Pre-Dredge Analysis Report 2010 - Floridap...container. These samples were labeled and returned to...

PRE-DREDGE SEDIMENT ANALYSIS

and SUBMERGED AQUATIC VEGETATION

REPORT for

FANNING SPRINGS STATE PARK Levy County, Florida

January 2011

ESI Project No. EJ10105.00

for Tim Adkinson, P.E.

Adkinson Engineering

Jacksonville, Florida

Environmental Services, Inc. 7220 Financial Way, Suite 100

Jacksonville, FL 32256 (904) 470-2200

TABLE OF CONTENTS

Page

I. INTRODUCTION .........................................................................................................1 II. SCOPE ...........................................................................................................................1 A. Location of Sampling Stations. ..........................................................................1 III. METHODS . ..................................................................................................................2 A. Quality Assurance/Quality Control . ..................................................................2 B. Grain Size Distribution Analysis. ......................................................................2 1. Sample Collection. .................................................................................2 2. Sample Processing. ................................................................................3

C. Sediment Core Boring Analysis.........................................................................3 1. Sample Collection. .................................................................................3 2. Sample Processing. ................................................................................3

D. Submerged Aquatic Vegetation . .......................................................................3 1. Survey Methodology. .............................................................................3 IV. RESULTS . ...................................................................................................................5

A. Grain Size Distribution . ...................................................................................5 B. Sediment Core Borings ………………………………………………………...5 C. Submerged Aquatic Vegetation . ......................................................................5

V. CONCLUSION .............................................................................................................6 VI. SIGNATURES ...............................................................................................................6 APPENDICES

A. Core Sample Pictographs B. Core Sample Photos C. Grain Size Distribution Curves

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LIST OF FIGURES

Page Figure 1. Sediment Analysis Station location map . ............................................................... 4

I. INTRODUCTION Fanning Springs is a “historic first-magnitude” spring with a current discharge flows being listed at 65 million gallons per day. It is a recreational attraction nestled within the boundary of Fanning Springs State Park, and it is not only a destination for tourists but also serves as a refuge for native wildlife. Fanning Springs consists of a single vent system which has a boil area approximately 175 feet wide and can have a maximum depth of up to 21 feet. In an effort to continuously improve the intrinsic and instrumental values of the water resources within the State of Florida, the Florida Fish and Wildlife Commission (FWC) and Fanning Springs State Park have initiated an aquatic habitat restoration project located in the spring run between the vent opening and the Suwannee River in Levy County, Florida. The intent of this project is to restore the spring run to depths similar to historic elevations as the spring run has accumulated sediment from various potential sources including stormwater runoff and deposition from backwaters of the Suwannee River. Consequently, a reduction of water quantity and flow has alter the natural hydraulics of the spring, decreased the availability of potential habitat to support submerged aquatic vegetation, and has decreased the minimal flow depths which impedes the accessibility by the Florida manatee (Trichechus manatus latirostris) to utilize the spring run as a cold weather refuge. ESI was contracted to provide ecological consultation regarding the existing site conditions and to determine the extent of excavation required to return the system to the historic conditions as to provide sufficient water depths and flow to improve manatee accessibility. On 17 November 2010, ESI personnel collected grain size samples and performed the submerged aquatic vegetative survey within the defined project boundary. On 16 December 2010, ESI returned to the spring-run and collected eight additional sediment profiles boring samples to evaluate depths of the deposition of sediment. This report details the methodologies utilized to evaluate the current site conditions, including a detailed analysis of the current and existing sediment composition, and recommends a proposed post-dredge elevation to restore the spring run to historic conditions. By removing any “recent” sediment deposition, the run will be restored to historic conditions which may support submerged aquatic vegetation and increase the accessibility (and consequently the usability) by the Florida manatee as a freshwater refuge during winter periods.

II. SCOPE Location of Sampling Stations

The spring is located within the property boundary of Fanning Springs State Park in Levy County, Florida but is also abutting the boundary of Gilchrist County. The spring run is approximately 300 feet in length, terminating at the Suwannee River. Eight (8) sampling stations were identified based on current topographic information to provide a detailed understanding of the existing site conditions of the proposed restoration area. Figure 1 depicts the locations of the eight stations and identifies the specific analyses to be performed at each location (i.e. soil core borings and/or grain size distribution analysis).

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A submerged aquatic vegetation survey was performed across the entire project boundary given the relatively small area within the project boundary.

· Stations 1 and 2: Located inside the docking facility area associated with Fanning Springs State Park’s recreational swimming area. These stations cover the northern extent of the vent area, where sedimentation has accrued. Core boring samples were collected at both stations while the grain size sample was collected at only Station 1.

· Stations 3 and 4: Located along the river-side of the docking facility associated

with Fanning Springs State Park recreational area. These stations represent the sedimentation accrual in the upper reaches of the spring-run. Core boring samples were collected at both stations while the grain size distribution was collected at only Station 4.

· Stations 5 and 6: Located in the central portion of the spring-run, these sampling

stations represent the accrual of depositional sediment along the edges of the spring channel. Core boring samples were collected at both stations while the grain size distribution was collected at only Station 6.

· Stations 7 and 8: Located at the mouth of the spring-run and the confluence of the

Suwannee River. These stations represent the deposited sediment potentially accrued from the tail waters of the main stem river. Only core boring samples were collected at these stations.

III. METHODS

Quality Assurance/Quality Control ESI personnel conducting the sediment sample collection and submerged aquatic resources survey are experienced in the methodologies set forth by Florida Department of Environmental Protection (FDEP) and FWC. Furthermore, all sampling activities were conducted in adherence to ESI’s Quality Manual which meets all applicable criteria set forth in Chapter 62-160 F.A.C. Grain Size Distribution Sampling

Sample Collection. All sediment sample collections followed the guidance as defined in

the Florida Standard Operating Procedures (SOPs) for General Field Sampling (FS1000) and for the Sediment Sampling (FS4000). Specifically, a single-barrel core boring device was inserted into the sediment (direct push methodology). The solid core was extracted from the substrate under vacuum pressure and composited into an approved soils container. These samples were labeled and returned to the laboratory for further analysis.

Sample Processing. At the ESI lab, the composited grain size samples were dried to

remove all moisture and homogenized for consistency. A 150-g aliquot was randomly selected from the homogenous sample and sorted via a mechanical sieve mechanism

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containing US Sieves No. 5 (4mm), 10, 35, 60, 120, 200, and 230 (0.063mm). Each sieve was cleaned and pre-weighted in order to accurately determine the total weight of the sediment of each grain size category. After mechanical sieving, the sediment granules and their sieves were weighted and recorded. As a general rule, all analyses maintained a <2% error factor for all distribution analyses. If the sum of the partitioned weights were greater than two percent different from the original total weight, the grain size distribution was discarded and re-initiated with a new aliquot. The percentage of grain size smaller than the sieve size (aka “percent finer by weight”) was calculated and plotted on the logarithmic scale in Excel with D Plot. Once graphically interpreted, ESI calculated the coefficient of uniformity (Cu) and the coefficient of curvature (Cc) by evaluating the 10th, 30th, and 60th percentiles. The overall statistics were analyzed through the flow model for the Unified Soils Classification System (USCS) to determine their classification. Sediment Core Sampling

Sample Collection. All sediment sample collections followed the guidance as defined in the Florida Standard Operating Procedures (SOPs) for General Field Sampling (FS1000) and for the Field Sampling of Sediments (FS4000). Specifically, a single-barrel core boring device was inserted into the sediment (direct push methodology), and a solid core was extracted from the substrate. These samples were removed from the sampler and stored in 12-inch incremental soil containers. These containers were appropriate labeled and returned to the laboratory for further analysis.

Sample Processing. At the ESI lab, the core samples were reassembled in a controlled

environment in order to evaluate changes in color scaling, texture, general composition. Detailed notes and measurements were collected and recorded for each core sample. Any compaction from the direct push collection methodology was extrapolated and corrected in the graphical interpretation in Appendix A. Scaled photo documentation (see Appendix B) was completed and the sediments were retained for an archeological investigation, given the historic context surrounding the spring-run, prior to discarding the remaining sample.

Submerged Aquatic Vegetation Survey

Survey Methodology. Given the relatively small area of the project boundary, a 100

percent survey was performed throughout the spring-run. ESI personnel, trained in the identification of aquatic plant taxonomy, traversed the project area in a small watercraft or on foot, depending on water depths. Given the extreme clarity of the spring water, the water visibility was equal to the total depth so ESI was able to clearly observe and identify submerged vegetation in the deepest portions of the spring-run from a watercraft. The extent of submerged vegetation coverage was delineated and recorded using a Global Positioning System (GPS). In addition to percent coverage, density estimations and a total species list of vascular and dominant non-vascular aquatic vegetation were derived for the spring-run.

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File: Q:\_Projects\EJ\2010\105\fig\sampling.mxd Printed: 1/18/2011 11:05 am

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7220 Financial Way, Suite 100Jacksonville, Florida 32256(904) 470-2200(904) 470-2112 Fax

0 6030

Feet

www.environmentalservicesinc.com

Sediment Sampling Map

Levy County, FloridaFanning Springs Dredging

1

EJ10105.00Jan. 2011JGB/JRN

ENVIRONMENTALSERVICES, INC.

Figure:

Project:Date:Drwn/Chkd:

Disclaimer: The information depicted on this figure is forconceptual purposes only, serves to aid a licensed engineer orgeologist in rendering professional services, and is subject toreview and approval by appropriate regulatory agencies.

!? Soil Boring Location!. Grain Size Sample Location

Approximate Edge of WaterApproximate Top of BankFloating DockTopographic Data

Source(s): Bing Aerial (2009).

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IV. RESULTS

Grain Size Distribution The three grain size distribution plots revealed similar characteristics of sediment within the top twenty-four to forty-eight inches. The predominant granular size of the sediments is classified as a fine sand (US Sieve No. 120, being 0.250 mm > xi > 0.125mm). Approximately 40 to 45 percent of each core boring fell into this category, while the second largest percentage (approx. 25-35 percent) was the next grain-size smaller (No. 200). Typically, no more than ten to twelve percent was classified as larger than a fine sand grain size. Grain Size Composite No. 2 (at Station 4) contained less than ten percent medium to course granular material, and was comprised mainly of the two sizes of fine and very-fine sands. Finally, only five percent of the sediments contained ultra-fines and silts/clays. With the overall percentages being skewed towards one to two predominant categorizations, the sediment analysis interprets the composite sediments to be a poorly sorted fine sand (SP). The Grain Size Analysis worksheets and corresponding Distribution Curves may be referenced in Appendix C. Sediment Core Borings Each individual core boring contained multiple layers of fine sands consisting of anywhere from two to different four chromatic color scales. In general, the upper five to seven inches (excluding Core Boring Nos. 3 and 6) contained a light grey fine sand which appeared fairly uniform and could be representative of the most recent layer of deposition. Core Boring Nos. 3 and 6 were the only abnormalities to this generalization, in that Core Boring No. 3 was one-hundred percent light grey sands with minimal shell debris sparsely intermingled throughout the core sample, while Core Boring No. 6 had only one inch of deposited light grey sand. This core sample will be discussed in the Conclusions section of this report. A second layer was observed at approximately fifteen inches, which consisted primarily of light to medium grey/brown sands. A third layer was faintly observed at the 21 to 25 inches below the surface. This demarcation was fairly consistent in Core Boring Nos. 1, 2, 4, 5, 7, and 8, but varied more so than the previous mentioned layers. Beyond 25 inches, most of the sediment cores contained medium brown sands, with organics and mucky texture. Submerged Aquatic Vegetation Of the surveyed area, two species of submerged aquatic vegetation were identified within the spring-run and vent areas, red ludwigia (Ludwigia repens) and the filamentous algae (Spirogyra spp.). This vegetation was observed throughout the spring-run, but the density within a square meter was observed as being only moderate. Patches of the aquatic vegetation were evident, but not widespread. An estimate of twenty-five percent coverage of the total area with sufficient sunlight would generalize the current vegetative conditions within the run.

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V. CONCLUSION Environmental Services, Inc has completed the sediment analyses and aquatic vegetative survey for the Fanning Springs State Park spring-run restoration project. Based on our observations and laboratory analyses, a layer of fine sand sediments, averaging approximately 24 inches in depth, resides along the northern edge of the boil/vent and along the edges of the run channel. The upper 7 to 15 inches in most core profiles were identified as grey fine sand which appears to be the most recent depositional material and would be necessary to be excavated to restore the spring-run to conditions more similar to historic bathymetric elevations. Furthermore, an additional 10 inches of darker medium grey sands, with a slight feel of organic materials, extends beyond the upper light grey profile layer of the soil column. This layer appears to be fairly recent, although indicator characteristics of longer-term deposition were becoming apparent. It is our opinion, however, that these sediments are within the time frame that is targeted for restoration and should also be included in the excavation efforts. Beyond this upper 24-inch zone, a predominant light to medium brown sand mixed with decomposed organic fibers is present in 7 of the 8 core borings. Core Boring No. 3 is the only boring to contain 100 percent of the light grey sand and no indication of historic sediments or hardpan/bedrock parent substrate. This area is in the upper-most reaches of the run, and it is potentially the least affected by the spring flow or backwaters. Furthermore, it is located immediately stream-ward of a drainage area of the adjacent uplands that is currently utilized by the State Park system and has a higher potential for an accumulation of sediment from stormwater runoff. The remaining portion of the spring-run has accumulated (at a minimum) fourteen inches of this grey sand, with minimal organics. This indicates higher sediment transport velocities and motility with the lack of observed smaller particles within the sediment substrate. Regular flushing of the organics keeps this sand relatively “clean” and grey. Core Boring No. 6 is the only exception to this observation, but this particular core boring is located directly beneath a dense deciduous canopy cover, which produces more leaf litter and other organic matter than the other stations, offering a continuous source of organic debris. As for the west end of the spring-run, the bar formation along the northern point of the confluence of the run and the main stem river consists of a similar sediment composition and color scaling, indicating the relative “newness” of these sediments. Minimal microbial activities were observed in these particular areas of the soil profiles, which typically are associated with more historic depositional events. As for the existing submerged aquatic vegetation, sub-optimal foraging species and density stands were present at the time of our investigation. As mentioned in the results section, red ludwigia and filamentous algae were the two dominant species, although their densities and percent coverage were relatively low. Typically, tape grass (Vallisneria americana) is a preferred foraging vegetation for the Florida manatee and is a strong indicator of optimal habitat. While the sediments grain size appear to be supportive of this type of vegetation due to its minimal silt concentrations, water depths and/or other environmental factors (i.e. nutrients) may be inhibiting this particular species from inhabiting the spring run. This concludes the report of our findings. If there are any questions concerning the observations made regarding the substrate compositions, sampling methodology or other analyses performed,

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please don’t hesitate to contact either Ms. Cara Connolly or Mr. Michael Stowe at our Jacksonville, FL office. VI. SIGNATURES ________________________________ Cara C. Connolly, Vice President ________________________________ Michael B. Stowe, Senior Scientist

APPENDIX A

Core Boring Analysis

Fanning SpringsSoil Coring Profiles

1 2 3 4 5 6 7 8

light Gray0‐1

Light GrayFine organics Light Gray Light Gray

Light Gray 0‐5 Woody Macrodebris Woody Macrodebris0‐7 Shell Debris 0‐5.5 Light Gray

0‐5 Shell Debris Minimal0‐8.5

Light GrayMedium Gray, organics small woody debris5‐7.5 0‐14

Light Gray/Md. BrownHeavy wooded debris, fibersShell Debris1‐14.5

Light Gray with Shell Debris7‐15.5 Light Gray with Shell Debris

5‐14 Medium grayShell debris7.5‐14.5

Light Gray/Md. BrownShell debris, organics5.5‐25.5

Medium BrownHeavy macrodebris Light Gray. Medium Brown

Light Gray Sand Medium Brown Twigs, fibers Scarce DebrisSmall Woody debris medium Brown sand Heavy macrodebris 14‐17 8.5‐25Minimal Shell Root materials, fibers, organics 14.5‐180‐42 14.5‐21

Medium Gray14‐23.5 Light Gray/Md Brown

Medium Brown, with organics Shell debris15.5‐26.5 17‐21

Light Brown21‐23

Dark BrownOrganics, Fibers18‐28.5

Medium Brown Light GrayOrganics, Fibers Scattered woody debris23‐30.5 21‐36

Medium Brown, with organics and shell debris26.5‐30.5

Medium Brown Medium BrownMedium Brown Fibers, organic coated Mucky Fine sand

Light Gray, with shell debris Shell Debris, organics Shell debris Macro woody debris30.5‐35.5 23.5‐42 Light gray Sand 25.5‐42 25‐42

Shell Debris30.5‐34.5

Dark BrownMuckyFine and woody organics28.5‐42

Debris36‐37

Medium Brown with woody debris Medium Brown Light Gray/Medium Brown35.5‐42 Shell Debris Heavy Macroorganics

34.5‐42 37‐42

0.75 0.64 0.65 0.95 0.74 0.88 0.99 0.71

Figure 5: Fanning Spring State Park, Sediment Core Borings Analysis Stacked Histogram

Compaction Factor

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APPENDIX B

Core Boring Photos

Fanning Springs Sediment Core Analysis December 2010

Photo 1: Sediment Core Boring Station 1.















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APPENDIX C

Grain Size Analysis & Distribution Curves

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