No problems were encountered during analysis of this workorder, except if noted in this report.

REVISED REPORT: Due to a calculation error, the trivalent chromium value changed.

Note: This is a reissue of a previously generated report. Information herein supersedes that of previously

issued report(s).

2005 N. Center Ave.

Somerset PA 15501

814-443-1671

814-445-6666

FAX:814-445-6729

Client: GenOn ENERGY INC. - KEYSTONE STATION

Project: Keystone 611 M(b) CASE NARRATIVE

Lab Order: G1403388

Legend: ND - Not Detected at the Quantitation Limit S - Spike Recovery outside accepted recovery limits

J - Indicates an estimated value R - RPD outside accepted recovery limits

U - The analyte was not detected at or above the listed E - Value above quantitation range

concentration, which is below the laboratory quantitation limit ** - Value exceeds Action Limit

B - Analyte detected in the associated Method Blank H - Method Hold Time Exceeded

Q - Qualifier QL - Quantitation Limit DF - Dilution Factor MCL - Contaminant Limit

Page 1 of 3
Physical Tests SM 2540D Analyst: KLS

 Total suspended solids 6 1 mg/L 1 03/11/2014 12:45

Inorganic Non-Metals SM 2540 C Analyst: KLS

 Total dissolved solids 27700 20 mg/L 1 03/11/2014 12:46

Indicator Organic Parameters SM 5210 B Analyst: MMR

 BOD 5-day < 2 2 mg/L 1.5 03/12/2014 06:26

Inorganic Non-Metals USGS I-1187-85 Analyst: CLS

 Chloride 17700 1000 mg/L 200 03/17/2014 12:23

Inorganic Metals EPA 200.8 Analyst: RXS

 Selenium, dissolved 0.020 0.001 mg/L 1 03/24/2014 16:04

Inorganic Metals EPA 200.8 Analyst: RXS

 Arsenic 0.002 0.001 mg/L 1 03/19/2014 19:01

 Chromium < 0.005 0.005 mg/L 1 03/19/2014 19:01

 Nickel 0.0051 0.0005 mg/L 1 03/19/2014 19:01

 Selenium 0.021 0.001 mg/L 1 03/14/2014 20:27

Inorganic Metals EPA 200.7 Analyst: GMG

 Iron, dissolved < 0.05 0.05 mg/L 1 03/13/2014 19:42

Inorganic Metals SM 3112B Analyst: RXS

 Mercury < 0.0002 0.0002 mg/L 1 03/17/2014 12:57

Inorganic Metals EPA 200.7 Analyst: GMG

 Aluminum < 0.1 0.1 mg/L 1 03/13/2014 19:39

 Beryllium < 0.001 0.001 mg/L 1 03/14/2014 15:32

 Boron 279 2.50 mg/L 50 03/14/2014 14:40

 Cadmium 0.003 0.002 mg/L 1 03/13/2014 19:39

 Copper < 0.01 0.01 mg/L 1 03/13/2014 19:39

Laboratory Results

2005 N. Center Ave.

Somerset PA 15501

814-443-1671

814-445-6666

FAX:814-445-6729

Client: GenOn ENERGY INC. - KEYSTONE STATION Client Sample ID: Outfall 101

Lab Order: G1403388

Project: Keystone 611 M(b) Sampled By: NRG

Lab ID: G1403388-001 Collection Date: 03/10/2014 09:15

Matrix: Aqueous Received Date: 03/10/2014 17:23

Analyses Result QL Q Units DF Date Analyzed

Page 2 of 3
 Iron 0.07 0.05 mg/L 1 03/13/2014 19:39

 Lead < 0.02 0.02 mg/L 1 03/13/2014 19:39

 Manganese 21.7 0.01 mg/L 1 03/13/2014 19:39

 Silver < 0.005 0.005 mg/L 1 03/13/2014 19:39

 Zinc < 0.01 0.01 mg/L 1 03/13/2014 19:39

Trivalent Chromium EPA 200.7/I-1230-85 Analyst: LAN

 Trivalent Chromium < 0.02 0.02 mg/L 1 03/21/2014 00:00

Indicator Organic Parameters EPA 1664 Analyst: MTM

 Oil & Grease < 5 5 mg/L 1.03 03/17/2014 17:22

 NOTES:

 S - Spike recovery indicates a possible matrix effect. The

method is in control as indicated by the LCS.

Laboratory Results

2005 N. Center Ave.

Somerset PA 15501

814-443-1671

814-445-6666

FAX:814-445-6729

Client: GenOn ENERGY INC. - KEYSTONE STATION Client Sample ID: Outfall 101

Lab Order: G1403388

Project: Keystone 611 M(b) Sampled By: NRG

Lab ID: G1403388-001 Collection Date: 03/10/2014 09:15

Matrix: Aqueous Received Date: 03/10/2014 17:23

Analyses Result QL Q Units DF Date Analyzed

Page 3 of 3