July 28, 2014
John S. Howard
Director, FERC Hydro Compliance
FirstLight Power Resources/GDF Suez
Northfield Mountain Station
99 Millers Falls Road
Northfield, MA 01360
Re: Field Sampling Plan for Study No. 3.2.1, Water Quality Monitoring Study
I have reviewed the “Relicensing Study 3.2.1. Water Quality Monitoring Study Field Sampling Plan” dated June 2014, and below are comments submitted on behalf of the Connecticut River Watershed Council (CRWC).
Temperature logger depths
According to page 4 of the draft sampling plan, the five loggers in the Turners Falls impoundment will be deployed in a “representative location at a minimum of 4 ft from the surface, but not deeper than 25% depth.” The loggers in the bypass reach, power canal, and below Cabot Station will be placed in a “representative location in mid-channel or thalweg at mid-depth, or just off the bottom depending on site-specific characteristics.” Then, on page 5, it says that the five temperature loggers to be placed between Cabot Station and the Holyoke Dam will be secured “off the bottom of the river with rocks or concrete blocks,… tethered to an immovable object on shore with polypropylene rope or cable.”
We don’t know how much variation there is in the Connecticut River at different widths and depths, and this sampling plan proposes a single logger at each proposed location. While CRWC thinks this approach may be appropriate within a given budget, we are also concerned that the varying depths and locations off shore proposed for the loggers are inconsistent and will likely yield a set of results that can’t be compared with the other river sections. Therefore, we recommend FirstLight determine the best approach for locating the loggers at a consistent depth and location off shore that will give “representative” results for the study objectives. That is, if the loggers are to be placed at mid depth in the thalweg, they be put there at ALL locations, not just some of the locations.
Calibration of temperature loggers
CRWC recommends that the loggers be placed in a room temperature bath and an ice water bath along with a NIST-certified thermometer prior to deployment. CRWC has a NIST-certified thermometer and a log sheet for doing this quality check procedure — FirstLight’s consultants are welcome to perform this calibration in our laboratory, if that would be helpful.
Dissolved oxygen and temperature profile sampling at three locations in the impoundment
The sampling plan does not specify time of day that the profile sampling will be performed. Dissolved oxygen levels vary in rivers during the day and are lowest just before dawn. CRWC recommends that the profile sampling be performed biweekly at a consistent time, preferably as early in the morning as feasible. CRWC concurs with MassDEP’s suggestion that you look at the DO diurnal patterns from the installed loggers to make your decision, but we add that you try to sample at the same time for each site during each monitoring event.
The sampling plan does not provide the rationale for the profile sampling. The plan does not provide the river depth information for Station No. 2 or 7. Please provide a rationale for the location of Station No. 2.
Temperature Data Collection between Cabot Station and the Holyoke Dam
New to the study plan are five loggers proposed for placement in the Connecticut River between Cabot Station and the Holyoke Dam, roughly a 33-mile stretch. Page B-6 of FERC’s Study Plan Determination dated 2/21/2014, stated, “We recommend FirstLight develop a temperature monitoring study plan for the reach between Cabot Station and the Holyoke dam to describe temperature and temperature rate of change associated with peaking operations… We note that effects of peaking operations may attenuate downstream due to tributary inflow and the backwatering effect of the Holyoke dam. These effects should be accounted for in the study’s design.”
Given the purpose of this part of the study being to look at temperature effects due to peaking, we are perplexed about the choice of logger locations. There are relatively few loggers proposed in the reach unaffected by the Holyoke impoundment (according to Holyoke Gas & Electric, the upstream extent of the Holyoke impoundment is just downstream of the Route 116 Bridge in Sunderland), and then there is a cluster of three closely-placed loggers in the Hadley area.
In addition, based on our own experience with temperature loggers, we do not recommend locating the loggers at marinas or locations of high recreational use. They will be stolen or the lines will be cut, and you will not have any data. See also our comment above on depth and location off banks proposed. If the loggers are tethered off shore and weighed down with cement blocks, the outside curve of the stream is often a good place to sample since the main current tends to hug this bank.
Additional comments are in the table below.
Station No. Proposed Logger Location Approx. River Mile Comment/Recommendation
Deerfield confluence 114
12 Downstream of Deerfield River confluence 112 Location seems okay.
13 Route 116 Bridge, Sunderland 104 8-mile gap between sites as proposed. Move to downstream of Third Island (RM 107) or further upstream to capture peaking effects.
14 Route 9 Bridge, Hadley 92 12-mile gap between sites as proposed. Move to RM 101 vicinity (Sunderland-Hadley town line).
15 Mitch’s Marina, Hadley 88.5 Move to RM 94-90 vicinity, away from heavy recreation use.
16 Brunelle’s Marina, South Hadley 85 Move away from heavy recreation use, perhaps at upstream end of Mt Tom generating station property.
Holyoke Dam 81
Additionally, if the MassDEP standard operating procedures referenced in the plan are not available online, it would be helpful to attach them in an appendix.
Thank you for the opportunity to provide input on the draft water quality sampling plan.
Andrea F. Donlon
Cc: Bob Kubit, MassDEP
Brian Harrington, MassDEP
Caleb Slater, MA Dept. of Fish and Game
Owen David, NHDES
Melissa Grader, USFWS
Ken Hogan, FERC