November 20, 2015
Honorable Kimberly D. Bose Secretary
Federal Energy Regulatory Commission
888 First Street, NE
Washington, DC 20426
Re: Northfield Mountain Pumped Storage Project No. 2485-065
Comments on FirstLight’s Answer to Motion to Intervene and Comments
Application for Amendment of License
Dear Secretary Bose,
The Connecticut River Watershed Council, Inc. (CRW C) submitted a motion to intervene and comments to the above referenced application for amendment of license dated October 29, 2015. The Connecticut River Streambank Erosion Committee (CRSEC), of which CRC is a member, filed a technical memorandum dated October 29, 2015. On November 6, 2015, FirstLight Hydro Generating Company filed an “Answer of FirstLight Hydro Generating Company to Motion to Intervene and Comments” (“Answer”). FirstLight’s Answer provided comments on several points made by CRC and FRCOG, and included revised transect figures. CRC has reviewed FirstLight’s Answer, and below includes our responses to the Answer and revised figures.
A. Revised transect figures have numerous technical problems
1. The revised transect figures provided in Attachment 1 of FirstLight’s Answer are not responsive to the CRSEC and CRC concerns that the transect data be presented at a scale that facilitates evaluation of changes in bank morphology over time. CRSEC requested that a more acceptable scale be used that has a vertical exaggeration (VE) of 1, with both the x- and y- axes shown in increments of 5 feet. FirstLight did present the transect data in Attachment 1 using 5-ft increments on both axes. However, the graphs do not show a vertical exaggeration of 1 as they claimed (see footnote 9 on page 3 of the Answer); the VEs vary from transect to transect, and in the example we provide below, the VE is 3.66, not 1.
CRSEC’s request was based on commonly used scientific and professional formats for presenting survey data. To review, vertical exaggeration is a comparison between the horizontal and vertical scales on a profile. In the diagram below, 1″ = 100′ on both the vertical and horizontal scales. Doing the division, 100’/100′ = 1; in other words, there is no vertical exaggeration. When the survey data for each bank is presented with no vertical exaggeration, there is no distortion or masking of changes in the profile of the bank morphology.
Figure 1. Vertical exaggeration defined
Source of the figure http://academic.brooklyn.cuny.edu/geology/leveson/core/linksa/vertexag.html
Figure 2 below is one example from FirstLight’s revised transect figures provided in the Answer. When we printed out Figure A-16 (LB), we measured the following dimensions:
X axis: 5 ft = 3/16 inches = 0.1875 inches
Y axis: 5 ft = 11/16 inches = 0.6875 inches
VE = 0.6875/0.1875 = 3.66
The measurements of the copied left bank profile in Figure 2 below will be different, because the figure has been shrunk. We have added the VE number to Figure 2, and we also added the river elevation limit of the Turners Falls pool; see further comment below.
Figure 2. Example of left bank transect (8B) where VE ≠ 1
2. To further confound interpretation of the data, FirstLight left hundreds of feet of river bed in the transects and still did not provide water level elevations. FirstLight no doubt records water levels when they measure bank transects. FirstLight should establish an elevation at which point a “bank” ends. This could be based on the FERC license limits (176 ft msl as measured at the Turners Falls dam), or something that varies depending on the location within the Impoundment. As we have seen in relicensing study 3.2.2 Hydraulic Model, impoundment water levels typically stay within a range between 180 and 186 ft. In 2014, the lowest water elevation was 178 ft.
Below in Figures 3 and 4, we provide transects 5D and BC-3 as an example, showing the span of the left bank and right bank profiles given in the Answer, in relation to the entire transect and the water elevation of 176 ft. The result of this is that so much is considered bank that the river bed width is excessively narrow. Moreover, once again, any changes from year to year will be masked because of the scale needed to provide an excessive amount of bank in the figure. In the extreme case, the left bank of transect BC-3 is a concrete abutment, yet the left bank profile given extends way below the abutment and out into the middle of the channel.
Figure 3. Transect 5D example showing extent of left and right “banks” as provided in FirstLight’s Answer
Figure 4. Transect BC-3 example showing extent of left and right “banks” as provided in FirstLight’s Answer
3. The profiles provided in the revised bank profiles have set an arbitrary lower elevation limit that does not even match from left to right bank within the same transect. In the most extreme case, the left bank’s lowest elevation at transect BC-2 ends 30 ft higher than the right bank’s lowest elevation at that same transect. Below in Table 1, we have summarized the lower elevations provide in the left and right bank figures in FirstLight’s Answer. FirstLight’s revised figures portray much river bed as bank, skewing the figures.
Table 1. Left and right bank lower elevations provided in revised transect figures in FirstLight’s Answer
Transect ID Left bank profile goes down to
(ft in MGVD29) Right bank profile goes down to
(ft in MGVD29)
1 190 194
11 175 175
2 175 177
3 176 175
4 165 177
5A 163 169
5B 143 137*
5D 129 135*
5E 135 147*
5C 166 172
10 169 171
6B 166 170
6A 167 170
12 169 180
7 167 173
8B 169 167
8A 172 167
9 160 167
BC-1 140 130
BC-5 173 175
BC-2 181 151
BC-3 133 130
License limit 176 ft at dam 176 at dam
* The transects for 5B, 5D, and 5E end at the same location on the right bank, but the right bank profiles go down to different levels for some reason.
Transect 1 does not give all of the bank.
Many of the other left and right bank figures extend 10-40 feet in elevation below the water line.
The elevations that are considered the lowermost extent of bank vary between 130 ft and 190 ft MBVD29, which makes little sense given the impoundment elevation license limits of 176 – 185 msl as measured at the dam.
B. Without information on the accuracy of equipment, “significance” is impossible to determine
FirstLight states on page 3 of the Answer that, “The minimal differences in the actual riverbanks and overall cross-sectional geometry from 2014 to 2015, shown in a comparison of the two surveys, indicate that no significant channel changes occurred during winter 2014-2015.” A footnote then explains that representation of the channel geometry is constrained by the accuracy of equipment. CRC does not know what FirsLight means by “actual riverbanks” here, since as we noted above, there appears to be confusion and inconsistent interpretation of what a “bank” is. We do note that some changes that were masked by the full river width cross-sections have started to become evident. However, FirstLight provides no margin of error and it is impossible to tell if any changes are “significant.”
C. FirstLight’s assertions about river level fluctuation patterns last winter are not backed by data
FirstLight states on page 3 that any variations in riverbanks between 2014 and 2015 are unlikely to be due to changes allowed by the temporary amendment, because the water level fluctuations were “well within the timing, rate, magnitude, and frequency of water elevation fluctuations in the Turners Falls Impoundment during the previous 14 winters.” FirstLight cites its September 1, 2015 license amendment application pages 9-11 and Figure 1 from Attachment 1. We stress that a flow duration curve for an entire year does not provide the level of detail needed to make a statement about timing and rate of water elevation fluctuation changes.
D. Monthly charts needed in Report summarizing Winter of 2014-2015
FirstLight’s answer at page 7 states that FirstLight’s September 1, 2015 Report Figure B-5 was an appropriate representation of baseline conditions for the winter of 2014-2015. We re-iterate our statement that FirstLight did not comply with FERC’s order. FERC ordered that the licensee must include monthly charts plotting lower reservoir elevations recorded during the 4-month amendment period against a baseline. FirstLight in Figure B-5 provided an impoundment delta duration curve for the entire winter. This is not a monthly chart showing reservoir elevations.
E. FirstLight uses winter of 2014-2015 data to assert no environmental impact but then criticizes CRC and CRSEC thinking 2014-2015 data are relevant to the pending license amendment Application.
FirstLight’s Answer on page 2 says, “Although many of CRC and CRSEC’s comments focus on the data FirstLight submitted in compliance with the Commission’s order approving the 2014-2015 temporary amendment, CRC and CRSEC claim that these data pertain as well to the Commission’s consideration of FirstLight’s pending Application.” Of course the 2014-2015 data pertain to the Commission’s consideration of the pending Application (as do other data)! FirstLight’s own 2015 Application in section B, Environmental Review (pages 8-12) repeatedly used an evaluation of the conditions during last year’s temporary amendment to argue that there has been and will continue to be minimal, if any, environmental impact.
1. We recommend that FirstLight provide a rational definition for “left bank” and “right bank,” and revise the transect figures showing the banks accordingly.
2. We recommend FirstLight revise the transect figures to show a vertical exaggeration of 1 for all left and right bank profiles, as CRSEC recommended.
3. We recommend that FirstLight provide a margin of error or information on the accuracy of its equipment used to measure the transects in 2014 and 2015.
4. The 2015 transect survey was completed in June of 2015, only a couple of months after the temporary amendment period ended on March 31, 2015. Effects from last winter’s temporary amendment may take a longer period to be observable. Future annual transect surveys should be completed later in the year than June. CRC recommends August.
5. We repeat our request for additional data and revised figures and graphs as described in our motion to intervene dated October 29, 2015.
Thank you for the opportunity to respond. I can be reached at email@example.com or 413-772-2020 x.205.
Andrea F. Donlon