SECTION REVISIONS, CLARIFICATIONS AND MODIFICATIONS ADDENDA. Date Issued No /26/ No.

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1 SECTION REVISONS, CLARIFICATIONS AND MODIFICATIONS ADDENDA Section No. ADDENDUM NUMBER No. of Pages Date Issued No /26/ No /10/14 ~ END OF SECTION ~ DC WATER REVISIONS, CLARIFICATIONS AND MODIFICATIONS IFB # POPE BRANCH STREAM RESTORATION

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3 DISTRICT OF COLUMBIA WATER AND SEWER AUTHORITY INVITATION NO DATE: December 10, 2014 TO: PROSPECTIVE BIDDERS SUBJECT: ADDENDUM NO. 02 REFERENCE: POPE BRANCH STREAM RESTORATION Bidders shall acknowledge receipt of this Addendum on the Bid Form. Failure to do so may result in the rejection of the bid. This Addendum is hereby included in and made a part of the Contract Documents. This Addendum is being provided to all registered planholders. All requirements of the original Project Specifications, Drawings and any previous Addenda shall remain in force except as amended by this addendum. Addendum No. 2 consists of: Twelve (12) pages of text Zero(0) pages of bid forms Zero (0) pages of drawings ============================================================================= The following corrections, changes, additions, deletions, revisions, and/or clarifications are hereby made a part of the Contract Documents for the above referenced project. In case of conflicts between this Addendum and previous issued Documents, this Addendum shall have precedence. Bidders shall make the following change to all pertinent sheets, pages, and paragraphs of the bid proposal, plans, specifications and other Contract Documents and take same into full consideration in arriving at the prices bid. 1. BID DATE: This Addendum does not alter the previously published bid date of December 17, 2014 at 2:00 p.m. DC WATER ADDENDUM NO. 2 IFB # POPE BRANCH STREAM RESTORATION

4 CHANGES TO CONTRACT DOCUMENTS 2. SECTION: : REVISION, CLARIFICATION AND MODIFICATIONS Page 1 Immediately following the previous existing Addenda No. 1 data; insert the following information: Section No ; Addendum No. 2; No. of Pages 12 and Date Issued December 10, CHANGES TO SPECIFICATIONS Trenchless Silt Fence and Filter Log Delete existing specification and insert the attached , dated December 10, 2014 (6 pages) Boulder Delete existing specification and insert the attached , dated December 10, 2014 (4 pages) CHANGES TO CONSTRUCTION DRAWINGS 5. No changes to Construction Drawings ~ END OF ADDENDUM NO. 02 ~ DC WATER ADDENDUM NO. 2 IFB # POPE BRANCH STREAM RESTORATION

5 TRENCHLESS SILT FENCE AND FILTER LOG PART 1 GENERAL 1.01 SUMMARY A. Work specified in this Section includes but is not limited to the following: 1. Furnishing, transporting, stockpiling, installing, and maintaining Trenchless Silt Fence or Filter Log for erosion and sediment control near tree roots, as specified in the Contract Documents RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and other Division 01 Specifications Sections, apply to this Section. B. Specifications throughout all Divisions of the Project Manual are directly applicable to this Section, and this Section is directly applicable to them RELATED SECTIONS: Specified Sections elsewhere may include but are not limited to: A. Section : Earthwork B. Section : Shredded Hardwood Mulch PART 2 PRODUCTS 2.01 MATERIALS A. Wood posts for trenchless silt fence shall be 1 ¾ X 1 ¾ ± 1/16 inch (minimum) square cut of sound quality hardwood. As an alternative to wooden posts, use standard "T" OR "U" section steel posts weighing not less than 1 pound per liner foot. B. Wood post for trenchless silt fence shall be 36 inch minimum posts drive 16 inch minimum into ground no more than 6 feet apart. C. Geotextile for trenchless silt fence shall be woven silt film geotextile as follows: Property Test Method Minimum Average Roll Value 1 Grad Tensile Strength ASTM D lb 200 lb Grad Tensile Elongation ASTM D % 10% Trapezoidal Tear Strength ASTM D lb 75 lb Puncture Strength ASTM D lb Apparent Opening Size 2 ASTM D-4751 U.S. Sieve 30 (0.59 mm) Permittivity ASTM D sec -1 Ultraviolet Resistance Retained at 500 hours ASTM D % strength 1 All numeric values except apparent opening size (AOS) represent minimum average roll values (MARV). MARV is calculated as the typical minus two standard deviations. MD is machine direction; CD is cross direction. MD CD TRENCHLESS SILT FENCE AND FILTER LOG IFB # POPE BRANCH STREAM RESTORATION

6 2 Values for AOS represent the average maximum opening. D. For trenchless silt fence, use wire ties or staples to fasten geotextile securely to upslope side of fence posts at the top and mid-section. E. Filter log shall be a tubular casting filler with compost filter media. Fiber log diameters shall range between 8 and 24 inches depending on average slope and maximum slope length where the logs are being used. Fiber rolls are not interchangeable with filter logs. Log Diameter 8 to 15 inches >15 to 24 inches Average Slope Maximum Slope Length (ft) Flatter than 50:1 (<2%) :1 to 10:1 (2-10%) <10:1 to 5:1 (>10-20%) <5:1 to 2:1 (>20-50%) N/A 50 F. Compost for filter log shall meet the following parameters: Parameters 1 Acceptable Range ph Moisture content 30%-60%, wet weight basis Organic matter content 25%-65%, dry weight basis Particle size % passing a selected mesh size, dry weight basis 3in (75mm), 100% passing 1in (25mm), % passing 0.75in (19mm), % passing 0.25in (6.4mm), 30-60% passing 0.04in (1mm), 30% min. passing Physical contaminants <1% dry weight basis (manmade inerts) Adapted from AASHTO Standards Specs for Compost Filter Socks and EPA Example Compost Filter Parameters. 1 Recommended test methodologies are provided in Test Methods for the Examination of Composting and Compost (TMEC, The U.S. Composting Council). G. Wooden stakes for filter log shall be 2 inches by 2 inches and of sufficient length to attain a minimum of 12 inches into the ground and 3 inches protruding above the log. H. Provide manufacturer certification to the authorized representative of the inspection/enforcement authority showing that the, soil stabilization matting, and compost used meets the requirements for trenchless silt fence and filter log shown above. TRENCHLESS SILT FENCE AND FILTER LOG IFB # POPE BRANCH STREAM RESTORATION

7 PART 3 EXECUTION 3.01 TRENCHLESS SILT FENCE INSTALLATION A. The Contractor shall install the Trenchless Silt Fence in accordance with the Contract Documents and Specifications along the downslope side of the Mulch Access Road or as directed by Engineer. B. Wood post shall be 36 inch minimum posts driven a minimum of 16 inch into ground no more than 6 feet apart. C. Fasten geotextile securely to upslope side of fence posts with wire ties or staples at top and mid-section. D. Geotextile shall not be embedded into the ground. Lay geotextile on existing ground surface a minimum of 10 feet from wooden stake. Soil stabilization matting and a minimum layer of 12 inches of shredded hardwood mulch shall be placed on top of the geotextile as shown in Contract Documents and Details. Replenish shredded hardwood mulch as needed. E. Where two sections of geotextile adjoin, overlap, twist, and staple to post in accordance with this detail. F. Extend both ends of the silt fence a minimum of five horizontal feet upslope at 45 degrees to the main fence alignment to prevent runoff from going around the ends of the silt fence. G. Remove accumulated sediment and debris when bulges develop in silt fence or when sediment reaches 25% of fence height. Replace geotextile if torn. It undermining occurs, reinstall fence FILTER LOG INSTALLATION A. Filter logs are an alternative to trenchless silt fence and can be used in hard to reach areas, on frozen ground and pavement, and near tree roots. B. Filter logs can only be used with sheet flow. C. Clear all obstructions including rocks, clods, and debris greater than one inch that may interfere with proper function of filter log prior to installation. D. Fill filter log netting uniformly with compost to desired length such that log do not deform. E. Install filter logs perpendicular to the flow direction and parallel to the slope with the beginning and end of the installation pointing up the slope creating a J shape at each end to prevent bypass. F. For untrenched installation place shredded hardwood mulch on the uphill side or the slope along the log. G. Stake filter logs every 4 feet maximum along the entire length of the log, or trench a minimum of 4 inches into the ground and stake every 8 feet maximum. H. Stake fiber log with wooden stakes of sufficient length to attain a minimum of 12 inches into the ground and 3 inches protruding above the log. I. When more than one log is needed, overlap ends 12 inches minimum and stake. J. Remove sediment and debris and replace mulch when sediment has accumulated to a depth of one half the exposed height of the log. Replace the filter log is clogged or torn. Reinstall if filter log is undermined or dislodged. TRENCHLESS SILT FENCE AND FILTER LOG IFB # POPE BRANCH STREAM RESTORATION

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9 PART 4 MEASUREMENT AND PAYMENT 4.01 MEASUREMENT A. Unit of measure will be linear feet for Trenchless Silt Fence and Filter Log PAYMENT A. Payment for Trenchless Silt Fence and Filter Log will be made at Contract unit price per linear feet, which price and payment will include full compensation for the transport of all materials, installation, and disposal of unsuitable excavated material and all labor, materials, tools, equipment and incidentals necessary to complete work specified. ~ END OF SECTION ~ TRENCHLESS SILT FENCE AND FILTER LOG IFB # POPE BRANCH STREAM RESTORATION

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11 BOULDER PART 1 GENERAL 1.01 SUMMARY A. Work specified in this Section includes but is not limited to the following: 1. Furnishing, transporting, stockpiling, installing, and maintaining boulder cross section and riffle boulders for riffle structures, boulders for the cascade structure, and boulders for the boulder wall and boulder toes structures, as specified in the Contract Documents RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and other Division 01 Specifications Sections, apply to this Section. B. Specifications throughout all Divisions of the Project Manual are directly applicable to this Section, and this Section is directly applicable to them RELATED SECTIONS: Specified Sections elsewhere may include but are not limited to: A. Section : Geotextile B. Section : Shredded Hardwood Mulch C. Section : Earthwork D. Section : Stream Channel Fill Material E. Section : Imported Clean Sand F. Section : Streambed Material G. Section : Riffle Structure H. Section : Boulder Wall and Boulder Toe 1.04 SUBMITTALS A. Product Data 1. The Contractor shall locate potential sources for sandstone or granite boulders. The Contractor and DC WATER will jointly visit the sites to determine whether the boulder meets the specified requirements. 2. The Contractor shall obtain from the quarry and submit to the Engineer a certificate stating that the provided materials conform with the contract requirements and verify the following: a. Rock Classification. b. Unit Weight (lbs. per cubic foot). c. Weight of boulders being supplied. d. Source B. Samples 1. Samples shall be submitted to the Engineer for approval, prior to its use in the project. Any unsuitable material shall be removed at the Contractor s expense. BOULDER IFB # POPE BRANCH STREAM RESTORATION

12 1.05 SCHEDULING A. The Contractor shall not be granted an extension of time or extra compensation due to delay caused by sampling, testing, approval or disapproval of rock protection material under the requirements of these Specifications. PART 2 PRODUCTS 2.01 MATERIALS A. Boulders shall consist of angular flat sandstone or granite rock obtained from an approved source. Granite rock must consist of green/gray, brown/gray, dark gray, and/or dark brown color. Concrete or limestone shall not be considered as an alternative. B. Boulders shall be free from laminations, weak cleavages and shall not disintegrate from the action of air, salt water and in handling and placing. C. Boulders shall have a minimum unit weight of 160 lbs per cubic foot. D. The dimensions of all boulders (weir, top, footer, tie-out and riffle) shall be as follows: Boulder Dimensions (FT) Boulder Type A-Axis B-Axis C-Axis Weir Top Footer Tie-out Riffle Large Wood Debris E. Source of rock shall be from an approved mining operation with up-to-date regulatory permits. F. Rock shall not be harvested from streams or rivers outside a commercial quarry operation. PART 3 EXECUTION 3.01 INSTALLATION A. The Contractor shall install boulders in accordance with the Contract Documents for riffle, boulder wall and boulder toe structures SCHEDULES A. Due to the anticipated quarry preparatory time, and/or demand for the rock as specified in the Contract, it shall be the contractor s responsibility to make all necessary arrangements with the source of supply in a timely fashion, so that the contractor shall maintain an adequate supply of rock material and that work shall not be unnecessarily delayed due to insufficient supply. BOULDER IFB # POPE BRANCH STREAM RESTORATION

13 PART 4 MEASUREMENT AND PAYMENT 4.01 MEASUREMENT A. Unit of measure will be cubic yards for Boulders installed in the Riffle structures and the Cascade structure. Measurement is based on the boulder material installed at each riffle structure (length x width x depth), as specified in the Construction Drawings. B. Measurement for Boulders installed in the Riffle Structures shall include field modified boulder limits only if modifications were approved by the Engineer. C. Boulders for Boulder Wall, Boulder Toe, and Floodplain Large Woody Debris will not be measured separately for payment PAYMENT A. Payment for Boulders for Riffle Structures and the Cascade structure will be made at Contract unit price per cubic yard, which price and payment will include full compensation for the transport of all materials, installation, geotextile, and excavation and/or backfill associated with installation, disposal of unsuitable excavated material; and all labor, materials, tools, equipment and incidentals necessary to complete work specified. B. Payment for Boulders for Boulder Wall and Boulder Toe shall be included in the Contract unit price per linear foot of Boulder Wall and Boulder Toe installed, which price and payment will include transport of all materials, installation, geotextile, and maintenance; and for all material, labor, equipment, tools, and incidentals needed to complete the work as specified. C. Payment for Boulders for Floodplain Large Woody Debris shall be included in the Contract unit price per linear foot of Floodplain Large Woody Debris installed, which price and payment will include transport of all materials, installation, and maintenance; and for all material, labor, equipment, tools, and incidentals needed to complete the work as specified. ~ END OF SECTION ~ BOULDER IFB # POPE BRANCH STREAM RESTORATION

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