250 hamilton avenue p.o. box 10250 palo alto, ca 94301

Date: March 5, 2015 Subject: Addendum Number Two (2) to City of Palo Alto Request for

Proposal (RFP) Number 158131 Project Title: Baylands Boardwalk Structural Feasibility Study Capital Improvements Project CIP# PE-14018 Department: Public Works Department, Engineering Services Division Proposal Due Date: 3:00 p.m., Tuesday, March 10, 2015 Please note the following changes, corrections, and clarifications that are hereby incorporated to the requirements of the RFP: The Proposal Due Date of 3:00 P.M. Tuesday, March 10, 2015 remains unchanged. Questions Question 1: I am proposing on the adjacent Baylands Boardwalk Feasibility Study project and

I understand from the pre-bid meeting earlier this week that the city would like the repairs/modifications to the boardwalk to be coordinated with the improvements to the Interpretive Center. Has a consultant team been selected for the Interpretive Center project, and if so, do you have any contact information for this consultant?

Answer 1: A consultant will likely be selected within a couple of weeks and staff will present

the contract to the City Council for approval in April 2015. City will forward the information at that time.

Question 2: What are the criteria for reopening the boardwalk temporarily? (particularly with

respect to ADA compliance) Answer 2: The temporary boardwalk reopening shall be determined through the

Consultant’s repair recommendations and professional opinion along with City

CITY OF PALO ALTO

PURCHASING AND CONTRACT ADMINISTRATION

250 HAMILTON AVENUE PALO ALTO, CA 94301

P.O. BOX 10250 PALO ALTO, CA 94303

CITY OF PALO ALTO RFP158131 PAGE 1 OF 4

staff concurrence. The goal for short-term reopening shall be focused on ensuring that there is a safe and stable walking surface.

Question 3: It seems like it would be difficult to execute Task 1 without doing a lot of Task 2.

It is unclear what is to be done in Task 2 that need not be addressed in Task 1. Answer 3: The intent of Task 1 is to perform field inspections and testing to develop

preliminary repair recommendations followed by Task 2 which is the refined analysis and creation of potential options more fully developed as described in the scope of work.

Question 4: Can a copy of the pre-proposal meeting sign-in sheet be distributed? Answer 4: Please see attached sign-up sheet. Question 5: Is an existing geotechnical report available for the adjacent Lucy Evans

Interpretive Center? Answer 5: No. However, please see attached Harding Lawson Associates’ and Lowney

Associates’ soil reports adjacent to the site for your reference. Question 6: At the pre-proposal meeting, Daren Anderson mentioned that a condition

assessment of the existing boardwalk structure may have been performed by the City of Palo Alto. If available, can this condition assessment information be distributed? Have there been additional repairs/upgrades to the boardwalk other than those shown on the existing drawing dated 1980. If so, can information regarding the nature of repairs be distributed?

Answer 6: There were some repairs done in 2007. Please see attachment A for additional

info. Question 7: Are CAD drawings required for the concept repair diagrams listed in Task #3, or

are neatly produced hand-drawn sketches acceptable for this task? Answer 7: AutoCAD drawings are preferred. Question 8: What is the anticipated average duration of City staff meetings listed in Section 3

of Attachment B? Answer 8: A staff meeting typically varies from 1 to 2 hours not including travel time. Question 9: Are the above mentioned City staff meetings, in addition to the required site

walks listed in Tasks #1a, #2c or can those meetings happen concurrently?


Answer 9: The site inspections should be considered separate from staff meetings. Question 10: Addendum #1 clarified the need to incorporate sea level rise in the design

concepts. Does the City have information indicating the current sea level including mean, maximum and minimum, or is the determination of this information the responsibility of the consultant team?

Answer 10: This information shall be provided by the Consultant. Question 11: Does the City have requirements for how much sea level rise should be

accounted for in the design concepts? Answer 11: The Consultant shall provide recommendations that consider the information

provided along with staff feedback. The design concepts should account for sea level rise where practicable.

Question 12: Does the City of Palo Alto have a listing of acceptable types of pressure treating

compounds for wood construction in wetland areas? Answer 12: No, the Consultant shall recommend materials as necessary for City review. Question 13: Does the City of Palo Alto have requirements for construction techniques in

wetland areas? Answer 13: The Consultant shall recommend specific techniques considering the sensitive

environment and general guidance from regulated agencies, the City master and comprehensive plans, if applicable.

Question 14: Does the City of Palo Alto have bird nesting requirements which would prohibit

construction activities during parts of the year? Answer 14: The Consultant shall determine if this is necessary for the repair options

proposed by the Consultant. If so, Consultant shall provide recommendations that shall meet regulated agencies, the City master and comprehensive plans requirements.

Question 15: Does the City of Palo Alto have requirements for disposal of waste from

construction activities? Answer 15: Yes. Contractor has to apply for a “Demolition Permit” and follow the

demolition permit procedures. For more information, please visit http://www.cityofpaloalto.org/gov/depts/ds/building/building_permits.asp


http://www.cityofpaloalto.org/gov/depts/ds/building/building_permits.asp

To assure that all Proposers have received each addendum issued, Proposers are required to acknowledge receipt of Addenda by completing the Proposer’s Information Form. Failure to acknowledge receipt of Addenda may be considered as an irregularity in the proposal. Cecilia Magana Contract Administrator City of Palo Alto Cc: Elizabeth Ames, Project Manager


July 19, 2001 195-4B

Mr. Chris Boyle

DES ARCHITECTS+ENGINEERS 399 Bradford Street Redwood City, California 94063

RE: GEOTECHNICAL SUMMARY REPORT

IMPROVEMENTS TO BAYLANDS

PARKING LOTS AND WIDENING OF

HARBOR ROAD

PALO ALTO, CALIFORNIA Dear Mr. Boyle: This report summarizes Lowney Associates’ findings and geotechnical recommendations for the proposed improvements to three parking lots and a portion of Harbor Road in the Baylands Nature Preserve in Palo Alto, California. The sites included in this study were: 1) the Byxbee Park parking lot and access road; 2) the Harbor Point parking lot; 3) the Evans Interpretative Center parking lot; and 4) the portion of Harbor Road between the harbor area entrance gate and the Evans Interpretive Center. Lowney Associates’ scope of work for this project is summarized in detail in Exhibit III of our Professional Services Subcontract with DES Architects+Engineers (DES), dated June 27, 2001. Our work included reconnaissance of each of the sites to assess their surface condition, collection of samples of aggregate base and/or subgrade soil from each of the sites, laboratory testing of selected material samples to aid in pavement thickness design, engineering evaluation of collected data, and preparation of grading and paving recommendations for the proposed improvements. We were provided with topographic information and preliminary design drawings, dated July 11, 2001, prepared by DES for each of the sites in the study area.

PROJECT DESCRIPTION

The project consists of improving the surface condition, appearance, and ride quality of three Baylands Nature Preserve parking lots, and widening, improving and overlaying a 1700-foot-long portion of Harbor Road. Since the Nature Preserve is in a sensitive baylands area, the City of Palo Alto will require the Byxbee Park and Harbor Point parking lots to be surfaced with a non-petroleum based product. Asphalt concrete may be used for resurfacing the Evans Interpretive Center parking lot, which is presently paved with asphalt concrete. Stormwater capture and filtration methods will be required due to the sensitive baylands environment in which the project sites are located.

SITE CONDITIONS

Subsurface Conditions in Study Area The subject parking lots and Harbor Road are all underlain by several feet of fill supported on soft to medium stiff, highly compressible, highly plastic clay known as Bay Mud. Based on our on-site observations and test results, the fill that composes the pavement subgrade is

DES Architects+Engineers195-4B, Improvements to Baylands Parking and Harbor Road

LOWNEYASSOCIATES ____________________________________________Page 2 Environmental / Geotechnical / Engineering Services

somewhat variable but is typically composed of stiff to hard, silty, clayey sand to sandy clay with gravel. This fill material ranges in plasticity from low to high and has variable expansion potential ranging from low to high. Plasticity Indices measured on samples of plastic clay fill ranged from 30 to 39. Atterberg Limits test results are summarized in Appendix A. Four R-value tests performed on samples of fill material indicate R-values of 22, 35, 37 and 45 at 300 psi exudation pressure. R-value by expansion pressure was estimated to be 26, 28, and 30 for the fill samples from Harbor Point, Harbor Road, and Byxbee Park that exhibited high expansion pressure. Based on previous exploration and testing in the baylands area, the Bay Mud below the fill is suspected to be highly compressible, to contain a variable amount of organics depending on location and depth, and to have a plasticity index in the range of about 40 to 50. Bay Mud contour maps prepared by the California Division of Mines and Geology (1966) indicate the thickness of Bay Mud in the area is less than 20 feet. Ground water in the baylands area is typically present at a shallow depth, in some locations a few feet below ground surface, at or near the surface of the Bay Mud.

Surface Conditions Byxbee Park Parking Lot and Access Road The Byxbee Park parking lot and 300-foot-long access road are located in the central portion of the Palo Alto Baylands Nature Preserve, near the landfill entrance and recycling center. Native grass and weeds are present on the soil surface around the perimeter of the access road and parking lot. The area around the restrooms east of the parking lot is paved with asphalt concrete. The ground surface south of some portions of the access road slopes toward the access road, directing surface water runoff onto the access road and down into the central and southern portion of the parking lot. Water appears to collect and pond in a low area along the southern side of the parking lot. The parking lot and access road are presently surfaced with aggregate base material. According to the City of Palo Alto, the aggregate base in the parking lot and access road was installed to a thickness of about 15 inches about 10 years ago. Although the majority of the aggregate base is very dense, the surface of the aggregate material is loose due to surface abrasion from traffic. Some of the aggregate base appears to be weakly cemented suggesting that a surface treatment may have been applied sometime in the past. A sample of aggregate base from the parking lot had an R-value of 80 at 300 psi exudation pressure. Numerous large, deep pot-holes have developed along the access road, and to a lesser degree in the parking lot, producing bumpy, difficult driving conditions. The bottoms of many of the pot-holes contain some loose uncemented sand and gravel. The parking lot and access road appear to have been constructed on about 3 to 5 feet of fill over native, highly-plastic Bay Mud. Where exposed, the fill generally consists of moderately plastic, sandy clay with gravel. Samples of fill material were collected along the northern edge of the parking lot. The fill that was tested had an R-value of 37 at 300 psi exudation pressure and an estimated R-value by expansion pressure of 30. Harbor Point Parking Lot



The Harbor Point parking lot is located in the northern portion of the Baylands Nature Preserve near the sailing station at the end of Harbor Road. The parking area appears to have been constructed on about 3 to 5 feet of sandy clay fill over native, highly-plastic Bay Mud. The parking lot is surfaced with aggregate base similar to the Byxbee Park parking lot. Although the aggregate base material appears to be similar to that in the Byxbee parking lot, the surface of the Harbor Point parking lot appears to be in somewhat better overall condition. The aggregate base at the Harbor Point parking lot may have been oiled or surface treated, and does not appear to have the number and depth of pot-holes as the Byxbee lot. Pot-holes in the Harbor Point parking lot are more prevalent and deeper in portions of the main traffic lanes and in localized low areas where surface water does not drain adequately. Samples of aggregate base were collected from the surface of the parking area. The aggregate surface was very dense and difficult to excavate into for hand-sampling. A composite sample of aggregate base taken from the Harbor Point parking lot had an R-value of 78 at 300 psi exudation pressure. Samples of the fill material were collected from around the perimeter of the Harbor Point parking lot. This fill material was generally composed of moderately plastic, sandy clay with a trace of gravel. The sand content appeared to be slightly higher than the fill material below the Byxbee parking lot. The sample of fill material that was tested had an R-value of 45 at 300 psi exudation pressure and an estimated R-value by expansion pressure of 26.

Evans Interpretive Center Parking Lot The Evans Interpretive Center parking lot is the only parking lot in the study area that has been surfaced with asphalt concrete (assumed to be on aggregate base). No curbs, gutters, or drainage inlets are present in or around the parking area. Native grass and weeds are growing on the ground surface around the perimeter of the parking lot. Numerous animal burrows are present in the fill around the perimeter of the pavement area. The swale between the north side of the parking lot and the adjacent portion of Harbor Road is currently an enclosed basin that collects surface water runoff. The parking lot pavement is supported on about 4 to 5 feet of fill over Bay Mud. Although the surface of the parking area generally slopes to the south, portions of center of the paved area appear to be slightly lower than around the perimeter, which is suspected to be from differential settlement due to consolidation of Bay Mud under the weight of the existing fill. The fill material that composes the pavement subgrade is generally composed of moderately to highly plastic silty clay with sand and a trace of gravel. Samples of the fill material were collected for examination and laboratory testing. A sample of the fill material had a plasticity index of 39. Another of the samples that was tested had an R-value of 22 at 300 psi exudation pressure. We suspect the fill may be native clay with organic material dredged from the surrounding areas. The asphalt concrete surface of the parking lot is in poor condition showing signs of significant distress and cracking. The surface of the parking lot pavement has been patched and repaired several times. Several portions of the pavement contains alligator cracking, block cracking, or edge cracking, all of which suggest deflection and/or differential movement of the underlying subgrade. Weeds are growing in many of the pavement cracks around the perimeter of the parking lot. A void has developed below the asphalt concrete along the



western edge of the trench backfill for the water line leading to the fire hydrant north of the parking area. Harbor Road

The 1700-foot-long subject section of Harbor Road is located between the entrance to the harbor area and the culvert bridge adjacent to the Evans Interpretive Center. The roadway alignment appears to be underlain by several feet of fill over Bay Mud. The existing Harbor Road pavement is surfaced with asphalt concrete (assumed to be over aggregate base). The subject section of roadway is in generally poor condition. Numerous portions of the pavement have been repaired by patching, and other portions of the roadway contain alligator cracking, longitudinal cracking, and edge cracking. Alligator cracking, which is indicative of excessive subgrade deflection, is particularly noticeable in the area adjacent to the “duck pond.” Surface water drainage gradients are relatively flat along the entire roadway alignment. Surface water appears to pond adjacent to the edge of the pavement in some locations. In many locations, native grass and vegetation, and animal burrows, are present immediately along the pavement edge. The fill material below the roadway appears to be composed primarily of highly plastic sandy clay with gravel and organics similar to the fill that underlies the parking lots in the study area. Some of the fill material encountered along the edges of Harbor Road contains a significant amount of organic material and root matter. Samples of the fill material that compose the pavement subgrade were collected from along the edge of Harbor Road. One of the samples that was tested had an R-value of 35 at 300 psi exudation pressure and an estimated R-value by expansion pressure of 28.

CONCLUSIONS AND RECOMMENDATIONS Based on laboratory testing performed for this study, we selected a design R-value of 20 for the fill material below the existing parking lots and roads, and an R-value of 75 for the existing aggregate base material. These design R-values were used as the basis for pavement thickness design along with assumed Traffic Indices of 4.0 for the parking lots and access road, and 5.5 for the subject section of Harbor Road. Below a thin surface crust, the native highly plastic clays underlying the thin surface fills in the project area are soft, wet, and compressible. These soils can easily become disturbed and unstable under the weight and impact of heavy construction equipment. To reduce the possibility of creating unstable subgrade conditions, excavations deeper than about one foot below existing grade should be avoided, and the weight of earthwork and construction equipment should be kept to a minimum.

Byxbee Park and Harbor Point Parking Lots We understand the objective of the proposed improvements to the parking lots and access road at Byxbee Park and Harbor Point is to provide improved ride-quality on a low-maintenance surface that is compatible with the sensitive environment in the Baylands Nature



Preserve. The use of non-petroleum based products for binding of the pavement surface will be required by the City of Palo Alto. Storm water runoff will be by sheet–flow to the perimeter of the pavements; no storm drain inlets will be allowed. In our opinion, there are three primary reasons for the development of pot-holes in the subject parking lots and access road: 1) relatively flat surface water drainage gradients leading to ponding of water on the ground surface; 2) saturation of aggregate base and localized softening of the soil subgrade; and 3) erosion of sand and fines from the uncemented aggregate base surfacing due to vehicles splashing through water-filled pot-holes. To improve ride-quality and reduce the potential for degradation of the surface of the parking lots and access road, remedial grading and resurfacing of the subject areas should be performed as recommended in the following sections. Site Preparation, Grading and Compaction To reduce the potential for ponding of surface water runoff, low points and pot-holes in the subject parking lots and access road should be cleaned of loose material and filled with Class 2 aggregate base. The surface of the aggregate base should be graded to promote proper surface water drainage without excavating below the present aggregate surface. Prior to filling, any loose or organically-contaminated material in the parking lots and access road should be removed, and the surface of the subject areas should be moistened by controlled spraying of water on the surface. All aggregate base should be compacted to at least 95 percent relative compaction based on ASTM Test D1557. Surface preparation, placement, and compaction of aggregate base should be observed and tested, as appropriate, by a member of our staff. Surfacing of Parking Lots and Access Road The surface of the compacted aggregate base in the “regraded” parking lots and access road should be sprayed with a “tack coat” of Road Oyl that is diluted and applied in accordance with manufacturer’s specifications. The parking lot and access road should not be driven on after the “tack coat” is applied. After the “tack coat” has been allowed to cure for at least 48 hours, the aggregate base should be surfaced with at least two inches of durable aggregate base that has been thoroughly blended with at least 15 percent by dry weight of Road Oyl. Based on information from the material supplier, Road Oyl treated aggregate base will have similar traffic supporting capacity as the same thickness of asphalt concrete. The mixture of aggregate base and Road Oyl should be prepared, placed, and compacted in accordance with the manufacturer’s specifications. Guideline specifications provided by the manufacturer of Road Oyl are attached.

Evans Interpretive Center Parking Lot The present asphalt concrete surface of the Evans Interpretive Center parking lot may either be removed and replaced or overlayed with asphalt concrete. The preferred alternative would be to remove the existing asphalt concrete surfacing, reshape and compact the exposed aggregate base, place and compact additional aggregate base as needed to achieve design grade, and resurface the aggregate base with at least 2½-inches of



asphalt concrete. If this alternative is selected, localized portions of the aggregate base that are unstable should be removed, and the underlying subgrade should be removed to a depth of at least 6 inches, and replaced with Class 2 aggregate base recompacted to at least 95 percent relative compaction based on ASTM Test D1557. Although this alternative will be more expensive than an asphalt concrete overlay, the appearance and service life of the parking lot is expected to be substantially better than with an asphalt concrete overlay, which will be subject to reflective cracking. If reflective cracks are acceptable in the new pavement surface, the existing surface of the parking lot can be overlayed with asphalt concrete. The overlay should be at least 2 inches thick using asphalt concrete with ½-inch maximum, medium grading. Prior to placement of the overlay, distressed portions of the existing pavement should be dug-out to a depth of at least 6 inches and replaced with compacted full-depth asphalt concrete. Minor pavement cracks and/or pavement areas over utility trenches may be reinforced with GlasGrid 8502 to delay formation of reflective cracking. GlasGrid should be installed in accordance with manufacturer’s specifications. An asphalt concrete leveling course should be used prior to placement of the pavement overlay where the present pavement surface has low spots, or if the overlay will have variable thickness in order to achieve specified final grades for improved surface water drainage. A member of our staff should observe and test, as appropriate, during pavement repair and construction.

Harbor Road Pavement Widening Harbor Road will be widened along one or both sides to produce a total width of 28 feet and curbs will be added along both sides. To reduce the initial project cost, the City is intending to use extruded curbs (rather than the preferred full-depth curbs that act as a seepage barrier around the edges of the pavement). The entire roadway will be resurfaced with asphalt concrete. Traffic on the edges of the widened pavement section will consist of bike traffic only except in localized parking and driveway areas. The City of Palo Alto has assigned a design Traffic Index of 5.5 to the subject section of Harbor Road. Where traffic will be limited to bicycles only, the pavement section along the widened road section should consist of at least 5 inches of asphalt concrete. The final lift of this asphalt concrete section should be placed and compacted concurrently with the adjacent road overlay. The asphalt concrete may be placed directly on the on-site soil provided the soil subgrade is compacted to at least 95 percent relative compaction based on ASTM Test D1557 and the subgrade is stable under wheel loading prior to paving. Pavement sections for roadway widening that will be driven on by vehicles should be constructed with at least 8 inches of asphalt concrete on the on-site soil. The final lift of this pavement section should be placed concurrently with the adjacent road overlay. The surface of the subgrade below pavement sections should be compacted to at least 95 percent relative compaction at a soil moisture content about two percent above the laboratory optimum value based on ASTM Test D1557. The pavement subgrade should be stable under wheel loads prior to paving.



A member of our staff should observe and test during site preparation, grading and compaction, as appropriate. Harbor Road Overlay The asphalt concrete overlay on Harbor Road should be at least 2 inches thick using asphalt concrete with ½-inch maximum, medium grading. Distressed portions of the pavement, as evidenced by alligator cracking or by closely-spaced edge cracking, should be dug-out, the subgrade recompacted to at least 95 percent relative compaction, and the removed section replaced with at least 8 inches of asphalt concrete prior to placement of the overlay. Surface cracks wider than about 1/8-inch should be cleaned of all loose debris and vegetation, and should be filled with a high quality flexible sealant. If reflective cracking of the pavement overlay is to be delayed, existing pavement cracks (not severe enough to be dug-out and repaired as described above) should be reinforced by placing a layer of GlasGrid 8502 along the cracks prior to placement of the overlay. GlasGrid should be installed in accordance with the manufacturer’s specifications. If GlasGrid or other approved pavement reinforcing material is not installed prior to placement of the overlay, reflective cracks should be expected in the pavement overlay within a year or two of its placement.

Surface Water Drainage All pavement surfaces should be designed and constructed with sufficient drainage gradients to promote proper drainage of surface water without ponding. We suggest using surface water drainage gradients of at least 1 percent in the principle direction of drainage.

Observation and Testing During Pavement Construction All site preparation, grading and compaction for this project should be observed and tested, as appropriate, by a member of our staff. We would appreciate at least three working days notice prior to the start of site preparation, grading, and earthwork construction so that we can schedule our staff accordingly.

CLOSURE This letter has been prepared for the sole use of DES Architects+Engineers to aid in the planning and design of improvements to three parking lots and the subject section of Harbor Road in the Palo Alto Baylands Nature Preserve. The opinions expressed in this letter were developed in accordance with generally accepted geotechnical engineering practices at this time and location. No warranty is expressed or implied. We hope this letter provides sufficient information for completion of the project plans and specifications. If you have any questions or comments about our findings or recommendations, please call me at (650) 967-2365 x-113. Very truly yours,

LOWNEY ASSOCIATES



Richard G. Woodard, P.E., G.E Senior Project Engineer CBB:RGW:GEI:sct Copies: Addressee (5) Projects:195-4B.doc

LOWNEYASSOCIATES ____________________________________________

A-1 Environmental / Geotechnical / Engineering Services

APPENDIX A

LABORATORY TESTING

The laboratory testing program was directed toward a quantitative and qualitative evaluation of the physical and mechanical properties of the soils underlying the site and to aid in verifying soil classification.

Plasticity Index: Plasticity Index measurements (ASTM D4318) were performed on two samples of the on-site fill to measure the range of water contents over which these materials exhibit plasticity. The Plasticity Index was used to classify the soil in accordance with the Unified Soil Classification System and to evaluate the soil expansion potential. Results of these tests are presented on Figure A-1.

R-Values: R-value tests (California Test Method No. 301) were performed on two samples of aggregate base and on four samples of on-site soil to provide data for pavement design. The tests indicated R-values of 78 and 80 on the samples of aggregate base, and 22, 35, 37 and 45 on the samples of on-site soil at an exudation pressure of 300 pounds per square inch. The test results are presented in Table A-1 on the next page.


LOWNEYASSOCIATES ____________________________________________

A-2 Environmental / Geotechnical / Engineering Services

Table A-1. Results of R-Value Tests

Sample

Description

of Material

Water

Content

(%)

Dry

Density

(pcf)

Exudation

Pressure

psi)

R-Value

Expansion

Pressure

(psf)

Byxbee Park Parking Lot

Bulk AB-1 Aggregate Base 6.5 126.3 585 80 39

7.9 127.5 302 80 4

8.2 126.31 238 80 0

8.6 127.1 56 76 9

Bulk SG-2 Brown sandy 28.0 87.7 94 14 56

Clay with 25.5 91.0 143 28 90

Gravel 22.5 94.3 381 38 189

Harbor Point Parking Lot

Combined Aggregate Base 7.0 134.7 189 77 0

Bulk Samples 6.2 133.4 301 77 0

AB-1 & AB-2 5.4 134.8 613 84 0

5.8 135.1 800 84 0

Bulk SG-2 Brown silty 18.1 104.9 481 55 288

sand with 19.4 102.9 303 45 202

Gravel 20.8 101.3 200 36 120

Evans Interpretive Center Parking Lot

Bulk SG-2 Gray brown 34.5 84.0 131 5 26

silty clay with 32.0 88.0 191 11 108

Gravel 28.2 91.1 352 27 129

Harbor Road

Bulk SG-1 Brown silty 34.0 73.2 69 23 60

sandy clay 27.5 76.8 175 31 176

with gravel 24.5 80.0 434 36 288

ATTACHMENT A

The City of Palo Alto proposes to repair the boardwalk at the Baylands Nature Center. The boardwalk has several damaged areas that require repair. There are 35 damaged 4''x4'' vertical supports, 50 damaged 1''x6''x-bracing, 8 missing 4"x6" mid-span supports, 30 rusted out L-brackets on the 4''x6'' mid-span supports. The repair project will consist of replacing damaged materials with similar materials of like-size. The boardwalk will be closed public during the repairs. To access the damaged material, the contractor, Phoenix Construction, will remove the boardwalk walkway planks above the damaged area. To repair the damaged 4''x4'' vertical supports, the contractor will drive a new 4''x4'' vertical support right next to the damaged ones using a pneumatic device. Once the new 4''x4'' support has been driven to the appropriate depth, it will be attached to the old 4''x4''. Project activities will adhere to the following Best Management Practices (BMPs). These BMPs include measures for preventative measures for soil and water contamination. Project activities will also adhere to BMPs for the protection of biological resources, specifically, for the protection of salt marsh harvest mouse (SMHM) and pickleweed habitat. This project qualifies as a Section 15301 Existing Facilities (Class 1) Categorical Exemption under the California Environmental Quality Act. Class 1 consists of "the operation, repair, maintenance, permitting, leasing, licensing, or minor alteration of existing public or private structures, facilities, mechanical equipment, or topographical features, involving negligible or no expansion of use beyond that existing at the time of the lead agency's determination." The proposed construction would take place for approximately 1 week and will begin after August 31, after the California clapper rail breeding season. The Service has determined that the proposed project is not likely to result in take of the California clapper rail, the salt marsh harvest mouse, or any other federally listed or proposed species. We base our determination on information provided by you that the proposed project would be confined to a relatively small area that would be either permanently or temporarily disturbed and all work will occur outside of the clapper rail breeding season. Unless new information reveals effects of the proposed project that may cause take of federally listed or proposed species in a manner not identified to date, or if a new species is listed or proposed that may suffer take by the proposed project, no further action pursuant to the Endangered Species Act of 1973 is necessary. Ryan Olah Coast Bay Delta Branch Chief U.S. Fish and Wildlife Service Sacramento Fish and Wildlife Office 2800 Cottage Way Sacramento, CA 95825 (916) 414-6623

Notes on Damage to LEBNIC Boardwalk 2-2-07 Explanation of numbering of the boardwalk supports: Bay Observation deck 1st support (I wrote the numbers of the support on or around the bolt heads) 2nd 3rd … 84th Nature Center Problems: -23rd support- the 4x4s are slightly rotted; metal brackets on the 4”x 6” that is between the 23rd and 24th supports are rusted out. -24th support- the 4”x 4”s are slightly rotted; metal brackets on the 4”x 6” that is between the 24th and 25th supports are rusted out. -26th through the 30th are missing the 4”x 6” that go between the supports. -29th- one of the 1”x 5” boards that cross between the 4x4s is broken. (Point of reference—31st support has the Clapper Rail Alley sign) 32nd – one 4x4 is broken; one 1x5 board is broken; metal bracket on 4x6 is rusted out. Note: metal brackets on the 4x6s are rusted out from 32nd support all the way to 58th support. 33rd- one broken 4x4; one broken 1x5. 33rd through 35th support is missing the 4x6 s. 34th- one broken 4x4; one broken 1x5. 35th- one broken 1x5. 36th- one broken 1x5 38th- partial rot on both 4x4s; both 1x5s are rotted out. 40th- both 1x5s are rotted out. 41st- both 1x5s are rotted out. 42nd- both 4x4s rotted out; both 1x5s are rotted out.

43rd- both 1x5s are rotted out. 44th- both 1x5s are rotted out; partial rot on the North 4x4 45th- both 1x5s are rotted out. 46th- both 4x4s rotted ½ way through; both 1x5s are rotted out. (Point of reference: between 46 and 47 is the PG&E catwalk.) 47th- one 4x4 broken; both 1x5s are rotted out. 48th- one 4x4 ½ rotten; both 1x5s are rotted out. 49th- both 4x4 ¾ rotten; both 1x5s are rotted out. 50th- both 4x4 ¾ rotten; both 1x5s are rotted out. 51st- both 4x4 ¾ rotten; both 1x5s are rotted out. 52nd- one 4x4 ¼ rotten; one 4x4 broken; both 1x5s are rotted out. 53rd- one 4x4 ¼ rotten; one 4x4 broken; both 1x5s are rotted out. 54th- one 4x4 ¼ rotten; one 4x4 ¾ rotten; both 1x5s are rotted out. 55th- both 1x5s are rotted out. 56th- one 4x4 ¼ rotten; both 1x5s are rotted out. 57th- one 4x4 ¼ rotten; one 4x4 ½ rotten; both 1x5s are rotted out. 58th- both 1x5s are rotted out. 59th- both 1x5s are rotted out. 60th- one 4x4 1/8th rotted out; one 1x5s are rotted out. 62nd- reattach one 1x5 63rd- reattach both 1x5s 64th- reattach both 1x5s (point of reference- there is a bench between the 65th and 66th support)

66th- reattach one 1x5 67th- reattach both 1x5s 68th- reattach one 1x5 69th- reattach one 1x5 80th- missing one 1x5 (Note: former repairs in 2000 on 78th through 83rd) Other problems: Uneven boards: 2 near 84 support (near the No Bikes sign) 1 near 83 on south side. 1 near 79 on south side 1 near 59 on north side 1 near 46 on south side 1 near 28 on south side 1 near 21 on south side Steel plates covering hole in the board near 57 support, and in the board near PG&E boardwalk Consider replacing boards. Huge dip in the boardwalk from 33rd to 35th support. And one high board there.

250 hamilton avenue p.o. box 10250 palo alto, ca 94301

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