
Phenolics (except § 307(a)(1)
									 (33 U.S.C.A. §
																		1317(a)(1)), Priority
									 Pollutants)
Phen
Maximum 0.005 mg/l.
PWS
Sulfate
Sul
Maximum 250 mg/l.
PWS
Temperature
Maximum temperatures in
									 the receiving water body resulting from heated waste sources regulated under
									 Chapters 92a, 96 and other sources where temperature limits are necessary to
									 protect designated and existing uses.
See the following table.
SYMBOL: CRITICAL USE:
									 PERIOD
TEMP1
									 CWF
TEMP2 WWF
									 TEMPERATURE °F
TEMP3
									 TSF
January 1-31
38
40
40
February 1-29
38
40
40
March 1-31
42
46
46
April 1-15
48
52
52
April 16-30
52
58
58
May 1-15
54
64
64
May 16-31
58
72
68
June 1-15
60
80
70
June 16-30
64
84
72
July 1-31
66
87
74
August 1-15
66
87
80
August 16-30
66
87
87
September 1-15
64
84
84
September 16-30
60
78
78
October 1-15
54
72
72
October 16-31
50
66
66
November 1-15
46
58
58
November 16-30
42
50
50
December 1-31
40
42
42
Parameter
Symbol
Criteria
Critical Use*
Total Dissolved Solids
TDS
500 mg/l as a monthly average value; maximum
									 750 mg/l.
PWS
Total Residual Chlorine
TRC
Four-day average 0.011 mg/l; 1-hour average
									 0.019 mg/l.
CWF, WWF, TSF, MF
* Critical Use: The designated or existing use the
						  criteria are designed to protect. More stringent site-specific criteria may be
						  developed to protect other more sensitive, intervening uses.
(b) For naturally reproducing salmonids,
						protected early life stages include embryonic and larval stages and juvenile
						forms to 30 days after hatching. The DO1 standard for
						naturally reproducing salmonid early life stages applies October 1 through May
						31. The DO1 standard for naturally reproducing salmonid
						early life stages applies unless it can be demonstrated to the Department's
						satisfaction, that the following conditions are documented:
1) the absence of young of the year salmonids
						measuring less than 150 mm in the surface water; and
2) the absence of multiple age classes of
						salmonids in the surface water. These conditions only apply to salmonids
						resulting from natural reproduction occurring in the surface waters. Additional
						biological information may be considered by the Department which evaluates the
						presence or absence of early life stages.