SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Information to Bidders Soil Excavation,Liner/Cap Construction Puregro/Brea Facility Section 1. Page 3 accordance with state and local regulations, and for testing same. Results of the maximum dry density determination(s) shall be transmitted via facsimile and shall also be mailed to Sierra- Pacific prior to proceeding with subgrade compaction testing. Results of subgrade compaction testing shall also be transmitted and mailed upon completion of testing to Sierra-Pacific. A minimum of one maximum dry density determination test shall be performed for each of the two former evaporation pond areas. A minimum of three subgrade compaction tests shall be performed for each of the two former evaporation pond areas, for a total of six subgrade compaction tests for the project. The bidder shall maintain careful control of moisture conditioning of subgrade soils during scarification and re-compaction. The use of excess water is strictly prohibited. The subgrade materials shall be in a stable, non-pumping condition prior to placement of liner and backfill materials. Subgrade surfaces shall be sloped at a minimum gradient of 2 per cent outward from the center of each former evaporation pond area to allow for positive drainage upon completion of the work described herein. Bid Item 3. Bid Item 3. shall include the procurement and placement of the geosynthetic composite liner (GCL), a layer of sand shading, and a layer of aggregate base material. After subgrade preparation, the GCL shall be placed and the seams overlapped in accordance with the manufacturer's specifications. For bidding purposes,the estimated quantity of installed liner shall be 10,275 square feet, divided as 7,200 square feet for the former north pond area, and 3,075 square feet for the former south pond area. The liner material shall consist of Gundle Gundseal® material or equivalent, which is a dual layer composite material having a high density polyethylene (HDPE) sheet to which is attached a layer of bentonite. After liner placement is completed, a layer of washed sand having a minimum thickness of three inches shall be placed over the GCL as a shading layer to protect the liner fabric from mechanical abrasion or cutting due to future traffic loading. After placement of the sand shading layer, a layer of aggregate baserock shall be placed. Aggregate baserock materials shall be moisture conditioned to near optimum moisture content, placed in lifts less than six (6) inches in loose thickness, and shall be compacted to at least 95 per cent relative compaction. Aggregate baserock materials shall meet the requirements of the State of California specification for Class II Aggregate Base. Baserock materials shall be in a stable, non-pumping condition prior to placement of paving materials.