Amendment 0004 with comments.pdf

Tillamook South Jetty Repairs

(8) Locations of all marine mammal observations.

(9) Other human activity in the area.

(10) Behavioral observations, to the extent practicable, if an animal has remained in the area during construction activities.

h. Conduct hydroacoustic monitoring in accordance with the requirements of the IHA.

i. In the event that the Corps or Contactor discovers and injured or dead marine mammal, and the lead PSO determines the injury or death is not associated with authorized activities, then the reporting requirements of the IHA must be followed.

3.3 PILE INSTALLATION

The following requirements apply to any installation of piles at the MOF.

a. Conduct pile driving only during daylight hours from sunrise to sunset when it is possible to visually monitor marine mammals.

b. If the shutdown zone is obscured by fog or poor lighting conditions, pile driving must not be initiated until the entire shutdown zone is visible.

c. At the MOF (excluding mooring systems), a maximum of 250 linear feet of sheet piles may be installed (Z-type, other types may be allowable upon approval by the CO). An additional 10 H-piles can be installed as anchor piles. Additional supports (i.e., tie-backs, dead man anchors, etc.) may be installed within the confines (land-side) of the sheet piles.

d. For the mooring systems at the MOF, a maximum of 24 pipe piles, with a maximum diameter of 24 inches, can be installed. It is anticipated that a maximum of (6) 4-pile dolphin clusters will be used, other configurations are allowable. If timber piles are used, piles must be untreated.

e. Vibratory driving is the preferred method for installing piles to minimize environmental impacts associated with pile driving noise.

Impact driving is allowed if vibratory methods are not feasible. If impact driving methods are used, then bubble curtains must be intalled and maintained for the duration of impact pile driving. See Subpart BUBBLE CURTAINS for requirements.

f. Jetty relict stone may be encountered during pile installation and may need to be relocated. Place relocated stone on the shoreline.

g. The allowable work windows for installing and removing piles areNovember 1 to February 15, and July 1 to August 31. Piles must not be installed or removed outside of these work windows.

h. For all pile driving, a shutdown and disturbance zone must be monitored.

(1) Monitoring must take place from 30 minutes prior to initiation through 30 minutes post-completion of pile driving.

SECTION 35 52 00.00 25 Page 6

Summary of Comments on Amendment_4_Specs.pdf Page: 1

Number: 1 Author: G2ECHMC9 Subject: Inserted Text Date: 8/24/2022 4:26:53 PM Replace with: To facilitate construction of the MOF, relict stone encountered during construction of the MOF may be moved within the available area for construction of the MOF shown in the plans. Movement of relict stone must be performed in compliance with environmental permits and requirements defined in the specifications, including but not limited to preventing adverse effect to eel grass. Relict stone that cannot be accommodated within the available area for construction of the MOF to construct the MOF in compliance with environmental requirements may be stockpiled in the MOF staging area in accordance with Section 31 00 10.00 25, TEMPORARY ROAD ACCESS AND STAGING, Paragraph 3.5b. Provide fencing (chain link fence or approved equal) around stockpiles to deter predators from establishing in the interstitial rock spaces. Maintain fencing through completion of the project.

Tillamook South Jetty Repairs

3.5 POST CONSTRUCTION

Maintain the MOF in place until no longer needed. The facilities must be completely removed and disposed of properly. Submit a Material Off-Loading Facility Removal Plan for CO approval prior to beginning removal activities at the MOF. Refer to SLOPES IV removal procedures in Attachment A7. Removal may only occur from November 1 to February 15, and July 1 to August 31. During removal, minimize debris falling into water and utilize low tides and calm conditions to minimize turbidity. Contractor-furnished materials remain the Contractor's property upon removal. Sand that was used for fill which originated as dredged material during the construction of the MOF may be spread along the shoreline above MLLW. Limit the height of shoreline placement to six feet.

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SECTION 35 52 00.00 25 Page 9

Page: 2 Number: 1 Author: G2ECHMC9 Subject: Cross-Out Date: 8/23/2022 11:33:50 AM Delete last 2 sentences in paragraph.