Transcript Monroe County Canal Management Master Plan

Update on Canal Restoration
Demonstration Projects and Related Issues
July 15, 2014
Prepared by AMEC Environment & Infrastructure, Inc
Update on DEP Grant for Sediment Characterization
and Design/Permit of Geiger Key Culvert
 Grant Paperwork signed December 16, 2013
 Two Major Tasks in the Grant Scope:
 Additional characterization of sediments at two
demonstration projects selected for organic
removal – #266 Doctors Arm BPK and #290 Ave
J BPK
 Design and permit of 3rd ranked demonstration
canal for culvert installation to enhance natural
flushing – #472 Geiger Key, Geiger Mobile
Homes
2
Update on DEP Grant Sediment Characterization
 Nine cores collected in each canal for detailed field logging

and laboratory testing to refine removal volumes
 Organic material found to top of limerock
 6 feet of organics (top of sediment at ~-6 MLW)
 Estimated volumes
– #266 8,300 cubic yards
– #290 4,700 cubic yards
– 4-5 x higher than from dual frequency survey data estimates
Laboratory Testing
 Physical Testing (Organic Content/Grain Size Distribution)
 Polymer Testing for dewatering
 Chemical Testing for disposal (#290 only)
– Arsenic 8.2 mg/kg and Copper 540 mg/kg (slightly above Residential SCTLs)
– #266 previously tested as clean fill
3
Update on DEP Grant for Design/Permit
of Geiger Key Culvert



Design and Permit a culvert to connect canals
#472 and #470 under Boca Chica Road
Field work completed in December 2013
 Topographic and bathymetric survey
 Benthic and threatened and endangered species
surveys – no sensitive resources will be impacted
 Geotechnical soil borings
 Tidal study
 Engineering site condition survey
Preliminary Design Plans including a Hydraulic
Evaluation Report completed by February 17
 Report approved by DEP State Hydrographic
Engineer (Mariano Guardo)
4
Update on DEP Grant for Design/Permit
of Geiger Key Culvert (con’t)

Pre-application permitting meetings with Canal Restoration
Designated Regulatory Staff completed by February 28, 2014
 SFWMD ERP – Trisha Stone
– Several General Permits (GP) could apply to the canal restorations
– GP for Environmental Restoration or Enhancement projects (62330.31), if qualify. No mitigation required.
– Culvert for Geiger Key meets criteria for Minor Activities within
Existing County ROW (GP 62-330.447(1)(c))
 USACE – Ivan Fannin & NOAA Fisheries – Brandon Howard
– Construction methodology key to determining ‘no effect’ and if a
Section 7 Consultation is required
 FKNMS – Joanne Delaney
– Reviewed benthic survey protocols
 Monroe County ROW/Building Permits
– Submitted by construction contractor
5
Update on DEP Grant for Design/Permit
of Geiger Key Culvert (con’t)


Final Designs completed and submitted with permit
applications by April 8, 2014
All Permits Received within 35 days
 SFWMD ERP General Permit - April 25, 2014
 USACE Nationwide (NW) 7 - May 13, 2014
SFWMD ERP 44-00-560-P
– NW 7 – Outfall Structures and Associated Intake Structures
 FKNMS - May 2, 2014


SAJ-2014-01041 (NW-IF)
Construction Plans with Technical Specifications
submitted June 6 ready for bidding
 Estimated Engineering Construction Cost $90,000 - $107,000
All deliverables submitted on, or ahead of schedule,
within budget.
FKNMS-2014-061
6
Update on Monroe County Demonstration Projects


AMEC was approved to start work for the design and permitting of 6 Monroe
County demonstration projects on May 21, 2014
Four different technologies being evaluated separately; one combination
Weed Barriers
Organic
Removal
Culvert
Installation
Pumping
Backfilling
Same Canal – 2 categories
#1
#4
#2
#5
Not Included in
current scope –
redesign in process
#3
#6
7
Update on Monroe County Demonstration Projects
(con’t)
 Site visits performed in June to meet with
homeowners to verify locations of equipment and
identify areas required for construction
 Field work underway in July/early August
 Baseline conditions surveys/engineering
reconnaissance
 Mangrove surveys
 Review of FIU benthic survey results
 Bathymetric and planimetric surveys
 Sediment and soil borings
The Loop Current
 Preliminary Design and Permitting - Aug/Sept/Oct
8
Monroe County Demonstration Project Permitting
Status




Monroe County has agreed to sign as applicant and operator, as well as
owner of submerged lands not identified as state or privately owned
“De Minimis” exemptions, GPs, and NW permits will be used where possible
USACE is re-issuing GP-82 and planning a meeting with the FKNMS to
identify what additional GPs can be utilized in the future in the Keys
Pre-application meeting held July 1 with Monroe County Growth
Management/Planning and Environmental Resources
1. Identified the need for a Temporary Use Variance for staging
equipment in residential vacant lots
2. Comprehensive Plan language prohibiting maintenance dredging to
below -6 feet mean low water – need for a waiver or Comp Plan
change
9
Canal #290 Avenue J Bathymetric Profile
Canal 290 Big Pine Key
0
Surveyed
TOS
Probe TOS
-2
-4
Elevation (ft NAVD)
Probe HB
Note:
- MLW = -1.11' NAVD
-6 MLW = -7.11' NAVD
-12 MLW = -13.11' NAVD
-6
-8
-10
-12
600
500
400
300
Distance From Back of Canal (ft)
200
100
0
10
Canal #266 Doctors Arm Bathymetric Profile
Canal 266 Big Pine Key
0
-2
Surveyed
TOS
Probe TOS
Note:
- MLW = -1.11' NAVD
-6 MLW = -7.11' NAVD
-12 MLW = -13.11' NAVD
Probe HB
Elevation (ft NAVD)
-4
-6
-8
-10
-12
-14
1400
1200
1000
800
600
Distance From Back of Canal (ft)
400
200
0
11
Next Steps for Monroe Demonstration Projects







Expedite permitting
Bid the construction of the restorations
 Target is to start several of the projects by January 2015
Construct restorations
 Ranges from 2 weeks to 3 months
Monitor effectiveness (FIU)
Identify additional sources of funds to implement more
restorations
Modify restoration implementation process as needed
Public outreach and education/Implement Best
Management Practices in canals
12
Revised #278 Eden Pines Conceptual Design
 Canal #278 Eden Pines, Big Pine Key was
selected for implementation of a pumping
technology
 The original conceptual design:
 Intake pipe near the box culverts in Big
Pine Slough, or
 Discharge pipe in Big Pine Slough
 Both locations required US FWS access,
which was not forthcoming
 Alternative designs have been evaluated
13
Canal #278 Eden Pines Objectives and Design Basis
Alternative Pump Evaluation
•Objectives:
•Increase Flushing
•Add Dissolved Oxygen
•Contain the pump system
within the canal footprint
•Design Basis
•4 day water system turnover
•>4 mg/L Dissolved Oxygen
•4 feet minimum draft clearance
at MLW
•Two pump systems were evaluated:
•Venturi Pump System
•Geyser Pump System
14
Canal #278 Eden Pines Alternate Conceptual
Pumping System
•Geyser Inertia Pumps (GIP):
Pros – Lower energy consumption smaller solar panel footprint (10’ x 5’).
Cons –
1. Does not provide sufficient gas
exchange, therefore a fine bubble
diffuser will need to be added to the
transmission line.
2. Does not pump water laterally more
than 100’.
3. Requires land access for
compressors.
•Venturi Pump System:
Pros – Provides good gas exchange
Cons – Higher energy consumption larger solar panel footprint (50’ x5’).
15
Canal #278 Eden Pines Alternate Conceptual Design
•
GIP System Components:
• 10 pump sites (1/3 HP
compressor for GIP
and 1/3 HP
compressor for
diffuser)
• 10’ of 6” Perforated
Suction pipe run along
bottom canal.
• 100’ of 6” Discharge
pipe affixed to canal
headwall at mid-depth
• Solar Panels(50 sq ft
for each system)
16
Canal #278 Eden Pines Alternate Conceptual Design
•
Venturi System
Components:
• 10 pump sites (5 HP
submersible pump with
venturi)
• 12” PVC Discharge
pipe run along the
canal bottom
• 6” HDPE Perforated
Suction pipe run along
bottom canal.
• Solar Panels(250 sq ft
for each system)
17
18