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HomeMy WebLinkAboutSuWa289sec5-5-suppl  Alaska Resources Library & Information Services  Susitna‐Watana Hydroelectric Project Document  ARLIS Uniform Cover Page  TK 1425 .S8 S92 no.289 sec.5.5 suppl. Title: SuWa 289  Baseline water quality study, Study plan Section 5.5, Supplement to the Study Completion Report Author(s) – Personal: Author(s) – Corporate: URS Corporation Tetra Tech, Inc. AEA‐identified category, if specified: October 24, 2016; AEA technical memoranda filings AEA‐identified series, if specified:  Series (ARLIS‐assigned report number): Existing numbers on document: Susitna-Watana Hydroelectric Project document number 289 Published by: Date published:  [Anchorage : Alaska Energy Authority, 2016] October 2016 Published for: Date or date range of report:  Alaska Energy Authority Volume and/or Part numbers: Final or Draft status, as indicated: Study plan Section 5.5 Document type: Pagination: Errata ii, 22 pages Related work(s): Pages added/changed by ARLIS: see below Notes: This document represents: Supplement to: Baseline water quality study, Study plan Section 5.5, Study Completion Report. (SuWa 289) Attachment 2 of: Response of the Alaska Energy Authority to Comments on the Initial Study Report. (SuWa 299) All reports in the Susitna‐Watana Hydroelectric Project Document series include an ARLIS‐ produced cover page and an ARLIS‐assigned number for uniformity and citability.  All reports  are posted online at http://www.arlis.org/susitnadocfinder/    Susitna-Watana Hydroelectric Project (FERC No. 14241) Baseline Water Quality Study Study Plan Section 5.5 Supplement to the Study Completion Report Prepared for Alaska Energy Authority Prepared by URS Corporation/Tetra Tech, Inc. October 2016 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page i October 2016 TABLE OF CONTENTS 1. Introduction ........................................................................................................................1 2. Tables ..................................................................................................................................1 LIST OF TABLES Table 1-1. Descriptions of updates to text and tables in Study 5.5 SCR and ISR Part B, Attachment 1, Initial Study Report or Study Completion Report ........................................... 1 Table 4.1-1. Susitna River Basin Temperature and Water Quality Monitoring Sites (Revised SCR Table 4.1-1.) ................................................................................................................... 5 Table 4.3-1. Sample Location and Frequency for Monthly Baseline Water Quality Sampling (Revised SCR Table 4.3-1) ..................................................................................................... 8 Table 6.1-1 Historic (1980s) and Current (2013 - 2014) Field Parameters (Revised SCR Table 6.1-1) ..................................................................................................................................... 12 Table 6.1-2. Ranges in Historic (1980s) and Current (2013 – 2014) Water Quality Monitoring Data (Revised SCR Table 6.1-2) .......................................................................................... 14 Table 6.1-3 Historic (1980s) and Current (2013 – 2014) Total Metals (Revised SCR Table 6.1-3) ............................................................................................................................................... 16 Table 6.1-4. Historic (1980s) and Current (2013 – 2014) Dissolved Metals (Revised SCR Table 6.1-4) ..................................................................................................................................... 19 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page ii October 2016 LIST OF ACRONYMS AND SCIENTIFIC LABELS ABBREVIATION DEFINITION AEA Alaska Energy Authority FERC Federal Energy Regulatory Commission ISR Initial Study Report PRM Project River Mile Project Susitna-Watana Hydroelectric Project, FERC No. 14241 RSP Revised Study Plan SCR 2014-2015 Study Completion Report TM Technical Memorandum TWG Technical Workgroup SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 1 October 2016 1. INTRODUCTION On November 24, 2015, the Alaska Energy Authority (AEA) filed with the Federal Energy Regulatory Commission (FERC) a Study Completion Report (SCR) for the Baseline Water Quality Study, Study Plan Section 5.5, for the proposed Susitna-Watana Hydroelectric Project, FERC Project No. 14241 (Project). In addition, AEA presented the results of Study 5.5 at that Initial Study Report March 23, 2016 meeting and filed the meeting summary. The purpose of this document is to submit revised information pertaining to that SCR. In June 2016, FERC, NMFS, USFWS, SRC et al., TNC, and Becky Long filed comments and requests for clarification or additional information in response to the Study 5.5 SCR. During development of the response to these comments, AEA noted inconsistencies in naming conventions (e.g., sample sites), locations (e.g., project river miles), description of water features sampled (e.g., main channel, off-channel, and tributary), and in transferring historical data (dissolved metals) in the 2014 SCR. Revisions were made as described in this document to accurately reflect the data that was collected and to update presentation of the data in the SCR filed November 24, 2015. This supplement to Study 5.5 SCR describes updates in text and tables based on reviewer comments from licensing participants. Table 1-1 describes specific updates that have been made in the Study 5.5 SCR and the ISR Part B, Attachment 1 QAPP by referencing the location of the updates to the document, accompanied by a detailed description of the update. Tables 4.1-1, 4.3- 1, 6.1-1, 6.1-2, 6.1-3, and 6.1-4 are updated versions that replace the corresponding original tables from the Study 5.5 SCR. Only in Table 6.1-4 were revisions made to actual values of water quality parameters reported in the SCR, all of which pertained to historical dissolved metals data and corrected transposition errors associated with some of the historical data. 2. TABLES Table 1-1. Descriptions of updates to text and tables in Study 5.5 SCR and ISR Part B, Attachment 1, Initial Study Report or Study Completion Report Reference Description ISR Part B – Attachment 1 (QAPP), Section A.5.2, Page 16, Paragraph 1 The statement “The ADEC limit for mercury in fish tissue that protects human health consumption is 0.3 mg/kg.” is incorrect. ADEC should be updated to “Alaska Division of Public Health”. The sentence should read: “The Alaska Division of Public Health limit for mercury in fish tissue that protects human health consumption is 0.3 mg/kg.” SCR Section 5.4.9, Page 25, Paragraph 2; SCR Section 6.2, Page 31, Paragraph 2; SCR Section 9, Page 49, Table 6.1-1 All instances of the word “conductivity” in the SCR should be updated to read, “specific conductivity” or “specific conductance” as follows: SCR Section 5.4.9, Page 25, Paragraph 2 “Specific conductivity in mainstem Susitna River samples ranged from 143.7 μmhos/cm to 193.3 μmhos/cm in September 2014 (Figure 5.4-13) with the highest specific conductivity recorded at PRM 235.2 above the Oshetna River. The lowest specific conductivity measured was at the Deshka River (PRM 45.1) which is not fed by glacial runoff with a range from between 44.5 μmhos/cm and 69.2 μmhos/cm. There is an order of magnitude difference contrasted between rivers supplied by glacial meltwater and those from snow meltwater and rain runoff.” SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 2 October 2016 Reference Description SCR Section 6.2, Page 31, Paragraph 2, Sentence 3 Other indicators confirming a problem with overestimation of TP concentrations included: no increase in Chl a, specific conductivity, SRP (soluble reactive phosphorus), or Nitrogen (TKN). SCR Section 9, Page 49, Table 6.1-1, Left Column, fourth item Revised Table 6.1-1: Corrected “Conductivity” to “Specific Conductivity” SCR Section 9, Page 36, Table 4.1-1 Some of the information in Study 5.5 SCR Table 4.1-1 has been revised to show updates to both water temperature monitoring sites and water quality monitoring sites. A revised Table 4.1-1 is attached to this document. • For clarification, the monitoring sites in revised Table 4.1-1 were grouped by river segment as follows: Lower Susitna River segment, Middle Susitna River Segment below Devils Canyon, Middle Susitna River Segment above Devils Canyon, and Upper Susitna River Segment. • A 2013 water quality monitoring site, PRM 174, Susitna below Watana Dam Site, previously omitted from the SCR table was added to the revised table. • Project River Miles (PRMs) for tributary sampling, where appropriate, were revised to reflect the standard PRMs of the Susitna River at the confluence of the respective tributary. Deshka River PRM 45.1 was updated to PRM 44.9. Indian River PRM 142.2 was updated to PRM 142.1. Susitna River above Watana Creek PRM 196.8 was updated to PRM 196.9. • Oshetna River PRM 235.2 site was divided into two locations to reflect temperature monitoring within the tributary (PRM 235.1) and water quality sampling on the Susitna River (PRM 235.2) upstream of the tributary. • Gold Creek site representing the tributary (PRM 140.1) was deleted. All Gold Creek data was collected on the man channel Susitna River site (PRM140.0). • Sampling site names were also clarified to differentiate between the Susitna River upstream or downstream from a tributary confluence versus the tributary itself. • Location Rationale for each sampling site was revised to reflect usage of standard language: Main Channel, Off-Channel, and Tributary. o The following sites had updates as main channel habitat: PRM 19.9, PRM 29.9, PRM 33.6, PRM 59.9, PRM 87.8, PRM 99.2, PRM 107, PRM 116.7, PRM 124.2, PRM 129.9, PRM 134.1, PRM 140, PRM 142.3, PRM 143.6, PRM 152.2, PRM 152.7, PRM 168.1, PRM 174, PRM 183.1, PRM 184.8/185.0, PRM 187.2/187.7, PRM 196.9, PRM 209.2, PRM 225.5, PRM 235.2. o The following sites had updates as off-channel habitat: PRM 88.3, PRM 129.6, PRM 132.7, PRM 141.0, PRM, PRM 143.6, and PRM 145.6. o The following sites had updates as tributary habitat: PRM 32.5, PRM 44.9, PRM 102.4, PRM 102.8,PRM 142.1, PRM 152.3, PRM 235.1. • A footnote was added below the table to clarify that Focus Area specific sampling program is not reflected in this table and to indicate where Focus Area sampling information can be found in the SCR and ISR. When a sampling location in the baseline sampling fell within a Focus Area, the Focus Area designation has been provided in the description column. • A footnote was added to identify monitoring sites at same location as historical and/or current USGS gaging stations. • Footnotes added to explain alternative site locations for a portion of the monitoring events due to helicopter access issues (184/185.0, 187.2/187.7 and 225.5/235.2). SCR Section 9, Page 38, Table 4.3-1 SCR Table 4.3-1 was revised such that: • Project River Miles (PRMs) for tributary sampling reflect the standard PRM of the Susitna River at the confluence of the respective tributary (PRM 45.1 updated to PRM 44.9; PRM 142.2 updated to 142.1). All tributaries in table are identified by footnote 1. SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 3 October 2016 Reference Description • Sampling site names were also clarified to differentiate between the Susitna River upstream or downstream from a tributary confluence versus the tributary. Description for site PRM 235.2 was updated from “Oshetna River” to “Susitna River above Oshetna River”. • A 2013 water quality monitoring site, PRM 174, Susitna below Watana Dam Site, previously omitted from the SCR Table 4.3-1 was added to the revised table. • PRM changed from 141.1 to 140.0 for the Susitna River near Gold Creek to reflect that the data are from the Susitna River and not the tributary. A Revised SCR Table 4.3-1 is attached. SCR Section 9, Page 48, Table 6.1-1 SCR Table 6.1-1 was revised such that: • Corrected “Conductivity” to read “Specific Conductivity” in left column. • Corrected PRM for Susitna River near Gold Creek from 140.1 to PRM 140.0. • Clarified “Gold Creek” to read “Susitna River near Gold Creek” to avoid confusion with the tributary. • Clarified “Talkeetna” to read “Talkeetna River” to clarify it is the tributary. • Corrected PRM for Talkeetna from 107 to 102.8 representing the PRM at the confluence with the Susitna River. • Added “*” to Chulitna River to identify it as a tributary site. A Revised SCR Table 6.1-1 is attached. SCR Section 9, Page 48, Table 6.1-2 and SCR Section 9, Page 48, Table 6.1-3 SCR Tables 6.1-2 and 6.1-3 were revised such that: • Corrected PRM for Susitna River near Gold Creek from 140.1 to 140.0. • Clarified “Gold Creek” to read “Susitna River near Gold Creek” to avoid confusion with the tributary. • Clarified “Talkeetna” to read “Talkeetna River” to clarify it is the tributary. • Corrected PRM for Talkeetna from PRM 107 to PRM 102.8 representing the PRM at the confluence with the Susitna River. • Added “*” to Chulitna River to identify it as a tributary site. Revised SCR Tables 6.1-2 and 6.1-3 are attached. SCR Section 9, Page 55, Table 6.1-4 SCR Table 6.1-4 was revised such that: • Corrected PRM for Susitna River near Gold Creek from 140.1 to 140.0. • Clarified “Gold Creek” to read “Susitna River near Gold Creek” to avoid confusion with the tributary. • Clarified “Talkeetna” to read “Talkeetna River” to clarify it is the tributary. • Corrected PRM for Talkeetna from PRM 107 to PRM 102.8 representing the PRM at the confluence with the Susitna River. • Added “*” to Chulitna River to identify it as a tributary site. • Incorrect units were provided for several of the dissolved metals parameters (Note: values reported had been provided consistent with the corrected units.) o Historical units for dissolved Ca and Mg corrected from ug/L to mg/L for both winter and summer o For Hg, the historical summer units were clarified to be ug/L and the current summer to be ng/L An error occurred in transposing dissolved metals values from the historical scanned PDF SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 4 October 2016 Reference Description document from the 1980s in which a significant number of values were copied from a column one over from the correct column. Rather than copying dissolved metals concentration, this error resulted in the column for metals concentrations in suspended sediment being copied and inserted in Table 6.1-4. This resulted in three types of errors which are listed below and the corresponding footnote used to identify the error is also listed: 1. Incorrect vales were entered in Table 6.4-1 which are corrected and identified as footnote 1. Corrected values are shown in Bold Italics. 2. In some cases, there were historical values in the incorrect metals in suspended sediments that were entered in the table when there were no corresponding dissolved metals values. In these cases the vales in Table 6.4-1 were deleted and replaced with “—2” which includes the footnote 2. 3. In the third case, there were in few instances where there was no historical metals in suspended sediment data, but there was dissolved metals data. In this case, the “—“ in Table 6.4-1 were replaced with the dissolved metals concentrations. The values have been entered in Bold Italics and identified with footnote 3. A Revised SCR Table 6.1-4 is attached. SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 5 October 2016 Table 4.1-1. Susitna River Basin Temperature and Water Quality Monitoring Sites (Revised SCR Table 4.1-1.) PRM1 Description Latitude (WGS84) Longitude (WGS84) Water Temperature Water Quality Monitoring Location Rationale Historic Current Historic Current W S S W S W S W S S W S 2012 2012-2013 2013 2013-2014 2014 2013 2013-2014 2014 Lower Susitna River Segment 19.9 Susitna above Alexander Creek 61.43903 -150.48456 X X X X Main Channel downstream boundary above tidal influence 29.9 Susitna Station6 61.54428 -150.51556 X X X X X X X X X Main Channel downstream of tributary (Yentna River); historic monitoring site 32.51 Yentna River 61.58760 -150.48301 X X X X X X X X X X X Major Tributary; historic monitoring site 33.6 Susitna above Yentna 61.57595 -150.42741 X X X X X X X Main Channel upstream of tributary (Yentna River) 44.91 Deshka River 61.71014 -150.32470 X X X X X X Major Tributary 59.9 Susitna 61.86220 -150.18463 X X X X X X X Main Channel upstream of tributary (Deshka River) 87.8 Susitna at Parks Highway East6 62.17453 -150.17368 X X X X X X X X Main Channel 88.3 Susitna at Parks Highway West 62.18109 -150.16787 X X X X X X X X X Off- Channel; historic monitoring site 99.2 LRX 1 62.30602 -150.10876 X X X X X Main Channel downstream of Three Rivers Confluence 102.41 Chulitna River 62.56770 -150.23782 X X X X X X X X X X X Major Tributary; historic monitoring site 102.81 Talkeetna River 62.34243 -150.11266 X X X X X X X X Major Tributary Middle Susitna River Segment below Devils Canyon 107 Susitna River at Talkeetna6 62.39724 -150.13728 X X X X X X Main Channel above Three Rivers Confluence; historic monitoring site 116.7 LRX 18 62.52653 -150.11467 X X X X Main Channel 124.2 Curry Fishwheel Camp 62.61783 -150.01373 X X X X X X Main Channel; historic monitoring site 129.6 Slough 8A (FA- 128)3 62.67048 -149.90324 X X X X Off- Channel 129.9 LRX 29 62.67391 -149.89903 X X X Main Channel 132.7 Slough 9 62.70236 -149.84189 X X X X Off- Channel; 134.1 LRX 35 62.71385 -149.80893 X X X X Main Channel 140 Susitna near Gold Creek6 (FA-138)3 62.76705 -149.69353 X X X X X X X X X X X Main Channel downstream of tributary (Gold Creek); historic monitoring site SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 6 October 2016 PRM1 Description Latitude (WGS84) Longitude (WGS84) Water Temperature Water Quality Monitoring Location Rationale Historic Current Historic Current W S S W S W S W S S W S 2012 2012-2013 2013 2013-2014 2014 2013 2013-2014 2014 141.0 Slough 16B 62.78021 -149.68536 X X X X Off-Channel 142.11 Indian River 62.78635 -149.65878 X X X X X Major Tributary 142.3 Susitna above Indian River (FA-141)3 62.78578 -149.64890 X X X X X X Main Channel upstream of tributary (Indian River) 143.6 Slough 19 62.79382 -149.61426 X X X X Off-Channel 143.6 LRX 53 62.79427 -149.61327 X X X X X Main Channel; historic monitoring site 145.6 Slough 21 (FA-144)3 62.81467 -149.57533 X X X Off-Channel 152.2 Susitna below Portage Creek (FA-151)3 62.83040 -149.38274 X X X X X Main Channel downstream of tributary (Portage Creek) 152.31 Portage Creek 62.83038 -149.38029 X X X Major Tributary 152.7 Susitna above Portage Creek 62.82700 -149. 82700 X X X X X X Main Channel upstream of tributary (Portage Creek) 168.1 Susitna 62.79170 -148.99382 X X Main Channel above Devils Canyon mid-point between neighboring sites 174 Susitna below Watana Dam Site (FA-173)3 62.76673 -148.85385 X Main Channel 183.1 Susitna below Tsusena Creek 62.81348 -148.65687 X X Main Channel; Downstream of tributary (Tsusena Creek) 184.8 / 185.04 Susitna River above Tsusena Creek6 (FA-184)3 62.82178 -148.60681 X X X Main Channel Upper Susitna River Segment 187.2/187 .75 Susitna at Watana Dam site 62.82260 -148.55300 X X X X X Main Channel boundary condition between the reservoir and riverine models historic monitoring site 196.9 Susitna River above Watana Creek 62.82960 -148.25900 X Main Channel upstream of tributary (Watana Creek) 209.2 Susitna River above Kosina Creek 62.78220 -147.94000 X X X X X Main Channel upstream of tributary (Kosina Creek) SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 7 October 2016 PRM1 Description Latitude (WGS84) Longitude (WGS84) Water Temperature Water Quality Monitoring Location Rationale Historic Current Historic Current W S S W S W S W S S W S 2012 2012-2013 2013 2013-2014 2014 2013 2013-2014 2014 225.5 Susitna near Cantwell 62.70520 -147.53800 X Main Channel uppermost main channel site in the proposed reservoir 235.11 Oshetna River 62.64020 -147.38300 X X X X X Tributary 235.22 Susitna River above Oshetna River 62.63961 -147.38311 X X Main Channel Notes: PRM=Susitna River Project River Mile W= Winter S=Summer 1 Indicates the Susitna River PRM at the confluence of the tributary (samples collected from the tributary). 2 Indicates an alternate monitoring location from PRM 225.5 due to river inaccessibility by helicopter during summer sample collection. 3 Indicates this site is in the Focus Area identified in parentheses. Other Focus Area locations were sampled under the 2013 and 2014 Focus Area specific program. Refer to Study 5.5 ISR Part A, Section 4.4 and Study 5.5 SCR Section 4.4 for details. 4Summer temperature monitoring was performed at PRM 184.8 and winter water quality sampling was performed at PRM 185.0 due to helicopter access issues at the summer location. 5 One summer sampling event moved upstream from PRM 187.2 to PRM 187.7 due to helicopter access issues. 6 Located at current and/or historical USGS Gaging Station. SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 8 October 2016 Table 4.3-1. Sample Location and Frequency for Monthly Baseline Water Quality Sampling (Revised SCR Table 4.3-1) Project River Mile (PRM) Description Sample Date(s) Summer 2013 Winter 2014 Summer 2014 29.9 Susitna Station 6/25/2013 1/28/2014 6/24/2014 7/19/2013 3/10/2014 7/23/2014 8/19/2013 8/14/2014 9/15/2013 9/11/2014 32.51 Yentna River 6/26/2013 6/24/2014 8/18/2013 7/23/2014 7/19/2013 8/14/2014 9/15/2013 9/11/2014 33.6 Susitna above Yentna 6/27/2013 6/24/2014 8/19/2013 7/23/2014 7/20/2013 8/14/2014 9/16/2013 9/11/2014 44.91 Deshka River 6/28/2013 6/24/2014 8/19/2013 7/23/2014 7/19/2013 8/14/2014 9/16/2013 9/11/2014 59.9 Susitna 6/29/2013 6/24/2014 7/19/2013 7/23/2014 8/19/2013 8/14/2014 9/17/2013 9/11/2014 87.8 Susitna at Parks Highway East 6/21/2013 1/28/2014 6/19/2014 7/17/2013 3/10/2014 7/22/2014 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 9 October 2016 Project River Mile (PRM) Description Sample Date(s) Summer 2013 Winter 2014 Summer 2014 8/17/2013 8/13/2014 9/14/2013 9/9/2014 102.41 Chulitna River 6/24/2013 6/19/2014 7/16/2013 7/22/2014 8/17/2013 8/13/2014 9/13/2013 9/9/2014 102.81 Talkeetna River 6/22/2013 6/19/2014 7/15/2013 7/22/2014 8/16/2013 8/13/2014 9/9/2013 9/9/2014 107 Susitna River at Talkeetna 6/21/2013 6/19/2014 7/18/2013 7/22/2014 8/16/2013 8/13/2014 9/9/2013 9/9/2014 124.2 Curry Fishwheel Camp 6/22/2013 6/19/2014 7/18/2013 7/22/2014 8/15/2013 8/12/2014 9/10/2013 9/9/2014 140.0 Susitna near Gold Creek 6/23/2013 1/30/2014 6/18/2014 7/17/2013 3/12/2014 7/21/2014 8/17/2013 8/12/2014 9/10/2013 9/8/2014 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 10 October 2016 Project River Mile (PRM) Description Sample Date(s) Summer 2013 Winter 2014 Summer 2014 142.11 Indian River 6/23/2013 6/18/2014 7/16/2013 7/21/2014 8/14/2013 8/11/2014 9/11/2013 9/8/2014 142.3 Susitna above Indian River 6/24/2013 6/18/2014 7/15/2013 7/21/2014 8/13/2013 8/11/2014 9/11/2013 9/8/2014 152.2 Susitna below Portage Creek 7/30/2013 6/18/2014 8/14/2013 7/21/2014 9/12/2013 8/11/2014 9/8/2014 152.7 Susitna above Portage Creek 7/30/2013 6/18/2014 8/14/2013 7/21/2014 9/12/2013 8/11/2014 9/8/2014 174 Susitna below Watana Dam Site 8/18/2013 8/31/2013 9/20/2013 184.82 Susitna River above Tsusena Creek 1/29/2014 3/11/2014 187.23 Susitna at Watana Dam Site 7/2/2013 6/22/2014 7/22/2013 7/20/2014 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 11 October 2016 Project River Mile (PRM) Description Sample Date(s) Summer 2013 Winter 2014 Summer 2014 8/18/2013 8/11/2014 8/31/2013 9/14/2014 9/20/2013 225.5 Susitna near Cantwell 1/29/2014 3/11/2014 235.24 Susitna River above Oshetna River 7/2/2013 6/22/2014 7/22/2013 7/20/2014 8/31/2013 8/11/2014 9/20/2013 9/14/2014 Notes: PRM=Susitna River Project River Mile. 1 For tributary sample sites, the PRM reflects the confluence of the tributary with the Susitna River. 2 Summer temperature monitoring was performed at PRM 184.8 and winter water quality sampling was performed at PRM 185.0 due to helicopter access issues during the winter at the summer location. 3 One summer sampling event moved upstream from PRM 187.2 to PRM 187.7 due to helicopter access issues. 4 Indicates an alternate monitoring location from PRM 225.5 due to river inaccessibility by helicopter during summer sample collection. SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 12 October 2016 Table 6.1-1 Historic (1980s) and Current (2013 - 2014) Field Parameters (Revised SCR Table 6.1-1) Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna at Watana Dam site Susitna above Portage Creek Susitna above Indian River Susitna River near Gold Creek Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna at Parks Highway West (current data collected from EAST) Yentna River* Susitna Station Temp (°C) Historic Winter -- -- -- ≈0 -- -- ≈0 ≈0 ≈0 ≈0 Current Winter -- -- -- 0 -- -- -- 0 -- 0 Historic Summer 1.9-14.4 -- -- 4.5-14.1 2.7-15.3 2.9-16.4 3.8-9.5 5-14 3.9-11.6 2.5-14.8 Current Summer 2.6-14.8 7.5-12.0 7.3-15.0 7.5-14.2 7.6-15.1 8.0-14.3 4.6-8.3 7.3-11.7 7.4-10.4 7.5-12.1 Dissolved oxygen (mg/L) Historic Winter -- -- -- 10.9-16.2 -- -- -- 12.8-14.4 10.9-11.1 9.9-12.7 Current Winter -- -- -- 13.9-14.5 -- -- -- 12.8-14.6 -- 10.8-13.9 Historic Summer 9.9-11.6 10.9-14.8 -- 8.5-12.7 10.1-13.9 9.8-12.0 -- 9-13.4 10.4-12.1 9-12.3 Current Summer 10.1-12.47 10.4-12.6 10.4-12.4 10.5-12.5 10.0-12.5 10.2-11.9 12.0-13.6 10.7-13.7 11.5-12.0 10.9-12.53 pH Historic Winter -- -- -- 7.6-8.0 -- -- ≈7.1 7.8-8.2 7.1-7.9 7.5-7.6 Current Winter -- -- -- 7.3-7.7 -- -- -- 7.1-7.2 -- 6.9-7.0 Historic Summer 8-8.2 6.8-8.2 -- 7.5-8.3 6.8-8.0 7.4-8.0 7.2-8.1 7.1-8.3 7.4-8.3 7.5-8.5 Current Summer 7.4-8.5 7.1-8.5 7.6-8.6 7.7-8.6 7.6-8.3 7.6-8.4 7.8-8.7 7.8-8.5 8.0-8.6 7.5-9.4 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 13 October 2016 Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna at Watana Dam site Susitna above Portage Creek Susitna above Indian River Susitna River near Gold Creek Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna at Parks Highway West (current data collected from EAST) Yentna River* Susitna Station Specific Conductivity1 (µmhos/cm) Historic Winter -- -- -- 84-300 -- -- ≈115 159-240 189-216 180-225 Current Winter -- -- -- 241-263 -- -- -- 190-220 -- 136-216 Historic Summer -- -- -- 87-227 -- -- 101-144 80-170 93-142 96-154 Current Summer 137.8-178.5 122.2-164.7 122-162.8 116-161.5 131-166.6 122-168.8 106.4-145.9 122-156.9 135.9-167 116.1-170 Notes: ND = non-detection “—“= data unavailable *Indicates major tributary sampling location 1 “Conductivity” corrected to read “Specific Conductivity” SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 14 October 2016 Table 6.1-2. Ranges in Historic (1980s) and Current (2013 – 2014) Water Quality Monitoring Data (Revised SCR Table 6.1-2) Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna at Watana Dam site Susitna above Portage Creek Susitna above Indian River Susitna River near Gold Creek Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna at Parks Highway West (current data collected from EAST) Yentna River* Susitna Station Orthophosphate (mg/L) Historic Winter -- -- -- 0.03-0.09 -- -- <0.01 0.031-0.12 <0.01 <0.01 Current Winter -- -- -- 0.005 - 0.006 -- -- -- 0.001 - 0.003 -- ND - 0.002 Historic Summer -- -- -- 0-0.184 -- -- <0.01 0.031-0.061 <0.01 <0.01 Current Summer ND - 0.032 ND - 0.011 ND - 0.007 ND - 0.011 ND - 0.007 ND - 0.041 ND - 0.019 ND - 0.027 ND - 0.008 ND - 0.019 Turbidity (NTU) Historic Winter -- -- -- 0.1-0.7 -- -- -- 0.5-2.7 -- 1-3 Current Winter -- -- -- -- -- -- -- -- -- -- Historic Summer -- 45-200 -- 23-290 20-396 16-480 -- 43-500 30-220 up to 790 Current Summer 18 - 650 90 - 600 75 - 400 50 - 1000 90 - 500 160 - 500 310 - 900 130 - 1300 110 - 950 110 - 950 TSS (mg/L) Historic Summer -- 52-482 -- -- 39-512 5.5-8.0 -- -- -- -- Current Summer 41.9 - 578 81 - 650 73 - 426 64 - 1050 99 - 480 186 - 488 470 - 1170 162 - 1420 186 - 744 194 - 780 TDS (mg/L) Historic Summer -- -- -- 55-140 -- -- -- -- -- -- Current Summer 100 - 154 87 - 146 92 - 174 72 - 156 70 - 132 66 - 154 92 - 166 44 - 138 62 - 152 82 - 190 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 15 October 2016 Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna at Watana Dam site Susitna above Portage Creek Susitna above Indian River Susitna River near Gold Creek Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna at Parks Highway West (current data collected from EAST) Yentna River* Susitna Station Total Hardness (mg/L) Historic Summer -- -- -- -- -- -- -- 44-72 -- 44-66 Current Summer 58 - 71 54 - 65 53 - 66 49 - 67 53 - 107 52 - 70 48 - 74 52 - 72 59 - 121 53 - 73 Total Alkalinity (mg/L) Historic Summer -- -- -- 23-87 -- -- -- -- -- 36-57 Current Summer 49 - 53 41 - 53 40 - 54 35 - 55 41 - 54 42 - 54 34 - 53 41 - 49 40 - 50 40 - 53 Total Organic Carbon (mg/L) Historic Summer -- 1.4-3.8 -- -- -- -- 1.7-3.2 -- 2.7-11 Current Summer 2.4 2.29 - 2.39 1.92 - 2.14 1.7 - 2.02 1.8 - 3.43 1.9 - 2.09 1.71 - 1.92 2.05 - 2.42 1.98 - 2.76 2.1 - 3.68 Chlorophyll-a (µg/L) Historic Summer -- -- -- -- -- -- -- -- -- ND-1.2 Current Summer 0 - 0.53 0 - 1.9 0 - 1.3 0 - 0.87 0 - 1.3 0 - 1.3 0 - 2.5 0 - 2.5 0 - 1.4 0 - 1.2 Total Coliform Bacteria (colonies/100 ml) Historic Summer -- -- -- -- -- -- -- -- ≤ 20 Current Summer 0 14 - 22 9 - 12 9 - 27 12 - 20 6 - 26 7 - 15 6 - 18 8 - 18 7 - 18 Notes: ND = non-detection “—“= data unavailable *Indicates major tributary sampling location SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 16 October 2016 Table 6.1-3 Historic (1980s) and Current (2013 – 2014) Total Metals (Revised SCR Table 6.1-3) Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna at Watana Dam site Susitna above Portage Creek Susitna above Indian River Susitna River near Gold Creek Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna at Parks Highway West (current data collected from EAST) Yentna River* Susitna Station Al (total) (µg/L) Historic Summer -- -- -- ≈13000 -- -- -- up to 15000 -- -- Current Summer 470 - 7990 959 - 5630 564 - 5830 476 - 5680 452 - 7350 420 - 7980 2341 - 20800 1650 - 19400 1249 - 23029 790 - 22584 As (total) (µg/L) Historic Winter -- -- -- 1 -- -- -- 1-2 -- 1-3 Current Winter -- -- -- ND -- -- -- ND -- ND Historic Summer -- -- -- 2-12 -- -- -- 1-3 -- 7-40 Current Summer 1.89 - 11.8 ND - 11.4 ND - 8.8 1.7 - 16.3 ND - 9.8 ND - 10.9 4.5 - 37.5 2.8 - 32.5 3.8 - 26.1 3.2 - 23.5 Ba (total) (µg/L) Historic Winter -- -- -- ≤ 100 -- -- -- 100 -- 100 Current Winter -- -- -- 50 -- -- -- 38 -- 35 Historic Summer -- -- -- 100-500 -- -- -- 100-500 -- up to 400 Current Summer 89.0 - 788 39.4 - 516 37.9 - 434 34.7 - 883 37.9 - 454 35.6 - 434 66.3 - 905 49.9 - 795 41.4 - 382 37.7 - 413 Cd (total) (µg/L) Historic Summer -- -- 0-30 -- -- -- 0-35 -- ≤ 1 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 17 October 2016 Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna at Watana Dam site Susitna above Portage Creek Susitna above Indian River Susitna River near Gold Creek Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna at Parks Highway West (current data collected from EAST) Yentna River* Susitna Station Current Summer 0.05 - 1.12 0.12 - 0.77 ND - 0.434 0.07 - 0.86 0.12 - 0.49 0.19 - 0.66 0.29 - 0.66 0.14 - 0.78 0.13 - 0.52 0.13 - 0.45 Se (total) (µg/L) Historic Summer -- -- -- ≤ 1 -- -- -- 0-1 -- ≤ 1 Current Summer 0.55 0.37 - 0.55 0.47 - 0.69 0.39 - 0.55 0.41 - 0.58 0.45 - 0.62 ND 0.62 - 0.91 0.57 - 0.78 0.48 - 0.71 Cu (total) (µg/L) Historic Summer -- -- -- 15-190 -- -- -- 0-35 -- 30-90 Current Summer 3.93 - 43.9 7.83 - 37.1 7.22 - 31.3 4.21 - 68.7 7.87 - 33.5 11.1 - 33.4 27.4 - 64 13.8 - 73 11.4 - 39.1 11.5 - 41.6 Fe (total) (µg/L) Historic Winter -- -- -- ≈120 -- -- ≈0 110-1100 -- 240-720 Current Winter -- -- -- 54 - 64 -- -- -- 89 - 628 -- 132 - 207 Historic Summer -- -- -- 430-24000 -- -- up to 4300 7600-32000 -- 7900-42000 Current Summer 8550 - 9430 1325 - 7160 958 - 7430 802 - 7010 743 - 9106 688 - 9935 3760 - 31091 2364 - 27403 2151 - 31889 1507 - 30894 Pb (total) (µg/L) Historic Summer -- -- -- ≤ 200 -- -- -- 2-13 -- ≤ 200 Current Summer 0.38 - 7.86 1.3 - 5.99 1.04 - 4.64 0.64 - 9.29 1.22 - 4.46 ND - 4.98 7.52 - 17.5 2.88 - 18.7 3.17 - 10.9 2.59 - 10.7 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 18 October 2016 Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna at Watana Dam site Susitna above Portage Creek Susitna above Indian River Susitna River near Gold Creek Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna at Parks Highway West (current data collected from EAST) Yentna River* Susitna Station Mn (total) (µg/L) Historic Winter -- -- -- ≤ 20 -- -- ≈10 2-10 -- 30-40 Current Winter -- -- -- ND -- -- -- 19 -- 9 Historic Summer -- -- 10-390 -- -- 20-280 170-670 -- 320-870 Current Summer 20.9 - 172 37.6 - 157 41.1 - 149 29.4 - 144 24.9 - 174 22.5 - 189 97.3 - 618 59.1 - 547 89.4 - 745 68.8 - 702 Hg (total) (µg/L) Historic Summer -- -- 2-13 -- -- -- 0.1-0.6 -- ≤ 1 Current Summer 0.83 - 22.0 2.94 - 25.8 1.92 - 23.1 1.53 - 21.1 1.09 - 18.5 1.02 - 25.3 4.95 - 54.5 3.49 - 80.1 8.43 - 33.6 6.09 - 32.1 Ni (total) (µg/L) Historic Summer -- -- ≤ 50 -- -- -- 18-30 -- 1-2 Current Summer 4.33 - 49.2 9.56 - 40.7 8.48 - 42.4 5.41 - 75.9 9.44 - 38.3 12.8 - 33.8 37.1 - 85.9 15.9 - 80.9 12.9 - 44.3 12.3 - 46.6 Zn (total) (µg/L) Historic Summer -- -- -- 20-120 -- -- -- 40-200 -- 80-180 Current Summer 8.62 - 106 19.1 - 98.2 17.5 - 77.3 10.8 - 163 19.5 - 80 27 - 86.3 72.9 - 191 33.5 - 202 30.7 - 124 29.2 - 121 Notes: ND = non-detection “—“= data unavailable *Indicates major tributary sampling location SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 19 October 2016 Table 6.1-4. Historic (1980s) and Current (2013 – 2014) Dissolved Metals (Revised SCR Table 6.1-4) Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna River at Watana Dam site Susitna River above Portage Creek Susitna River above Indian River Susitna River near Gold Creek Susitna River at Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna River at Parks Hwy West (current data collected from EAST) Yentna River* Susitna River at Susitna Station Al (dissolved) (µg/L) Historic Winter -- -- -- --2 -- 10-1603 -- --2 -- -- Current Winter -- -- -- ND - 3 -- -- -- 4 - 9 -- 4 - 22 Historic Summer -- -- -- --2 -- 20-2903 -- --2 -- 40-350 Current Summer 18.9 - 1030 22.9 - 117 20.1 -105 40.1 - 122 36.1 - 237 36.4 - 2880 72.7 - 700.4 49.6 - 198 32 - 189 35 - 133 As (dissolved) (µg/L) Historic Winter -- -- -- 11 -- ≤13 -- 11 -- 0-31 Current Winter -- -- -- ND -- -- -- ND -- ND Historic Summer -- -- -- 1-21 -- 0-23 -- 1-31 -- 1-31 Current Summer 0.63 - 1.35 0.72 - 1.21 0.79 - 1.24 0.77 - 1.63 0.83 - 1.16 0.87 - 1.74 1.12 - 5.16 0.93 - 5.36 1.16 - 1.73 1.1 - 1.81 Ba (dissolved) (µg/L) Historic Winter -- -- -- ≤ 100 -- ≤ 1003 -- 25-100 -- ≈40 Current Winter -- -- -- 48 -- -- -- 35 -- 26 Historic Summer -- -- -- 0-44 -- 7-233 -- 0-70 -- 20-200 Current Summer 36.9 - 69.7 34.0 - 49.5 32.8 - 47.9 27 - 73.8 32.1 - 46 32.6 - 88.9 14.1 - 69.9 17.4 - 111 15.9 - 23.4 17.7 - 27.5 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 20 October 2016 Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna River at Watana Dam site Susitna River above Portage Creek Susitna River above Indian River Susitna River near Gold Creek Susitna River at Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna River at Parks Hwy West (current data collected from EAST) Yentna River* Susitna River at Susitna Station Cd (dissolved) (µg/L) Historic Summer -- -- -- 0-20 -- 0-53 -- 0-24 -- ≤ 2 Current Summer ND - 0.06 ND - 0.02 ND - 0.02 ND - 0.06 ND - 0.04 ND - 0.07 ND - 0.08 ND - 0.11 ND - 0.52 ND - 0.02 Se (dissolved) (µg/L) Historic Summer -- -- -- ≤ 1 -- ≤ 23 -- 0-11 -- ≤ 1 Current Summer 0.52 0.36 - 0.58 0.57 - 0.62 0.45 - 0.58 0.48 - 0.57 0.47 - 0.66 0.71 - 0.87 0.51 - 0.79 0.51 - 0.66 0.51 - 0.68 Ca (dissolved) Historic Winter (mg/L) -- -- -- 18-39 -- 17-263 ≈19 18-39 -- 24-31 Current Winter (µg/L) -- -- -- 19100 -- -- -- 11600 -- 14300 Historic Summer (mg/L) -- -- -- 10-37 -- 6.8-173 14-18 10-37 -- 15-22 Current Summer (µg/L) 19,000 – 22,300 17,600 – 21,700 17,100 – 21,900 15,700 – 22,500 17,100 – 21,300 17,300 – 22,600 14,200 – 21,626 16,900 – 20,100 17,700 – 20,000 16,200 – 22,200 Cu (dissolved) (µg/L) Historic Summer -- -- -- 2-51 -- ≤ 103 -- 2-101 -- ≤31 Current Summer 0.56 - 2.46 0.53 - 1.23 0.58 - 1.09 0.44 - 2.58 0.28 - 4.77 0.42 - 2.91 0.24 - 6.8 0.09 - 9.62 0.33 - 1.02 0.34 - 1.39 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 21 October 2016 Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna River at Watana Dam site Susitna River above Portage Creek Susitna River above Indian River Susitna River near Gold Creek Susitna River at Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna River at Parks Hwy West (current data collected from EAST) Yentna River* Susitna River at Susitna Station Fe (dissolved) (µg/L) Historic Winter -- -- -- ≈10 -- -- -- 17-401 -- 60-1501 Current Winter -- -- -- ND -- -- -- ND -- 59 - 109 Historic Summer -- -- -- 50-3201 -- -- -- 10-3301 -- 10-4601 Current Summer 19.4 - 1480 15.8 - 249 16.4 - 120 18.5 - 1680 27.4 - 171 ND - 2000 11.5 - 5530 6.41 - 7310 9.63 - 480 7.19 - 190 Pb (dissolved) (µg/L) Historic Summer -- -- -- 0-51 -- ≤103 -- ≤13 -- ≤51 Current Summer ND - 0.31 ND - 0.07 ND - 0.04 ND - 0.42 ND - 0.07 ND - 0.46 ND - 1.77 ND - 2.06 ND - 0.19 ND - 0.11 Mg (dissolved) Historic Winter (mg/L) -- -- -- 3.2-10 -- 1.9-5.63 ≈1.9 2.9-10 -- 3.6-5.0 Current Winter (µg/L) -- -- -- 4680 -- -- -- 4260 -- 5040 Historic Summer (mg/L) -- -- -- 1.2-7.81 -- 0.4-3.93 2.5-4.1 1.2-7.8 -- 2.0-3.3 Current Summer (µg/L) 2350 - 3570 2290 - 2730 2380 - 2730 2320 - 2940 2220 - 2750 2040 - 3160 2950 - 5640 2460 - 5390 3230 - 4540 2700 - 4690 SUPPLEMENT TO THE SCR BASELINE WATER QUALITY STUDY (5.5) Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No. 14241 Page 22 October 2016 Project River Mile 187.2 152.7 142.3 140.0 124.2 102.8 102.4 88.3 32.5 29.9 Description Susitna River at Watana Dam site Susitna River above Portage Creek Susitna River above Indian River Susitna River near Gold Creek Susitna River at Curry Fishwheel Camp Talkeetna River* Chulitna River* Susitna River at Parks Hwy West (current data collected from EAST) Yentna River* Susitna River at Susitna Station Mn (dissolved) (µg/L) Historic Winter -- -- -- --2 -- 3-103 -- 2-101 -- 10-301 Current Winter -- -- -- --2 -- -- -- 6 -- 9 Historic Summer -- -- -- 2-1801 -- 3-203 -- 7-121 -- 6-201 Current Summer 2.86 - 29.2 2.53 - 7.38 2.31 - 5.78 1.75 - 35.8 2.79 - 7.58 2.47 - 37 4.86 - 118 1.85 - 151 1.21 - 12.4 1.3 - 17.9 Hg (dissolved) Historic Summer (µg/L) -- -- -- ≤0.21 -- -- -- ≤0.11 -- ≤0.51 Current Summer (ng/L) ND - 1.46 ND - 0.958 ND - 12.3 ND - 0.82 ND - 2.28 ND - 1.21 ND - 3.54 ND - 1.54 ND - 0.874 ND - 1.48 Ni (dissolved) (µg/L) Historic Summer -- -- -- 0-31 -- 0-53 -- 0-21 -- 0-21 Current Summer 1.46 - 3.53 0.674 - 1.98 0.988 - 1.81 0.78 - 4.18 0.689 - 2.11 1.05 - 3.97 0.924 - 9.14 0.856 - 10.8 0.742 - 1.71 0.793 - 1.5 Zn (dissolved) (µg/L) Historic Summer -- -- -- 6-201 -- 6-303 -- 14-651 -- 8-1601 Current Summer 0.75 - 7.59 0.657 - 2.77 ND - 1.72 0.569 - 17.3 ND - 3.73 0.495 - 8.35 0.545 - 21.2 ND - 26.8 0.578 - 4.87 0.517 - 4.26 Notes: ND = non-detection “—“= data unavailable * Indicates tributary sampling location Values in Bold Italics represent updates to historical concentration ranges reported in the Study 5.5 SCR Table 6.1-4, filed with the Commission November 24, 2015. 1 Indicates values that were corrected from metals in suspended sediments to dissolved metals. 2 Indicates deleted metals in suspended sediments values and no corresponding dissolved metals data are available. 3 Indicates dissolved metals value added where metals in suspended sediment value was not available.