2010-11-03_HYDROLOGY - C1982056 ‎(4)‎

• Permit No: C1982056
• IBM Index Class Name: HYDROLOGY
• Doc Date: 11/3/2010
• Doc Name: 3rd Qtr 2010 DMR ‎(CO0036684)‎
• From: Twentymile Coal Company
• To: DRMS
• 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
?` r v [phone] aqua-tox.com

ACUTE TOXICITY REPORT
Cerioda hnia dubia
CLIENT NAME: 20-Mile Coal Company SAMPLE I.D.: 093010-1
50 % MORTALITY TEST: Pass TEST RESULT LC50: >>100%
% SURVIVAL IN 100% DILUTION: 85%
SAMPLE DATE: 09-29-10 TIME: 13:30P CLIENT ID: Site 62
ORGANISM: Ceriodaphnia dubia AGE: < 24 hours old
TEST START: 09-30-10 13:40P TEST FINISH: 10-02-10 13:40P
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: 97.22 mg/L CHLORINE: ND _
ALKALINITY: 58.47 mg/L TEMPERATURE: 19.6 deg C
- - -pH: -- 8:03
SURVIVAL DATA DILUTIONS (%)
DATE (HOURS) CONTROL 6.25 12.5 25 50 75 100
9/30/2010 INITIAL 20 20 20 20 20 20 20
10/l/2010 24 20 20 20 20 20 20 19
10/2/2010 48 20 20 20 20 20 20 17
MORTALITY: 0 0 0 0 0 0 3
% SURVIVAL: 100% 100% 100% 100% 100% 100% 85%
DAILY CHEMISTRY - (MIN/MAX) DILUTIONS (%)
0 6.25 12.5 25 50 75 100
CONDUCTIVITY (microS) 311/331 505/536 947/975 145811486 202012070 2790/2830 347013520
D.O. (mg/L) 7.0/7.3 7.117.3 7.2/7.3 7.3/7.3 7.3/7.4 7.4/7.4 7.4/7.5
pH 8.0/8.4 8.0/8.3 7.9/8.3 7.9/8.4 7.8/8.5 7.8/8.6 7.7/8.7
TEMPERATURE (deg C) 19.6/20.0 19.6/20.0 19.6/20.0 19.6/20.0 19.6/20.0 19.6120.0 19.6/20.0
GENERAL CHEMISTRY - SAMPLE
AMMONIA: 0.22 mg/L D.O.: 7.48 mg/L
HARDNESS: 2,006.01 mg/ L CHLORINE: ND
ALKALINITY: 611.70 mg/L TEMPERATURE: 19.6 deg C
pH: 7.74 D.O AFTER AERATION: NA
ANOEC CALCULATION METHOD METHOD REFERENCE
75% SPEARMAN-KARBER EPA -821-R-02-012 October 2002 pg.78
ADDITIONAL COMMENTS:
Analysis
Conducted by: Reviewed by,
Date: - - (C, Dat . '`/, rc ,? 11 1
Al/_ 7
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