2010-02-01_HYDROLOGY - C1982056

• Permit No: C1982056
• IBM Index Class Name: HYDROLOGY
• Doc Date: 2/1/2010
• Doc Name: 4th Quarter 2009 DMRS ‎(CO-0036684)‎
• From: Twentymile Coal Company
• To: WQCD
• Permit Index Doc Type: DMR’s
• Email Name: JHB
• Media Type: D
• Archive: No

Aqua-Tox, Inc.
4880 Robb Street, Suite 8
Wheat Ridge, CO 80033
[phone] aqua-tox.com
ACUTE TOXICITY REPORT
Pimephales prome/as - Fathead Minnow
CLIENT NAME: Twentymile Coal Company SAMPLE I.D.: 101509-6
50 % MORTALITY TEST: Pass TEST RESULT LC50: >100%
% SURVIVAL IN 100% DILUTION: 65%
SAMPLE DATE: 10-14-09 TIME: 15:OOPM CLIENT ID: Site 62
ORGANISM: Fathead Minnow AGE: DOH 10-10-09
TEST START: 10-15-09 11:55AM TEST FINISH: 10-19-09 11:55AM
TYPE OF TEST: LC50, 96 hours, static, renewal, moderately hard fresh synthetic dilution water.
MODERATELY HARD FRESH SYNTHETIC DILUTION WATER CONSTITUENT
AMMONIA: ND D.O.: 7.06 mg/L
HARDNESS: 92.00 mg/L CHLORINE: ND
ALKALINITY: 54.42 mg/L TEMPERATURE: 19.7 deg C
pH: 8.10
SURVIVAL DATA DILUTIONS (%)
DATE (HOURS)CONTROL 6.25 12.5 25 50 75 100
10/15/2009 INITIAL
10/16/2009 24
10/17/2009 48
10/18/2009 72
10/19/2009 96
MORTALITY:
% S URVIVAL:
20 20 20 20 20 20 20
20 20 20 20 20 20 19
20 20 20 20 20 20 16
20 20 20 20 20 19 16
20 20 20 20 20 19 13
0 0 0 0 0 1 7
100% 100% 100% 100% 100% 95% 65%
DAILY CHEMISTRY - (MIN/MAX) DILUTIONS (%)
CONTROL 6.25 12.5 25 50 75 100
CONDUCTIVITY (micros) 314/348 638/645 955/983 1501/1522 2660/2710 3610/3640 4430/4520
D.O. (mg/L) 5.7/7.1 5.7/7.1 5.7/7.2 5.8/7.4 5.9/7.7 5.8/8.2 5.8/8.6
pH 7.5/8.1 7.6/8.1 7.7/8.1 8.0/8.2 8.0/8.3 7.9/8.1 7.8/7.9
TEMPERATURE (deg C) 19.7/20.4 19.7/20.4 19.7/20.4 19.7/20.4 19.7/20.4 19.7/20.4 19.7/20.4
GENERAL CHEMISTRY - SAMPLE
AMMONIA: ND D.O.: 8.61 mg/L
HARDNESS: 2618.00 mg/L CHLORINE: ND
ALKALINITY: 451.19 mg /L TEMPERATURE: 19.7 deg C
pH: 7.94 D.O AFTER AERATION: NA
ANOEC'"' CALCULATION ;METHOD METHODREFERENCE
75% SPEARMAN-KARBER EPA -821-R-02-012 October 2002 pg.78
ADDITIONAL COMMENTS:
Analysis
Conducted by: Reviewed by:
Date: Date: ra z.