2011-02-02_HYDROLOGY - C1982056 ‎(6)‎

• Permit No: C1982056
• IBM Index Class Name: HYDROLOGY
• Doc Date: 2/2/2011
• Doc Name: 4th Quarter 2010 DMRS ‎(CO-0027154)‎
• From: Twentymile Coal Company
• To: WQCD
• Permit Index Doc Type: DMR’s
• Email Name: JDM
• Media Type: D
• Archive: No

Aqua-Tox, Inc.
4880 Robb Street, Suite 8
Wheat Ridge, CO 80033
== [phone] aqua-tox.com
ACUTE TOXICITY REPORT
Daphnia magna

CLIENT NAME: 20-Mile Coal Company SAMPLE I.D.: 111610-1
50 % MORTALITY TEST: _Pass TEST RESULT LC50: _>100%
% SURVIVAL IN 100% DILUTION: 55%
SAMPLE DATE: 11-15-10 TIME: 15:OOP CLIENT ID: Site 84
ORGANISM: Daphnia magna AGE: < 24 hours old
TEST START: 11-16-10 13:30P TEST FINISH: 11-18-10 13:30P
TYPE OF TEST: LC50, 48 hours, static, renewal, moderately hard fresh synthetic dilution water.

MODERATELY HARD FRESH SYNTHETIC DILUTION WATER CONSTITUENT
AMMONIA: ND D.O.: 6.94 mg/L
HARDNESS: 98.91 mg/L CHLORINE: ND
ALKALINITY: 58.26 mg/L TEMPERATURE: 19.5 deg C
pH: 8.04

SURVIVAL DATA DILUTIONS (%)
DATE HOURS CONTROL 6.25 12.5 25 50 75 100
11/16/2010 INITIAL 20 20 20 20 20 20 20
11/17/2010 24 .20 20 19 20 20 17 15
11/18/2010 48 20 20 19 20 20 17 11
MORTALITY: _ 0 0 1 0 0 3 9
% SURVIVAL: 100% 100% 95% 100% 100% 85% 55%
DAILY CHEMISTRY - (MIN/MAX) DILUTIONS (%)
0 6.25 12.5 25 50 75 100
CONDUCTIVITY (micros) 323/329 1127/1143 2010/2030 2920/2950 3830/3860 4340/4370 6770/6800
D.O. (mg/L) 6.0/7.4 7.0/7.4 7.0/7.4 7.1/7.4 7.2/7.4 73/7.4 7.4/7.4
pH 8.0/8.4 8.1/8.6 8.2/8.7 8.3/8.8 8.4/8.9 8.5/9.0 8.6/9.1
TEMPERATURE (deg C) 19.5/20.1 19.5/20.1 19.5/20.1 19.5/20.1 19.5/20.1 19.5/20.1 19.5/20.1
GENERAL CHEMISTRY - SAMPLE
AMMONIA: ND D.O.: 8.13 mg/L
HARDNESS: 631.63 mg/L CHLORINE: _ ND
ALKALINITY: 641.00 mg/L TEMPERATURE: 19.5 deg C
pH: 8.64 D.O AFTER AERATION: NA
ANOEC CALCULATION METHOD METHOD REFERENCE
50% SPEARMAN-KARBER EPA -821-R-02-012 October 2002 pg.78
ADDITIONAL COMMENTS:
Analysis_
Conducted by: Reviewed bye
Date: r/-2r-t0 Dat ,? z, ,o