2018-03-01_HYDROLOGY - C1981010 ‎(2)‎

• Permit No: C1981010
• IBM Index Class Name: Hydrology
• Doc Date: 3/1/2018
• Doc Name: CDPS/NPDES Permit
• From: Department of Public Health & Environment
• To: DRMS
• Permit Index Doc Type: NPDES
• Email Name: RAR
• Media Type: D
• Archive: No

COLORADO
M1) ' Department of Public
Health b Environment
Water Quality Assessment
Table A-12
Ambient Water Quality Data Summary for AD Period Outfall 025
Parameter
Number of
Samples
15th
Percentile
50th 85th
Percentile Percentile
Mean Location
As, Dis (pg/1)
4
0
0 0.19
0.085 Upstream
As, TR (pg/1)
1
2
2 2
2 Upstream
Cd, Dis (pg/1)
24
0
0 0
0.00075 Upstream
Cr+3, TR (pg/1)
0
0
0 0
0 No Data
Cr+3, Dis (pg/1)
3
0
0 0
0 Upstream
Cu, Dis (pg/l)
5
0
0 6
3 Upstream
Pb, Dis (pg/1)
24
0
0.031 0.095
0.039 Upstream
Mn, Dis (pg/1)
30
10
17 23
20 Upstream
Hg, Tot (pg/1)
0
0
0 0
0 No Data
Ni, Dis (pg/1)
3
0
0 1.4
0.67 Upstream
Se, Dis (pg/1)
24
0.049
0.2 0.77
0.44 Upstream
Zn, Dis (pg/l)
24
0
0 3.9
1.7 Upstream
Table A-13
BWQ Concentrations for Outfall 025, Not Existing Prior to September 30, 2000
Pollutant
Meff
Qeff (cfs)
I M„/,
Qu,s (cfs)
BWQ
WQS
Aquatic Life Parameters
As, Dis (pg/1) 0.19 340
Cd, Dis (pg/1) 0 1.2
Cr+3, Dis (pg/1) - 0 231
Cu, Dis (pg/1) - - 6 29
Pb, Dis (pg/l) 0.095 11
Mn, Dis (pg/() 23 1772
Ni, Dis (pg/1) - - 1.4 168
Se, Dis (pg/l) 0.77 4.6
Zn, Dis (pg/l) - 3.9 428
Human Health Parameters
As, TR (pg/1)
-
2
0.02
Cr+3, TR (pg/1)
-
No Data
50
Hg, Tot (pg/()
No Data
0.01
In cases where the BWQ concentration exceeds the water quality standard, the calculated BWQ concentration
must then be set equal to the water quality standard. This occurred for total recoverable arsenic.
Bioaccumulative Significance Test
Pae 34 of 40 .
4300 Cherry Creek Drive S., Denver, CO 80246-1530 303-692-2000 www.colorado.gov/cdphe/wqcd I ��