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HARS - Historic Area Remediation Site
Figure 1. Backhoe dredge New York (Great Lakes
Dredge and Dock Company) working in the Kill Van
Kull.
Dredging navigation channels, berthing piers and anchorage areas in the Port of New York and New Jersey is necessary to maintain our harbor and
its water dependent facilities (Figure 1). The harbor requires dredging because fine-grained sediments, transported by rivers and within
estuaries, settle and accumulate on the sea floor, causing shoaling which interferes with safe navigation.
The success of ocean commerce within the Port depends on a regular and predictable maintenance and new work dredging program. Existing
channel depths must be maintained to allow safe clearance, and deeper navigation channels must be excavated for modern cargo ships if the
viability of the Port is to continue.
Using dredged material from the Harbor to cover existing sediments at the Historic Area Remediation
Site (HARS) represents an environmentally beneficial use of this resource. Bottom sediments at the HARS
which may have the potential to cause adverse effects are being capped with cleaner sediments
dredged from the Harbor which meet the criteria of the Ocean Dumping Act and will not cause adverse
effects. Placement of this material at the HARS is remediating the site by reducing impacts to
acceptable levels and improving habitat conditions for bottom dwelling organisms.
The following passages provide a brief history of dredged material disposal activities in the New York
Bight and creation of the HARS, a discussion of remediation activities, and a summary of monitoring
activies conducted since HARS designation in 1997.
Figure 2. Location of old Mud Dump Site (MDS) and
Historic Area Remediation Site (HARS) off the coast
of Sandy Hook, New Jersey, within the inner New York
Bight. (Click picture to
enlarge)
Historically, most of the material dredged from the
Port has been disposed in the Atlantic Ocean, in and
around an area known as the New York Bight Dredged
Material Disposal Site. Commonly referred to as the
Mud Dump Site (MDS), it is located in a region of
the inner New York Bight known as the New York Bight
Apex (Figure 2). The location of the former MDS is
still marked by a surface buoy (Figure 3). The use
of this region as an area for the disposal of an
assortment of materials dates back to the mid-1800s
(Figure 4).
Figure 3. Buoy marking the position of the Mud Dump Site within the inner New York Bight.
![[1884 NY Harbor Waste Barges]](oldmds.gif)
Figure 4. Tugboats pulling waste barges in NY Harbor, 1884
To accommodate the increasing need for the
disposal of the assorted material, The Office of
Supervisor of New York Harbor was established by an
act of Congress in 1888. The Harbor Supervisor,
acting through the Office of the Chief of Engineers
(of the U.S. Army Corps of Engineers), was
responsible for the designation of specific disposal
sites and for ensuring that ocean disposal would not
be detrimental to navigation or pollute adjacent
beaches (Williams and Duane, 1974).
Materials including garbage, city refuse, cellar
dirt (natural rock and soil excavated during
building construction), floatable materials, and
sediments derived from dredging during the
maintenance, deepening and construction of new
channels in New York Harbor, were dumped at specific
locations in the New York Bight Apex. Records
indicate that approximately six locations were
selected to receive this wide range of materials.
As the material accumulated at these locations, the
sites were relocated farther seaward where increased
water depths alleviated concerns of potential
navigation threats posed by accumulation of
materials.
Hydrographic data
spanning the period from 1845 to 1934 revealed that
mounds of material were being formed in the general
area of the submerged Hudson Shelf Valley
(Christiaensen Basin), the Ambrose Light Station
(Diamond Hill), and the Scotland Light Buoy. By
1914, shoaling at one of the sites reserved for
dredged material and cellar dirt became a critical
factor in the decision of the Supervisor of New York
Harbor to separate the site usages and thus
segregate the material being disposed at each site.
Figure 5. Analysis of historical bathymetric change
at MDS and vicinity, 1936 to 1995
(Click picture to enlarge)
From 1914 until 1977, when the U.S. Environmental
Protection Agency designated an interim ocean
dredged material disposal site, the general area
reserved specifically for a "mud dumping ground" was
defined as a point not less than 7 nautical miles
bearing 120° from Sandy Hook Light at Latitude 40°
23'48" N and Longitude 73° 51'21" W
(Pararas-Carrayannis, 1973). The boundary
coordinates of the interim site that became the MDS,
were:
40° 23'48" North Latitude, 73° 51'28" West Longitude 40° 21'48" North Latitude, 73° 50'00" West Longitude 40° 21'48" North Latitude, 73° 51'28" West Longitude 40° 23'48" North Latitude, 73° 50'00" West Longitude
![[Starfish in MDS]](n08c.gif)
Figure 6. Bottom photograph of starfish at old Mud
Dump Site
During those sixty-three
years of disposal it is estimated that more than 200
million cubic yards of dredged material were
deposited there. An analysis of bathymetric change
from 1936 to 1995 shows that significant mounding
occurred in the area, with a net volume increase of
190 million cubic yards (mcy) (Figure 5). Although
open ocean bathymetric surveys are subject to large
potential errors, this volume change indicates an
average of 3.2 mcy of dredged materials per year
were disposed.
The
interim site was officially designated as a dredged
material ocean disposal site in 1984. From 1976 to
1997, when more reliable disposal volume records
were kept, approximately 115 million cubic yards of
dredged sediment were disposed within the boundaries
of the 2.2 square nautical mile (sq. nmi) MDS. The
composition of this material varied from the coarser
fraction of "one-man stone" and "derrick stone" to
the finer grained material of sand, silt and clay.
The wide variety of bottom sediment types supported
a diverse ecosystem
(Figure 6). Since mid-1991 the larger stones have been
directed to artificial reef sites, increasing the
life of the site for the sands and silts more
commonly disposed at the MDS.
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Figure 7. The nine Priority Remediation Areas within
the HARS and location of former MDS.
An effort to expand
the MDS was started in September 1994 when the
United States Environmental Protection Agency
(USEPA) began preparing a Supplemental Environmental
Impact Statement (SEIS). The study area was
initially comprised of an 18 sq. nmi section that
included and surrounded the MDS. The area was
enlarged in October 1995 to 23 sq. nmi to encompass
areas of the Apex which had been previously impacted
by historic dredged material disposal.
Because of concerns about contaminants associated
with some dredged materials, many environmental and
citizens groups sought an end to ocean dumping of
dredged material. To address these
concerns, a July 24, 1996 letter (The 3 Party
Letter), signed by EPA Administrator Carol Browner,
Secretary of Transportation Frederico Pena, and
Secretary of the Army Togo D. West, Jr., to several
U.S. Congressional Representatives from New Jersey,
called for the closing of the MDS and the
establishment of a remediation area.
In September 1997, the
USEPA de-designated and terminated the use of the
MDS and simultaneously redesignated the
site and surrounding areas that had been used
historically as disposal sites for dredged materials
as the HARS (40 CFR Sections 228.15(d)(6); see 62
Fed. Reg. 46142 (August 29, 1997); 62 Fed. Reg.
26267 (May 13, 1997)). The HARS is managed to
reduce impacts of historical disposal activities at
the site to acceptable levels in accordance with 40
CFR Sections 228.11(c). The need to remediate
the HARS is supported by the presence of toxic
effects, dioxin bioaccumulation exceeding Category 1
levels in worm tissue, as well as TCDD/PCB
contamination in area lobster stocks (proposed
dredged sediment is determined to be Category 1 if
test results indicate no unacceptable toxicity or
bioaccumulation in test systems).
Although individual elements of those data did not
establish that sediments within the HARS were
imminent hazards to the New York Bight Apex
ecosystem, living resources, or human health,
the collective evidence presented cause for concern,
and justified the need for remediation.
Further information on the conditions in the Study
Area and the surveys performed may be found in the
Supplemental Environmental Impact Statement (USEPA,
1997).
The HARS designation identified an area in and
around the MDS which had exhibited the potential for
adverse ecological impacts. The HARS is being
remediated with dredged material that meets current
Category 1 standards and does not cause significant
undesirable effects including through
bioaccumulation. This dredged material is referred
to as "Material for Remediation" or "Remediation
Material.”
The HARS, which includes the 2.2 square nautical
mile area of the MDS, is an approximately 15.7
square nautical mile area located approximately 3.5
nautical miles east of Highlands, New Jersey and 7.7
nautical miles south of Rockaway, New York. When
determined by bathymetry that capping is complete,
the USEPA will initiate any necessary rulemaking to
de-designate the HARS. The HARS includes the
following three areas:
Priority Remediation Area (PRA): An
approximately 9.2 square nautical mile area (Figure
7) to be remediated with at least 1 meter of
Remediation Material. The PRA encompasses the
area of degraded sediments as described in greater
detail in the SEIS.
Buffer Zone: An approximately 5.7
square nautical mile area (0.27 nautical mile wide
band around the PRA) in which no placement of the
Material for Remediation will be allowed, but may
receive Material for Remediation that incidentally
spreads out of the PRA.
No Discharge Zone: An approximately 1.0
square nautical mile area in which no placement or
incidental spread of Material for Remediation is
allowed.
The designation of the
HARS in September 1997 allowed the beginning of
remediation of contaminated dredged materials dumped
prior to modern environmental regulations.
Standardized chemical and biological testing of
sediments from proposed dredging projects is
conducted to determine suitability of material for
HARS remediation. Only sediments classified as
Category I are permitted for placement at the HARS.
During the period from HARS designation to 31
December 2008, 61 dredging projects involving ~36
million cubic yards (mcy) of dredged material have
been used to remediate the HARS. In addition,
approximately 2.4 mcy of sand were used to cap the
1997 Category II project at the former MDS from 21
August 1997 to 18 January 1998. A Site
Management and Monitoring Plan was developed prior
to HARS designation to provide guidelines for
monitoring of HARS remediation activities. A
revised SMMP is presently being prepared for public
review and comment in 2009.
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The Site Management
and Monitoring Plan (SMMP)
for the HARS was developed according to the
provisions of 40CFR part 228 for management of ocean
dredged material disposal sites. The SMMP
provides guidelines to monitor placement activities,
assess the progress of remediation, analyze
environmental conditions, and address potential
environmental issues. The SMMP specifies three
tiers of monitoring, with different criteria for
implementation of monitoring activities associated
with each tier. The nine Priority Remediation
Areas (PRAs) within the HARS are prioritized
based on the perceived degree of sediment
degradation; i.e. PRA #1 was considered to pose the
greatest potential for environmental impacts, and
was slated for remediation first, followed by PRA#2,
and so on. An updated SMMP that accounts for
technological improvements since 1977, changes in
placement procedures, and past remediation
activities, is being reviewed for final
adoption in 2008. The following sections
describe the various systems and methods used to
monitor the progress of HARS remediation.
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Table 2 lists reports associated with HARS monitoring activities and allows direct downloading of most
reports. A hard copy of the report listed in Table 2 that is not available in PDF format is available by
request. Supplemental technical reports indirectly associated with the HARS are listed at the end of this report.
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Figure 8. Example placement grid within the HARS
(used for the KVK Phase II, Contract I dredging
project). The area of the grid is 1,000,000 yd2.
The estimated 1,293,000 yd3 of dredged material
from the project provided an average coverage of
approximately 4 ft (~1.2m) within the grid.
(Click picture to enlarge)
Figure 9. The ADISS (Automated Disposal
Surveillance System) system used to monitor
open-water dredged material placement.
(Click picture to enlarge)
Figure 10. ADISS placement locations for
remediation projects at the HARS. See Figure 8
for project identification. The CDF and 1998 PST
placement locations are based on Inspector Log
information.
(Click picture to enlarge)
Each dredging
project approved for HARS remediation is
considered a separate remediation project. The
estimated volume of dredged material, sediment
characteristics, and the status of past and
present remediation at the HARS, are used to
develop placement grids within one of the nine
PRAs within the HARS. Grids are located far
enough from the HARS boundaries to ensure that
water quality guidelines are not exceeded during
placement. Grids are developed to provide from
0.5 to 2.5 feet of cover across the area of the
grid. Grids are divided into sequentially
numbered cells, with placement scheduled to
occur in a manner that will produce uniform
coverage, depending on the characteristics of
the dredged material (coarser materials do not
spread out much on the bottom) (Figure 8).
A
state-of-the-art electronic monitoring system
(ADISS) is used to track the position of dredged
material scows being transported to the HARS.
ADISS, Automated DIsposal Surveillance System,
is a DGPS (Differential Global Positioning
System) based positioning and vessel draft
monitoring system developed by Science
Applications International Corporation (SAIC)
(Figure 9). The heart of the system is a
"black box" recorder mounted on each scow used
to transport dredged materials to the HARS.
The "black box" digitally records the time and
position of scows as they are loaded with
dredged materials at the dredging site based on
the increase in scow draft recorded by a
pressure sensor on the scow. Throughout
each trip to the HARS, the ADISS system records
the time, position, and draft of the scow.
During maintenance dredging projects, that
usually involve high water content sediments, a
scow bin-level sensor is also used to help
detect potential leaks of dredged material from
the scows. As the HARS is approached, the
frequency of data recording increases. At
the time of placement, when the scow draft
rapidly decreases as dredged materials are
emptied, the position and time information is
transmitted through a wireless transmission
system, which in turn transmits the data to a
computer for eventual viewing on a website.
The ADISS system continues to record the time,
position, and draft data past the initial scow
door opening, during placement, and throughout
the trip back to the dredging site. ADISS
data are downloaded from scows after completion
of placement, processed, and eventually input to
the Disposal Analysis Network for the New York
District (DAN-NY) computer system. DAN-NY
is a GIS-based system used to manage HARS
placement and monitoring data.
Scow navigation
capability aboard towing vessels is another
feature of the ADISS system. The ADISSWay
component allows USACE certified Dredged
Material Inspectors (DMIs) and vessel captains,
to view the position of scows on a laptop
computer throughout the trip to the HARS.
Placement grids designated for each project are
projected on a map of the inner New York Bight
and NY Harbor region. DMIs can zoom in or out
of the map view to observe the position of the
scow relative to landmarks, navigation aids, and
in particular, the grid cell scheduled for
placement. A digital version of the USACE
Transportation and Placement Log form is
included with the system, which the inspector
completes during each trip to the HARS. ADISS
locations of placement events associated with
the projects are illustrated in Figure 10.
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Although estimation of remediation progress can
be made based on the size of each project grid and
the volume of material placed, bathymetric surveying
is the only quantitative way to document the
thickness of cover associated with dredged material
placement. Bathymetric surveys conducted since
HARS designation have included the entire HARS, and
surveys of one or several PRAs. Complete, or
nearly complete, HARS surveys were conducted in the
fall of 1998 and the winter of 2000, and the summers
of 2002, 2004, 2005, 2006, 2007, and 2008.
Surveys of individual PRAs have been conducted in
1998, 1999, 2000, 2003, and 2007. The baseline
survey used to determine remediation progress at the
HARS was conducted in 1995, although the more
detailed survey of PRAs 1-3 conducted in 1998 has
been used as the “baseline” for comparison with
later surveys. Complete HARS surveys conducted
in 2000 and 2002 provide baseline data for areas of
the HARS that had not received remediation materials
pre-dating the surveys.
Table 1 lists the bathymetric surveys conducted
at the HARS since designation. Reports
on the data, if available, may be downloaded from
Table 2.
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Sidescan sonar is analogous to bathymetric
surveying in that sound is transmitted from
a survey vessel, bounces off the bottom, and
returns to a receiver. The time for the
sound to make the round trip is proportional
to the distance, which equates to water
depth. However, sidescan sonar uses sound to
obtain the distance and reflective
characteristics of bottom features,
providing images that look like photographs.
Sidescan sonar is considered a qualitative
tool, providing the general location and
morphology of bottom features, but usually
without the precision of bathymetric
surveys. When sidescan and multi-beam
bathymetric surveys are conducted
concurrently, exquisite detail of the bottom
may be documented. Past side-scan sonar
surveys at the HARS have been used to
identify rock outcrops, large sedimentary
bedforms, and shipwrecks. Since HARS
designation, a side-scan sonar survey has
been conducted for PRA1-3 (Table
2).
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The REMOTS® (Remote Ecological Monitoring Of The
Seafloor) is a trademarked sediment profile imagery
(SPI) system. SPI systems utilize a prism that
penetrates the seafloor, allowing photography of
nearly undisturbed vertical sections of bottom
sediments. The REMOTS® apparatus also includes a
camera for obtaining plan-view photographs of the
bottom at each station analyzed. SPIimages are most
useful in delineating the contact between recently
placed dredged materials and older bottom sediments.
SPI images can also document infaunal organisms, gas
bubbles, and sediment grain size. The rapid
deployment capability of the SPI systems allow large
areas to be surveyed in a relatively short amount of
time. SPI imagery has been particularly useful in
mapping the dredged material "footprint" associated
with past dredged material placement. Twelve SPI
(REMOTS®) surveys have been conducted at the HARS (Table
2).
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Cores provide a
vertical sample of the sediments comprising the
ocean bottom. Since sediments are deposited
vertically, with the oldest sediments at the bottom,
cores provide a record of the sedimentation history
at a sampling station. Cores reveal differences in
color and grain size that are associated with a
sedimentary unit. Deposition of fine-grained dredged
material on top of sandy sediments usually produces
a well-defined interface; i.e. darker colored
dredged materials overlying lighter colored sandy
sediments. In addition to color and grain-size
characteristics of sediments, cores may be used to
determine geotechnical and chemical properties of
sediments contained within, and provide calibration
and verification data for seismic surveys. Six
sediment coring surveys have been conducted at the
HARS, all associated with the 1997 and/or 1993
Category II capping projects (Table
2).
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Seismic data are used to map the sedimentary
units beneath the ocean surface based on the sound
reflection and transmission characteristics of the
sediments. Although cores provide discrete samples
of sub-surface sedimentary information, their time
and expense limits the practical number of sample
stations. Seismic data allow analysis of large areas
of the sub-surface without physically collecting
sediment samples, although cores are often used to
calibrate and verify seismic data. A seismic survey
of the 1997 Category II capping project was
conducted in April 1998 (Table
2). Seismic surveys of the 1993 and 1997 capping
projects were conducted in 1998 and 2003 (Table
2).
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Figure 11. Current meter data from ARESS
pods deployed in HARS PRA#1 from 15 –29
October 1998. Data are from sensors
15cm above the bottom
(Click picture to enlarge)
In
addition to the more typical monitoring work,
usually involving mapping of some kind, physical
oceanographic data have been collected at the
HARS to provide a better understanding of the
waves, currents, and potential for sediment
suspension and transport. Instrumented pods
developed by SAIC have been deployed on several
occasions. The pods are equiped with acoustic
doppler current profilers, electromagnetic
current meters, optical backscatter sensors (for
detecting suspended sediment), and pressure
transducers (waves and tides). Some limited data
sets have been collected during the testing
phases of the equipment. Some of these results
are illustrated in Figures 11 and 12. A report
of physical oceanographic data collected in 2000
and 2001 is available from
Table 2.
Figure 12. ARESS
current meter data from the shelf region
between the HARS and the NJ shore. The
western record is positioned at the
approximate location of the ARESS pod
deployments. The records are separated
to differentiate the two deployment periods,
although the deployment positions were
essentially equal. The darker green
record is from 38cm above the bottom,
collected from 9 November to 4 December
1999. The lighter green record is from
30 cm above the bottom, collected from 5
December 1999 to 28 January 2000. The
data show a strong N-S current component,
dominanted by northerly directed current
flow.
(Click picture to enlarge)
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Prior to designation of the formal HARS
boundaries, one of the tools used by EPA to
determine areas of degraded sediments
requiring remediation was the use of the
amphipod toxicity test. This is one of the
tests used in our ocean placement testing
program when we analyze proposed dredged
sediment for use as Remediation Material.
Toxicity surveys conducted at the HARS are
used to gauge the effectiveness of the
remediation effort through comparison to
EPA's original toxicity results, as well as
to determine what areas may need additional
remediation sediment. The first toxicity
survey conducted since the EPA survey was
initiated in September of 2000. Additional
toxicity surveys were conducted in 2002 and
2005. Reports from these surveys are
available from Table 3. In general, sediment
toxicity at the HARS is lower at almost all
stations than was observed at the same
stations prior to HARS designation.
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Figure 13. HARS
remediation as of July, 2008. Areas
where at least 1m of remediation thickness
has been achieved are colored green.
(Click picture to enlarge)
By comparing recent bathymetric surveys
with past surveys, the depth of remediation
material at the HARS can be analyzed.
Figure 13 shows the remediation status as of
July, 2008, based on a comparison between
the 1998 “baseline” survey and the full HARS
survey conducted in July of 2008.
Almost all of HARS PRA #1 has been capped
with at least 1m of clean dredged material.
Most of HARS PRA #2 has also achieved the
minimum 1m cap thickness, along with areas
within PRA #3. Some minor portions of
PRA #4 have been covered with at least 1m of
clean dredged material. (Note: The
1998 “baseline” bathymetric survey only
covered PRAs 1-3. Remediation status
of PRAs 4-9 will be compared with later,
full-HARS bathymetric surveys that pre-date
remediation activities there.)
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Point of Contact
HARS Manager
Stephen C. Knowles, Ph.D.
Dredged Material Management Section
Operations Division
U.S. Army Corps of Engineers, NY District
26 Federal Plaza
New York, NY 10278-0090 P
hone: (917) 790-8538
Fax: (212) 264-1463
Email:
Stephen.C.Knowles@usace.army.mil
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