2021-05-18_HYDROLOGY - C1981019

• Permit No: C1981019
• IBM Index Class Name: Hydrology
• Doc Date: 5/18/2021
• Doc Name: Correspondence
• From: Tri-State Generation and Transmission Association, Inc.
• To: DRMS
• Email Name: ZTT
• Email Name: JDM
• Media Type: D
• Archive: No

DocuSign Envelope ID: D07924E6-3D94-4398-A066-B683COBAB33E
4.5 Pimephales promelas Chronic Toxicity Test
TEST: 7-day chronic with Pimephales promelas OPERATORS: JW, AW, TE, CL
Start: 11/5/20 13:00
End: 11/12/20 12:00
Test Substance: 0.5 g ethanol/g SO4-treated Effluent
Client/Project: Elk Ridge Mining and Reclamation, LLC
Table 13: Summary results of P.promelas chronic toxicity test.
Treatment 0 100
%Treated Effluent
#alive/#exposed 38/40 29/40
%survival 95 72.5
Dry weight(mean wt. (mg)/ 0.388 0.197
#exposed±SD) ±0.040 ±0.064
Dissolved 02 range 6_1 5_4
(mg/L) 5.5 3.6
pH range(SU) 8_1 8_9
7.9 8.6
Conductivity range 401 4500
(pmho/cm) 341 3860
Temperature range(°C) 25.0 25.0
21.3 21.1
Statistical Analysis:
Survival:
(Equal Variance t Two-Sample) = No significant effects (Pass)
Growth:
(Equal Variance t Two-Sample) = Significant effects (Fail) )
GEI Consultants,Inc. 15 February 2021
Ecological Division Whole Effluent Toxicity Test Report
Stantec-Elk Ridge Mining and Reclamation,LLC