RECOVERY--Z--PROJECT NUMBER 114255, Perofrmance Oriented Construction Activity Contract (POCA), Grade and Pave Access Roads, Alamo Dam, La Paz County, Arizona

This contract action was accomplished using other than competitive procedures because this is an order under an existing contract that was awarded using non-competitive procedures. This contract action was accomplished using other than competitive procedures because this is an order under an existing contract that was awarded using non-competitive procedures. 1. GENERAL WORK REQUIREMENTS: The Contractor shall furnish all labor, material, equipment, supervision, transportation and all else necessary to perform the following Task Order Scope of Work at Alamo Dam, Arizona. The scope of this effort generally includes milling of the existing asphalt pavement, integration of the milled asphalt into the existing aggregate base course (ABC), grading and compaction of the milled asphalt/ABC, and paving with an asphalt concrete surface course. The work area includes the Spillway Access Road, Nelson Road, and the driveway and parking area for the Dam Tenders Residence. This scope of work generalizes major work elements and is not all inclusive. The Government will rely on the Contractor's expertise and experience to successfully execute this contract. This Task Order Scope of Work shall be performed in accordance with the Unified Facilities Guide Specifications per your basic contract, Occupation Safety and Health Requirements (29 CFR 1910 and 1926), US Army Corps of Engineers Safety and Health Requirements Manual (EM 385-1-1), and all applicable state and local codes. 2. PROJECT INFORMATION: The following areas are planned for grading and paving under this task order: 2.1 Spillway Access Road: This road is approximately 3,170 feet in length, and the majority of this reach varies from approximately 24 to 26 feet in width. There is an approximately 300 foot long section that is approximately 32 feet wide between the control tower and the generator house. There is an approximately 250 foot long section that is approximately 10 feet wide between the end of the dam embankment and the spillway. The existing roadway pavement section is 2 inches of asphalt concrete over 4 inches of ABC. 2.2 Nelson Road: The portion of this road planned for paving is approximately 2,670 feet in length and 12 feet wide. This road provides access from the Spillway Road to the base of the dam and gauging station. The road has multiple switch backs and the grade is approximately 10-12%. The existing roadway pavement section is 2 inches of asphalt concrete over 4 inches of ABC; although, this section is significantly deteriorated over the approximate lower third of this reach. 2.3 Driveway: The driveway is approximately 230 feet in length and 12 feet wide. The existing roadway pavement section is 2 inches of asphalt concrete over 4 inches of ABC. 2.4 Parking Area: The parking area is delineated on the attached Detail 1. The thickness of the existing pavement section is unknown. The Corps of Engineers shall remove and fill the existing manhole located near the entrance to the Parking Area prior to Contractor starting work in this area. 3. CLIN 0001, GRADE AND PAVE ACCESS ROADS: Construct new asphalt concrete pavement surface for the Spillway Access Road, Nelson Road, Driveway, and Parking Area. 3.1 Asphalt Pavement Section: Pavement section shall be 2.5 inches of asphaltic concrete (AC) pavement over a minimum of 4 inches of milled asphalt/ABC. The pavement section shall include a thickened edge constructed in accordance with Uniform Standard Details for Public Works Construction, Maricopa Association of Governments (MAG), Standard Detail No. 201, Type B. Asphalt concrete pavement materials shall be in accordance with the requirements of the Uniform Standard Specifications for Public Works Construction, MAG Standard Specifications for Asphalt Concrete (Section 710, inch, Marshal Mix). Placement and testing requirements for the asphaltic concrete pavement should be in accordance with MAG Standard Specifications for Asphalt Concrete Pavement (Section 321). 3.2 Milling of Existing Asphalt Concrete Pavement and Base Preparation: The existing asphalt concrete pavement shall be milled to provide a well graded mixture with a maximum nominal particle size of inch. The Spillway Access Road shall be milled to full width; however, only 22 feet of width shall be repaved (except for those areas specifically noted above as wider or narrower). Nelson Road shall be milled to full width and repaved to a 12 foot width. The Driveway shall be milled to full width and repaved to a 12 foot width with an approximate 15 foot radius on both sides of the connection point to Marina Road. All existing pavement in the Parking Area shall be milled and the area repaved to the approximate limits shown on the attached Detail 1. Milling where paving extends below guard rails shall be as close as possible without damaging the guardrails. Pavement below or beyond the guardrail shall be left in place if undisturbed by milling. If it is loosened by the milling it shall be removed and disposed of by additional milling. The milled asphalt concrete in the Spillway Access Road, Nelson Road, and the Driveway shall be integrated/mixed into the full depth of the existing ABC to provide a minimum 4 inch depth of base material. In the Parking Area, 4 inches of Aggregate Base Course (ABC) shall be placed after milling of the existing pavement. ABC materials shall be in accordance with Uniform Standard Specifications for Public Works Construction, MAG Standard Specifications for Base Materials (Section 702, Aggregate Base). Any excess subgrade materials shall be exported to the low spot on Nelson Road and used as subgrade fill, as described below. Drainage in the Parking Area is to be maintained to the existing central drain. All milled asphalt concrete/ABC shall be compacted to a minimum of 95 percent of the maximum dry density at a moisture content of optimum or lower as determined by ASTM D1557 (Modified Proctor). Testing of milled asphalt concrete/ABC for field density, field moisture content, and moisturedensity relationship shall be in accordance with US Army Corps of Engineers Construction Control Manual Pamphlet No. 415-1-2 with the test frequencies as described in Table 2.1-C, 1 and 3. 3.3 Grading and Subgrade Preparation: Grading shall generally be accomplished to the existing elevations and slopes or as shown on the attached Details 2 and 3. Grading shall include the removal of all existing surface vegetation and other organics, any fills and/or backfills, any disturbed soil, and any unstable (loose, soft, wet, etc.) soils, if encountered, from all proposed pavement areas. All areas of excavation should be observed by a representative of the Corps of Engineers after clearing and during subsequent scarification to verify removal of all undesirable materials before any filling operations begin at the Site. Widen any resulting depressions as necessary to accommodate compaction equipment and provide a level base for placing fill. Subsequent to the surface clearing and grubbing efforts, the exposed natural ground surface in those areas not currently covered with existing pavement should be prepared to a minimum depth of 6 inches below all proposed pavement areas. Subgrade preparation shall include scarification, moisture conditioning (or aeration), and compaction. Subgrade shall be compacted to a minimum of 90 percent of the maximum dry density at a moisture content of 2 percent below optimum or lower as determined by ASTM D1557 (Modified Proctor). Material testing shall be in accordance with US Army Corps of Engineers Construction Control Manual Pamphlet No. 415-1-2 with the subgrade test frequencies as described in Table 2.1-B, 1 and 3. 3.4 Drainage Improvements: The low spot identified along the Spillway Access Road just west of the access gate shall be filled after milling, such that a minimum slope of 1/2 of 1 % grade shall be maintained to a discharge point near the south west edge of the drainage where erosion was noted. Rough surveying indicates that fill will be required for a distance of approximately 80 feet to the west of the inlet location. A flaired end culvert and approximately 40 feet of 12-inch diameter corrugated metal pipe (CMP) pipe shall be placed for conveying runoff down the road embankment. A rolled asphalt berm shall extend approximately 150 feet from this discharge point going east along the south edge of the roadway. This berm shall be 4 to 6 inches higher than the edge of the road surface, and provide secure water passage to the inlet. A similar berm shall extend approximately 25 feet to the west to conduct water from the west into the inlet. To minimize import of material, the milled asphalt concrete and existing ABC from the low area should be salvaged by rolling to the edge or grading up station toward the dam for later spreading on the fill section. Subgrade fill and ABC shall be placed and compacted as described above. At each end of the new fill section, a vertical curve will be required to transition from the two slopes. Surveying is not anticipated for this work, and the acceptance criteria will be pleasing to the visual eye and not an abrupt change in slope at 25 miles per hour. 3.5 Storm Water Pollution Prevention Plan: The Contractor shall develop and implement a Storm Water Pollution Prevention Plan in accordance with the requirements of the Arizona Department of Environmental Quality. 4. CLIN 0002, AGGREGATE BASE FILL: Contractor shall provide a per ton price (based on full truck loads) to procure, load, transport, place, and compact ABC in the Parking Lot Area and in areas where following milling of the existing surface the milled asphalt concrete/ABC thickness/quality is deemed deficient by the Contracting Officers Representative. An estimated quantity of 350 tons has been established for this item. ABC materials shall be in accordance with Uniform Standard Specifications for Public Works Construction, MAG Standard Specifications for Base Materials (Section 702, Aggregate Base).