American Fisheries Society Annual Meeting August 30 – September 7, 2009

1. Water, LLC Performance of Exclusionary Devices to Minimize Impingement and Entrainment in the Taunton River, Massachusetts Nathan Henderson, B. Courchene, R. Robitaille, B. Shreve-Gibb and J. Gaztelu American Fisheries Society Annual Meeting August 30 – September 7, 2009

2. Project Background • Planning and permitting for the Taunton River Desalination Plant (TRDP) ongoing since 1994. • 14 miles upstream where the Taunton River dumps into Mount Hope Bay. • Treatment of 10 MGD brackish water from the Taunton River, MA. • 5 MGD per day to communities in SE MA. • TDRP operates in desalination mode when salinity > 5ppt. (July –November) • Design and permitting efforts received substantial scrutiny Narragansett Bay

3. Need for Desalination • City of Brocton particularly water starved dating back to the 1800’s. • Desalination a way to relieve stressed ground and surface water bodies. • Extensive review of alternatives revealed that desalination was the most viable alternative. • Question??? – Do the environmental benefits of a desalination plant out weigh the environmental impact of operation??

4. Key Permitting Issues • Effects of brine discharge on water quality and aquatic resources. • Salt wedge, changes in salinity. • Presence of MA endangered plant species. • Impacts from withdrawal on aquatic resources in Taunton River. • Entrainment- The incorporation of fish, eggs, and larvae entering a water system. • Impingement- The entrapment of organisms on exclusionary screening device. Long’s Bitter-cress

5. Impingement and Entrainment • Third intake facility within the Taunton River basin. • Brayton Point – 42 mgd (Significant reductions in fisheries resources in Mount Hope Bay) • Taunton Municipal Lighting Plant (~ 2 miles Upriver) • Brayton Point used as EPA case study for the establishment of section 316(b) of the Clean Water Act in 2001. • 316(b) Best Technology Available (BTA) to minimize impingement and entrainment. Brayton Point, Somerset MA • TRDP not regulated under 316(b); held to equal standards of Phase I for new facilities.

6. Designing Entrainment and Impingement Controls • Identified 36 fish species in river • Determined egg and larval size • (0.8mm alewife, 0.85mm rainbow smelt) • Designed multiple redundant mechanisms to minimize entrainment and impingement. • Controlled approach velocities at all intake screens • Controlled discharge velocities Chain Pickerel Hogchocker Menhadden Yellow Perch

7. Exclusionary Devices Incorporated into the Design of the Plant • Gunderboom Marine Life Exclusion System™ • 0.5mm AOS - 0.016 ft/s approach velocity - Airburst System

8. Trash Racks within each intake bay • 0.37 ft/s approach velocity • Bars spaced 5.0 cm Wedgewire Screen - ¼ inch mesh - 0.5ft/s slot velocity 6 Johnson Screens (3 in each bay) - 0.2 ft/s slot velocity - 0.8mm AOS - Airburst system Redundant Exclusionary Devices at the Intake Structure Raw Water Pump Station Intake Bays ¼” Wedgewire Screen Trash Racks

9. Fisheries Monitoring Program • Evaluation Criteria • Achieve annual entrainment and impingement exclusion rates of not less that 80% for Representative Important Species (RIS) • Alewife, blueback herring, white perch, American eel, rainbow smelt, American shad ,and menhaden • Baseline Monitoring (2006- 2008) • Operational sampling (2008 – 2009) (TRDP online May 2008) • In-river sampling- (identical to baseline sampling program) • Entrainment monitoring- (Gunderboom, and pump station) • Impingement monitoring at all screens- (all life stages) • Determine weekly, monthly and annual exclusion rates on each screen • Model age- 1 adult equivalent mortality (Equivalent Adult Models (EAM)

10. Baseline and Operational Finfish and Icthyoplankton Sampling • In-river- icthyoplankton tows • (3 stations) • In-river fyke nets, beach seines, • shrimp trawls, gill nets (baseline) Beach Seine Fyke Net

11. Impingement and Entrainment Sampling • Impingement sampling during intake • Gunderboom, before and after airburst (vacuum sampling) • Wedgewire screens (basket sampling) • Johnsons screens before and after airburst (vacuum sampling) • Entrainment sampling during intake • Intake structure (shoreward of the Gunderboom) • Raw water pump station (shoreward of the Johnsons Screens)

12. Results - Impingement Sampling • Gunderboom - 13 / 122 samples contained eggs or larvae (46 total ) • Trash racks daily observations – no impingement • Wedgewire screens 7/61 samples contained juvenile fish (10 total) • Johnsons Screens 5/109 total samples (3 eggs and 3 juveniles) Airburst effectiveness at removing eggs and larvae

13. Exclusion Rates Results Entrainment RIS species Alosa Species Exclusion Rates >80% exclusion White Perch Exclusion Rates American Shad

14. Results Weekly Entrainment All Species Monthly percent exclusion rates for all species when eggs and larvae were collected in the river

15. Equivalent Adult Model Estimates based on equations presented in USEPA (2002) Assumed to be 100% impingement and entrainment mortality 1 Estimates based on equations presented in USEPA (2002)

16. Conclusion • Species diversity very high • Impingement • Gunderboom system combined with the high velocity river flowing across the exclusionary mesh appear to be effective at minimizing impingement. • Very low rates of impingement on Wedgewire screens and Johnsons screens • Entrainment • Exclusion rates for all RIS resulted in exclusion rates above the 80% exclusion benchmark • Annual entrainment exclusion rate for all eggs and larvae 91% • EAM predicted 12 white perch and 1 alosa sp. (Age 1 equivalents) lost by operation of TRDP • As more water is withdrawn for drinking water I&E rates may become higher • Agencies have required additional monitoring in 2009-2010

17. Questions