Tappan Zee Constructors, Llc
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TAPPAN ZEE CONSTRUCTORS, LLC July 18, 2014 Ref: LT-TZC-NYSDEC-00016 Mr. William Clarke, Regional Permit Administrator New York State Department of Environmental Conservation, Region 4 1130 North Westcott Road Schenectady, NY 12306 Re: New NY Bridge Project Approach Span Sub-assembly Staging Area at Port of Coeymans Town of Coeymans, Albany County, New York Subject: Response to June 24, 2014 NYSDEC Comments on Joint Permit Application Dear Mr. Clarke, Tappan Zee Constructors, LLC ("TZC"), has prepared documents and responses to address your comment letter dated June 24, 2014. To facilitate your review, the comments and responses in this letter are organized in the same order and under the same headings as in the comment letter. L Sturgeon/Part 182. Comment: The Department has determined that a taking will occur for this specific project at Coeymans and a 182 permit along with a species habitat mitigation/conservation plan covering the net conservation benefit is required. As discussed we still owe you and hope to have to you shortly a specific mitigation measure/project commensurate with this taking to incorporate into such a plan that TZC will be preparing and is needed for the complete application. Response: Please see our June 11, 2014 response letter regarding the measures taken to avoid the take of shortnose and Atlantic sturgeon in the project area. TZC maintains that the potential effects of planned in-water construction activities, specifically trestle pile installation and dredging, to sturgeon would not constitute a take and therefore a habitat mitigation/conservation plan is not required. Our assessment is based on the following: Tappan Zee Constructors, LLC Phone: (914) 789-3200 HDA, Inc. Page 1 of 6 www. tappanzeeconstructors.com 555 White Plains Road, Suite 400 Phone: (845) 735-8300 Tarrytown, NY 10591 https://share.hdrinc.com/sites/tzb/default.aspx TAPPANZEE CONSTRUCTORS, llC Timing of Pile Driving. Because sturgeon are most likely to seasonally occur south of the Coeymans site during the proposed pile driving schedule, the pile driving noise associated with construction of the four temporary finger trestles at the Port of Coeymans is not expected to adversely affect sturgeon. Pile driving of the 102 24-inch temporary steel piles to support the four trestles is expected to begin in late-summer and be completed by early-fall over approximately seven weeks. Unlikely Exposure of Sturgeon to Underwater Noise. In the unlikely event that a sturgeon would be present during pile driving, the area where piles would be installed would be enclosed by a double-walled silt curtain to prevent sturgeon from entering the work or ensonified area. It is anticipated that the 206 dB re 11J,Pa peak SPL isopleth (the physiological effects threshold for underwater noise impacts to sturgeon and other fish species) from only 14 piles in the trestles would extend outside of the silt curtain and that the 206 dB re 11J,Pa peak SPL isopleth from all other piles would be within the silt curtain. These 14 piles would result in approximately 28 minutes of impact pile driving over a period of about 4 to 7 days. Pile installation would generally occur starting from the shoreline to deeper water, such that these 14 piles will not be installed prior to August 15. Timing of Dredging. The proposed dredging schedule has been modified to adhere to the dredging window of September 1 thru November 30 identified in your May 20, 2014 letter. Dredging would occur during an approximate two-week period beginning September 2014. A closed environmental clamshell bucket will be used to prevent the inadvertent discharge of sediment. Avoiding Deepwater Sturgeon Habitat. Trestle pile installation and dredging at the Coeymans site will not reduce available sturgeon habitat. As described previously, the Port of Coeymans is an active shipping port and the 1.1-acre area proposed to be dredged is a currently disturbed, working waterfront much of which is maintenance dredged and lined with an armored shoreline (rip-rap and bulkheaded). The plan for the installation, operation and removal of the assembly facility at the site will be limited to this disturbed area. The pile supported trestles are shoreline structures that extend out into the river. All piles are outside of the navigation channel in water depths of less than 35 feet below MLW and the majority of the proposed activity would occur in water depths between 5 to 15 feet below MLW. The total pile area would occupy approximately 320 square feet or less than 0.007 acre in this disturbed area. The proposed project would not impact sturgeon spawning habitat, which is in the channel, and Tappan Zee Constructors, LLC Phone: (914) 789-3200 HDR, Inc. Page 2 of 6 www.tappanzeeconstructors.com 555 White Plains Road, Suite 400 Phone: (845) 735-8300 Tarrytown, NY 10591 https:l/share.hdrinc.com/sites/tzb/default.aspx the disturbed benthic habitat would return to existing conditions in a short time after dredging is completed. This would not result in the take of sturgeon habitat within the meaning of Part 182. However, TZC will incorporate, as part of the proposed project, provisions for providing up to six Vemco acoustic telemetry receiver equipment as currently valued (Vemco VR2W-69kHz) or equivalently valued equipment related to monitoring acoustically-tagged sturgeon in the Hudson River. 2. Sturgeon/ Part 182: In-water acoustic monitoring Comment: (TZC will be putting together a monitoring plan) is to be used to confirm and assure the predicted acoustic levels during pile driving will be no greater than the 150db level (which can induce behavioral change) outside the silt curtain. This silt curtain will also be designed to exclude the Sturgeon from the work area and to prevent them from getting close enough to the pile driving to be exposed to either the 187 db level (which can induce physiological damage) or the 206 db level (which can induce mortality). The plan needs to include noise monitoring frequency and should there be an exceedence of the 150 db level contingent steps to be taken by TZC to assure compliance with the 150db level outside the silt curtain. This item is needed for the complete application. Response: TZC will monitor a representative number, approximately 10%, of the piles to be installed at the Coeymans site during impact pile driving to confirm underwater noise levels are equivalent to that predicted based on the NMFS April 2, 2014 BO for impact driving 2-ft piles. Representative piles will be monitored during installation of the Assembly Sled and Crane Trestles. Underwater acoustic monitoring will be performed using similar methods as described for 2- and 3-ft piles in the NMFS April 2, 2014 BO (see Page 89}. 3. H20 {SPDES) Comment: Table showing requirements for the dredge spoil sediment dewatering discharge sampling frequencies, discharge limits and PCB exceedence level shutdown level is attached. This item will be incorporated into the permit and the application needs to reflect these reqtirements. Response: The dredge spoil sediment dewatering discharge sampling frequencies, discharge limits, and PCBexceedence shutdown level monitoring requirements have been incorporated into the Stormwater Pollution Prevention Plan (SWPPP) report, dated March 27, Tappan Zee Constructors, LLC Phone: (914) 789-3200 HDR, Inc. Page 3 of 6 www.taooanzeeconstructors.com 555 White Plains Road, Suite 400 Phone: (845) 735-8300 Tarrytown, NY 10591 httpsJ/share.hdrinc.com/sites/tzb/default.aspx TAPPANZEE CONSTRUCTORS, LLC 2014, revised June 27, 2014. Please refer to 11Section 4.3 Inspections" of the attached SWPPP report for additional detail. 4. Stormwater SPDES Storm Water Pollution Prevention Plan Comment: Storm water SPDES Storm Water Pollution Prevention Plan comments attached. In order to qualify for coverage under the General Permit, the SWPPP needs to be complete and accepted by the Department, other necessary DEC permits issued and the Notice of intent filed with the Department. These items are not needed for the complete application but necessary in order to commence ground disturbance for this project covered by the GP andSWPPP. Response: The SWPPP application has been revised according to NYSDEC comments received, and a revised SWPPP application is provided in Attachment 1. The Notice of Intent is included within the SWPPP report. The NOI was submitted to NYSDEC Bureau of Water Permits on July 17, 2014. 5. Solid Waste-Beneficial Use Determination (BUD} Comment: Solid Waste-Beneficial Use Determination {BUD) for reuse of Class B material Review pending. In the interim the application needs to reflect that all dredge spoils material will be managed as a solid waste similar to the Class C material contaminated with 1-7 ppm ofPCBs. The BUD is not needed for the complete application. Response: The BUD application has been revised to assume that all dredge spoil material will be handled as Class C material contaminated with 1-7 ppm of PCBs. A revised BUD application will be provided once comments have been received from NYSDEC Solid Waste Division. 6. SEQR Comment: As discussed noise impact study under review with potential increases greater than 6 db(A) to Coeymans residential and Schodack Island State Park receptors of concern particularly operational noise over the three year project life. Mitigation may need to be considered. We will discuss further later this week. Tappan Zee Constructors, LLC Phone: (914) 789-3200 HDR, Inc. Page 4 of 6 www.taopanzeeconstructors.com 555 White Plains Road, Suite 400 Phone: (845) 735-8300 Tarrytown, NY 10591 https:l/share.hdrinc.com/sites/tzb/default.aspx TAPPANZEE CONSTRUCTORS, LLC Response: The Port of Coeymans noise analysis has been refined using the CadnaA model and adjusting the impact hammer usage from 20% to a more accurate but still conservative 5% usage factor (impact hammer usage will likely be less than 1%).