Project # W06888

NOTICE TO PLANHOLDERS
FOR CONSTRUCTION OF

A.   Changes to Division I, Bidding and Contract Documents

1. Changes to the Notice Inviting Bids, Section 00020

Substitute revised Engineer's Estimate (Pages 3 and 4 of 5 attached)

2. Changes to Bid Form, Section 00300

Substitute revised Bid Form (Pages 2 and 3 of 5 attached)

3. Changes to Instruction to Bidders, Section 00100

Section 16, "Bid Protest," is modified in part to read, "... before 5 o'clock p.m. (As determined by the clock on the wall in the receptionist area of the Department of Transportation and Public Works) of the fifth (5^th) business day following ...

Add Section 17, "Response to Certain Inquiries From Prospective Bidders," as follows:

a.  Question: Where will the strippings be stockpiled as required under Division IV, Section 02110, Subsection 3.4(C)?

Response: Strippings shall be hauled to the NW Stockpile, Area 2 (6-inch minus).

b.  Question: To determine the extent of unsuitable material in the abandoned sedimentation pond can pot holing be performed?

Response: Potholing is acceptable, but the actual limits of overexcavation will depend on field observations made by CQA Engineer. Potholing may not be sufficiently deep depending on the equipment used.

c. Question: Regarding Bid Item 17C, Geotextile Filter (7 oz/sy): Is the 7 oz/sq filter fabric between the LCRS and Operations Layer the same material as the 7 oz/sy separation fabric at subgrade?

Response: Yes

d. Question: Regarding Bid Item 17D, Geotextile Separator (12 oz/sy): Is the bid quantity correct for covering all of the tipping apron and shaded area of the AB covered east perimeter bench road?

Response: Refer to the revised Engineer's Estimate (Section 00020) and revised Bid Form (Section 00300) for Item 17D. The revised quantity of 80,000 sf includes quantity for entire plan area of the tipping apron and short approach ramp, and the shaded area of the AB covered east perimeter road, directly underneath the crushed drain rock. Please note that in Detail 3 on Drawing 8, the geotextile appears to extend only 12 feet from the grade separation. The geotextile is to extend over the entire tipping apron, while the geogrid only extends 12 feet.

e. Question: I understand that there is slope repair work at the top of the cut at the "hair-pin turn near monitoring well DW-5. What is this work and how is it paid for?

Response: Some local instability has occurred in the area of a cut slope in the eastern portion of the site, close to monitoring Well DW-5 (shown on Drawing 3). For the purpose of bidding, the affected area is located between elevations contours 316 ft and 300 ft above mean sea level in Drawing 3. The repair of this area shall be comprised of the following:

1.  Remove sloughed-off materal (estimated volume 200 cubic yards)
2.  Remove failed material from the crest and flatten the top of the slope back in the affected crest area to a slope of approximately 3H:1V.  For the estimation purposes, this regrading shall affect a plan area of 2,500 sq. ft.
3.  Cut a v-ditch, 1-ft deep, with 1:1 side-slopes along the crest of the slope at a distance of 4 feet from the regraed slope crest to intercept flow from up-slope areas - total length of the v-deitch is 150 lf.
4.  Connect two 12-inc. CMP, one at each end of the v-ditch, with Caltrans standard flared end sections, to convey water from the ditch onto the side of the road along each side of the slope.  Estimated total length of pipe:  225 ft.
5.  This work is paid as lump sum under bid Item No. 37.

f. Question: Regarding Items 8A and 8B, Drilling and Blasting: Is there an estimated quantity of drill and shoot for just the NW stockpile area?

Response: The approximate volume of the rock knobs in the NW stockpile area is 7,200 cu yds.

g. Question: Is there a traffic count of approximate number of public vehicles using the planned haul route to the NW Stockpile area that can be used to prepare Traffic Management Plan?

Answer: There will be changes in the traffic patterns at the Central Landfill beginning as early as May 2002. They can be described generally as follows:

• Beginning in May 2002 select loads of refuse (materials which present the least risk of damage to the lined floor of the Part 1 area ) will be delivered to the Part 1 area. These vehicles are likely to include 100 cu yd transfer vehicles and side-loader refuse collection trucks. These vehicles will share the existing Class 2 roadway between Traffic Conflict Nos. 1 and 5 with heavy equipment returning from the NW Stockpile. The remainder of vehicles will continue to haul refuse to the existing tipping apron of the 1971 permitting area sharing the Class 2 roadway between Traffic Conflicts Nos. 1 and 2.
  
  
• Beginning sometime during the summer of 2002, vehicles as large as articulating dump trucks will be hauling refuse from the yet-to-be-operational tipping building north of the East Canyon, to the East Canyon Part 1 area. These vehicles will share the existing Class 2 roadway between Traffic Conflict Nos. 1 and 5 with heavy equipment returning from the NW Stockpile.
  
  
• Until the above mentioned transfer station becomes operational, the full volume of traffic bringing refuse to the Central Landfill will share the existing outbound haul route between Traffic Conflict No. 1 and 2 with heavy equipment hauling to the NW Stockpile.
  
  
• After the above mentioned transfer station becomes fully operational, a fraction of vehicles will continue to utilize the existing Class 2 roadway between Traffic Conflict Nos. 1 and 2. These vehicles include commercial yard waste collection vehicles, self-haul yard and wood waste customers, and compost sales customers.
  
  
• As the rock extraction project southeast of the NW Stockpile (and directly south of the compost sales area) is no longer in operation, Traffic Conflict No. 3 is no longer a significant conflict with rock trucks back hauling to the local quarry.
  
  
• Traffic counts as tallied at the Central Landfill cashier booths for the months of June and July 2001 are presented below.

h. Question: Regarding Division III, Section 1.13, Maintaining Traffic, page 8 of 24, paragraphs 6 and 7 seem to be in conflict. Can the public traffic be placed in a reversing, one-way configuration between 7 a.m. and 4 p.m., controlled by flaggers?

Response: Paragraphs 6 and 7 have been replaced by the language shown below under Changes to Division III, Special Provisions, Section 1.13, Maintaining Traffic.

i. Question: Regarding Bid Item No. 25; 24-Inch Diameter CMP Downchutes: Does Caltrans Standard Specification Section 69: Overside Drains apply to this work? If it does, will you provide more information and detail on the anchor assemblies, pipe joints and mitered joints that would be required?

Response: Consistent with Division III Section 1.17, the downchute CMP should conform to provisions of Section 66 of Caltrans Standard Specifications for the CMP pipe. Section 69 of Caltrans also applies to this work. In either case, the standard joints anchor assemblies as per applicable Caltrans Specifications shall apply.

j. Question: Regarding Bid Item No. 30B; Drainage Ditch - 3-in. Thick Fiber-Reinforced Shotcrete-Lined: What are the pay limits? If the pay limits are to the "CDS" unit, where is it located? If the ditch extends south of the Part 2 limits of excavation, has the ditch been constructed to the shape shown on Section 1 on Drawing 8?

Response: The pay limits extend from Control Point 519 to the drop inlet at the head of the downchute leading to Sedimentation Pond No. 6 (Coordinate N15209.82, E16490.38. Between Control Points 519 and the CDS unit (labeled as "Existing CDS Unit" on Drawings 3 and 4) a new ditch must be excavated where none currently exists and shall be shotcreted. Between the CDS Unit and the drop inlet mentioned above, an existing ditch must overexcavated to conform to the dimensions shown on Section 1 of Sheet 8, and shotcreted. Reinforcing the ditch as the drop inlet is an existing sack concrete berm (approximately 3 feet tall and 8 feet long). This berm is to be shotcreted 3 inches thick, both sides. The ditch at the roadway intersections at the top and bottom of the 22% grade, shall be "softened" at the direction of the Engineer so that vehicles can drive across the ditch.

k. Question: Regarding Item 30A; Drainage Ditch - 2-ft Deep Erosion Mat Lined: What material specification applies to the erosion mat fo the ditch lining?

Response: The erosion mat used in the mat lined ditches shall be one that is intended for use as ditch lining material by the manufacturer and shall be capable of retaining its function over a period of at least 3 years from date of installation. The material to be used shall be P300 manufactured by North American Green, or its equivalent. Adequacy of the material shall be determined by a submittal to the Design Engineer. The erosion mat shall be installed in a manner consistent with manufacturers recommendations.

l. Question: What requirements are there on the NW Stockpile as to maximum slope?

Response: Stockpiles in the NW Stockpile area shall have slopes no steeper than 2.5H:1V, with 15 foot wide benches at 50 ft intervals (measured vertically, starting at the toe of the slopes.

m. Question: The following are missing from the bound specification book

• Division I, Section 00411, Bidder's Bond
• Division IV, Section 02772, Sacrificial Geomembrane, page 8 of 10
• Division IV, Section 02281, Fiber Rolls (entire section)

Response:  The missing items are attached to this Addendum No. 2.

n. Question: Will existing recycling center be relocated prior to award of contract and how is the removal of the grade separation within recycling center paid for?

Response: The recycle center will be moving north across paved entrance road to a new facility. Bidders should note that earthwork may have to commnce elsewhere and a claim for delays will only be granted when earthwork cannot proceed without the recycle center being relocated. Removal of grade separation, including piles, will be paid for under lump sum for clearing, grubbing and stripping, and modification to Division IV, Section 0210, 4.1A is made by this reference.

o. Question: Since the quarry operation at the Central Landfill has been completed, is there an actual traffic conflict at the Traffic Conflict No. 3 as shown on drawing No. 2?

Response: As it is correct that rock trucks are no longer hauling from the Central Landfill, Traffic Conflict No. 3 is of minimal conflict.

B. Changes to Division III, Special Provisions:

1. Section 1.13, Maintaining Traffic, page 8 of 24, paragraph 6 (which begin with, "A minimum of one traffic lane ...") and paragraph 7 (which begin with, "Lane closures or traffic stoppages ...") are replaced with the following language, "Public traffic heading between Traffic Conflict Nos. 1 and 2, can be placed in a single reversing, one-way configuration controlled by flaggers, which would allow scrapers to operate in their own dedicated lane, so long as all scrapers run in a tight formation (pack) thereby allowing both lanes to serve the public when scrapers are not driving on the public roadway between Traffic Conflict Nos. 1 and 2. Scrapers shall use the outside lane (adjacent down hill slope). Individual lane closures shall be restricted to the time it takes to run the pack of scrapers between said Traffic Conflicts. Should scrapers not maintain pack formation to the satisfaction of the Engineer, resulting in excessive delays to the public, Engineer may revoke lane closure option. Should hauling to NW Stockpile be performed using trucks, which by nature will be evenly spread over the haul loop, lane closure will not be allowed."

C. Changes to Division IV, Technical Specifications:

1.  Section 02227, Subsection 4.2 (A), Payment, a third sentence is added to read, "Such price shall include construction of new ditches and reworking (overexcavating) of existing ditches as described in Addendum No. 2."

2. Section 02281, Fiber Rolls, is attached to this Addendum No. 2

3. Section 02225, Operations Layer, Subsection 2.1(C) second sentence is modified in part to read, "... exhibits a hydraulic conductivity of 1 x 10 ^-4 cm/sec or less, Gravel-Filled Finger Drains shall be constructed. The specification for finger drains is included below."

The third sentence under Subsection 2.1(C) is deleted.

The following paragraphs are added to Subsection 2.1(C):

"The design for a modified operations layer shall be as follows: Gravel filled drains shall be installed within the operations layer in the cell floor area to enhance the flow of leachate into the granular LCRS layer that underlies the operations layer. One drain should be placed along the center-line of the floor area, immediately above the LCRS pipe. Two additional drains should be placed, one each along the toe of east (which will wrap around on the north side) and west slopes. Feeder drains should be placed in a chevron pattern joining the drains along the toe to the central drain. The locations of the feeder drains will be provided by the Design Engineer prior to construction. The total estimated length of drains required is approximately 2,500 lf.

The drains shall be located in 3-ft wide trenches going into the full depth (2 ft) of the operations layer, lined with a 7 oz/yd² non-woven geotextile such that the bottom of the drains will be in contact with the geotextile separator that lies on top of the granular leachate collection and removal system (LCRS) layer. (This 7 oz/sy non-woven geotextile is the same material as Bid Item 17C. Note that the geotextile material quantity for finger drains is not included in Bid Item 17C, but shall be included in the cost per lineal foot of Gravel-Filled Finger Drains provided in Bid Item 36. Clean, uniform gravel (having particle size of between 1-in. and 1.5-in. with a maximum of 5% by weight passing the #200 sieve) shall be placed within the geotextile to a full thickness of 2 ft (i.e. level with the operations layer) and the geotextile shall be wrapped over the top, with a minimum of 2 ft overlap.

Note that equipment will not be allowed directly on top of the geotextile (which lies over the granular LCRS layer). Equipment may be allowed over soil placed on top of the geotextile. Schedule of equipment loads allowed over soil on top of the geotextile is provided in Section 3.6B of Construction Specification 02714 (Geotextile).

A schematic cross section through the Gravel-Filled Finger Drains within the Operations Layer is shown below:"