This master should be used by designers working on Port of Portland construction projects and by designers working for PDX tenants (“Tenants”). Usage notes highlight a few specific editing choices, however the entire section should be evaluated and edited to fit specific project needs.

This section is written with oversight from Port Environmental Affairs. Retain only those articles applicable to your project. Retained articles should not be altered unless approved by Port Environmental staff. You may choose to move any of these articles into other pertinent technical sections if that seems more practical.

SECTION 354000 – WATERWAY CONSTRUCTION

PART 1 - GENERAL

1.1  DESCRIPTION

  1. This section describes riverbank excavation and fill, pile driving and removal, and bank protection riprap.

1.2  RELATED WORK SPECIFIED ELSEWHERE

  1. Section 352023, Dredging
  2. Section 355912, Heavy Timber Pier Construction
  3. Section 355913, Timber Fender Piles
  4. Section 356214, Precast, Prestressed Concrete Piles
  5. Section 356216, Steel Pipe Piles

PART 2 - PRODUCTS

2.1  BANK PROTECTION RIPRAP

  1. Rock Size and Condition:
  2. Use the smallest size riprap necessary to complete the work as specified in the contract documents and as approved by the Port.
  3. Riprap shall be composed of clean rock material obtained from a quarry approved by the Port. The Port will determine the suitability of the riprap prior to installation.
  4. Riprap installed below the ordinary high water elevation shall be choked with filter gravel (less than 10 percent fines with no sharp edges) to minimize the size of the interstitial spaces.

PART 3 - EXECUTION

3.1  RIVERBANK EXCAVATION AND FILL

  1. Riverbank excavation and/or fill shall be performed during summer low flow conditions, to the extent practicable.
  2. Minimize alteration or disturbance of stream banks and existing riparian vegetation. No trees shall be removed unless necessary for the completion of the specified work.
  3. Provide a work area isolation plan, as specified in Section 015719, Environmental Construction Controls.
  4. Removal material shall be handled in a manner consistent with its characterization, in accordance with State and Federal guidelines.
  5. Obtain fill material from a source approved by the Port.
  6. Monitor water quality during excavation and fill activities, as stated in the Federal and State permits, to ensure compliance with water quality standards. Take corrective action immediately if water quality exceedances occur. Implement corrective actions as directed by the Port Inspector until water quality compliance is achieved.
  7. No visible or measurable erosion material shall exit the construction site.
  8. Unless otherwise specified by the Port, soils that are temporarily exposed and/or disturbed during construction-related activities shall be stabilized (e.g. plastic sheeting, silt fencing, straw bales, temporary seeding and mulching, or similar techniques). Erosion controls will remain in place until the project area is stabilized, as determined by the Port Inspector.
  9. Revegetate banks with native plants and stabilized following construction activities. Perform bank bioengineering techniques to the extent practicable. Such erosion control techniques may include willow baffles or staking, coir fascines, contour wattling, or similar methods that are suited for the project site.
  10. Soil layers left exposed after plantings shall be covered with a turf reinforcement mat.

K.  Herbicide Use:

1.  Only apply chemical herbicides as a transitional tool to suppress weeds. Herbicides shall be spot applied with backpack sprayers following the Portland Parks Waterway Management Policy.

  1. Do not apply herbicide under any wind conditions greater than six miles per hour, and the applicators shall use a spray shield, coarse spray nozzle, or drift retardant to eliminate drift.
  2. Protect native plantings with portable metal plant shields during all herbicide applications.

3.2  BANK PROTECTION RIPRAP PLACEMENT TECHNIQUES

  1. Riprap may be placed from shore or from a barge. Use a conveyor system or directional chute to place rock material in the specific locations requested by the Port.
  2. Where appropriate, interplant native willow stakes within the riprap to control bank erosion and improve riparian conditions.
  3. Use a bin-barge or flat-deck barge with watertight sideboards to transport and offload rock material. Do not allow material to leak from the bins or overtop the walls of the barge.

Delete entirely if pile driving is not part of the work.

3.3  PILE DRIVING

  1. “Pile driving” refers to installation by vibratory hammers and impact hammers.
  2. Underwater Noise Attenuation:
  3. Pile driving shall be conducted with a vibratory hammer to the extent practicable.
  4. When impact drivers are necessary, the smallest feasible or practical driver and the minimum force necessary will be used to complete the job. A diesel hammer or a hydraulic impact hammer will be used, when necessary, and the drop height will be set to the minimum necessary to drive the piling.
  5. Pile Driving with Impact Hammers:
  6. Employ sound attenuation measures including vibration dampeners, and unconfined or confined bubble curtains, to reduce sound pressure levels, as needed, to comply with State and Federal permit requirements, or amendments thereof.
  7. Use a bubble curtain during pile driving with an impact hammer as specified below, unless modified by the State and Federal permit, or amendments thereof. The bubble curtain shall be kept one foot off the river bottom to prevent sediment resuspension.
  8. If river currents are 1.7 miles per hour or less, the piles to be driven shall be surrounded by an unconfined bubble curtain. The bubble curtain, shall distribute small air bubbles around 100 percent of the piling perimeter for the full depth of the water column (less 1 foot from the river bottom).
  9. If river currents are greater than 1.7 miles per hour, surround the sheet piles being driven by a confined bubble curtain (i.e., a bubble ring surrounded by a fabric or metal sleeve) that will distribute air bubbles around 100 percent of the piling perimeter for the full depth of the water column (less 1 foot from the river bottom).
  10. Substrate Resuspension and Water Quality:
  11. Do not replace piles with any material treated with creosote, pentachlorophenol, or other potentially toxic wood preservative.
  12. Use a directional chute or tube to fill hollow steel piles.
  13. If concrete is used to fill hollow steel piles, follow the construction controls article, Uncured Concrete In or Around Water, in Section 015719 Do not allow concrete or contaminated water in the pipe pile to enter the river.
  14. Do not use hydraulic water jets during piling installation.
  15. Perform water quality monitoring to ensure compliance with State and Federal water quality standards. Implement measures to reduce impacts as directed by the Port.
  16. If field-testing confirms exceedances of water quality criteria, then cease pile driving until corrective actions are taken.
  17. Work may resume once water quality standards have been satisfied, as specified in the State and Federal permits, as amended.

3.4  PILE REMOVAL

  1. Use care during piling removal to minimize sediment resuspension that may result from sediments that adhere to piling. This material shall not be washed off the piling or otherwise allowed to reenter the waterway.
  2. All debris removed shall be lifted by crane onto a barge or truck and then disposed of at an appropriate upland facility.
  3. Wood Piles:
  4. Wood piling treated with wood preservatives, such as creosote or pentachlorophenol, shall be identified prior to removal.
  5. Remove piles using a vibratory hammer, direct pull, clamshell grab, or by cutting/breaking the pile at the mudline.
  6. Deploy containment booms and absorbent booms before and during the removal of all treated pilings.
  7. Broken piling shall be cut off at the mud line and removed if they protrude more than two feet above the mud line or appear to be a safety concern.
  8. Immediately remove any wood debris that falls into the water.
  9. Do not leave any treated wood pilings in the water or stacked on the streambank.
  10. Dispose of all treated wood debris removed at an upland facility approved for hazardous materials of this classification.

END OF SECTION 354000

2/8/2016 / WATERWAY CONSTRUCTION
S:\MASTERS\DIV-35\354000MT.DOC / 354000-3