Dredged Material Beneficial Uses/Alafia

Banks, Whiskey Stump Key and McKay Bay

Dredge HolesAugust 12, 2004

Presentation to ABM

Tampa Bay Dredge Hole Assessment Project

“WORST” DREDGE HOLE

McKAY BAY (hypoxia, sediment contaminants, degraded benthos, degraded fish community)

Conclusions:

Dredge hole Fisheries Benthos

McKay Bay 1 1

St. Pete Air 2 6

Northshore 3 3

Whiskey Stump1 4 4

Whiskey Stump2 5 5

MacDill Runway 6 8

Cypress Point 7 2

Gandy N. 8 9

Shore Acres 9 7

Spearman Rank Corr. = 0.583, P = 0.0992

[Based on FIM Index 1 (minus seine data) and approx. mean TBBI from spring and fall]

Source: FWC FWRI Fisheries Independent Monitoring Program

Alafia Banks enhancement: beneficial use project to stabilize erosion and enlarge intertidal habitat

US Army Corps of Engineers Alafia River Turning Basin dredging area

Alafia Banks: one of the most important and diverse wading bird rookery in the Southeastern US

ACOE and FDEP Requirements

• ACOE: For economic viability, place at least 700,000 cubic yards of material - Alafia Banks can take 450,000 cy

• FDEP: For permitting the Alafia Banks project, shallow-up 20 acres of bay bottom by filling artificial hole

ACOE project: Fill one or both Whiskey Stump Key holes

Recommend-ations from July 8, 2004 Dredge Hole Assessment Advisory Group meeting:

Do not fill Whiskey Stump Key holes, due to existing habitat value

Whiskey Stump Key holes: West and East

Dredge Hole Assessment Advisory Group Recommendations:

July 8, 2004

• Recommend that the US ACOE strongly consider the feasibility of using the McKay Bay Dredge hole for placement of beneficial use material from the Alafia River project.

Dredge Hole Assessment Advisory Group Recommendations:

July 8, 2004

• Recommend that beneficial uses of material from the Alafia River project be prioritized as follows:

1. Alafia Banks enhancement 2. McKay Bay Dredge Hole

McKay Bay dredge hole

Sediment Contamination Action Plan Sites

1. Palm River/McKay Bay

2. Ybor Channel

3. West Davis Island

4. East Bay

As recommended by TBEP Sediment Quality Assessment Group:

July 2004

Site 1

Site 2

Site 3

Site 4

US ACOE obstacles for use of the McKay Bay hole for Alafia River

Project material

• Very fast time table• Permitting (FDEP and NEPA)• Funds to make up the difference

in transporting material to McKay Bay vs. Whiskey Stump Keys

Hillsborough County PRF: $75,000TBEP: $25,000 (staff request)

• PROJECT OBJECTIVE: – Restore McKay Bay dredge hole by capping with

cleaner dredged material from the Alafia River ACOE project, by supporting the transport of clean dredged material to McKay Bay

• BENEFITS:– Restoration of polluted area (PRF priority)– Cost-effective method (ACOE is primary funder)– Supports Tampa Bay sediment quality goals – Supports approved Dredged Material Management Plan – Supports enhancement of bird rookery at Alafia Banks