ECOLOGICAL STUDIES OF THE CONNECTICUT RIVER

PERFORMED BY VERMONT YANKEE 1968-2012

VT

NH

ME

RI

CT

MA

VERMONT YANKEE ECOLOGICAL STUDIES

• Robust and Extensive Body of NPDES-related River Ecological Studies

– 41 Annual Reports

– 1971 - 2011

• Substantial, Additional Objective-Specific Studies Focused on Key Considerations

– 92 Topical Reports (Analytical Bulletins)

– 1984 – 2011

– Many, American shad focused.

Overview of Studies 1968-2012

VERMONT YANKEE ECOLOGICAL STUDIES

• Monitoring study plans developed under a conscientious process involving the oversight and direction of regulators, guided by aquatics experts

• Reports reviewed and approved by regulators (and more recently by the Vermont Environmental Court and Vermont Supreme Court)

• Reports used by other regulatory bodies and fisheries scientists

Overview of Studies 1968-2012

VERMONT YANKEE ECOLOGICAL STUDIES

• Both In-Plant and In-River Studies

– Water Temperature: 1968 -2012

– Water Chemistry: 1968-2012

– Primary Producers (Phytoplankton):1968-1995

– Primary Consumers (Zooplankton): 1968-1995

– Benthic Macroinvertebrates: 1968-2012

– Ichthyoplankton: 1968-2012

– Resident Fish: 1968-2012

– Migratory Fish: 1968-2012

NPDES Studies 1968-2012

VERMONT YANKEE ECOLOGICAL STUDIES Study Area in the Connecticut River 1968-2012

Bellows Falls Dam (mile 174)

Turners Falls Dam (mile 119)

Study Area = 55 miles

•Vernon Pool = 32 miles

•Turners Pool = 23 miles

Vermont Yankee (mile 143)

Figure 1 from Marschall et al. 2011. Ecol. App. 21(8): page 3016.

VERMONT YANKEE ECOLOGICAL STUDIES 2012 NPDES Monitoring Program Sampling Stations

VERMONT YANKEE ECOLOGICAL STUDIES 2012 NPDES Monitoring Program Sampling Stations

Click to add text – or delete if not needed Downstream Stations in Turners Pool Station Number Station Name Sample Type(s)

217 Station 2 NH South General electrofishing 227 Station 2 VT South Macroinvertebrates 031 Station 3 NH Macroinvertebrates, anadromous electrofishing 032 Station 3 VT Water quality, general electrofishing 624 Lower Anadromous electrofishing 614 Lower Anadromous electrofishing, general efishing 613 Mid Anadromous electrofishing 615 Upper Anadromous electrofishing 724 0.1 Mi. South of Dam (Lower) General electrofishing 725 0.1 Mi. South of Dam (Upper) Anadromous electrofishing 020 Dam Fish Ladder Water temperature, adult shad

Upstream Stations in Vernon Pool 051 Station 5 NH Zebra mussel, corbicula, general electrofishing 053 Station 5 Mid-River Zebra mussel, corbicula 052 Station 5 VT Zebra mussel, corbicula, general electrofishing 072 Station 7 VT Water quality 091 NH Setback General electrofishing 102 Rum Point General electrofishing 300 VY Discharge Water quality 416 Station 4 NH North Zebra mussel, corbicula, general electrofishing 436 Station 4 Mid-River North Zebra mussel, corbicula 426 Station 4 VT North Zebra mussel, corbicula, general electrofishing 800 VY Intakes Larval fish, impingement

VERMONT YANKEE ECOLOGICAL STUDIES NPDES Phytoplanton and Zooplankton Studies 1968-1995

Phytoplankton

• Estimate #/liter sampled (pump sampler)

• Sampled monthly Jan – Dec

• Station 3, Station 7, Intake, Discharge

• Six classes and 21 genera of phytoplankton

• Nearly all survive passage through the plant

• 98% survival at intake, 94% survival at discharge

Zooplankton

• Estimate #/liter sampled (pump sampler)

• Sampled monthly Apr – Nov

• Station 3, Station 7, Intake, Discharge

• Four phyla and 24 genera of zooplankton

• Nearly all survive passage through the plant

• 92% survival at intake, 83% survival at discharge

VERMONT YANKEE ECOLOGICAL STUDIES NPDES Benthic Macroinvertebrates 1968-2012

Dredge and rock basket samples

• Estimate #/m2 sampled (dredge) or #/month (basket)

• Sampled monthly Jun, Aug, Oct

• Vernon Pool Stations 4 and 5

• Turners Pool Stations 2 and 3

• Diverse community with nine groups of macroinvertebrates represented by up to 91 genera

• Clams (Pelecipoda) and fly larvae (Diptera) most abundant in dredge samples

• Fly larvae (Diptera) and caddisfly larvae (Tricoptera) most abundant in cage samples

gammarids

VERMONT YANKEE ECOLOGICAL STUDIES NPDES Ithyoplankton Studies 1968-2012

0.5 m, 500 micron mesh hoop net samples

• Abundance of fish eggs and larvae per 100 m3

• Weekly when present May through mid-July

• Near intake samples

• Surface, mid-depth, bottom

• In-Plant entrainment sampling

• April through September (peak in late June early July)

• Carp and minnow larvae dominate ichthyoplanklton samples

• Sunfish larvae, perch and walleye larvae were also present in lower abundance

VERMONT YANKEE ECOLOGICAL STUDIES NPDES Resident and Migratory Fish Studies 1968-2012

Ct River Sampling

• Provides index of abundance

• Catch per standard unit of effort

•Gear Deployed and sampling periods

• Year round sampling in first decade (1968-1978); seasonally appropriate after that.

•Electrofish sampling (Apr-Oct of 1968-2012)

• Trap nets (Apr – Oct of 1968-1999)

• Seines (Jul – Nov of 2000-2012)

VERMONT YANKEE ECOLOGICAL STUDIES NPDES Resident and Migratory Fish Studies 1968-2012

Sampling Program

Years Number of Samples

Number of Fish Caught

Trap net 1968-1999 2,208 38,148

Electrofishing 1968-2011 2,886 112,304

Seine 2000-2011 2,848 68,261

Total 1968-2011 7,942 218,713

Fishing effort and total catch by gear

Upper Connecticut River Fish Assessment Study for USEPA collected 46 electrofishing samples (1 km segments) from Aug – Oct 2008 between Turners Falls Dam and Lake Francis and caught 7,262 fish.

VERMONT YANKEE ECOLOGICAL STUDIES Objective Specific Studies 1984-2011

92 Analytical Bulletins

• Each represents a one- or two-year targeted study

• 49 studies of American shad

• 2 studies of Atlantic salmon

•14 studies of resident fish (targeting RIS)

• 9 thermal plume studies

• 2 water quality studies

• 4 phytoplankton/zooplankton studies

• 3 macroinvertebrate studies

• 1 ichthyoplankton study

• 5 impingement/entrainment studies

• 4 sampling design studies

VERMONT YANKEE ECOLOGICAL STUDIES Objective Specific Studies 1984-2011

49 American Shad Analytical Bulletins

• Turners Pool and Vernon Pool

• age and growth

• bioenergetics

• habitat selection

• larval and juvenile distribution

• adult age and gender from Vernon and Turners fish passage facilities

•fish passage efficiency at Vernon Dam fishway

• juvenile shad abundance

VERMONT YANKEE ECOLOGICAL STUDIES NPDES Thermal Compliance 1968-2012

Key Components of a Holistic Thermal Compliance System

• Calculated hourly average temperature increase attributable to Vermont Yankee (Equation 1.1)

• Continuously measured hourly average temperature

• Upstream ambient Station 7

• Downstream mixed Station 3

• Vernon Dam fishway during its period of operation

Station 7

Station 5 NH Setback

Vermont Yankee Generating Station

Station 4

Station 3

Rum Point

NH

MA

Station 2

Stebbins Island

Vernon Dam and Powerhouse

Connecticut River

VT

Upstream Measured Temperature

Downstream Measured Temperature

Vernon Fishway Water Temperature

VERMONT YANKEE ECOLOGICAL STUDIES Thermal Compliance with NPDES Permit Limits (NPDES Permit 2006)

Upstream Monitoring Station 7 Ambient Temperature

Calculated River Water Temperature Increase Above Ambient at Downstream Monitoring Station 3

16 May – 15 June Limits 16 June – 14 October Limits >78 ºF 2 ºF 2 ºF

>63 ºF, ≤78 ºF 2 ºF 3 ºF >59 ºF, ≤63 ºF 3 ºF 4 ºF ≥55 ºF, ≤59 ºF 4 ºF 5 ºF

<55 ºF 5 ºF 5 ºF

Winter Compliance –

• Measured hourly rate of change not to exceed 5 F

at downstream Station 3

• Measured hourly maximum temperature not to exceed 65 F at downstream Station 3

• Calculated hourly increase at downstream Station 3 not to exceed 13.4 F

Summer Compliance –

Measured hourly maximum temperature not to exceed 85 F at downstream Station 3

VERMONT YANKEE ECOLOGICAL STUDIES

• Vermont Yankee has performed a robust and extensive set of ecological studies in a 55 mile reach of the Connecticut River, i.e., from Turners Falls to Bellows Falls.

• All major components of the aquatic ecosystem have been studied for more than 40 years.

• Oversight and approval of all studies by a multi-agency Environmental Advisory Committee and regulators.

• Studies consistently have found that the permitted thermal discharge from Vermont Yankee has assured the protection and propagation of the balanced indigenous populations of fish, shellfish and wildlife in the Connecticut River.

Conclusions