# Supplemental Environmental Impact Statement for the

Designation of Dredged Material Disposal Site ( s ) in Eastern Long Island Sound, Connecticut and New York



# APPENDIX F

Disposal Area Monitoring System

– DAMOS: Data Summary Report of the New London Disposal Site and Vicinity Sediment Profile

and Plan

- View Imaging Survey

Prepared for : 

# United States Army Corps of Engineers

Prepared by: 

# DAMOS Vision

March 20 1 5

### [This page intentionally left blank.]

# Data Summary Report: New London Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey September 2014



# Disposal Area Monitoring System
DAMOS

Data Summary Report

2015-01

March 2015

### This report should be cited as:

Carey, D. A.; Bellagamba Fu cile, E. 2015. Data Summary Re port of the New London Disposal Site and Vicinity Sediment-Profile and Plan -View Imaging Survey, September 2014. U.S. Army Corps of Engineers, New Engl and District, Concord, MA, 45 pp.

Note on units of this report : As a scientific data summary, information and data are presented in the metric system. However, given the prevalence of English units in the dredging indus try of the United States, conversions to English units are provided for general in formation in Section 1. A table of common conversions can be found in Appendix A.i 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

TABLE OF CONTENTS

Page

1.0 INTRODUCTION .......................................................................................................... 1

1.1 Overview of the DAMOS Program ................................................................................ 1

1.2 Overview of EPA’s Preparation of an SEIS for ELIS .................................................... 2

1.3 Introduction to the New London Disposal Si te, Historic Nian tic Bay Disposal Site, and the General Survey Area .................................................................................. 2

1.4 Previous NLDS Monitoring Surveys .............................................................................. 2

1.5 Recent Dredged Material Disposal Activity at NLDS .................................................... 3

1.6 2014 Survey Objectives .................................................................................................. 3

2.0 METHODS ..................................................................................................................... 5

2.1 Navigation and On-Board Data Acquisition ................................................................... 5

2.2 Sediment-Profile and Plan-View Imaging Survey .......................................................... 5

2.2.1 Sediment-Profile Imaging ........................................................................................... 5

2.2.2 Plan-View Imaging ..................................................................................................... 6

2.2.3 SPI and PV Survey Planning ...................................................................................... 7

2.2.4 SPI and PV Data Collection ........................................................................................ 7

2.2.5 SPI and PV Data Analysis .......................................................................................... 8

2.3 NLDS Substrata Characteristics ..................................................................................... 9

3.0 RESULTS ..................................................................................................................... 1 9

3.1 Sediment-Profile and Plan-View Imaging .................................................................... 19

3.1.1 Eastern Reference Areas (NE-REF, and NLON-REF) ............................................. 19

3.1.2 New London Disposal Site Stations ......................................................................... 20

3.1.3 Northern and Southern Transect Sta tions, Including the Central Reference Areas (NLON-ALT, and WREF) ............................................................................. 20

3.1.4 Niantic Bay Disposal Site Stations ........................................................................... 21

4.0 SUMMARY .................................................................................................................. 39

5.0 REFERENCES ............................................................................................................. 44

6.0 DATA TRANSMITTAL .............................................................................................. 45ii 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

APPENDICES

A Table of Common Conversions

B NLDS/NBDS 2014 Survey Actual SPI/PV Replicate Locations

C Sediment-Profile and Plan-View Image Analysis Results for NLDS/NBDS Survey, September 2014

D Grain Size Scale for Sedimentsiii 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

LIST OF TABLES Page

Table 2-1. NLDS Target SPI/PV Sta tion IDs/Locations ........................................................ 10

Table 2-2. Substrata Habitat Types ........................................................................................ 13

Table 3-1. Summary of Substratum and Grain Size Major Mode (averaged across replicates) .............................................................................................................. 22

Table 4-1. Cross-walk of Substrata to LISS Habitats (Auster et al. 2009) ............................ 40iv 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

LIST OF FIGURES Page

Figure 1-1. Location of NLDS and NBDS ................................................................................ 4

Figure 2-1. Schematic diagram of the SPI/PV camera deployment ........................................ 14

Figure 2-3. Actual SPI/PV station locations an d names at NBDS and the western

section of the transects .......................................................................................... 16

Figure 2-4. Actual SPI/PV station locations and names at NLDS, the eastern section of the transects, and the central reference areas ........................................................ 17

Figure 2-5. Actual SPI/PV station locations at the eastern-most reference areas ................... 18

Figure 3-1. Sediment grain size major mode (phi units) at the eastern-most reference

areas ...................................................................................................................... 24

Figure 3-2. Substrata characterist ics at the eastern-most reference areas ............................... 25

Figure 3-3. Camera penetration depths at th e eastern-most reference areas ........................... 26

Figure 3-4. Successional stage at the easte rn-most reference areas ........................................ 27

Figure 3-5. Apparent Redox Potential Discontinu ity (aRPD) at the eastern-most

reference areas ...................................................................................................... 28

Figure 3-6. Sediment grain size major mode (phi units) within NLDS, the eastern transect stations, and the central reference areas .................................................. 29

Figure 3-7. Substrata characteristics within NLDS , the eastern transect stations, and

the central reference areas ..................................................................................... 30

Figure 3-8. Camera penetration depths within NLDS , the eastern transect stations, and

the central reference areas ..................................................................................... 31

Figure 3-9. Successional stage within NLDS, the eas tern transect stations, and the

central reference areas ........................................................................................... 32

Figure 3-10. Apparent Redox Potential Discontinuity (aRPD) within NLDS, the eastern transect stations, and the central reference areas .................................................. 33

Figure 3-11. Sediment grain size major mode (phi units) at stations within NBDS and

the western transect stations.................................................................................. 34

Figure 3-12. Substrata characteristics at stations within NBDS and the western transect

stations .................................................................................................................. 35v 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Figure 3-13. Camera penetration depths at stations within NBDS and the western

transect stations ..................................................................................................... 36

Figure 3-14. Apparent Redox Potential Discontinuity (aRPD) at stations within NBDS

and the western transect stations ........................................................................... 37

Figure 3-15. Successional stage at stations within NBDS and the western transect

stations areas ......................................................................................................... 38

Figure 4-1. Representative images from western part of the study area ................................. 41

Figure 4-2. Representative images from eastern part of the study area ................................... 42

Figure 4-3. Representative images from eastern-most reference areas ................................... 43vi 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

LIST OF ACRONYMS

aRPD apparent redox potential discontinuity

CAD confined aquatic disposal

CLDS Central Long Island Sound

CSDS Cornfield Shoals

DAMOS Disposal Area Monitoring System

DGPS differential global positioning system

ELIS Eastern Long Island Sound

EPA Environmental Protection Agency

GIS graphic information system

GPS global positioning system

JPEG Joint Photographic Experts Group

NBDS Niantic Bay Disposal Site

NLDS New London Disposal Site

NAE New England District

NEF Nikon Electronic Format

ODMDS Ocean Dredged Material Disposal Sites

PV plan-view

RGB red green blue (file format)

SBAS satellite-based differential corrections

SEIS Supplemental Environmental Impact Statement

SHP shapefile or geospatial data file

SOP Standard Operating Procedures

SPI sediment-profile imaging

TIF tagged image file

USACE U.S. Army Corps of Engineers

USCG U.S. Coast Guard

WLDS Western Long Island SoundPage 1 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

1.0 INTRODUCTION

A sediment-profile (SPI) and plan-view (PV) imaging survey was conducted at the New London Disposal Site (NLDS) and within an area extendi ng west of NLDS to, and including, the historic Niantic Bay Disposal Site (NBDS) . This SPI/PV survey took place in September 2014 as part of the U.S. Army Corps of Engineers (USACE) New England District (NAE) Disposal Area Monitoring System (DAMOS) Program. DAMOS is a comprehensive monitoring and management program designed and conducted to address environmental concerns surrounding the placement of dredged materi al at aquatic disposal sites throughout the New England region. An introduction to the DAMOS Program, NLDS, and NBDS, including br ief descriptions of previous dredged material disposal and site monitoring activities, is provided below.

1.1 Overview of the DAMOS Program

The DAMOS Program features a tiered manageme nt protocol designed to ensure that any potential adverse environmental impacts associated with dredged material disposal are promptly identified and addressed (Germano et al. 1994) . For over 35 years, the DAMOS Program has collected and evaluated dispos al site data throughout New England. Based on these data, patterns of physical, chemical, a nd biological responses of seafl oor environments to dredged material disposal activity have been documented (Fredette and French 2004).

DAMOS monitoring surveys fall into two general categories: confirmatory studies and focused studies. Confirmatory studies are designed to test hypotheses related to expected physical and ecological response patterns following placement of dredged material on the seafloor at established, active disposal sites. The data collected and evalua ted during these studies provide answers to strategic management questions in de termining the next step in the disposal site management process. Focused studies are peri odically undertaken within the DAMOS Program to evaluate inactive or historical disposal si tes and contribute to the development of dredged material placement and capping techniques. The resulting information from DAMOS surveys is used to guide the management of disposal activities at existing sites, plan for use of future sites, and evaluate the long term stat us of historic sites. The 2014 NLDS/NBDS investigation was a focused study designed as a reconnaissance surv ey in support of the Environmental Protection Agency’s (EPA) Supplemental Environmental Imp act Statement (SEIS) for designating one or more regional dredged material disposal sites in Eastern Long Island Sound (ELIS).

Two primary goals of DAMOS confirmatory monitoring surveys are to document the physical location and stability of dredged ma terial placed into the aquatic environment and to evaluate the biological recovery of the bent hic community following placement of dredged material. Several survey techniques are employed in order to char acterize these responses to dredged material placement. Sequential acoustic monitoring surveys (including bathymetric, acoustic backscatter, and side-scan sonar data collection) are perfor med to characterize the height and spread of discrete dredged material deposits or mounds created at open water sites as well as the accumulation/consolidation of dredged material in to confined aquatic disposal (CAD) cells. Sediment-profile imaging (SPI) and plan-vie w underwater camera photography, referred to as plan-view (PV) imaging, surveys are performed to provide further physical characterization of the material and to support eval uation of seafloor (benthic) ha bitat conditions and recovery overPage 2 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

time. Each type of data collec tion activity is conducted periodical ly at disposal sites, and the conditions found after a defined period of disposal activity are compared with the long-term data set at a specific site to determine the next step in the disposal site ma nagement process (Germano et al. 1994). Focused DAMOS monitoring survey s may also feature additional types of data collection activities as deemed appropriate to ac hieve specific survey objectives, such as subbottom profiling, towed video, sedi ment coring, or grab sampling.

1.2 Overview of EPA’s Preparation of an SEIS for ELIS

Currently there are four dredged material di sposal sites in Long Island Sound: Western Long Island Sound (WLDS), Central Long Island Sou nd (CLDS), Cornfield Shoals (CSDS), and New London (NLDS). WLDS and CLDS were designat ed for long-term use by the Environmental Protection Agency (EPA) as Ocean Dredged Ma terial Disposal Sites (ODMDSs) on June 5, 2005. CSDS and NLDS sites were selected by US ACE for short-term use and are due to close on December 16, 2016. As these two eastern sites are slated to close, the EPA posted a Notice of Intent on 4 October 2012 to prepare a Supplementa l Environmental Impact Statement (SEIS) to evaluate the potential designati on of one or more new ODMDSs to serve the eastern Long Island Sound region.

1.3 Introduction to the New London Disposal Site, Historic Niantic Bay Disposal Site, and the General Survey Area

NLDS is an active open-water dredged material di sposal site located 5.4 km (3.1 nmi) south of Eastern Point, Groton, Connecticut (Figure 1- 1) centered at 41o16.306 ́ N, 72o 04.571 ́ W (NAD 83). Water depths range from 13.4 m (43 ft) to 24.3 m (79 ft) at its deepest point (AECOM 2009).

NBDS is an inactive historical di sposal site that has not been used since likely 1972 (per notes from 1990 from Dr. Thomas Fredette, former DAMOS Program Manager). The center of the site is located approximately 2.6 km (1.4 nmi) southeast of Black Point, Niantic, Connecticut, and is being examined as a potential location for disposal site alte rnatives (Figure 1-1).

The area surveyed between these two disposal site s includes a wide range of depths and zones of apparent active sediment transport. The SEIS is considering sites deeper than 18 m in the vicinity of major shipping corrido rs and lanes and may consider sites shallower than 18 m that are more remote from transportation corridors. The areas surveyed were selected to represent water depths at, or deeper th an, the water depths of NLDS.

1.4 Previous NLDS Monitoring Surveys

The most recent survey at NLDS was conducted in July/August 2007 (AECOM 2009). Historic and previous dredged material disposal activ ity and monitoring events are summarized in AECOM (2009).Page 3 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

1.5 Recent Dredged Material Disp osal Activity at NLDS

Since the July/August 2007 survey approximately 20,000 cy (15,290 m3 ) of dredged material has been disposed of at NLDS.

1.6 2014 Survey Objectives

The objective of this survey was to use SPI/PV imag ing to define the physical characteristics of

surficial sediment and to assess the benthic commun ity status of selected areas within NLDS and over an area extending 7 km west up to and including the historic NBDS.Page 4 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 1-1.Location of NLDS and NBDS72°2'0"W72°2'0"W72°3'0"W72°3'0"W72°4'0"W72°4'0"W72°5'0"W72°5'0"W72°6'0"W72°6'0"W72°7'0"W72°7'0"W72°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°19'0"N 41°19'0"N

41°18'0"N 41°18'0"N

41°17'0"N 41°17'0"N

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)New LondonNiantic 5 . 3 8 k mEastern PointCTRI ́File: NLDS_2014_Overview0 21KilometersNew London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)NYNLDSNBDS

2

. 9

k mBlack PointDepth (m)Page 5 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

2.0 METHODS

The September 2014 survey at NLDS, NBDS and the area between the tw o sites was conducted by a team of investigators from DAMOSVision (CR Environmental and Germano & Associates)

aboard the 45-foot F/V Florence . The SPI/PV survey was conducted on 16-17 September 2014. An overview of the methods used to collect, pro cess, and analyze the survey data is provided below. Detailed Standard Operating Procedures (SOPs) for data colle ction and processing are

available in Care y et al. (2013).

2.1 Navigation and On-Board Data Acquisition

Navigation for the survey was accomplished using a Trimble AG132 Differential Global Positioning System (DGPS) capable of receiving sa tellite-based differential corrections (SBAS) and U.S. Coast Guard (USCG) Beacon corrections. The DGPS system was interfaced to a laptop computer running HYPACK® hydrogr aphic survey software.

The focus was to accurately occupy pre-estab lished SPI survey target locations. HYPACK® continually recorded vessel posi tion and DGPS satellite quality a nd provided a steering display for the vessel captain to navigate to the pre-established targets.

Station target locations were entered into HYP ACK® and viewed with a heads up display by the ship’s captain. When the vessel approached the center of the target lo cation, the winch operator began the process of lowering the camera to the seafloor. The camera was lifted over the starboard side using a Pullmaster winch and boom, and then transferred to a stern gallows frame

and trawl winch. The trawl winch lowered the cam era to the seafloor. When the winch wire went slack, the deck hand signaled the winch operator and navigator to stop the winch and electronically record the vessel’s position. Each replicate camera posi tion was electronically recorded and linked to the SPI log by stati on number and replicate with a time stamp and position.

2.2 Sediment-Profile and Plan-View Imaging Survey

Sediment-profile imaging (SPI) and plan-view (P V) imaging are monitoring techniques used to provide data on the physical characte ristics of the seafloor and the st atus of the benthic biological community.

2.2.1 Sediment-Profile Imaging

Sediment-profile imaging (SPI) involves depl oying an underwater camera system to photograph

a cross section of the sediment-water interface. In the 2014 survey at NLDS/NBDS, highresolution SPI images were acquired using a Ni kon® D7100 digital singl e-lens reflex camera mounted inside an Ocean Imaging® Model 3731 pr essure housing system. The pressure housing sat atop a wedge-shaped prism with a front faceplate and a back mirror. The mirror was mounted at a 45° angle to reflect the profile of the sediment-wat er interface. As the prism penetrated the seafloor, a trigger activated a time-delay circuit that fired an internal strobe to obtain a cross-sectional image of the upper 15–20 cm of the se diment column (Figure 2-1).Page 6 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

The camera remained on the seafloor for approxima tely 20 seconds to ensure that a successful image had been obtained. Details of the camera se ttings for each digital image are available in the associated parameters file embedded in each electronic image file. Fo r this survey, the ISOequivalent was set at 640, shutter speed was 1/ 250, f-stop was f9, and storage was in compressed raw Nikon Electronic Format (NEF) files (approxi mately 20 MB each). Electronic files were converted to high-resolution JPEG (8-bit) format files (3264 × 4928 pixels) using Nikon Capture® NX2 software (Version 2.2.7).

Test exposures of the Kodak® Color Separati on Guide (Publication No. Q-13) were made on deck at the beginning and end of the survey to ve rify that all internal electronic systems were working to design specifications and to provide a color standard against which final images could be checked for proper color balance. Afte r deployment of the camera at each station, the

frame counter was checked to ensure that the re quisite number of replicates had been obtained. In addition, a prism penetration de pth indicator on the camera frame was checked to verify that the optical prism had actually penetrated the botto m to a sufficient depth. If images were missed or the penetration depth was insu fficient, the camera frame stop collars were adjusted and/or weights were added or removed, and additional replicate images were taken. Changes in prism weight amounts, the presence or absence of mud doors, and frame stop collar positions were recorded for each replicate image.

Each image was assigned a unique time stamp in th e digital file attributes by the camera’s data logger and cross-checked with the ti me stamp in the navigational system’s computer data file. In addition, the field crew kept redundant writte n sample logs. Images were downloaded periodically to verify successful sample acquisition and/or to assess what type of sediment/depositional layer was present at a particular station. Digital image files were renamed with the appropriate station names immediately after downloading as a fu rther quality assurance

step.

2.2.2 Plan-View Imaging

An Ocean Imaging® Model DSC16000 plan-view underwater camera (PV) system with two Ocean Imaging® Model 400-37 Deep Sea Sca ling lasers mounted to the DSC16000 was attached to the sediment-profile camera frame a nd used to collect plan -view photographs of the seafloor surface; both SPI and PV images were collected during each “drop” of the system. The PV system consisted of a Nikon D-7000 encased in an aluminum housing, a 24 VDC autonomous power pack, a 500 W strobe, and a bounce trigger. A weight was attached to the bounce trigger with a stainless steel cable so th at the weight hung below the camera frame; the scaling lasers projected two red dots that are separated by a cons tant distance (26 cm) regardless of the field-of-view of the PV system, which can be varied by increasing or decreasing the length of the trigger wire. As the camera apparatus was lowered to the seafloor, the weight attached to the bounce trigger contacted the seafloor prio r to the camera frame hitting the bottom and triggered the PV camera (Figure 2-1). Details of the camera settings for each digital image are available in the associated parameters file embedded in each electronic image file; for this survey, the ISO-equivalent was set at 640 on the fi rst survey day and then changed to 400 on the second survey day due to overexposure because of shell hash. The additional camera settings used were as follows: shutter speed 1/20, f14, white balance set to flash, color mode set toPage 7 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Adobe RGB, sharpening set to none, noise reduction off, and storage in compressed raw NEF files (approximately 20 MB each). Electronic fi les were converted to high-resolution JPEG (8- bit) format files (3264 × 4928 pixels) using Nikon Captur e® NX2 software.

Prior to field operations, the inte rnal clock in the digital PV sy stem was synchronized with the GPS navigation system and the SPI camera. E ach PV image acquired was assigned a time stamp in the digital file and redundant notations in the field and navigati on logs. Throughout the survey, PV images were downloaded at the same time as the SPI images after collection and evaluated for successful image acquisition and image clarity.

The ability of the PV system to collect usable images was dependent on the clarity of the water

column. Water conditions at NLDS allowed a tri gger wire length of 45 to 53 cm, resulting in an area of bottom visualization approx imately 60 cm × 40 cm in size.

2.2.3 SPI and PV Survey Planning

For the NLDS/NBDS survey, a total of 60 SPI/PV stations were planned; 6 stations within NLDS, 11 stations within NBDS, 27 transect stat ions in the area between the two sites, and 4

stations in each of four re ference areas (Figure 2-2).

Survey planning included stations at which prior EPA monitoring was performed. All 6 of the NLDS stations were original EPA stations; 8 of the 11 NBDS stations were original EPA stations and 12 of the 26 transect stations were also orig inally EPA stations. The reference stations and the newly added stations at NBDS and the transect area were chosen by consultation with EPA, the DAMOS Program Manager, Steve Wolf and senior scientist Drew Carey of DAMOSVision (Figures 2-3, 2-4, and 2-5).

The eastern reference stations (NLON-REF and E-REF) and WREF stations were randomly

located within standard reference areas ut ilized by DAMOS (AECOM 2009). NLON-ALT stations were randomly selected within a refere nce area chosen as a potential future reference

area. The northern and southern transects were selected to provide a profile of conditions between the two disposal sites (Figure 2-2).

Table 2-1 provides the original EPA Site Sta tion ID numbers paired with the 2014 survey’s Station ID numbers and target locations.

2.2.4 SPI and PV Data Collection

The SPI/PV survey was conducted at NLDS/N BDS on 16-17 September 2014 aboard the F/V

Florence . At each station, the vessel was positioned at the target coordinates and the camera was deployed within a defined station tolerance of 10 m. Four replicate SPI and PV images were collected at each of the stations (Figures 2-3, 2-4, and 2-5; Appendix B). The three replicates with the best quality images from each stati on were chosen for analysis (Appendix C).

The DGPS described above was interfaced to HYP ACK® software via laptop serial ports to provide a method to locate and record target sampling locations. Throughout the survey, the HYPACK® data acquisition system received DGPS data. The incoming data stream wasPage 8 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

digitally integrated and stored on the PC’s hard drive. Actual SPI/PV sampling locations were recorded as target files using this system.

2.2.5 SPI and PV Data Analysis

Computer-aided analysis of the resulting images provided a set of standard measurements to allow comparisons between different locations an d different surveys. The DAMOS Program has successfully used this technique for over 30 years to map the di stribution of disposed dredged

material and to monitor benthic reco lonization at disposal sites.

Following completion of data collection, the di gital images were analyzed using Adobe Photoshop® CS 5 Version 12.1. Images were firs t adjusted in Adobe Photoshop® to expand the available pixels to their maximum light a nd dark threshold range. Linear and areal measurements were recorded as number of pixels and converted to scientific units using the Kodak® Color Separation Guide for measurement cal ibration. Detailed resu lts of all SPI and PV image analyses are presented in Appendix C.

2.2.5.1 SPI Data Analysis



### Analysis of each SPI image was performed to pr ovide measurement of the following standard set of parameters:

Sediment Type–The sediment grai n size major mode and range were estimated visually from the images using a grain size comparator at a simila r scale. Results were reported using the phi scale. Conversion to other grai n size scales is provided in Appendix D. The presence and thickness of disposed dredged material were also assessed by inspection of the images.

Penetration Depth–The depth to which the camera pe netrated into the seafloor was measured to provide an indication of the sediment density or bearing capacity. Th e penetration depth can range from a minimum of 0 cm (i.e., no penetrat ion on hard substrata) to a maximum of 20 cm (full penetration on ve ry soft substrata).

Surface Boundary Roughness–Surface boundary roughness is a measure of the vertical relief of

features at the sediment-water interface in the se diment-profile image. Surface boundary roughness was determined by measuring the vertical distance between th e highest and lowest points of the sediment-water in terface. The surface boundary roughness (sediment surface relief) measured over the width of sediment-profile imag es typically ranges from 0 to 4 cm, and may be related to physical structures (e.g., ripples, rip-up structures, m ud clasts) or biogenic features (e.g., burrow openings, fecal mounds, foraging depressions). Biogenic roughness typically changes seasonally and is related to the inte raction of bottom turbul ence and bioturbational

activities.

Apparent Redox Potential Discontinuity (aRPD) Depth–The aRPD depth provides a measure of the integrated time history of the balance betw een near-surface oxygen conditions and biological reworking of sediments. Sediment particles e xposed to oxygenated waters oxidize and lighten in color to brown or light gray. As the partic les are buried or moved down by biological activity, they are exposed to reduced oxygen concentratio ns in subsurface pore waters and their oxicPage 9 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

coating slowly reduces, changing color to dark gr ay or black. When bi ological activity is high, the aRPD depth increases; when it is low or abse nt, the aRPD depth decreases. The aRPD depth was measured by assessing color and re flectance boundaries within the images.

Infaunal Successional Stage–Infaunal successional stage is a measure of the biological community inhabiting the seafloor. Current theory holds that orga nism-sediment interactions in fine-grained sediments follow a predictable sequ ence of development after a major disturbance (such as dredged material disposal), and this sequence has been divided subjectively into three stages (Rhoads and Germano 1982, 1986). Successi onal stage was assigned by assessing which types of species or organism-related ac tivities were apparent in the images.

Additional components of the SPI analysis incl uded calculation of means and ranges for the parameters listed above and mapping of means of replicate values from each station. Station means were calculated from three replicates from each station and used in st atistical analysis.

2.2.5.2 PV Data Analysis



### The PV images provided a much larger field-of-v iew than the SPI images and provided valuable information about the landscape ecology and sedi ment topography in the area where the pinpoint “optical core” of the sediment profile was taken. Unusual surface sediment layers, textures, or structures detected in any of the sediment-profile images can be interpreted in light of the larger context of surface sediment features; i.e., is a surface layer or topographic feature a regularly occurring feature and typical of the bottom in this general vicini ty or just an isolated anomaly? The scale information provided by the underwater lasers allows for accurate density counts (number per square meter) of attached epifauna l colonies, sediment burrow openings, or larger macrofauna or fish which may have been mi ssed in the sediment-profile cross section. Information on sediment transport dynamics and bedform wavelength were also available from PV image analysis. Analysts calculated the im age size and field-of-view and noted sediment type; recorded the presence of be dforms, burrows, tubes, tracks, tr ails, epifauna, mud clasts, and debris; and included descrip tive comments (Appendix C).

2.3 NLDS Substrata Characteristics

In order to provide an integrated characterization of the seafloor substrata in the vicinity of the New London Disposal Site and Niantic Bay Disposal Site the results of SPI and PV imagery was used to define five broad habitat types (Table 2-2).Page 10 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Table 2-1.

NLDS Target SPI/PV Station IDs/Locations

LOCATION STATION ID Original EPA

Site ID EASTING 1 NORTHING 1 LATITUDE 2 LONGITUDE 2

NEW LONDON DISPOSAL SITE LOCATIONS

New London NLDS 1 NL015 

### 360852 201668 41° 16.500' 72° 4.860'

New London NLDS 2 NL014 

### 360686 201444 41° 16.380' 72° 4.980'

New London NLDS 3 NLR014 

### 360856 201112 41° 16.200' 72° 4.860'

New London NLDS 4 NL013 

### 360522 200888 41° 16.080' 72° 5.100'

New London NLDS 5 NL011 

### 361442 201117 41° 16.200' 72° 4.440'

New London NLDS 6 NLP009 

### 361446 200673 41° 15.960' 72° 4.440'

NIANTIC BAY DISPOSAL SITE LOCATIONS

Niantic NBDS 1 NTP017 

### 352401 199941 41° 15.600' 72° 10.920'

Niantic NBDS 2 NTP018 

### 352564 200609 41° 15.960' 72° 10.800'

Niantic NBDS 3 NTP018 

### 352143 200828 41° 16.080' 72° 11.100'

Niantic NBDS 4 NTP023 

### 351729 200159 41° 15.720' 72° 11.400'

Niantic NBDS 5 NTP025 

### 352228 200717 41° 16.020' 72° 11.040'

Niantic NBDS 6 NTR001 

### 351479 199824 41° 15.540' 72° 11.580'

Niantic NBDS 7 NTR004 

### 351721 201269 41° 16.320' 72° 11.400'

Niantic NBDS 8 NTR018 

### 353317 200725 41° 16.020' 72° 10.260'

New Niantic NBDS 9 - 

### 353104 201281 41° 16.321' 72° 10.410'

New Niantic NBDS 10 - 

### 352918 199856 41° 15.552' 72° 10.550'

New Niantic NBDS 11 - 

### 351413 200759 41° 16.045' 72° 11.623'

EPA TRANSECT STATIONS

EPA Transect

Reference EPA-P006 Refp006 

### 357344 200086 41° 15.660' 72° 7.380'

EPA Transect

Reference EPA-P008 Refp008 

### 358845 201097 41° 16.200' 72° 6.300'

EPA Transect

Reference EPA-P010 Refp010 

### 358509 201206 41° 16.260' 72° 6.540'

EPA Transect

Reference EPA-P020 Refp020 

### 353569 200615 41° 15.960' 72° 10.080'

EPA Transect

Reference EPA-P021 Refp021 

### 354323 200731 41° 16.020' 72° 9.540'

EPA Transect

Reference EPA-P023 Refp023 

### 358760 201207 41° 16.260' 72° 6.360'

EPA Transect

Reference EPA-P024 Refp024 

### 358684 200207 41° 15.720' 72° 6.420'

EPA Transect

Reference EPA-P025 Refp025 

### 357344 200086 41° 15.660' 72° 7.380'

EPA Transect

Reference EPA-P026 Refp026 

### 357176 200085 41° 15.660' 72° 7.500'Page 11 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

LOCATION STATION ID Original EPA

Site ID EASTING 1 NORTHING 1 LATITUDE 2 LONGITUDE 2

EPA Transect

Reference EPA-P027 Refp027 355669 199963 41° 15.600' 72° 8.580'

EPA Transect

Reference EPA-R007 Refr007 360100 201329 41° 16.320' 72° 5.400'

EPA Transect

Reference EPA-R024 Refr024 353658 199950 41° 15.600' 72° 10.020'

NEW TRANSECT STATIONS

New Transect

Reference NLT 1 - 360052 201892 41° 16.624' 72° 5.431'

New Transect

Reference NLT 2 - 359488 201848 41° 16.603' 72° 5.835'

New Transect

Reference NLT 3 - 356723 200925 41° 16.115' 72° 7.821'

New Transect

Reference NLT 4 - 356022 200792 41° 16.047' 72° 8.323'

New Transect

Reference NLT 5 - 355046 200683 41° 15.991' 72° 9.022'

New Transect

Reference NLT 6 - 354363 199922 41° 15.583' 72° 9.515'

New Transect

Reference NLT 7 - 354994 199941 41° 15.590' 72° 9.063'

New Transect

Reference NLT 8 - 356142 200002 41° 15.619' 72° 8.241'

New Transect

Reference NLT 9 - 357942 200125 41° 15.679' 72° 6.952'

New Transect

Reference NLT 10 - 359030 200225 41° 15.728' 72° 6.172'

New Transect

Reference NLT 11 - 359499 200342 41° 15.790' 72° 5.836'

New Transect

Reference NLT 12 - 360144 200354 41° 15.794' 72° 5.374'

New Transect

Reference NLT 13 - 359895 200635 41° 15.946' 72° 5.550'

New Transect

Reference NLT 14 - 360050 200972 41° 16.128' 72° 5.438'

New Transect

Reference NLT 15 - 359738 201161 41° 16.231' 72° 5.660'

NLDS REFERENCE AREA STATIONS

NE-REF NE-REF 1 - 362910 201970 41° 16.654' 72° 3.384'

NE-REF NE-REF 2 - 362832 202080 41° 16.714' 72° 3.440'

NE-REF NE-REF 3 - 362939 202098 41° 16.724' 72° 3.363'

NE-REF NE-REF 4 - 363006 202060 41° 16.703' 72° 3.315'

NLON REF NLON REF 1 - 364970 201976 41° 16.649' 72° 1.909'

NLON REF NLON REF 2 - 364787 201997 41° 16.661' 72° 2.040'

NLON REF NLON REF 3 - 364889 201907 41° 16.612' 72° 1.967'

NLON REF NLON REF 4 - 364893 202073 41° 16.702' 72° 1.963'

NLON-ALT EPA NLON-ALT 1 - 357631 201201 41° 16.261' 72° 7.168'Page 12 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

LOCATION STATION ID Original EPA

Site ID EASTING 1 NORTHING 1 LATITUDE 2 LONGITUDE 2

NLON-ALT EPA NLON-ALT 2 - 357753 201102 41° 16.207' 72° 7.082'

NLON-ALT EPA NLON-ALT 3 - 357860 201138 41° 16.226' 72° 7.005'

NLON-ALT EPA NLON-ALT 4 - 357776 201262 41° 16.294' 72° 7.064'

WREF WREF 1 - 359347 201065 41° 16.181' 72° 5.941'

WREF WREF 2 - 359425 201108 41° 16.204' 72° 5.884'

WREF WREF 3 - 359202 201132 41° 16.218' 72° 6.044'

WREF WREF 4 - 359326 201227 41° 16.268' 72° 5.955'



### Notes 1. Grid coordinates are Connecticut State Plane FIPS 0600 (NAD83), in meters 2. Geographic coordinates are WGS84 degrees decimal minutesPage 13 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Table 2-2.

Substrata Habitat Types

Substratum Characteristics Ha bitat Sediment transport
Rock Hard bottom, boulders or large cobbles. Dominated by encrusting organisms: sponges, hydroids, algae,

anemones and mobile epifauna Assumed to be eroded ridges of glacial till or drift. Some periodic

settlement of fines as drape over rock

surfaces. Shell Layer of disarticulated

shells: common mussel ( Mytilus ), slipper shell ( Crepidula ), cockles ( Cerastoderma ) and clams ( Ensis, Spisula,

Mercenaria ). Surface layer of clean shells and pebbles on

coarse to fine sand. Infauna in layer of coarse shell hash overlying fine

sand and silt. Some encrusting organisms on pebbles. Assumed to be area of active strong near-bed currents moving shells (absence of epifaunal growth).

Mobile sand Fine sand with bedforms, isolated shells and pebbles. Active infauna including

acorn worms ( Saccoglossus ), deep burrowing polychaetes. Some resistant epifauna

on shells or isolated pebbles. Assumed to be area of

moderate near-bed

currents sufficient to periodically move sand

in bedload.

Transitional Surface with shell layer and mud drape. Epifauna on shell layer and infaunal burrowing organisms. Episodic transport of shell alternating with deposition. Depositional Very fine sand or silt

with no bedforms.

Some isolated shells and pebbles Dominated by deep burrowing infauna and some encrusting organisms (hydroids, bryozoans, anemones) on

hard surfaces Assumed to be low

near-bed currents with very infrequent storm transport of surface

sediment.Page 14 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 2-1.Schematic diagram of the SPI/PV camera deploymentPage 15 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 2-2.Actual SPI/PV station locations at NLDS, NBDS, transects, and reference areas!(!(")")")#*#*#*#*")")")")")$+$+$+$+$+$+$+$+$+$+$+")#*#*#*#*#*#*#*#*#*#*#*#*!(!(!(!(")")")")")")")")")")")")")")")")")")WREFNE-REFNLON-REFNLON-ALT EPA72°2'0"W72°2'0"W72°3'0"W72°3'0"W72°4'0"W72°4'0"W72°5'0"W72°5'0"W72°6'0"W72°6'0"W72°7'0"W72°7'0"W72°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°19'0"N 41°19'0"N

41°18'0"N 41°18'0"N

41°17'0"N 41°17'0"N

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)New LondonNiantic 5 . 3 8 k mEastern PointCTRI ́File: NLDS_2014_Overview_SPI0 21KilometersNew London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference AreaNYNLDSNBDS

2

. 9

k

mBlack PointNorthern TransectSouthern TransectDepth (m)SPI/PV Station Locations$+Niantic Bay EPA Station$+New Niantic Bay Station!(New London EPA Station")EPA Transect Reference Station")New Transect Reference Station#*Reference Area Station

B a r t l e t t R e e fPage 16 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 2-3.Actual SPI/PV station locations and names at NBDS and the western section of the transects")")")")")$+$+$+$+$+$+$+$+$+$+$+")")")")")NLT-6NLT-7NLT-8NLT-5NLT-4NLT-3NBDS-1NBDS-6NBDS-4NBDS-9NBDS-7NBDS-3NBDS-5NBDS-2NBDS-8NBDS-10NBDS-11EPA-P027EPA-R024EPA-P021EPA-P02072°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: NOS Multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25Kilometers ́File Name: NLDS_2014_Popup_West_blueDepth (m)New London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference Area$+Niantic Bay EPA Station$+New Niantic Bay Station!(New London EPA Station")EPA Transect Reference Station")New Transect Reference Station#*Reference Area StationSPI/PV Station LocationsPage 17 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 2-4.Actual SPI/PV station locations and names at NLDS, the easternsection of the transects, and the central reference areas!(!(")")")#*#*#*#*#*#*#*#*!(!(!(!(")")")")")")")")")")")")")")NLT-1NLT-2NLT-9NLT-10NLT-11NLT-12NLT-13NLDS-4NLDS-3NLDS-6NLDS-5WREF-4WREF-3NLT-15NLT-14NLDS-2NLDS-1EPA-P025EPA-P008EPA-P023EPA-P026EPA-R007NLON-ALT3NLON-ALT4WREF-1WREF-2EPA-P010EPA-P006EPA-P024NLON-ALT2NLON-ALT172°4'0"W72°4'0"W72°5'0"W72°5'0"W72°6'0"W72°6'0"W72°7'0"W72°7'0"W

41°17'0"N 41°17'0"N

41°16'0"N 41°16'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference Area$+Niantic Bay EPA Station$+New Niantic Bay Station!(New London EPA Station")EPA Transect Reference Station")New Transect Reference Station#*Reference Area Station ́SPI/PV Station LocationsFile Name: NLDS_2014_Popup_East_blueDepth (m)Page 18 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 2-5.Actual SPI/PV station locations atthe eastern-most reference areas#*#*#*#*#*#*#*#*NE-REF1NE-REF2NE-REF3NE-REF4NLON-REF2NLON-REF3NLON-REF4NLON-REF172°2'0"W72°2'0"W72°3'0"W72°3'0"W72°4'0"W72°4'0"W

41°17'0"N 41°17'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 USACE NLDS Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Niantic Bay Disposal Site (NBDS)Reference Area$+Niantic Bay EPA Station$+New Niantic Bay Station!(New London EPA Station")EPA Transect Reference Station")New Transect Reference Station#*Reference Area Station ́SPI/PV Station LocationsDepth (m)File Name: NLDS_2014_Popup_Refs_bluePage 19 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

3.0 RESULTS

3.1 Sediment-Profile and Plan-View Imaging

The primary purpose of the SPI/PV survey at NLDS/NBDS was to characterize the physical features of the surface sediment throughout the st udy area and to assess the status of benthic recolonization within the disposal site. A total of 60 SPI/PV stations were occupied; 6 stations within NLDS, 11 stations within NBDS, 27 transect stations in the area between the two sites,

and 4 stations in each of four reference area s (NLON-ALT, WREF, NE-REF, and NLON-REF).

A station summary of some measured parameters can be found in Table 3-1 with a complete set of results in Appendix C.

3.1.1 Eastern Reference Areas (NE-REF, and NLON-REF)

Physical Sediment Characteristics

The eastern reference areas were primarily very fine sand (4 to 3 phi) but some replicates had evidence of silt layers beneath th e surface (Figure 3-1 and Appendix C). NE-REF had fine (3 to 2 phi) and very fine sand with no evidence of se diment transport, which was classified as a depositional substratum (Figure 3-2). NLON-REF had very fine sand with evidence of sediment transport, which was classified as mobile sand substratum (fine sand with bedforms, isolated shells and pebbles; assumed to be area of modera te near-bed currents su fficient to periodically move sand in bedload). However, several replic ates had silt (>4 phi) below the very fine sand and clearly had experienced periods of deposition (Appendix C). The difference between the reference areas was illustrated by the relative pe netration depths of the camera (Figure 3-3;

NLON-REF mean 5.3 cm and NE -REF mean of 9.1 cm).

Biological Conditions

The eastern reference areas had ty pical shallow water estuarine in faunal characteristics (burrows, bioturbation, and deep aRPDs) and numerous epifaunal scavenging organisms (Appendix C). Common infaunal deposit feeders in fine sand habitats of eastern Long Island Sound include numerous polychaetes and Saccoglossus kowalewskyi , an enteropneust that deposits a distinctive

fecal coil on the surface. Saccoglossus is typically found in mobile sand habitats in eastern Long Island Sound and more quiescent ha bitats in the Gulf of Maine. Another typical infaunal organism, Chaetopterus variopedatus forms a thick parchment tube in the sediment and pumps water through the tube. Both Saccoglossus coils and Chaetopterus tubes were found at NLONREF but not at NE-REF (Appendix C). NE-REF had large burrow openings and polychaetes

visible below the sediment-water interface.

All stations at the eastern reference areas had at least one replicate with evidence of Stage 3 equilibrium conditions ( Saccoglossus coils are one type of such evidence, Figure 3-4). The mean

aRPD for all stations at NLON-REF was 3.6 cm and for NE-REF, 4.6 cm (Figure 3-5).Page 20 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

3.1.2 New London Disposal Site Stations

Physical Sediment Characteristics

The NLDS stations were located in areas that re ceived dredged material over many years and are typical of conditions seen there (AECOM 2009, Carey et al. 2013). The surface sediments consisted of fine to medium sand overlying silt (F igure 3-6). In one case, there was a large rock that prevented grain size assessment with SPI but the PV images clearly showed a surface layer of sand (Appendix C). The surface layer had cl ear evidence of sediment transport and lag deposits (shells and pebbles) but the shells were covered with a thin layer of silt (‘mud drape’). As a result, the substrate was classified as transitio nal (Figure 3-7). In this case, the presence of consolidated silt underneath a surface layer of fine to medium sand, shells and silt layers, indicated periodic sediment transport sufficient to move unconsolidated fine sand but not enough to move shells and silt. The camera penetration depth was a clear indicator of the presence of soft dredged material below the surface of fine sand; penetration depths ranged from 0 (rock) to 18.8 cm (Figure 3-8).

Biological Conditions

The sediments at NLDS were heavily bioturbated with numerous burrows and evidence of subsurface feeding (Appendix C). The shell lag and pebbles had encrusting and attached epifauna, further evidence that th e shells do not move frequently. All of the stations that could be measured had evidence of Stage 3 equilibr ium conditions (feeding voids and burrows, Figure 3-9). The mean aRPD for all stations at NLDS was 3.1 cm (Figure 3-10).

3.1.3 Northern and Southern Transect Stations , Including the Central Reference Areas (NLON-ALT, and WREF)

Physical Sediment Characteristics

The northern and southern transect s were selected to provide a pr ofile of conditions between the two disposal sites. As such, the physical cond itions along the transects covered a wide range.

Both transects crossed north-so uth oriented boulder ridges and a southeast-northwest oriented sand ridge (Figure 2-2). One of the ridges is an extension of Ba rtlett Reef and these ridges are likely part of a complex of gl aciolacustrine systems in Long Is land Sound representing deltaic and ice-marginal deposits (Figure 2-2 and Stone et al. 2005). Between the ridges the seafloor deepens and forms small erosional basins. Th e two central reference areas had four random stations each and conditions were quite similar w ithin them. WREF has been used routinely for assessment of NLDS disposal activities, NLON-A LT has not. WREF had consistent shelly fine sand over silt (3 to 2/ >4 phi) while NLON-A LT was primarily shelly fine sand with some underlying silt and a visible mud drape over the sh ells (Figure 3-6). WREF had clear evidence of sediment transport features and was classified as mobile sand while NLON-ALT appeared to be more transitional with mud deposits and epifa una (Figure 3-7). These results suggested that

the two reference areas are similar to NLDS: experiencing periodic bottom stress capable of moving sand or shell particles, but also periods of quiescent conditions th at allow deposition ofPage 21 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

silt. The camera penetration depth measurements indicated that WREF was softer than NLONALT with a mean penetration depth of 7.6 cm compared to 4.8 cm (Figure 3-8).

The northern transect included st ations previously sampled by EP A and newly selected stations to provide a characterization of a corridor connecting the central reference stations to the two disposal sites (Figure 2-2). St ation grain sizes ranged from fine sand to medium sand over silt,

with several indeterminate stati ons due to hard bottom or shel ls (Figures 3-6 and 3-11). The

southern transect stations were chosen to link the existing EPA sta tions to a corridor between the two disposal sites (Figure 2-2). Station grain sizes ranged from very fine sand to gravel over silt (Figures 3-6 and 3-11). The north ern transect stations in the east (near NLDS) were all mobile sand or transitional substrata, consistent with th e two reference areas (Figure 3-7). The northern transect stations in the west (near NBDS) were a mix of coarse shells on the margins of ridges;

mobile sand and transitional in th e deeper basin (Figure 3-12). Th e southern transect stations in the east were mobile sand or transitional up to a re sistant hard ridge with rock and shells (Figure 3-7). The southern transect stati ons in the west were rock and sh ells over another hard ridge and

then transitional in the basin to rock on another hard ridge at the eastern edge of NBDS (Figure 3-12). Camera penetration depths varied widely along the northern transect from 0 to 9.2 cm and along the southern transect from 0 to 10.9 cm (Figure 3-8 and 3-13).

Biological Conditions

The sediments at WREF and NLON-ALT were bioturbated with some evidence of subsurface feeding (Appendix C). The shell lag and pebbles had encrusting and attach ed epifauna, further evidence that the shells do not move frequently. All of the stations that could be measured had evidence of Stage 3 equilibrium conditions at WREF, and evidence of mostly Stage 2 at NLONALT (Figure 3-9). The mean aRPD for all st ations at WREF was 3.6 cm and at NLON-ALT only one station had a measurable aRPD due to layers of shell on the surface (Figure 3-10).

Along both transects the pr esence of shells ( Mytilus and Crepidula ) and rock surfaces provided substrata for many epifaunal organisms (s ponges, anemones, bryozoans, hydroids, and barnacles). In the softer sediments within the basins, there was evidence of burrowing organisms and, in places, large numbers of Crepidula shells. The aRPD values in the northern transect ranged from 2.9 to 6.5 cm and in the southern tr ansect ranged from 2.0 to 4.7 cm (Figures 3-10 and 3-14).

3.1.4 Niantic Bay Disposal Site Stations

Physical Sediment Characteristics

The NBDS stations were located in an area that had not received dredged material in many years; despite the history of the site, no dredged material was detected in the stations sampled. The southeast triangular portion of the site (Stations 1, 2, 6, 8 and 10) had a surface layer of coarse shells overlying fine and very fi ne sand (Figure 3-11). The presen ce of the shell la yer appears to be a lag deposit overlying sand a nd was classified as shell subs tratum (Figure 3-12). In the northwest triangular portion of th e site (Stations 3, 4, 5, 7, 9 and 11) the surface layer had fewer shells and fine sand (Figure 3-11). In this area the surface layer had clear evidence of sedimentPage 22 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

transport; as a result, the substrate was classifi ed as mobile sand (Figure 3-12). In both cases, there was evidence of active bedload transport su fficient to move unconsolidated fine sand and periodically enough to move shells (shells had some evidence of epifauna but appeared to be fairly clean). The camera penetration depth was a clear indicator of the re lative distribution of compacted sand and shells; mean penetration dept hs were 5.1 cm in the southeast and 6.5 cm in the northwest (Figure 3-13). Stations 1 and 10 in the southeast had more fine sand and silt below the surface and deeper pe netration; Station 5 had compacted sand and very limited penetration (Figure 3-13).

Biological Conditions

The mobile sand and shelly substrata had relativ ely little evidence of biological activity: some signs of bioturbation and epifaunal organisms on sh ells. These substrata are typically inhabited by highly mobile epifauna, and some infauna th at are adapted to moving surface layers (but

without fine sediment content there was little evidence of burrows or aRPDs). Only one replicate had evidence of Stage 3 (Station 4B); ag ain a typical result in coarse sediments where Stage 2 evidence (shallow burrowing, lack of anoxic subsurface sediments) is most common (Figure 3-15). The aRPDs were indeterminate in six of the eleven stations; the mean aRPD was 3.1 cm (Figure 3-14).

Table 3-1.

Summary of Substratum and Grain Size Ma jor Mode (averaged across replicates)

Location Station Substratum Grain Size Major Mode

NLDS NLDS 1 Transitional 3 to 2/ >4

NLDS 2 Transitional 3 to 2/ >4

NLDS 3 Transitional 2 to 1/ >4

NLDS 4 Transitional 3 to 2/ >4

NLDS 5 Transitional 3 to 2/ >4

NLDS 6 Transitional ind

EPA P006 Shell 3 to 2/ >4

EPA P008 Transitional 3 to 2/ >4

EPA P010 Transitional 3 to 2/ >4

EPA P020 Shell 3 to 2/ >4

EPA P021 Mobile Sand 2 to 1/ >4

EPA P023 Transitional 3 to 2/ >4

EPA P024 Rock < 1 / >4

EPA P025 Shell 1 to 0

EPA P026 Shell 3 to 2/ >4

EPA P027 Shell 1 to 0

EPA R007 Mobile Sand 3 to 2

EPA R024 Rock ind

NBDS NBDS 1 Shell 2 to 1/ >4

NBDS 2 Shell 2 to 1Page 23 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Location Station Substratum Grain Size Major Mode

NBDS 3 Mobile Sand 3 to 2

NBDS 4 Mobile Sand 3 to 2

NBDS 5 Mobile Sand 3 to 2

NBDS 6 Shell 3 to 2

NBDS 7 Mobile Sand 3 to 2

NBDS 8 Shell 3 to 2

NBDS 9 Mobile Sand 3 to 2

NBDS 10 Shell 3 to 2

NBDS 11 Mobile Sand 3 to 2

New Transect NLT 1 Transitional 3 to 2/ >4

NLT 2 Mobile Sand 3 to 2/ >4

NLT 3 Shell ind

NLT 4 Shell ind

NLT 5 Transitional 2 to 1/ >4

NLT 6 Transitional 2 to 1/ >4

NLT 7 Transitional 3 to 2

NLT 8 Rock ind

NLT 9 Shell 2 to 1/ >4

NLT 10 Mobile Sand 1 to 2

NLT 11 Mobile Sand 3 to 2/ >4

NLT 12 Mobile Sand 3 to 2/ >4

NLT 13 Mobile Sand 3 to 2/ >4

NLT 14 Transitional 3 to 2/ >4

NLT 15 Mobile Sand 3 to 2/ >4

Reference Areas WREF 1 Mobile Sand 3 to 2/ >4

WREF 2 Mobile Sand 3 to 2/ >4

WREF 3 Mobile Sand 3 to 2/ >4

WREF 4 Mobile Sand 3 to 2/ >4

NLON ALT1 Transitional 3 to 2

NLON ALT2 Transitional 3 to 2

NLON ALT3 Transitional 3 to 2

NLON ALT4 Transitional 3 to 2/ >4

NLON REF1 Mobile Sand 4 to 3

NLON REF2 Mobile Sand 4 to 3

NLON REF3 Mobile Sand 4 to 3

NLON REF4 Mobile Sand 4 to 3/ >4

NE REF1 Depositional 3 to 2

NE REF2 Depositional 4 to 3

NE REF3 Depositional 4 to 3

NE REF4 Depositional 4 to 3Page 24 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-1.Sediment grain size major mode (phi units) at the eastern-most reference areas ! <!!!!!!!NE-REF1NE-REF2NLON-REF2NLON-REF3NE-REF3NE-REF4NLON-REF1NLON-REF472°2'0"W72°2'0"W72°3'0"W72°3'0"W72°4'0"W72°4'0"W

41°17'0"N 41°17'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_Refs_NLDS_GrainSizeGrain Size Major Mode (phi)

! <gravel over silt/clay (<-1 / >4)!coarse sand (1 to 0)!medium sand (2 to 1) ! <medium sand over silt/clay (2 to 1 / >4)!fine sand (3 to 2)

! <fine sand over silt/clay (3 to 2 / >4) ! <very fine sand over silt/clay (4 to 3 / >4)!very fine sand (4 to 3)indeterminateDepth (m)Page 25 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-2.Substrata characteristics atthe eastern-most reference areas!!!!!!!!!!!!!!!!NE-REF1NE-REF2NLON-REF2NLON-REF3NE-REF3NE-REF4NLON-REF1NLON-REF472°2'0"W72°2'0"W72°3'0"W72°3'0"W72°4'0"W72°4'0"W

41°17'0"N 41°17'0"NMarch 2015Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_REfs_NBDS_5x_spectrum_substrataBackground: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)Substrata!!Depositional!!Transitional!!Mobile SandûRocktsShellDepth (m)Page 26 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-3. Camera penetration depths atthe eastern-most reference areas¶¶¶¶¶¶¶¶NE-REF1NE-REF2NLON-REF2NLON-REF3NE-REF3NE-REF4NLON-REF1NLON-REF472°2'0"W72°3'0"W72°4'0"W

41°17'0"N 41°17'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_Refs_PenDepth (m)Mean Camera Penetration (cm)¶0.0¶2.5 - 4.9¶5.0 - 9.9¶10.0 - 14.9¶15.0 - 20.4Page 27 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-4. Successional stage at the eastern-most reference areasNE-REF1NE-REF2NLON-REF2NLON-REF3NE-REF3NE-REF4NLON-REF1NLON-REF472°2'0"W72°2'0"W72°3'0"W72°3'0"W72°4'0"W72°4'0"W

41°17'0"N 41°17'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_Refs_SSDepth (m)Successional StageStage 1Stage 1-2, 2Stage 1 on 3, 2-3, 3IndeterminatePage 28 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-5. Apparent Redox Potential Discontinuity (aRPD) at the eastern-most reference areasNE-REF1NE-REF2NLON-REF2NLON-REF3NE-REF3NE-REF4NLON-REF1NLON-REF472°2'0"W72°2'0"W72°3'0"W72°3'0"W72°4'0"W72°4'0"W

41°17'0"N 41°17'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_Refs_aRPDDepth (m)Mean aRPD (cm)0.6 - 1.61.7 - 3.0>3.0IndeterminatePage 29 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-6.Sediment grain size major mode (phi units) within NLDS, the eastern transect stations, and the central reference areas

! <

! <! ! <

! <

! < ! <

! < ! <! ! <!! ! <

! <

! <

! < ! <

! <!

! <

! <

! <

! < ! < ! < ! < ! <! ! <NLT-1NLT-2NLT-9NLT-10NLT-11NLT-12NLT-13NLDS-4NLDS-3NLDS-6NLDS-5WREF-4WREF-3NLT-15NLT-14NLDS-2NLDS-1EPA-P025EPA-P008EPA-P023EPA-P026EPA-R007NLON-ALT3NLON-ALT4WREF-1WREF-2EPA-P010EPA-P006EPA-P024NLON-ALT2NLON-ALT172°4'0"W72°5'0"W72°6'0"W72°7'0"W

41°17'0

" 41°17

41°16'0"N 41°16'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_East_NLDS_GrainSizeGrain Size Major Mode (phi)

! <gravel over silt/clay (<-1 / >4)!coarse sand (1 to 0)!medium sand (2 to 1) ! <medium sand over silt/clay (2 to 1 / >4)!fine sand (3 to 2)

! <fine sand over silt/clay (3 to 2 / >4) ! <very fine sand over silt/clay (4 to 3 / >4)!very fine sand (4 to 3)indeterminateDepth (m)Page 30 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-7.Substrata characteristics within NLDS, the eastern transect stations, and the centralreference areas!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!ûtststs!!!!!!!!ts!!NLT-1NLT-2NLT-9NLT-10NLT-11NLT-12NLT-13NLDS-4NLDS-3NLDS-6NLDS-5WREF-4WREF-3NLT-15NLT-14NLDS-2NLDS-1EPA-P025EPA-P008EPA-P023EPA-P026EPA-R007NLON-ALT3NLON-ALT4WREF-1WREF-2EPA-P010EPA-P006EPA-P024NLON-ALT2NLON-ALT172°4'0"W72°4'0"W72°5'0"W72°5'0"W72°6'0"W72°6'0"W72°7'0"W72°7'0"W

41°17'0"N 41°17'0"N

41°16'0"N 41°16'0"NMarch 2015Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: MeterBackground: 2007 NLDS USACE Bathymetric depth data over NOS multibeam 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_East_NBDS_5x_spectrum_substrataDepth (m)Substrata!!Depositional!!Transitional!!Mobile SandûRocktsShellPage 31 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-8. Camera penetration depths within NLDS, the easterntransect stations, and the central reference areas¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶NLT-1NLT-2NLT-9NLT-10NLT-11NLT-12NLT-13NLDS-4NLDS-3NLDS-6NLDS-5WREF-4WREF-3NLT-15NLT-14NLDS-2NLDS-1EPA-P025EPA-P008EPA-P023EPA-P026EPA-R007NLON-ALT3NLON-ALT4WREF-1WREF-2EPA-P010EPA-P006EPA-P024NLON-ALT2NLON-ALT172°4'0"W72°4'0"W72°5'0"W72°5'0"W72°6'0"W72°6'0"W72°7'0"W72°7'0"W

41°17'0"N 41°17'0"N

41°16'0"N 41°16'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_East_PenDepth (m)Mean Camera Penetration (cm)¶0.0¶2.5 - 4.9¶5.0 - 9.9¶10.0 - 14.9¶15.0 - 20.4Page 32 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-9. Successional stage within NLDS, the eastern transect stations, and the central reference areasNLT-1NLT-2NLT-9NLT-10NLT-11NLT-12NLT-13NLDS-4NLDS-3NLDS-6NLDS-5WREF-4WREF-3NLT-15NLT-14NLDS-2NLDS-1EPA-P025EPA-P008EPA-P023EPA-P026EPA-R007NLON-ALT3NLON-ALT4WREF-1WREF-2EPA-P010EPA-P006EPA-P024NLON-ALT2NLON-ALT172°4'0"W72°5'0"W72°6'0"W72°7'0"W

41°17'0

" 41°17

41°16'0"N 41°16'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_East_SSDepth (m)Successional StageStage 1Stage 1-2, 2Stage 1 on 3, 2-3, 3IndeterminatePage 33 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-10. Apparent Redox Potential Discontinuity(aRPD) within NLDS, the eastern transect stations, and the central referenceareasNLT-1NLT-2NLT-9NLT-10NLT-11NLT-12NLT-13NLDS-4NLDS-3NLDS-6NLDS-5WREF-4WREF-3NLT-15NLT-14NLDS-2NLDS-1EPA-P025EPA-P008EPA-P023EPA-P026EPA-R007NLON-ALT3NLON-ALT4WREF-1WREF-2EPA-P010EPA-P006EPA-P024NLON-ALT2NLON-ALT172°4'0"W72°5'0"W72°6'0"W72°7'0"W

41°17'0

" 41°17

41°16'0"N 41°16'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: 2007 NLDS USACE bathymetric depth data over NOS multibeam 5x vertical exagerration (compiled by DAMOSVision 2014)0 0.50.25KilometersNew London Disposal Site (NLDS)Reference Area ́File Name: NLDS_2014_SPI_East_aRPDDepth (m)Mean aRPD (cm)0.6 - 1.61.7 - 3.0>3.0IndeterminatePage 34 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-11.Sediment grain size major mode (phi units) at stations within NBDS and the western transect stations

! <

! <

! <!!!!!!!!! ! <!!!

! <NLT-6NLT-7NLT-8NLT-5NLT-4NLT-3NBDS-1NBDS-6NBDS-4NBDS-9NBDS-7NBDS-3NBDS-5NBDS-2NBDS-8NBDS-10NBDS-11EPA-P027EPA-R024EPA-P020EPA-P02172°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25Kilometers ́File Name: NLDS_2014_SPI_West_NBDS_GrainSizeGrain Size Major Mode (phi)

! <gravel over silt/clay (<-1 / >4)!coarse sand (1 to 0)!medium sand (2 to 1) ! <medium sand over silt/clay (2 to 1 / >4)!fine sand (3 to 2)

! <fine sand over silt/clay (3 to 2 / >4) ! <very fine sand over silt/clay (4 to 3 / >4)!very fine sand (4 to 3)indeterminateNiantic Bay Disposal Site (NBDS)Depth (m)Page 35 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-12.Substrata characteristics atstations within NBDS and the western transect stationststs!!!!tststs!!!!!!!!!!!!tststsûûts!!!!NLT-6NLT-7NLT-8NLT-5NLT-4NLT-3NBDS-1NBDS-6NBDS-4NBDS-9NBDS-7NBDS-3NBDS-5NBDS-2NBDS-8NBDS-10NBDS-11EPA-P027EPA-R024EPA-P020EPA-P02172°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NMarch 2015Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal Conic Units: Meter0 0.50.25Kilometers ́File Name: NLDS_2014_SPI_West_NBDS_5x_spectrum_substrataDepth (m)Background: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014)Substrata!!Depositional!!Transitional!!Mobile SandûRocktsShellNiantic Bay Disposal Site (NBDS)Page 36 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-13. Camera penetration depths at stations within NBDS and the western transect stations¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶¶NLT-6NLT-7NLT-8NLT-5NLT-4NLT-3NBDS-1NBDS-6NBDS-4NBDS-9NBDS-7NBDS-3NBDS-5NBDS-2NBDS-8NBDS-10NBDS-11EPA-P027EPA-R024EPA-P020EPA-P02172°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25Kilometers ́File Name: NLDS_2014_SPI_West_PenNiantic Bay Disposal Site (NBDS)Depth (m)Mean Camera Penetration (cm)¶0.0¶2.5 - 4.9¶5.0 - 9.9¶10.0 - 14.9¶15.0 - 20.4Page 37 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-14. Apparent Redox Potential Discontinuity (aRPD) at stations within NBDS and the western transect stationsNLT-6NLT-7NLT-8NLT-5NLT-4NLT-3NBDS-1NBDS-6NBDS-4NBDS-9NBDS-7NBDS-3NBDS-5NBDS-2NBDS-8NBDS-10NBDS-11EPA-P027EPA-R024EPA-P020EPA-P02172°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25Kilometers ́File Name: NLDS_2014_SPI_West_aRPDNiantic Bay Disposal Site (NBDS)Depth (m)Mean aRPD (cm)0.6 - 1.61.7 - 3.0>3.0IndeterminatePage 38 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Figure 3-15. Successional stage at stationswithin NBDS and the western transect stations areasNLT-6NLT-7NLT-8NLT-5NLT-4NLT-3NBDS-1NBDS-6NBDS-4NBDS-9NBDS-7NBDS-3NBDS-5 NBDS-2NBDS-8NBDS-10NBDS-11EPA-P027EPA-R024EPA-P020EPA-P02172°8'0"W72°8'0"W72°9'0"W72°9'0"W72°10'0"W72°10'0"W72°11'0"W72°11'0"W72°12'0"W72°12'0"W

41°16'0"N 41°16'0"N

41°15'0"N 41°15'0"NDecember 2014Coordinate System: NAD 1983 StatePlane Connecticut FIPS 0600 Projection: Lambert Conformal ConicUnits: MeterBackground: NOS multibeam data 5x vertical exaggeration (compiled by DAMOSVision 2014)0 0.50.25Kilometers ́File Name: NLDS_2014_SPI_West_SSNiantic Bay Disposal Site (NBDS)Depth (m)Successional StageStage 1Stage 1-2, 2Stage 1 on 3, 2-3, 3IndeterminatePage 39 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

4.0 SUMMARY

The SPI/PV survey obtained images of cross-secti ons of the sediment-wat er interface and planview images of the seafloor surface. The results included es timated grain-size information, evidence of sediment transport cond itions, biological characteristic s, and the effects of biological activity. SPI and PV can detect some conspicuous species but are primarily used to infer process from patterns of sedimentologi cal and biological processes (G ermano et al. 2011, Carey et al. 2014). The observed textures and patterns in the seafloor su rface and subsurface provided evidence of the recent history of physical and biological processes th at is relevant to management decisions (i.e., dr edged material placement).

The SPI/PV survey characterized the physical char acteristics of selected stations by measuring properties visible in SPI images (grain size major mode, penetration depth, boundary roughness, mud clasts), and observations from both SPI and PV images (sediment layers, sediment transport features). The biological assessment utilized the standard SPI biol ogical assessment (Germano et al. 2011) to generate measured parameters (a RPD, feeding voids, methane, successional stage)

and included additional observations from SPI and PV images on infauna, epifauna and traces of biological activity). Representative images for each reference area, transect, and disposal site illustrated the range of sediment conditions samp led during the survey (Figures 4-1, 4-2, 4-3).

In order to provide an integrat ed characterization of the seaflo or, the results of physical and biological characterization from SPI and PV imager y was used to define five broad habitat types (Table 2-2). Seafloor habitats can be defined for many different scales but for this study represented distinctive bottom t ypes of substrata and associated organisms within eastern Long

Island Sound. These were defined based on vi sual characteristics a nd are not intended to

correlate one to one with national standards or Long Island Sound Study (LISS) habitat mapping schemes (Auster et al. 2009, Shumchenia et al. 2014). The purpose was to allow specific areas of eastern Long Island Sound to be related to bottom stress modeling re sults. However, the general types described had a one to many relationship to the LISS approach (Table 4-1). The

results could be cross-walked to the Coastal and Marine Ecological Cl assification Standard (CMECS) with additional analysis, but the simple ha bitat types are sufficient to assess suitability of areas for potential dis posal sites (FGDC 2012).

The habitat types: rock and she lls are expected to correlate wi th modeled or measured bottom

stress values above the critical shear stress for transport of consolidated fine materials. The mobile sand habitat is expected to correlate with modeled or measured bottom stress values above the critical shear stress for bedload transp ort of sand particles. The transitional and depositional habitats are expected to correlate with modeled or measured bottom stress values below the value for transport of unconsolidated fi ne particles. Open wa ter disposal sites are generally placed in habitats with relatively fine sediments below the wave base that experience transitional or depos itional conditions.Page 40 of 45DAMOS Data Summary Report – New London Disposal Site and VicinitySediment-Profile and Plan-View Imaging Survey, September 2014Table 4-1.Cross-walk of Substrata to LISS Habitats (Auster et al. 2009)Seascape: Fishers Island SoundSubsystem: Deep SubtidalSubstratum Characteristics HabitatSediment transport Class SubclassSecondary Subclassand ModifiersRock Hard bottom, boulders orlarge cobbles.Dominated by encrustingorganisms: sponges, hydroids,algae, anemones and mobileepifauna.Assumed to be erodedridges of glacial till or drift.Some periodic settlementof fines as drape over rocksurfaces.Moraine orBoulderreefBoulder Boulder and pebblepavementsShell Layer of disarticulated shells:common mussel (Mytilus),slipper shell (Crepidula),cockles (Cerastoderma) andclams (Ensis, Spisula,Mercenaria).Surface layer of clean shells andpebbles on coarse to fine sand.Infauna in layer of coarse shellhash overlying fine sand and silt.Some encrusting organisms onpebbles.Assumed to be area ofactive strong near-bedcurrents moving shells(absence of epifaunalgrowth).Moraine,Boulderreef orSand dunesPebble Biogenic deposit ofcoarse shells andepifaunaMobile Sand Fine sand with bedforms,isolated shells and pebbles.Active infauna including acornworms (Saccoglossus), deepburrowing polychaetes. Someresistant epifauna on shells orisolated pebbles.Assumed to be area ofmoderate near-bed currentssufficient to periodicallymove sand in bedload.Sand dunesor Sand barSand Sand dune, smallasymmetrical ripples andarcuate ripplesTransitional Surface with shell layer andmud drape.Epifauna on shell layer andinfaunal burrowing organisms.Episodic transport of shellalternating with deposition.Basin,Sand bar orArtificialstructureMixedsedimentsLag deposits of shell andpebbles with epifaunaand mud; dredgedmaterialDepositional Very fine sand or silt with nobedforms. Some isolatedshells and pebbles.Dominated by deep burrowinginfauna and some encrustingorganisms (hydroids, bryozoans,anemones) on hard surfaces.Assumed to be low nearbed currents with veryinfrequent storm transportof surface sediment.Mud fields Mud Lobster burrow; infaunalcommunityPage 41 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Figure 4-1. Representative images from western part of the study areaPage 42 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Figure 4-2. Representative images from eastern part of the study areaPage 43 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

Figure 4-3. Representative images from eastern-most reference areasPage 44 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

5.0 REFERENCES

AECOM. 2009. Monitoring Survey at the New London Disposal Site, July/ August 2007. DAMOS Contribution No. 180. U.S. Army Corp s of Engineers, New England District, Concord, MA, 80 pp.

Auster, P. J.; Heinonen, K. B.; Witharana, C.; McKee, M. 2009. A habitat classification scheme for the Long Island Sound region. Long Isla nd Sound Study Technical Report. EPA Long Island Sound Office, Stamfo rd, Connecticut 06904. 83 p.

Carey, D. A.; Hickey, K.; Germano, J. D.; Read, L. B.; Esten, M. E. 2013. Monitoring Survey at the Massachusetts Bay Disposal Site Se ptember/October 2012. DAMOS Contribution No. 195. U.S. Army Corps of Engineers, New England District, Concord, MA, 87 pp.

Carey, D. A.; Hahn, M.; Germano, J. D.; Little , D. I.; Bullimore, B. 2014. Marine Habitat Mapping of the Milford Haven Waterway, Wales, UK: Comp arison of Facies Mapping

and EUNIS Classification for M onitoring Sediment Habitats in an Industrialized Estuary. Journal of Sea Research, 2014, doi:10.1016/j.seares.2014.09.012

. FGDC (Federal Geographic Data Committee). 2012. Coastal and Marine Ecological Classification Standard version 4, 353pp.

Fredette, T. J.; French, G. T. 2004. Understandi ng the physical and environmental consequences of dredged material disposal: history in New England and current perspectives. Mar.

Pollut. Bull. 49:93–102.

Germano, J. D.; Rhoads, D. C.; Lunz, J. D. 1994. An Integrated, Tiered Approach to Monitoring and Management of Dredged Material Dis posal Sites in the New England Regions. DAMOS Contribution No. 87. U.S. Army Corp s of Engineers, New England Division, Waltham, MA, 67 pp.

Germano, J. D.; Rhoads, D. C.; Valente, R. M.; Carey, D. A.; Solan, M. 2011. The use of Sediment-profile Imaging (SPI) for environm ental impact assessments and monitoring studies – lessons learned from the past f our decades. Oceanography and Marine Biology:

An Annual Review 49: 247-310.

Rhoads, D. C.; Germano, J. D. 1982. Characteriz ation of organism-sediment relations using sediment profile imaging: An efficient me thod of remote ecological monitoring of the seafloor (REMOTS System). Mar. Ecol. Prog. Ser. 8:115–128.

Rhoads, D. C.; Germano, J. D. 1986. Interpretin g long-term changes in benthic community structure: A new protoc ol. Hydrobiologia 142:291–308.

Shumchenia, E.; Guarinello, M.; Carey, D. A. ; Lipsky, A.; Greene, J.; Mayer, L.; Nixon, M.; Weber, J. 2014. Inventory and comparative ev aluation of seabed ma pping, classification and modeling activities in the Northwest Atlantic, USA to support regional ocean planning. Journal of Sea Research, 2014, doi:10.1016/j.seares.2014.09.010

. Stone, J. R.; Schafer, J. P.; London, E. H.; Di Giacomo-Cohen, M. L.; Lewis, R. S.; Thompson, W. B. 2005. Quaternary Geologic Map of Connecticut and Long Island Sound Basin, USGS Scientific Investigations Map 2784.Page 45 of 45 

### DAMOS Data Summary Report – New Lon don Disposal Site and Vicinity Sediment-Profile and Plan-View Imaging Survey, September 2014

6.0 DATA TRANSMITTAL

Data transmittal to support this data report will be provided as a se parate deliverable for inclusion in a Technical Support Notebook. The data submittal will include:

 Report figures and associated files, including an ArcGIS geo-database

 Raw NEF and adjusted SPI/PV images

 SPI/PV Field log, station locat ion, and analysis tables

 Pop-up and pull-out image files