20130430_-_NJDEP_WQC_for_Economic_Loading.pdf

CHRIS CHRISTIE

Governor

KIM GUADAGNO

Lt. Governor

Charles P. Macintosh Acting Chief, Planning Division

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DEPARTMENT OF ENVIRONMENTAL PROTECTION

OFFICE OF DREDGING AND SEDIMENT TECHNOLOGY

P.O. Box420 MAlL CODE 1140 l-04P

TRENTON, NEW JERSEY 08625

(609) 633-3801

Philadelphia District- U.S. Army Corps of Engineers Wanamaker Building 100 Perm Square East Philadelphia, PA 19107-3390

RE: Delaware River Main Channel Deepening Project Water Quality Certification: Reach E- Use of Economic Loading Water Quality Certification: Use of Mechanical Dredges Coastal Zone Consistency: Use of Fort Mifflin Confined Disposal Facility File No. 0000-13-0008.1 CDT 130001

Dear Mr. Macintosh:

BOB MARTIN

Commissioner

Aplil30, 2013

The Office of Dredging and Sediment Technology of the New Jersey Department of Environmental Protection (Department) has reviewed the U.S. Army Corps of Engineers-Philadelphia District (USACE) request (letter dated February 21, 2013) for a Clean Water Action Section 401 Water Quality Ce1iification (WQC) for a proposed change to the Delaware River Main Channel Deepening Project to use economic loading operations (barge overflow conditions) in Reach E (Delaware Bay). The use of economic loading would be limited to dredging in situ sediment comprised of greater than 90% coarse-grained material (sand, gravel, etc.). The USACE evaluated this proposed change in a Draft Environmental Assessment Delaware River Main Channel Deepening Project: Delaware Bay Economic Loading, Mechanical Dredging and Placement of Dredged Material at the Fort Mifflin Confined Disposal Facility (DEA;

February 2013).

The February 2013 DBA also evaluated the use of mechanical (as opposed to hydraulic) dredges in the Delaware River Main Channel Deepening Project, and the disposal of dredged material from Reach AA and the upper portion of Reach B of the project into the Fort Mifflin (Permsylvania) Confined Disposal Facility (CDF). The Department has determined that a WQC is also required from the State of New Jersey for the use of mechanical dredges in the Delaware River Main Chatmel Deepening Project. In addition, the Department has determined that a Coastal Zone consistency determination is required from the State of New Jersey for the use of the Fort Mifflin CDF. Although these two authorizations were not requested by the USACB in the above-referenced February 21, 2013 letter, they have been addressed herein.

In situ Sediment Grain Size Data

The Office of Dredging and Sediment Technology has provided its review comments on the February 2013 DBA in a letter from Suzanne Dietrick dated March 21, 2013. This letter noted that the Office of Dredging and Sediment Technology and the Department's Bureau of Shellfisheries were conducting a detailed review of the available Reach B sediment data to evaluate the potential impacts of the proposed use of economic loading on New Jersey's Delaware Bay oyster beds. The results of this review have been used to develop the Reach B economic loading WQC and associated conditions.

The USACB divided Reach E (Delaware Bay) into nine Sub-Reaches, and provided sediment characterization data for each Sub-Reach in support of the February 2013 DBA. The Office of Dredging and Sediment Technology reviewed this data to identify those Sub-Reaches (or portions of the Sub Reaches) that do not appear to be consistently comprised of greater than 90% coarse-grained sediment:

• Sub-Reach B-1: averaged 97.9% coarse-grained material, with 15 of the 16 sediment samples comprised of greater than 90% coarse-grained material.

• Snb-Reach B-2: only 1 sample was collected in the navigation channel, and it was comprised of only I 7.3% coarse-grained material.

• Sub-Reach B-3: averaged 93.5% coarse-grained material, with only 2 of 9 samples comprised of less than 90% coarse-grained material.

• Sub-Reach B-4: averaged 87.9% coarse-grained material, with 11 of the 18 sediment samples comprised of less than 90% coarse-grained material; these II samples were distributed throughout this Sub-Reach.

• Sub-Reach B-5: averaged 52.6% coarse-grained material, with 4 of 5 samples comprised of less than 90% coarse-grained material.

• Sub-Reach E-6: averaged 97.6% coarse-grained material, with all 4 samples comprised of greater than 90% coarse-grained material.

• Sub-Reach B-7: averaged 90.4% coarse-grained material, with 5 of the 18 sediment samples comprised of less than 90% coarse-grained material; these 5 samples were located in the central and lower p011ions ofthis Sub-Reach.

• Sub-Reach B-8: averaged 94.9% coarse-grained material, with only 2 of 21 sediment samples comprised of less than 90% coarse-grained material.

• Sub-Reach B-9: only two sediment samples were available, one comprised of 98.9% coarse grained material, while the other was only 83.0% coarse-grained material.

The USACB concluded (in the February 2013 DBA) that Sub-Reaches B-2 and B-5 were not characterized by in situ sediment comprised of greater thru1 90% coarse-grained material. The available Reach B data also indicate that the in situ sediment in Sub-Reaches B-4, B-7, and B-9 are heterogeneous in nature, with a significant percentage of the sample data in each of these Sub-Reaches indicative of in situ sediment comprised of less than 90% coarse-grained material.

New Jersey Delaware Bay Oyster Beds

A number of oyster beds are located in close proximity to the Reach B main navigation channel, and thus are particularly susceptible to the direct and indirect effects of dredging. The Depat1ment's March 21, 2013 comment letter on the February 2013 DEA did not agree with the conclusions of the DEA that the use of economic loading operations would not result in impacts to New Jersey's Delaware Bay oyster beds. In addition, while Figure 3 in the DEA shows the areas with higher oyster concentrations it does not display all of the areas that the Department considers to be seed beds.

Of particular concem are the Ship Jolm, Shell Rock, and Be1mies oyster beds:

• the Ship John bed is of considerable economic value, and is located just south of Ship John light in Sub-Reach E-1;

• the Shell Rock bed is considered to be the "heart" of the oyster grounds, has the highest catch per area of any New Jersey oyster bed, and is the main focus of New Jersey's oyster bed restoration work;

• Bennies is the largest oyster bed by area, is economically important, and is located just south of the Shell Rock bed.

The Shell Rock and Bennies oyster beds are located near Sub-Reach E-2 and the upper half of Sub-Reach E-3.

It is also noted that Figure 2 of the February 2013 DEA shows an unidentified area of the navigation channel in Reach E upstream/north of Sub-Reach E-1. No sediment data were included in the DEA for this area, and thus it is assumed that no dredging (or the use of economic loading) is proposed for this area. If this assumption is incorrect, please note that there is an oyster bed located adjacent to the main navigation channel in this area that could be impacted by dredging operations.

The study conducted by the U.S. Army Engineer Research and Development Center (Miller et al., 2002) and cited in the February 2013 DEA to support the proposed use of economic loading in Reach E examined only one economic loading/overflow operation in Delaware Bay (i.e. did not include any replication). In addition, the in situ sediment dredged in this study was comprised of 97% coarse-grained material. These two factors limit the utility of this study in evaluating the potential impacts of the use of economic loading for in situ sediment comprised of greater than 90% coarse-grained material.

Economic Loading WQC Approval and Conditions

The Office of Dredging and Sediment Technology has concluded that in situ sediment in Sub-Reaches E- 2, E-4, and E-5 is not consistently comprised of greater than 90% coarse-grained material. Thus, the Department will not authorize the use of economic loading operations in Sub-Reaches E-2, E-4, and E-5.

While the in situ sediment in Sub-Reach E- I was consistently comprised of greater than 90% coarse grained mate1ial, the close proximity of the navigation channel in this Sub-Reach to the economically and ecologically important Ship John oyster bed is of concern. Therefore, the Department will not authorize the nse of economic loading operations in Sub-Reach E-1.

The Department is concerned about potential impacts to the economically and ecologically important Shell Rock and Bennies oyster beds due to the use of economic loading operations in the upper half of Sub-Reach E-3. However, it appears that the data from only three in situ sediment samples are available from the lower half of this Sub-Reach, one of which was comprised of only 73.5% coarse-grained material. Therefore, the Department will not authorize the use of economic loading operations in Sub-Reach E-3.

Sub-Reaches E-1 through E5 of the Delaware River Main Channel Deepening Project extend from approximately STA 351 +200 to STA 432+200.

The in situ sediment in Sub-Reach E-6 and Sub-Reach E-8 were consistently comprised of greater than 90% coarse-grained material. On average, the in situ sediment in Sub-Reach E-7 was comprised of greater than 90% coarse-grained material. However, the Office of Dredging and Sediment Technology has identified the portion of the Delaware River Main Channel Deepening Project extending from approximately STA 446+ 150 to STA 462+200 (in the central and lower portions of Sub-Reach 7 and the top of Sub-Reach 8) to be comprised of heterogeneous in situ sediment frequently less than 90% coarse grained material. The limited available data for Sub-Reach E-9 (STA 510+300 to STA 512+000) indicates that the in situ sediment in this small area may or may not be comprised of greater than 90% coarse-grained material.

Economically and ecologically important New Jersey oyster beds are not located in close proximity to the navigation channel in Sub-Reaches E-6, E-7, E-8, and E-9.

Therefore, the Department will authorize the use of economic loading operations in Sub-Reaches E- 6, E-7, E-8, and E-9, contingent upon USACE compliance with the following six conditions:

(1) The USACE must develop a list ofbest management practices (BMPs) that it will use to minimize the suspended sediment/turbidity generated by the dredging and economic loading operations in these Sub Reaches.

(2) The USACE must develop and implement a program to monitor and manage the suspended sediment/turbidity generated by dredging and economic loading operations in these Sub-Reaches.

(3) The monitoring and management program mnst include a real time performance standard, consistent with the applicable Delaware River Basin Commission and New Jersey Water Quality Standards for turbidity in Delaware Bay, and approved by the Office of Dredging and Sediment Technology. An exceedance of this performance standard will require (as a BMP) the temporary cessation of economic loading operations.

( 4) The monitoring and management program must include an adaptive management component that includes the joint evaluation of the suspended sediment and turbidity data by the Office of Dredging and Sediment Technology and USACE on a bi-weekly basis. The purpose of this evaluation will be to determine if (a) revisions to the monitoring and management program are needed, and (b) it is appropriate to continue the use of economic loading operations, or require the use of more stringent BMPs, in the remaining areas ofthe Sub-Reaches to be dredged.

(5) Pending its review of the monitoring data collected in Sub-Reaches E-9, E-8, and/or E-6, the Office of Dredging and Sediment Teclmology may, at its sole discretion, prohibit the use of economic loading operations in the dredging project area in Sub-Reach E-7 from approximately STA 446+150 to STA 462+200.

( 6) The monitoring and management program and list of BMPs must be submitted to the Office of Dredging and Sediment Technology for its review and approval no later than 45 days prior to the initiation of dredging operations in Sub-Reaches E-6, E-7, E-8, and E-9.

Use of Mechanical Dredges WOC Approval and Conditions

The February 2013 DEA evaluated the use of mechanical (as opposed to hydraulic) dredges in the Delaware River Main Channel Deepening Project. This proposed change in dredging operations has the potential to significantly increase the resuspension and dispersal of sediment and associated contaminants.

The Department currently requires non-USACE dredging projects in the Delaware River (marinas, berthing areas, etc.) using mechanical dredges to use a closed (environmental) clamshell bucket and no barge overflow operating conditions. A standard bucket/clamshell can be used after dredging to refusal using a closed (environmental) clamshell has been completed (i.e. when it is not practical to use a closed clamshell due to sediment conditions). These requirements serve to minimize the potential adverse impacts to surface water quality and the aquatic ecosystem that could result from a mechanical dredging operation.

The Department authorizes the use of mechanical dredging operations for the Delaware River Main Channel Deepening Project, subject to the following three conditions:

(1) A closed clamshell/environmental bucket, with the following characteristics, shall be used for all mechanical dredging operations.

• Welded steel covers, metal screens, and rubber seals specifically designed and installed by the bucket manufacturer to minimize leakage from the closed bucket.

• Vertical side plates, with rubber seals, that overlap in some method to reduce sediment loss at bucket closure and will act as an enclosure to limit the release of dredged material from the bucket.

• Vents along the top of the bucket, protected by metal screens with hole diameters of appropriate size to reduce the release of dredged material if the bucket is overfilled. The outside of the vents will be covered by rubber flaps.

• A switch, with a signal light in the control station, to verify the bucket is closed and sealed.

• Design characteristics to produce a flat cut and to minimize resuspension during closing and lifting.

• A system inclucling a combination of software, sensors, and data that will allow the dredge operator to see the location of the bucket in three (3) dimensions in real time.

o The bucket will be displayed on the monitor in the dredge operating cab relative to the existing bottom.

o The system will use a three-dimensional differential global positioning system

(DGPS) and real time data from tide gages to determine the position of the dredge.

o Sensors placed on the dredge (as needed) will be used to accurately reproduce the position of the bucket.

A standard bucket/clamshell can be used after dredging to refusal using the closed/environmental clamshell has been completed (i.e. when it is not practical to use a closed clamshell due to sediment conditions).

(2) Overflow of dredged material-water slurry from the dredge barges/scows is not permitted (no-barge overflow operating condition).

(3) The following BMPs must be implemented when conducting mechanical dredging operations:

• The dredge shall be operated to maximize the vertical cut of the clamshell bucket, while not penetrating the sediment beyond the vertical dimension of the open bucket (i.e. overfilling the bucket).

• The dredging operation shall be conducted by slowly withdrawing the clamshell through the water column (maximum speed of two feet per second) and using slower bucket drop speeds.

• The dredged material shall be deliberately placed within barges in order to prevent spillage of material overboard.

• The gunwales of the dredge barges shall not be rinsed during dredging.

Use of the Fort Mifflin CDF Coastal Zone Consistency

The February 2013 DEA evaluated the disposal of dredged material from Reach AA and the upper portion of Reach B of the Delaware River Main Channel Deepening Project into the Fort Mifflin (Pem1sylvania) CDF. Pursuant to the Routine Program Change language in New Jersey's Coastal Zone Management Program (CZMP; effective March 17, 2008), the Office of Dredging and Sediment Technology has reviewed this proposed use of the Fort Mifflin CDF and found it to be consistent with the New Jersey CZMP.

The use of the Fort Mifflin CDF for the Delaware River Main Channel Deepening Project must be consistent with any requirements/conditions of the Pennsylvania Department of Environmental Protection, particularly those addressing the discharge of dredged material dewatering effluent fi·om the facility. The Office of Dredging and Sediment Technology requests that the USACE provide it with any monitoring data it collects associated with the use of the Fort Mifflin Upland CDF for the Delaware River Main Cham1el Deepening Project.

If you have any questions regarding the WQC authorizations and Coastal Zone consistency determination issued herein, I may be contacted at (609) 633-6801.

c. Kelly Davis, DFW