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Home My WebLink AboutMINUTES - 03212000 - C1-C5 BCOrCing Requested By: ILII III Ill III��IIII I II III II II IIIII I IIII II IIII II C Contra Costa County Public Works Dept. CONTRA COSTA Cc Recorder Office Construction Division STEPHEN L. WEIR Clerk-Recorder 255 Glacier Drive Martine, CA 94553 DDC— 2000-0058258--00 T, MAR 23, 2000 14:17:33 Return to: FRE $0.00 Ttl Pd $0.00 Nbr-0000842488 WHEN RECORDED, RETURN TO CLERK ire/R0/1o1 BOARD OF SUPERVISORS BOARD OF SUPERVISORS, CONTRA COSTA COUNTY, CALIFORNIA In the Matter of Accepting and Giving ) RESOLUTION OF ACCEPTANCE Notice of Completion of Contract for ) and NOTICE OF COMPLETION Crockett Area Road Reconstruction ) (C.C. § 3086, 3093) and Overlay ) Project No.0662-6R4218-99) RESOLUTION NO-2000/ 1.7 The Board of Supervisors of Contra Costa County RESOLVES that: The County of Contra Costa on June 30, 1999 contracted with Carone and Company, Inc., for roadway reconstruction, overlay, curb ramp reconstruction and traffic signal reconstruction, with Insurance Company of the West as surety, for work to be performed on the grounds of the County; and The Public Works Director reports that said work has been inspected and complies with the approved plans, special provisions and standard specifications and recommends its acceptance as complete as of October 20, 1999. Therefore, said work is ACCEPTED as completed on said date, and the Clerk shall file with the County Recorder a copy of this Resolution and Notice as a Notice of Completion for said contract. PASSED BY THE BOARD on March 21, 2000 by the following vote: AYES: SUPERVISORS GIOIA, UIIKEt A, DESAULNIER, CANCLILIA AND GERBER NOES: NONE ABSENT: NONE CERTIFICATION AND VERIFICATION I hereby certify that this is a true and correct copy of an Contact: Mike Carlson (925)313-2321 action taken and entered on the minutes of the Board of Orig. Dept.:Public Works(Const.) Supervisors on the date shown. cc: Record and Return Auditor Public Works- Accounting ATTESTED: MARCH 21 2000 - Construction, R.Bruno PHIL BATCHELOR, Clerk the Board of Supervisors and - Env.,C.Sellgren CountyAdministrator p Traffic,S. Kersevan Contractor RB:kj By h4z , Deputy G:\GrpUata\Const\60\2000\03-March\21-CRR0-accept.doc _""1 SOLUTION NO. 2000/ 117 Tt - BOARD OF SUPERVISORS C'Z FROM: J. MICHAEL WALFORD, PUBLIC WORKS DIRECTOR DATE: March 21, 2000 SUBJECT: Approve plans and specifications and Advertise for bids for the Delta Road Bridge Replacement Project in the Knightsen area and Adopt the CEQA Mitigated Negative Declaration. Project No.: 0662-6R4216-95, CDD-CP # 00-02 Specific Request(s) or Recommendation(s) & Background & Justification 1. RECOMMENDED ACTION: APPROVE the Plans and Specifications for the Project and FIND, on the basis of the initial study and all comments received, that there is no substantial evidence that the project will have a significant effect on the environment, ADOPT the Mitigated Negative Declaration in compliance with the California Environmental Quality Act, (the custodian of which is the Public Works Director who is located at 255 Glacier Drive, Martinez) and Continued on Attachment: X SIGNATURE: G _RECOMMENDATION OF COUNTY ADMINISTRATOR _RECOMMENDATION OF BOARD COMMITTEE APPROVE OTHER SIGNATURE(S): ACTION OF BOARD ON MARCH 21, 2000 APPROVED AS RECOMMENDED_X_OTHER I hereby certify that this is a true and correct vo E OF N SUPERVISORS(As None copy of an action taken and entered on the uYES:nn©us IABs�niT } minutes of the Board of Supervisors on the AYES: NOES: p ABSENT: ABSTAIN: date Shown. BF:sd 1\PWS4\SHARDATA\GrpData\Design\Board Orders\ INCH 21 2000 BO 2000\Delta Road Bridge Replacement 3-21.doc ATTESTED: Orin, Div: Public Works(Design Division) PHIL BATCHELOR Contact: Bill Fernandez(313-2294) , Clerk of the Board of cc: E.Kuevor,CAO Supervisors and County Administrator Auditor-Controller Community Development—D.Foley PW Accounting Construction L.Chavez,Engineering Services By QaZ!� dbr A4— Deputy y � LYBJECT: Approve plans and specifications and Advertise for bids for the Delta Road Bridge Replacement Project in the Knightsen area and Adopt the CEQA Mitigated Negative Declaration. Project No.: 0662-6R4216-95, CDD-CP # 00-02 DAVE: March 21, 2000 PAGE: 2 DIRECT the Director of Community Development to file a Notice of Determination with the County Clerk DIRECT the Public Works Director to arrange for the $1250 Fish and Game filing fee to be transferred to the County Clerk. AUTHORIZE the Public Works Director to arrange for payment of a $25 fee to Community Development for processing, and a $25 fee to the County Clerk for filing the Notice of Determination. ADVERTISE for bids to be received on Tuesday, April 25, 2000 at 2:00 p.m. DIRECT the Clerk of the Board to publish the Notice to Contractors in accordance with Section 22037 of the Public Contract Code. AUTHORIZE the closure of Delta Road Bridge between 10 p.m. and 5 a.m. for approximately four nights. 11. FINANCIAL IMPACT: The estimated contract cost of the project is $641,000, funded by Highway Bridge Rehabilitation and Replacement (Federal) Funds (80%), Road Funds (20%). 111. REASONS FOR RECOMMENDATION/BACKGROUND: The project is needed to replace an aging, one-lane bridge with a two-lane, concrete bridge. The Public Works Director has filed with the Board of Supervisors the Plans and Specifications for the project. The general prevailing rates of wages, which shall be the minimum rates paid on this project, have been filed with the Clerk of the Board and copies will be made available to any interested party upon request. The project has been found to be in compliance with the General Plan and on the basis of the initial study and all comments received, that there is no substantial evidence that the project will have a significant effect on the environment and adopted the Negative Declaration in compliance with the California Environmental Quality Act. IV. CONSEQUENCES OF NEGATIVE ACTION: If the project is not approved for advertising, it will not be constructed and Federal funding may be jeopardized. tir • .GA11Ft]RNll�SISINGAi4 iAA P Cki1CN ANb H[1l1SIN6 AGFNCY GRAY DEPARTMENT OF TRANSPORTATION ';�;,• r,{,: ;, � P o aoocneeo .. . �.. EM OAfaR0,ca 94$n-VM ERWMEM Tel.01M #i" Far WO)n&W19 X10 MAR PM TDD(510) C% 4. 32 March 8, 2000 CC-00436.58 /A File#CC004549 CH#2000022052 Ms. Leigh Chavez Contra CostaCounty Community Develop rne 1 X000 4a'Floor,North Wing "/ 651 Pine StreetlDN11q� r Martinez, CA 945530053 AL Dear Ms. Chavez: Delta Road Bridge Replacement Project- County File#CP 00-02 Thank you for including the California Department of Transportation (Caltrans) in the environmental review process for the above-referenced project. We have reviewed the Mitigated Negative Declaration and Initial Study, and are satisfied that the project will not have a significant impact to State highway facilities. Should you require further information or have any questions regarding this letter, please call Paul Svedersky of my staff at(510) 622-1639. Sincerely, HARRY Y. YAHATA District Director By s '� JEAN C. R. FINNEY District Branch Chief IGRICEQA c: State Clearinghouse CONTRA PUBLIC WORKS DEPARTMENT COSTA INITIAL STUDY COUNTY OF ENVIRONMENTAL SIGNIFICANCE PROJECT#0662-6R4216 CP# 00-02 PROJECT NAME: Delta Road Bridge Replacement Project PREPARED BY: Leigh Cha v z DATE: 2/3/00 APPROVED BY: DATE: 4111100 RECOMMENDATIONS: {} Categorical Exemption (Class) ( X ) Mitigated Negative Declaration { ) Environmental Impact Report Required ( ) Conditional Negative Declaration The project will not have a significant effect on the environment. The recommendation is based on the following: I. Agricultural Resources - the project will not impact any locally or statewide important farmland. All work associated with the project will occur within the County's existing right-of-way and within an existing temporary construction easement located within a grouping of buildings adjacent to the bridge. The grouping of buildings includes a home and associated outbuildings that are abandoned. Although the home and associated outbuildings was once used for agricultural activities, the Historic Architectural Survey Report (HASR) produced for the project indicates that the three buildings were not significant in the development of agriculture in the Delta. 2. Cultural Resources -the results of both the Archaeological Survey Report (ASR) and the Historic Architectural Survey Report (HASR) conducted for the project were negative. In addition, as referenced in the HASR, the Delta Road Bridge is ineligible for listing in the National Register of Historic Places (NRHP) according to the Caltrans Bridge Inventory. 3. Geology and Soils - the project will not create unstable earth conditions, changes in geologic substructure or increase the exposure of people or property to geologic or water related hazards. 4. Land Use and Planning - The new bridge will not increase the capacity of Delta Road, nor will it result in a change in the location, distribution, density, or growth rate of human population in the area. Construction of the bridge will not require removal of any homes or the displacement of any people. kc Delta Road Bridge Replacement—Initial Study Project No. 0662-6114216; CP 00-02 Page 2 of 4 Construction activities will create minor, short-term, temporary impacts. But no significant impacts will occur since the following mitigation measures and best management practices are incorporated into the project description and/or project specifications. 5. Airuali -there will be no significant change in the air quality at the site as a result of the project. Construction machinery and vehicles will generate short-term emissions and possibly objectionable odors during construction which may temporarily deteriorate air quality at the project site. To minimize the impact, contract specifications will stipulate the use of properly tuned and muffled equipment. Air quality impacts will also be reduced by eliminating unnecessary idling of machines when not in use. Dust palliatives or water may be applied to minimize fugitive dust during construction, if warranted. 6. Aesthetics - no significant negative aesthetic effect will result from the project. Construction activities will impact the minimum amount of vegetation necessary to complete the replacement bridge. A small stand of approximately four cottonwood trees may require removal to allow for the new bridge design; however, if it is feasible, the four cottonwood trees will be left in place. Any trees that are impacted due to the project will be replaced at a 3:1 ratio with like species. Cottonwood trees are rapidly growing species, and if removal is required, the replacement trees will grow quickly and reduce any aesthetic impact to less than significant. 7. Biological Resources - no new species will be introduced into the area as a result of the project. No construction activities will occur within any areas designated as "Environmentally Sensitive Areas" on the project plans. Any potential direct impacts to wildlife will be minimized to less than significant through installation of silt trapping devices, avoiding placement of fill on emergent wetland vegetation, and limiting in- water work to August 1 through November 301'of any given year. Although this work window extends beyond end of the typical work window (October 15), all of the regulatory agencies have agreed to this work window. The work window will be strictly adhered to unless mutually agreed upon through coordination between the County and National Marine Fisheries Service and U.S. Fish and Wildlife Service. Any trees that are impacted due to the project will be replaced at a 3:1 ratio with like species. Please see the Mitigation Summary for more details. 6. Hydrology and Water Quality - fewer piles will be installed for the new bridge than there are currently in the slough supporting the existing bridge, and the new abutments will be placed farther back on the levees than the existing abutments. The existing creosote pilings will be cut off at mudline to remove them as a navigational hazard yet minimize potential impacts to water quality due to total removal. The new piles will consist of steel encasing concrete and will not have potential toxic characteristics. Contract specifications will require the implementation of silt trapping devices of the contractor's design during pile driving and other in-water work activities. In addition, in order to prevent work materials from entering Rock Slough removal of the old bridge and construction of the new bridge, contract specifications Delta Road Bridge Replacement—Initial Study Project No. 0662-6114216; CP 00-02 Page 3 of 4 will require the implementation of debris containment methods (e.g., a net barrier) of the contractor's design. Both the silt trapping devices and debris containment barriers proposed for implementation by the contractor will be reviewed by the County. 9. Traffic and Circulation - during pile driving activities and any other activites that will cause a delay of more than 15 minutes, the bridge may require temporary closure. The temporary closure will occur at nighttime in order to minimize traffic impacts. The temporary closure is expected to occur over a maximum of four nights. 10. Public Services - closure of the bridge will isolate Holland Tract and Quimby Tract; therefore, a fire crew from the Oakley County Fire District will be located on Holland Tract to handle any potential emergencies. 11. Noise - Caltrans Standard Specifications, including the use of properly tuned and muffled equipment, will apply regarding construction noise. Pile driving activities are expected to occur over a maximum of four nights. Sensitive receptors are located at least 0.4 mile from the bridge. Based on the limited duration of pile driving activities and the distance of the nearest sensitive receptors from the construction site, impacts due to noise will not be significant. With the exception of pile driving and any other activites that will cause more than a 15-minute delay, work hours will be limited to 7:30 a.m. to 5:00 p.m., Monday through Friday, unless modified upon written approval from the Resident Engineer. 12. Hazards and Hazardous Materials - standard construction safety practices will be followed during construction to ensure no accidental release of hazardous substance or increase in the potential for exposure to these substances. In the event of any toxic substances discharge into Rock Slough, the Contract Costa Water District, Diablo Water District, City of Antioch, City of Pittsburg, Southern California Water Company and the City of Martinez will be notified of the type of discharge, its volume and other information on its characteristics. What changes to the project would mitigate the identified impacts NIA USGS Quad Sheet Woodward Island Base Map Sheet# J28 Parcel # NIA GENERAL CONSIDERATIONS: 1. Location: The Delta Road Bridge is located over Rock Slough in the Knightsen area of east Contra Costa County (Figures 1, 2). The bridge is the only access to Holland and Quimby Tracts. a1 06 Delta Road Bridge Replacement—Initial Study 7 Project No. 0682-6114218; CP 00-02 Page 4 of 4 2. Project Description: The Contra Costa County Public Works Department proposes to replace the existing deteriorating one-lane timber decked Bailey-style bridge over Rock Slough with a 26-foot wide two-lane bridge. The new bridge abutments will be installed on the upland portion of the levee farther back from the edge of the slough than the existing abutments are located. No grading of the banks of the slough will be necessary. In the area below the existing bridge abutments, rock slope protection armors the banks of the slough. The existing riprap will remain in place and no new riprap will be placed. The project also includes realigning Delta Road approximately 100 feet on the south side and 70 feet on the north side of the bridge to conform to the new wider bridge. A retaining structure will be built on the southeast side of the bridge to support the realigned bridge approach. The alignment of the new bridge will be similar to the original configuration. Minor fill will be placed on the top of the levee to widen the northern levee approach; however, this fill will be placed in an upland area and will not impact the slough. With the exception of the new piles, there will be no temporary or permanent fill within the slough. A house with associated agricultural buildings is located adjacent to the bridge; however, the house is currently abandoned. The existing bridge will remain open during the majority of the construction of the replacement bridge. Once the eastern half of the replacement bridge is complete, it will be opened for traffic while the existing bridge is removed and the western half of the replacement bridge completed. The bridge will be closed during installation of the piles or during any other activites that would cause delays of more than 15 minutes. These activities will be conducted at night to avoid disruption to daily traffic patterns. If the bridge requires closure, a fire crew from the Oakley County Fire Protection District will be positioned on Holland Tract to handle any emergencies. All work associated with the bridge pilings will be conducted either from a barge or from the existing bridge (if the contractor is able to demonstrate that the bridge will be able to sustain the weight of the heavy equipment). Contract specifications will require the installation of silt trapping devices of the contractor's design to ensure that siltation in the slough as a result of the pile driving and any other in water work is kept to a minimum. To prevent work materials from entering Rock Slough during removal of the old bridge and construction of the new bridge, debris containment methods (e.g., a net barrier) of the contractor's design will be required per contract specifications. The existing creosote-coated piles will be cut off at mudline in order to remove them as a navigational hazard yet minimize the potential impacts to water quality due to total removal. The new piles installed for the replacement bridge will consist of steel encasing concrete. The piles will not have potential toxic characteristics. All in-water work will occur between August 1"and November 30th unless otherwise agreed to by the resource agencies and the County. Delta Road Bridge Replacement—Initial Study Project No. 0662-6114216; CP 00-02 Page 5 of 4 3. Does It appear that any feature of the project will generate significant public concern? [] yes [X] no [ ] maybe (Nature of concern): 4. Will the project require approval or permits by other than a County agency? [X] yes a no Agency Name(s) California Department of Fish and Game (Streambed Alteration Agreement), U.S. Army Corps of Engineers (Nationwide 23— Categorical Exclusions), California Regional Water Quality Control Board (Water Quality Waiver of Certification), U.S. Fish and Wildlife Service (Informal Section 7 Consultation), National Marine Fisheries Service (Informal Section 7 Consultation); Federal Highways Administration (NEPA Categorical Exclusion). 5. is the project within the Sphere of Influence of any city? No G:\GrpData\BngSvc\ENVI R©\99projects\DeltandBridge\I nitialStudy.doe eta *o:) D C °m °m m XM . C) u x K � x , 8 m rnCD x cz co co )> z m1> tid V 0 F 6 ��f1Jl� ' 1A ' _ y FIGURE 2 ` MikA blKkatCl , a. wRaarsrrrrr _...__..__.,...___ f l J►= ♦x. ��.•�.�•• Cl •.' M#.M'�.MRif M.Il R.RW.%Ri RR.Ic![J1,i[WAKj�R sr21w �+ j'/ y . . DELTA RtAO BRIDGE W ; PROJECT �OCATIO i N • 11 , '9t - _ '' ;i�}7f{7it,71t�� .._.. ... _ � •....VfKNC�((�%R'Yt'lf;'YIfl2C'IKWiYdNlt4Y j � + }/� �,� #-'". .77 ... a�: 'i' �`P(tmp Nouxa� Slption , i � tt � _ :+i�.``�•~ r ws ww.Ssw�r'i s`i�w ";;Li Q. wsa• rRr.iw+as F.rww`es®r ri{"w`:wrw4 t`s-_ t3 ( i ii b a s .I! • r0 ..... � .' —� ;�' -. .,�-'-•-- - _ .� tom,! i 1 V EPA L E ,` T R A s r � i r — t i s p N pump C p. .A. !`" 1 - r y� 4 ` 1 N R A C 1 YICIN1I 1 f!!A .i DELTA ROAD BRIDGE REPLACEMENT PROJECT SCALE:124,000 CONTRA COSTA COUNTY PUBLIC WORKS DEPARTMENT 255 GLACIER DRIVE SOURCE:USGS,Woodward MARTINEZ, CA 94553 Island,California Quadrangle Il Mitigation Summary Delta Road Bridge Replacement Project Project Name: Delta Road Bridge Replacement Project Project Proponent: Contra Costa County Public Works Department 255 Glacier Drive Martinez, California 94553 Project Location: The Delta Road Bridge is located over Rock Slough in the Knightsen area of east Contra Costa County. The bridge is the only access to Holland and Quimby Tracts. Project Description: The Contra Costa County Public Works Department proposes to replace the existing deteriorating one-lane timber decked Bailey-style bridge over Rock Slough with a 26- foot wide two-lane bridge. The new bridge abutments will be installed on the upland portion of the levee farther back from the edge of the slough than the existing abutments are located. No grading of the banks of the slough will be necessary. In the area below the existing bridge abutments, rock slope protection armors the banks of the slough. The existing riprap will remain in place and no new riprap will be placed. The project also includes realigning Delta Road approximately 100 feet on the south side and 70 feet on the north side of the bridge to conform to the new wider bridge. A retaining structure will be built on the southeast side of the bridge to support the realigned bridge approach. The alignment of the new bridge will be similar to the original configuration. Minor fill will be placed on the top of the levee to widen the northern levee approach; however, this fill will be placed in an upland area and will not impact the slough. With the exception of the new piles, there will be no temporary or permanent fill within the slough. A house with associated agricultural buildings is located adjacent to the bridge; however, the house is currently abandoned. The existing bridge will remain open during the majority of the construction of the replacement bridge. Once the eastern half of the replacement bridge is complete, it will be opened for traffic while the existing bridge is removed and the western half of the replacement bridge completed. The bridge will be closed during installation of the piles or during any other activates that would cause delays of more than 15 minutes. These activities will be conducted at night to avoid disruption to daily traffic patterns. If the bridge requires closure, a fire crew from the Oakley County Fire Protection District will be positioned on Holland Tract to handle any emergencies. All work associated with the bridge pilings will be conducted either from a barge or from the existing bridge (if the contractor is able to demonstrate that the bridge will be able to sustain the weight of the heavy equipment). Contract specifications will require the 1 installation of silt trapping devices of the contractor's design to ensure that siltation in the slough as a result of the pile driving and any other in water work is kept to a minimum. To prevent work materials from entering Rock Slough during removal of the old bridge and construction of the new bridge, debris containment methods (e.g., a net barrier) of the contractor's design will be required per contract specifications. The existing creosote-coated piles will be cut off at mudline in order to remove them as a navigational hazard yet minimize the potential impacts to water quality due to total removal. The new piles installed for the replacement bridge will consist of steel encasing concrete. The piles will not have potential toxic characteristics. All in-water work will occur between August 1st and November 30th unless otherwise agreed to by the resource agencies and the County. Project Impacts and Mitigation Measures/Best Management Practices: In order to minimize the identified environmental impacts due to the proposed project, the following mitigation measures and best management practices will be implemented. The mitigation measures will be implemented in order to reduce a potentially significant impact to a level of insignificance. Best management practices are routinely implemented practices that are normally a part of construction and /or revegetation contracts. IMPACT: 1: Potential aesthetic impact due to tree removal Best Management Practices • Construction activities will impact the minimum amount of vegetation necessary to complete the project • Environmentally Sensitive Area (ESA) fencing shall be placed to protect vegetation. • Trees removed as a result of the project will be replaced at a 3:1 ratio with like species • For trees that do not require removal, contract specifications will include protective measures such as clean trimming of roots or limbs IMPACT 2: Potential temporary short-term air quality emissions during construction activities Best Management Practices • Contract specifications will require the use of properly tuned and muffled equipment and the elimination of unnecessary idling of equipment 2 l� + Implementation of dust control practices including general watering of exposed areas and/or use of chemical stabilizers IMPACT 3: Potential impact to riparian habitat Best Management Practices • If riparian trees require removal, they will be replaced with like species at a 3:1 ratio • Any replacement trees will be maintained for three years and monitored for five years • A survival rate of 75% will be required at the end of the five year monitoring period, if the survival rate has not been achieved after five years, additional plantings will be required • For trees that do not require removal, contract specifications will include protective measures such as clean trimming of roots or limbs IMPACT 4: Potential impact to state and federally listed fish species Mitigation Measures: • In water work will be limited to August 1st through November 30th of any given year • Silt trapping devices will be employed during pile driving and any other in water work activities • No fill will be placed on emergent wetland vegetation Best Management Practices + ESA fencing will be installed at each corner of the bridge to protect the existing wetland vegetation in the slough IMPACT 5: Potential impact to cultural resources Best Management Practices • Surveys for historic and archaeological resources were negative, however, contract specifications for the project will include measures related to the discovery of cultural resources 3 /zJ • The Resident Engineer for the project will receive instruction regarding identification of archaeological and/or historical resources in the field. In particular, the specifications will require work to be halted in the event of an archaeological discovery within 85 feet of the discovery. An archaeological consultant shall be contacted and he/she shall inspect the site before advising the resident engineer to authorize further work. IMPACT 6: Potential erosion due to soil disturbance Best Management Practices • Standard due control and erosion control practices, including, but not limited to, general watering of exposed areas and/or use of chemical stabilizers will be required by contract specifications • All areas left exposed due to construction activities will be seeded with a mix including native grasses and wildflowers upon completion of the project to stabilize exposed soil IMPACT 7: Potential release of hazardous substances Best Management Practices • In the event of any toxic substances discharge into Dock dough, the Contra Costa Water District, Diablo Water District, City of Antioch, City of Pittsburg, Southern California Water Company, and the City of Martinez will be immediately notified of the type of discharge, its volume and other information on its characteristics. • The contractor will be required to coordinate with these agencies to contain and remove the discharged substances from the public water supply to an appropriate location for remediation • Contact specifications will require standard construction safety practices to ensure no accidental release of hazardous substances or increase in the potential for exposure to hazardous substances In particular the contractor will be required to fuels equipment outside of the stream zone. The fueling area will be required to have a berm placed around the perimeter. Any generators within the stream zone will be required to have a containment system in case of accidental spills. 4 IMPACT 8: Potential interference with emergency evacuation or response Best Management Practices • Contract specifications for the project will require the installation of sufficient warning signs regarding the construction and associated work hours • Residents of Holland, Quimby and Veale Tracts will be notified regarding project hours and potential closures • A fire crew from the Oakley County Fire Protection District will be positioned on-site on the Holland Tract during closures of the bridge in order to handle any emergencies IMPACT 9; Potential impacts to water quality Best Management Practices • All work associated with the installation of the bridge pilings in the slough will be conducted from the existing bridge or from a barge • Standard construction safety practices will be incorporated into the project to reduce the possibility of a spill of gasoline, oil, or other pollutant that could have a significant impact on water quality • In the event of any toxic substances discharge into Rock Slough, the Contra Costa Water District, Diablo Water District, City of Antioch, City of Pittsburg, Southern California Water Company, and the City of Martinez will be immediately notified of the type of discharge, its volume and other information on its characteristics. The Department of Fish and Game will also be notified in the event of a spill. • The contractor will be required to coordinate with these agencies to contain and remove the discharged substances from the public water supply to an appropriate location for remediation • Silt trapping devices of the contractor's design will be employed during pile driving and any other in-water work to minimize siltation within Rock Slough • To prevent any work materials from entering Rock Slough during removal of the old bridge and construction of the new bridge, debris containment methods (e.g., a net barrier) of the contractor's design will be required per contract specifications 5 -c� IMPACT 10: Potential noise impacts Best Management Practices • Contract specifications will require the use of properly tuned and muffled equipment to minimize noise during construction • Pile driving activities are expected to occur over a maximum of four nights. Residents, business owners, and property owners will be notified one week prior to the activity of the potential for night work to occur, and the duration expected • With the exception of pile driving activities and other construction activities that will cause more than a 15 minute delay, working hours will be limited to 7:30 a.m. to 5"00 p.m. Monday through Friday unless modified upon written approval of the Resident Engineer WPACT 11. Traffic impacts due to temporary closure Best Management Practices • In order to minimize traffic impacts due to temporary closure, pile driving activities and any other activities that will cause a delay of more than 15 minutes will occur at nighttime. The temporary closures are expected to occur over a maximum of four nights G:tGrpDatalEngSvc\ENVfROJ 99projects\DeftandBridge\Mit{gaSon Summaary.doc 6 Environmental Checklist Form 1. Project Title: Delta Road Bridge Replacement Project 2. Lead Agency Name and Address: Contra Costa County Community Development Department 651 Pine Street,North Wing- 4th Floor Martinez, CA 94553 3. Contact Person and Phone Number: Leigh Chavez(925) 313-2366 4. Project Location: The subject site is located over Rock Slough in the Knightsen area of east Contra Costa County. The bridge is the only access to Holland Tract and Quimby Tract. 5. Project Sponsor's Name/Address: Contra Costa County Public Works Department 6. General Plan Designation: Local Road (Major Road per Resource Mapping System) 7. Zoning: Public Right of Way 8. Description of Project: The Contra Costa County Public Works Department proposes to replace the existing deteriorating one-lane timber decked Bailey-style bridge over Rock Slough with a 26-foot wide two-lane bridge. The new bridge abutments will be installed on the upland portion of the levee farther back from the edge of the slough than the existing abutments are located. No grading of the banks of the slough will be necessary. In the area below the existing bridge abutments, rock slope protection armors the banks of the slough. The existing riprap will remain in place and no new riprap will be placed. The project also includes realigning Delta Road approximately 100 feet on the south side and 70 feet on the north side of the bridge to conform to the new wider bridge. A retaining structure will be built on the southeast side of the bridge to support the realigned bridge approach. The alignment of the new bridge will be similar to the original configuration. Minor fill will be placed on the top of the levee to widen the northern levee approach; however, this fill will be placed in an upland area and will not impact the slough. With the exception of the new piles, there will be no temporary or permanent fill within the slough. A house with associated agricultural buildings is located adjacent to the bridge; however, the house is currently abandoned. The existing bridge will remain open during the majority of the construction of the replacement bridge. Once the eastern half of the replacement bridge is complete, it will be opened for traffic while the existing bridge is removed and the western half of the replacement bridge completed. The bridge will be closed during installation of the piles or during any other activites that would cause delays of more than 15 minutes. These activities will be conducted at night to avoid disruption to daily traffic patterns. If the bridge requires closure, a fire crew from the Oakley County Fire Protection District will be positioned on Holland Tract to handle any emergencies. All work associated with the bridge pilings will be conducted either from a barge or from the existing bridge (if the contractor is able to demonstrate that the bridge will be able to sustain the weight of the heavy equipment). Contract specifications will require the installation of silt trapping devices of the contractor's design to ensure that siltation in the slough as a result of the pile driving and any other in water work is kept to a minimum. To prevent any work materials from entering / eld, l� Rock Slough during removal of the old bridge and construction of the new bridge, debris containment methods (e.g., a net barrier)of the contractor's design will be required by the contract specifications. The existing creosote--coated piles will be cut off at mudline in order to remove them as a navigational hazard yet minimize the potential impacts to water quality due to total removal. The new piles installed for the replacement bridge will consist of steel encasing concrete. The piles will not have potential toxic characteristics. All in-water work will occur between August 1"and November 30`h unless otherwise agreed to by the resource agencies and the County. 9. Surrounding Land Uses and Setting. Land surrounding the project area has been reclaimed for agricultural purposes and is largely undeveloped. 10. Other public agencies whose approval is required (e.g., permits, financing approval, or participation agreement): U.S. Army Corps of Engineers (Nationwide Permit 23 — Categorical Exclusions),Regional Water Quality Control Board(Water Quality Certification or Waiver), California Department of Fish and Game (Streambed Alteration Agreement issued — Notification #II-726-96), U.S. Fish and Wildlife Service (Informal Section 7 Consultation), National Marine Fisheries Service(Informal Section 7 Consultation) ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED: The environmental factors checked below would be potentially affected by this project, involving at least one impact that is a "Potentially Significant Impact" as indicated by the checklist on the following pages. _ Land Use and Transportation/ _ Public Services Planning Circulation o Utilities & Service Population&Housing X Biological Resources Systems Geological Problems — Energy & Mineral _ Aesthetics Water Resources Cultural Resources — Air Quality — Hazards Recreation — Mandatory Findings of _ Noise e No Significant Significance Impacts Identified 3 DETERMINATION On the basis of this initial evaluation: _ I find that the proposed project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared. ✓ I find that although the proposed project could have a significant effect on the environment, there will not be a significant effect in this case because the mitigation measures described on an attached sheet have been added to the project. A MITIGATED NEGATIVE DECLARATION will be prepared. I find that the proposed project MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is required. I find that the proposed project MAY have a significant effect(s)on the environment,but at least one effect (1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and(2)has been addressed by mitigation measures based on the earlier analysis as described on attached sheets, if the effect is a "potentially significant impact" or "potentially significant unless mitigated." An ENVIRONMENTAL IMPACT REPORT is required,but it must analyze only the effects that remain to be addressed. I find that although the proposed project could have a significant effect on the environment, there WILL NOT be a significant effect in this case because all potentially significant effects (a)have been analyzed adequately in an earlier EIR pursuant to applicable standards and(b) have been avo' or mitigated pursuant to that earlier EIR,including revisions or mitigation e ur s th imp sed on the proposed project. 92 r� Signature Date .11 1Z CCC Communily Development Depart7t�ent 'Printed Name For 4 SOURCES In the process of preparing the Checklist and conducting the evaluation, the following references (which are available for review at the Contra Costa County Community Development Department, 651 Pine Street 5th Floor-North Wing, Martinez)were consulted. 1. Contra Costa Resource Mapping System- Quad Sheet Panels for Clayton Quadrangle, CA 2. The(Reconsolidated) County General Plan(July 1996) and Draft ETR.on the General Plan (September 1990) 3. Contra Costa County Important.Farmland Map 1998, California Department of Conservation Division of Land Resources Protection, 1999 4. Delta Rd Bridge Replacement Project Negative Declaration (Public Works Dept., 1/96) CP#96-1 5. Archaeological Survey Report and Historic Architectural Survey Report,Delta Road Bridge Replacement,Basin Research Associates,Busby Guedon Tannam and Garaventa- authors, September 1996 6. Field reviews and/or Project Description(including coordination with Design Engineer) 7. Coordination with US Fish and Wildlife Service Biologist, (pens. cam. P. Hanna, USFWS, 12/23/99) 8. Soil Survey of Contra Costa County, Soil Conservation Service, 9/77 9. Contra Costa County Flood Insurance Rate Zone Information Map 10. State of California Hazardous Waste and Substances Sites List, April 1998 11. Geotechnical Investigation,Hultgren Geotechnical Engineers,Edwin Hultgren, April, 1996 12. Mike Rugg, Department of Fish and Game, (pers. corn. 12/4/95) 13. Manu Ankhad, Contra Costa Water District(pens. com. 3/3/99) 14. California Seismic Hazard Map 1996, Caltrans, Office of Earthquake Engineering, L. Maulchin, Engineering Seismologist EVALUATION OF ENVIRONMENTAL IMPACTS: Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Imuact Incomoration Fact Impact I. AESTHETICS. Would the proposal: a. Have a substantial adverse effect on a X scenic vista? (Source#1,2,4,6) b. Substantially damage scenic resources, _ _ X _ including,but not limited to, trees,rock outcroppings,and historic buildings within a state scenic highway?(Source#1,2,4,6) C. Substantially degrade the existing _ _ X 5 visual character or quality of the site and its surroundings?(Source#1,2,4,6) d. Create a new source of substantial light _ _ X _ or glare which would adversely affect day or nighttime views in the area? Source#4,6) SUMMARY: The replacement bridge will be constructed in approximately the same location as the existing bridge, therefore, the visual quality of the new bridge will not be significantly different than the existing bridge. Construction equipment will be visible temporarily during construction,however this is a minor and short-term impact, ending upon completion of the project. Construction activities will impact the minimum amount of vegetation necessary to complete the replacement bridge. A stand of approximately four cottonwood trees (ranging in size from 12 to 24 inches dbh)may require removal for installation of the replacement bridge. The cottonwood trees will likely be able to be retained in place. If the trees do require removal, they will be replaced at a 3:1 ratio with like species. The replacement trees will be planted within the County's right-of-way in a location near where the trees were removed. Cottonwood trees are rapidly growing species, and any aesthetic impact due to the removal of the trees will be minimized by the quick growth of the replacement trees. In order to minimize damage to any additional trees that may be impacted by construction, but will not require removal, contract specifications will include protective measures such as clean trimming of roots and limbs. Removal of the trees will not have a substantial adverse effect on scenic resources. Replacing the Delta Road Bridge will not create a permanent source of new light or glare. Please see the Mitigation Summary for Best Management Practices that will be implemented as part of the contract. Potentially Significant Potentially Unless Cess than Significant Mitigation Significant No Impact Inc tion Impact [mnact II. AGRICULTURAL RESOURCES: In determining whether impacts to agricultural resources are significant environmental effects, lead agencies may refer to the California Agricultural Land Evaluation and Site Assessment Model (1997) prepared by the California Dept Of Conservation as an optional model to use in assessing impacts on agricultural and farmland. Would the project: a. Convert Prime Farmland,Unique Farmland, X _ or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use?(Source#1,3) b. Conflict with existing zoning for X 6 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impac IncoMMtion a t Impact agricultural use, or a Williamson Act contract?(Source#1,2,4) C. Involve other changes in the existing _ X environment which,due to their location or nature,could result in conversion of Farmland,to non-agricultural use?(source#1,2,3,4,6) SUMMARY: The project will not impact any locally or statewide important farmland. The land immediately adjacent to the project consists of undeveloped and agricultural land. The replacement bridge will be installed in approximately the same location as the existing bridge. The Contra Costa County Important Farmland 1998 map identifies the Delta Road Bridge project as located on the border of"Farmland of Local Importance"and"Farmland of Statewide Importance";however, all work associated with the replacement bridge will be located within the County's existing right-of- way. A temporary construction easement has been obtained in order to store construction equipment. The easement is located in the area adjacent to the bridge that contains a house, a warehouse, and a storage shed. The area surrounding the buildings consists of a gravel driveway with invasive weeds. According to the Historic Architectural Survey Report produced for the project, the three buildings do not appear to be significant in the development of agriculture in the Delta. III. AIR QUALITY. Where available,the significance criteria established by the applicable air quality management or air pollution control district may be relied upon to make the following determinations. Would the project: a. Conflict with or obstruct implementation _ X of the applicable air quality plan? (Source#2,4) b. Violate any air quality standard or X contribute to an existing or projected air quality violation?(Source#2,4) C. Result in a cumulatively considerable _ X net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard(including releasing emissions which exceed quantitative thresholds for ozone precursors)? (Source#2,4) d. Expose sensitive receptors to substantial _ _ X _ pollutant concentrations?(Source#2,4,6) 7 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No [moact Incorporation I Impact e. Create objectionable odors affecting a _ _ X substantial number of people? (Source#2,4,6) SUMMARY: Short-term emissions and objectionable odors maybe generated during construction; however, they will be minor and temporary. In order to minimize impacts due to construction activities, contract specifications will stipulate the use of properly tuned and muffled equipment and the elimination of unnecessary idling of equipment when not in use. Implementation of dust control practices including general watering of exposed areas and/or use of chemical stabilizers will also minimize air quality impacts. The minor temporary deterioration of ambient air quality at the construction site will have no potentially adverse long- term impacts to air quality. No additional permanent air quality impacts due to vehicle traffic will be generated by the project since no additional trips will be generated by the replacement of the bridge. Replacement of the bridge will not increase the capacity of Delta Road. Please see Mitigation Summary for Best Management Practices that will be implemented as part of the contract. IV., BIOLOGICAL RESOURCES. Would the project: a. have a substantial adverse effect,either X _ directly or through habitat modifications, on any species identified as a candidate, sensitive,or special status species in local or regional plans,polices,or regulations, or by the California Department of Fish and Game or U.S.Fish and Wildlife Service? (Source#2,6,7) b. Have a substantial adverse effect on any X riparian habitat or other sensitive natural community identified in local or regional plans,policies,regulations or by the California Department of Fish and Game or US Fish and Wildlife Service?(Source#2,6,7) C. Have a substantial adverse effect on _ X _ federally protected wetlands as defined by Section 404 of the Clean Water Act (including,but not limited to,marsh, vernal pool, coastal,etc.)through direct removal, filling,hydrological interruption,or other means?(Source#2,6,8) d. Interfere substantially with the movement X _ of any native resident or migratory fish or wildlife species or with established native 8 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impact Incoroomtion impact Impact resident or migratory wildlife corridors,or impede the use of native wildlife nursery sites? Source#2,6,7) e. Conflict with any local policies or X ordinances protecting biological resources, such as tree preservation policy or ordinance? Source#2) f. Conflict with the provisions of an X adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local,regional,or state habitat conservation plan? Source#2) SUMMARY: The Delta is considered critical habitat for Delta smelt(Hypomesus transpacificus), a state and federally listed endangered fish. In addition, Rock Slough has potential habitat for state threatened and federally proposed endangered spring run salmon (Onocorhynchus tshawytscha), state endangered and federally endangered winter run salmon (Onocorhynchus tshawytscha), Delta smelt, federally threatened Sacramento splittail (Pogonichthys macrolepidotus), and federally threatened steelhead(Onocorhynchus mykiss). To avoid potential impacts to fish spawn and/or fry, all in-water work will be limited to August 1' through November 30th of any given year, as agreed to during informal consultation with U.S. Fish and Wildlife Service(USFWS)representatives(pers. com. P. Hanna, USFWS). This work window will be strictly adhered to unless otherwise agreed to by the County and the agencies with jurisdiction over the listed fish species (NMFS and USFWS). There will be fewer piles installed for the new bridge than are currently in the slough supporting the existing bridge, and the new abutments will be placed farther back on the levees than the existing abutments. A total of eight piles will be driven within the slough. During pile driving activities, contract specifications will require the installation of silt trapping devices of the contractor's design to ensure that siltation in the slough is kept to a minimum. The silt trapping devices used will be at the discretion of the contractor and will be reviewed by the County. The use of silt trapping devices was agreed to during informal consultation with USFWS representatives (pers. com. P. Hanna, USFWS). Construction activities will impact the minimum amount of riparian vegetation necessary to complete the replacement bridge, however, some tree and shrub removal may be necessary. Approximately four large cottonwood(Populus fremontii) trees (ranging in size from 12 to 24 inches dbh) may require removal for installation of the replacement bridge. The cottonwoods are located on the southeast side of the bridge. If the trees require removal, they will be replaced at a 3:1 ratio with like species up to one gallon in size. The replacement trees will be planted within the County's right-of-way on the northwest and southwest sides of the bridge. The newly planted 9 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impart Incomoration 1=ac f act trees will be maintained for a period of three years and monitored annually for a period of five years. At the conclusion of the five year monitoring period, a survival rate of 75%will be required. If the survival rate has not been achieved, additional plantings will occur. Cottonwood trees are rapidly growing species, and any impact due to the removal of the trees will be minimized by the quick growth of the replacement trees. In order to minimize damage to any additional trees that may be impacted by construction, contract specifications will include protective measures such as clean trimming of roots and limbs. In the area on the southeast side of the bridge where the retaining structure will be installed, several blackberry bushes(Rubus sp.)may require trimming or removal. Blackberry readily regenerates, and the project will not create a barrier to the normal replenishment of the species. On the northeast side of the bridge a patch ofmulefat(Bacharris salicifolia)may be impacted by activites associated with construction of the replacement bridge. Impact to the mulefat will likely consist of trimming rather than total removal. The project will not create a barrier to the normal replenishment of the species. Small patches of cattails(Typha sp.),bulrush(Scirpus sp.), and water hyacinths (Eichhornia crassipes) are located in the slough adjacent to the bridge. Orange construction fencing will be installed to delineate the limits of construction impact. The fencing will serve to isolate environmentally sensitive areas (ESAs) from construction activities. The BSA fencing will be installed at each corner of the bridge to protect the existing wetland vegetation in the slough. No impact to emergent wetland vegetation is expected. No fill or riprap material will be placed on existing emergent vegetation as agreed to during informal consultation with USFWS (pers. com., P. Hanna, USFWS). Some of the construction activities associated with replacement of the bridge will be conducted within U.S. Army Corps of Engineers, Regional Water Quality Control Board, and California Department of Fish and Came jurisdiction. Public Works Department staff have coordinated with staff from the regulatory agencies regarding the project, and all appropriate permits will be obtained prior to implementation of the project. The County will comply with all conditions required by the various regulatory permits. A California Department of Fish and Game Streambed Alteration Agreement was issued for the project on February 4, 1997 (Notification# II-726-96). The Agreement has been renewed and will remain valid until December 31, 2000 unless the project is substantially modified. On December 6, 1999, the U.S. Army Corps of Engineers issued a Nationwide Permit#23 (Categorical Exclusions) for the project. The permit is denied without prejudice until the Federal Highway Administration and U.S. Fish and Wildlife Service/National Marine Fisheries conclude coordination regarding listed species potentially impacted by the project and the County obtains water quality certification or waiver for the project from the Regional Water Quality Control Board. Please see the Mitigation Summary for Mitigation Measures to be incorporated into the project and Best Management Practices to be implemented as part of the contract. 10 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impact IncotporationImpac Impact V. CULTURAL RESOURCES. Would the project: a. Cause a substantial adverse change in the _ X _ significance of a historical resource as defined in §15064.5?(Source#1,5) b. Cause a substantial adverse change in the _ _ X _ significance of an archaeological resource pursuant to §15064.5?(Source#1,5) C. Directly or indirectly destroy a unique X paleontological resource or site or unique geologic feature? (Source#1,5) d. Disturb any human remains, including X those interred outside of formal cemeteries? (Source#1,5) SUMMARY: An.Archaeological Survey Report(ASR) and an Historic Architectural Survey Report(HASR)were prepared for the project in September of 1996. The results of both survey reports were negative. According to the ASR,no positively identified prehistoric or historic sites are within or immediately adjacent to the archaeological Area of Potential Effect(APE) for the project. In addition, according to the ASR, review of available historic maps indicates an extremely low potential for potentially significant subsurface historic resources, and no surface indicators of either prehistoric or historic cultural materials were observed during the archaeological inventory. The APE for the Historic Architectural Survey Report also includes the grouping of three small buildings to the southeast of the bridge. As referenced in the HASR, the Delta Road Bridge is ineligible for listing in the National Register of Historic Places (NRHP) according to the Caltrans Bridge Inventory. In addition, the complex of three buildings adjacent to the Delta Road Bridge (house, warehouse, and storage shed) and the Holland Tract levee itself, appear to be ineligible for listing in the NRNP according to the HASR. The three buildings will not be impacted by the construction of the replacement bridge. Contract specifications for the project will include measures related to discovery of cultural resources, including informing personnel connected with the project of the possibility of finding archaeological and/or historical resources, requiring notification of the Resident Engineer in the event of a discovery, and retention of a cultural resources consultant to provide assistance in the event of a discovery. In addition, the Resident Engineer for the project will receive instruction regarding identification of archaeological and historical resources in the field. Please see the Mitigation Summary for Best Management Practices that will be implemented as part of the contract. L`l 11 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No impact Incomomtion Impact Impact VI. GEOLOGY AND SOILS -Would the project? a. Expose people or structures to potential substantial adverse effects, including the risk of loss, injury,or death involving: 1.Rupture of a known earthquake fault, _ X _ as delineated on the most recent Alquist- Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. (Source#1,2,14) 2. Strong seismic ground shaking? _ X _ 3. Seismic-related ground failure, including _ X liquefaction? (Source#1,2,6,14) 4. Landslides? (Source#1,2,6) b. Result in substantial soil erosion or the loss _ X of topsoil? (Source#1,6,8) C. Be located on a geologic unit or soil that is X unstable,or that would become unstable as a result of the project,and potentially result in on-or off-site landslide, lateral spreading, subsidence, liquefaction or collapse? (Source#1,2,8,14) d. Be located on expansive soil, as defined in _ X_ Table 18-1-B of the Uniform Building Code (1994), creating substantial risks to life or property?(Source#1,2,8) e. Have soils incapable of adequately supporting X the use of septic tanks or alternative waste disposal systems where sewers are not available for the disposal of waste water? (Source#N/A) SUMMARY: Construction of the replacement bridge will not expose people to adverse effects due to seismic activity. The soil which underlies the area in which the Delta Road Bridge will be constructed contains a layer of unconsolidated sand. Various alternatives to consolidate this sand lense were investigated. As a result, it was determined to be more cost effective and reliable to design the bridge substructure around the liquifiable layer. There is an earthquake fault with an uncertain location that runs in a north-south direction in the vicinity of the project, however, in addition to the sand tense, the fault has been accounted for, and the replacement bridge has been ;2- 12 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impact Incorporation Impact Impact designed to handle the Maximum Credible Earthquake (MCE) event (California Seismic Hazard Map, 1996). The MCE event is the largest earthquake reasonably expected to impact the structure based on recorded data. According to the Contra Costa County Soil Survey, soils of Veale Tract(found on the southern side of the bridge) consist of Sacramento clay, alkali (nearly level). Piper loamy soil (0 to 2 percent slope) is found on Holland Tract(on the northern side of the bridge). The Sacramento clay, alkali, has no hazard of wind erosion, while the Piper loamy soil has a hazard of wind erosion when soil is exposed or tilled. The project is located on levees constructed of material hauled in from off-site prior to 1916. Grading of the construction site will result in a minor change in topography and temporarily increase the exposure of soils to wind erosion. However, this is an insignificant and temporary impact. Adherence to standard dust control and erosion control practices, including, but not limited to, general watering of exposed areas and/or use of chemical stabilizers will minimize impacts. These measures will be incorporated into the construction contract. Pile driving activities will cause minor waves as a result of vibration; however, this type of vibratory wave dissipates rapidly, and the pile driving activities are not expected to cause significant wave-based erosion on the banks of the levees. Superficial grading of the project area is not expected to result in unstable earth conditions or change geographical substructures. Exposure of people or property to geologic hazards is not expected to increase as a result of the project. The project is not expected to result in modifications to the channel of Rock Slough as a result of changes in deposition or erosion. All areas left exposed due to construction of the bridge will be seeded with a mix including native grasses and wildflowers upon completion of the project in order to stabilize exposed soil. Please see the Mitigation Summary for Best Management Practices that will be implemented as part of the contract. VII. HAZARDS AND HAZARDOUS MATERIALS- Would the project: a. Create a significant hazard to the public _ X _ or the environment through the routine transport, use,or disposal of hazardous materials? (Source#1,2,6) b. Create a significant hazard to the public _ X or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? (Source#1,2,6) C. Emit hazardous emissions or handle X 13 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No lmoact Incomomtion Impact Irmact hazardous or acutely hazardous materials, substances,or waste within one-quarter mile of an existing or proposed school? (Source#1,2) d. Be located on a site which is included on a _ X list of hazardous materials sites compiled pursuant to Government Code Section 65862.5 and,as a result,would it create a significant hazard to the public or the environment? (Source#1,2) e. For a project located within an airport land X use plan or,where such a plan has not been adopted,within two miles of a public airport or public use airport,would the project result in a safety hazard for people residing or working in the project area. (Source#N/A) f. For a project within the vicinity of a private e _ X airstrip,would the project result in a safety hazard for people residing or working in the project area? (Source#N/A) g. Impair implementation of or physically _ _ X _ interfere with an adopted emergency response plan or emergency evacuation plan? (Source#1,2) h. Expose people or structures to a significant _ X _ risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands? (Source#1,2) SUMMARY: According to the"State of California Hazardous Waste and Substances Site List (April 1998), there are no listed hazardous waste sites in or near the project area. The project has the potential to release hazardous substances, such as accidental petroleum spills, during construction. :per the contract specifications, standard construction safety practices will be followed during construction to ensure no accidental release of hazardous substances or increase the potential for exposure to these substances. In addition, the Fish and Game Agreement for the project requires that oil spill booms and sorbent materials be readily available in the event of spills. As the Fish and Game Agreement is part of the contract specifications, these measures are by definition part of the contract as well. Rock Slough contains San Joaquin Delta water supplies used by the Contra Costa Water District (CCWD) for treatment and distribution to 400,000 municipal and industrial customers in Contra Costa County. The Contra Costa Canal intake is located at the west terminus of dock Slough, 14 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No inw_ac Inc�corooration Impact Impact approximately 1.2 miles to the west of the project. In the event of any toxic substances discharge into Rock Slough, the Contra Costa Water District, Diablo Water District, City of Antioch,City of Pittsburg, Southern California Water Company, and the City of Martinez will be immediately notified of the type of discharge, its volume and other information on its characteristics. In addition,the Department of Fish and Game will be notified in the event of a spill. The contractor will use his best efforts to work with these agencies to contain and remove the discharged substances from the public water supply to an appropriate location for remediation. The County Resource Mapping System for the project area did not identify any petroleum pipelines or electric transmission lines within the immediate project area. No interference with an emergency evacuation or response is expected to result from the project. Traffic control measures will minimize the potential for accidents. The existing bridge will remain open during construction of the eastern half of the replacement bridge. The eastern half of the new bridge will be open during the removal of the existing bridge and construction of the western half of the new bridge. If necessary, temporary bridge closure for pile driving activities (or other activates that will cause delays of more than 15 minutes)will only occur at night in order to avoid significant impacts to traffic. If closure of the bridge becomes necessary, a fire crew from the Oakley County Fire Protection District will be positioned onsite on the Holland Tract for the duration of the closure to handle any emergencies. Standard specifications for the project will require installation of sufficient warning signs regarding the construction and associated work hours, and residents of Holland Tract, Quimby Tract and Veale Tract will be notified regarding the project and potential closures. Please see the Mitigation Summary for Best Management Practices that will be implemented as part of the contract. VIII. HYDROLOGY AND WATER.QUALITY- Would the project: a. Violate any water quality standards or _ X waste discharge requirements?(Source#2,4,6) b. Substantially deplete groundwater supplies _ X or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)? (Source#1,2,4,6) C. Substantially alter the existing drainage X pattern of the site or area, including through the alteration of the course of a stream or river, in a manner which would result in substantial erosion or siltation on-or off-site? (Source#4,6) 3 ate G 15 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impact Incorporation Irmac Impact d. Substantially alter the existing drainage _ X pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner which would result in flooding on-or off-site? (Source#1,4,6) e. Create or contribute runoff water which _ _ X would exceed the capacity of existing or planned storm water drainage systems or provide substantial additional sources of polluted runoff?(Source#1,4,6) f. Otherwise substantially degrade water _ X _ quality? (Source#6) g. Place housing within a 100-year flood _ X hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? (Source#1,2,9) h. Place within a 100-year flood hazard area _ _ X structures which would impede or redirect flood flows? (Source#1,4,6,9) i. Expose people or structures to a significant _ X risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam?(Source#1,4,6,9) j. Inundation by seiche,tsunami,or mudflow? _ X (Source#1,6) SUMMARY: The Delta Road Bridge crosses over Rock Slough. According to the Contra Costa County Flood Control District Flood Insurance Rate Zone Information Map and the Resource Mapping System, the slough and both Holland Tract and Veale Tract are in a floodplain. However, since the new bridge will be constructed at approximately the same location as the existing bridge, and since the clearance of the new bridge will be the same as the existing bridge, there will be no increased exposure of people or property to flooding. Additionally, since the design of the new bridge is not significantly different than the existing bridge, it will not impair the flow of water; nor will it alter the course or flow of floodwaters. There will be fewer piles installed for the new bridge than there are currently in the slough supporting the existing bridge and the new abutments will be placed farther back on the levees than the existing abutments. The increase in the bridge size is necessary to add an additional lane and will not create an impervious surface area that will substantially increase the rate and amount of runoff. Therefore, the amount of surface water in Rock Sough will not change significantly as a result of the project. Building the bridge will not adversely affect the quantity or quality of surface water, ground water or public water supply. 16 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Imnact Incomoration Im,act Impact Rock Slough contains San Joaquin Delta water supplies used by the Contra Costa Water District (CCWD) for treatment and distribution to 400,000 municipal and industrial customers in Contra Costa County. The Contra Costa Canal intake is located at the west terminus of Rock Slough, approximately 1.2 miles to the west of the project. The project will not result in a substantial reduction of the amount of water available for this water supply. The Bureau of Reclamation and Contra Costa Water District are planning a joint project to install a fish screen on a Contra Costa Canal intake; however, coordination with the project manager for the fish screen project has indicated that access for that project will be from Cypress Road rather than Delta Road and the Delta Road Bridge Replacement Project should, therefore, not impact the construction of the fish screen project(pers. com. Manu Ankhad, 3/3/99). Measures will be undertaken in the design and construction of the Delta Road Bridge project to avoid adverse impacts to water quality. Contract specifications will require the installation of silt trapping devices of the contractor's design to ensure that siltation in the slough during pile driving and other in-water work is kept to a minimum. The silt trapping devices will be reviewed by the County. In addition, to prevent any work materials from entering Rock Slough during construction of the new bridge and removal of the old bridge, debris containment methods (e.g., a net barrier)will be required per contact specifications. The design of the debris containment will be at the contractor's discretion and will be reviewed by the County. The existing creosote pilings will be cut off at mudline to remove them as a navigational hazard yet minimize potential impacts to water quality due to total removal. The new piles installed for the replacement bridge will consist of steel encasing concrete. The piles will not have potential toxic characteristics. According to water quality experts with the Department of Fish and Game(pers. com. M. Rugg, December 14, 1995),pile driving in the slough is not likely to create significant water quality impacts. All work associated with the installation of the bridge pilings in the slough will be conducted either from a barge or from the existing bridge(if the contractor is able to demonstrate that the bridge will be able to sustain the weight of the pile driving equipment). The contractor will not be allowed to drive the piles by installing a trestle to hold the pile driving equipment. No temporary structures or falsework will be installed within the slough. Standard construction safety practices will be incorporated into the project to reduce the possibility of a spill of gasoline, oil, or other pollutant that could have a significant impact on water quality. The Fish and Game Agreement for the project requires that oil spill booms and sorbent materials be readily available in order to handle spills of deleterious materials. In the event of any toxic substances discharged into Rock Slough, the Contra Costa Water District, Diablo Water District, City of Antioch, City of Pittsburg, Southern California Water Company, and the City of Martinez will be immediately notified of the type of discharge, its volume and other information on its characteristics. In addition, the Department of Fish and Game will be 17 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No ImDact lnoWration Inipact Inivac notified of any spills. The contractor will be required to use his best efforts to work with these agencies to contain and remove the discharged substances from the public water supply to an appropriate location for remediation. Total disturbance due to construction of the replacement bridge will be less than five acres. At the completion of the project, all disturbed areas will be stabilized through the use of hydroseeding and/or erosion control blanketing, as appropriate. Water Quality Certification or waiver thereof will be obtained from the San Francisco Bay Regional Water Quality Control Board(RWQCB)prior to construction of the project. Special conditions required by the certification or waiver will be complied with during construction in order to minimize the possibility of water quality impacts. Please see the Mitigation Summary for Best Management Practices that will be implemented as part of the contract. IX. LAND USE AND PLANNING-Would the project: a. Physically divide an established community? _ X (Source#2,6) b. Conflict with any applicable land use plan, — X policy,or regulation of an agency with jurisdiction over the project(including,but not limited to the general plan, specific plan, local coastal program,or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect? (Source#1,2,4) C. Conflict with any applicable habitat _ _ X conservation plan or natural community conservation plan? (Source#1,2,4) SUMMARY: The Delta Road Bridge is already in place; therefore, constructing the replacement bridge will not physically divide an established community. Capacity of the roadway outside of the project limits will not increase. The project will not result in a substantial alteration of the present or planned land use of the area. The County General Plan defines Delta Road as a local road with the existing land use surrounding the project being primarily agricultural. A temporary construction easement has been obtained in order to store construction equipment. The easement is located in the area adjacent to the bridge that contains an abandoned house, warehouse, and storage shed. The area surrounding the buildings consists of a gravel driveway with invasive weeds. Based on the limited agricultural value associated with the grouping of buildings, the project will not impact agricultural resources. 3� 18 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No hffmct Incomration Im ac Impact The project is consistent with the County General Plan Transportation and Circulation Elements Roadway and Transit Goals#5-A(To provide a safe, efficient and balanced transportation system),Policy#5-9 (Existing circulation facilities shall be improved and maintained by eliminating structural and geometric design deficiencies), and Policy#5-17 (The design and the scheduling of improvements to arterials and collectors shall give priority to safety over other factors including capacity). Replacing the bridge will not result in an increase in population, displacement of people, or create a demand for additional housing. X. MINERAL RESOURCES -Would the project: a. Result in the loss of availability of a known — — X mineral resource that would be of value to the region and the residents of the state? (Source#1,2) b. Result in the loss of availability of a locally- _ _ — X important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan? (Source#1,2) SUMMARY: ]During construction, the project will use paving materials(i.e., asphalt), wood products, concrete and other materials derived from natural resources however, the project will not significantly impact these resources. The use of oil and gasoline to operate the machinery for construction purposes is negligible and of a short-term, temporary nature. In order to minimize impacts due to construction activities, contract specifications will stipulate the elimination of unnecessary idling of equipment when not in use. XI. NOISE-Would the project result in: a. Exposure of persons to or generation of _ — X m noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? (Source#2,6) b. Exposure of persons to or generation of — — X — excessive ground borne vibration or ground borne noise levels?(Source#6) C. A substantial permanent increase in — _ _ X ambient noise levels in the project vicinity above levels existing without the project? (Source#2,6) 19 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No m ct Incomom on Inivact Impact d. A substantial temporary or periodic increase _ X in ambient noise levels in the project vicinity above levels existing without the project? (Source#2,6) e. For a project located within an airport land i _ X use plan or,where such a plan has not been adopted,within two miles of a public airport or public use airport,would the project expose people residing or working in the project area to excessive noise levels? (Source#N/A) f. For a project within the vicinity of a private _ X airstrip,would the project expose people residing or working in the project area to excessive noise levels?(Source#N/A) SLMIAR'Y: The dominant source of noise in the project area comes from vehicles already using Delta Road. The new bridge will not increase the capacity of Delta Road. The existing bridge is the only access to Holland Tract and Quimby Tract, and all vehicles accessing the island already use the bridge, therefore the ambient noise levels associated with routine use of the new bridge will remain the same. Construction of the project will increase the noise level temporarily. In general, construction activities produce noise levels of 86 dBA at 50 feet which is well below the threshold of pain of 120-140 dBA. Pile driving activities will occur at night in order to avoid significant impacts to traffic circulation on the Holland Tract. Pile driving activities produce a noise level of approximately 100 dBA at 50 feet. This level is also well below the pain threshold. Pile driving activities are expected to occur over a maximum of four nights. There are no sensitive receptors (i.e.,houses, schools, churches) within 0.4 mile of the bridge on the Holland Tract side of the slough and within 0.5 mile of the bridge on the Veale Tract side of the slough. The nearest sensitive receptors on the Holland Tract consist of a marina and several residences including house boats adjacent to the marina. The nearest sensitive receptors on the Veale Tract consist of homes associated with agricultural properties. Residents, business owners and property owners within a one mile radius of the bridge will be notified of the potential for night work to occur, and the duration expected. Although the pile driving activities will produce ground vibrations, sensitive receptors are located far enough away from the project site that vibration will not create a significant impact. Contract specifications will require the use of properly tuned and muffled equipment to minimize other noise due to construction. With the exception of the pile driving (and other construction activites that will cause more than a 15 minute delay) at nighttime, working hours will be limited to 7:30 a.m. to 5:00 p.m. Monday through Friday, unless modified upon written approval by the resident engineer, to reduce construction noise levels. These working hours will be incorporated as part of the construction contract. 20 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impact Incomoration act Impact The slightly modified alignment of the bridge will bring the bridge approximately 10 feet closer to the complex of buildings on the southeast side of the bridge, however, the movement of the bridge will not significantly increase the noise level experienced by potential occupants of the adjacent structures since roadway capacity and vehicle trips generated will not increase as a result of the project. Since the house is abandoned, construction activities associated with the installation of the replacement bridge, as well as ambient noise levels due to the new bridge, should not significantly increase the noise levels experienced by residents. Please see the Mitigation Summary for Best Management Practices that will be implemented as part of the contract. XII. POPULATION AND HOUSING- Would the project: a. Induce substantial population growth in an _ X area, either directly(for example,by proposing new homes and businesses)or indirectly(for example, through extension of roads or other infrastructure)? (Source#2,6) b. Displace substantial numbers of existing _ _ X housing,necessitating the construction of replacement housing elsewhere? (Source#2,6) C. Displace substantial numbers of people, _ e X necessitating the construction of replacement housing elsewhere? (Source#2,6) SUMMAIt' The proposed project is on an existing roadway. Installation of the replacement bridge will not affect available capacity of Delta Road Bridge and will, therefore, not induce population growth. Construction of the bridge will not result in the displacement of any homes or residents. The project will not result in a change in the location, distribution, density or growth rate of human population in the area. The project will not affect existing housing, or create a demand for additional houses. Construction of the replacement bridge will not require the removal of any homes or the displacement of any people. XIIL PUBLIC SERVICES 21 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No JmRact Incotporation Impact Impact a. Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities,need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios,response times or other performance objectives for any of the public services(Source#2,6): 1. Fire Protection? X 2. Police Protection? — — X —_ 3. Schools? — — X 4. Parks? — — — X 5. Other Public facilities? — — X SUMMARY: The replacement bridge will be installed in approximately the same location as the existing bridge and will not increase the capacity of Delta Road outside of the project limits. Once constructed, the new bridge will not increase the need for fire or police protection, schools, parks or other governmental services. However, during pile driving activites and other activities causing a delay of greater than 15 minutes,the bridge may require temporary closure. The temporary closure is expected to occur over a maximum of four nights. Since this closure activity will isolate Holland Tract and Quimby Tract, a fire crew from the Oakley County Fire District will be located on Holland Tract to handle any potential emergencies. Utilization of the temporary crew has been coordinated with the Fire District. Coverage of the remainder of the Fire District's jurisdiction will not be impacted by the temporary utilization of the District's crew. The County currently maintains Delta Road and periodic maintenance of road improvements will continue to be performed by the County. XIV. RECREATION- a. Would the project increase the use of — _ _ X existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated? (Source#1,2,6) b. Does the project include recreational — _ — X facilities or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment? (Source#1,2,6) 22 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No Impact Inoornan PLOOII IM— t Impact SUMMARY: The County Resource Mapping System and the field reviews did not identify any recreational opportunities in the immediate project area. Surrounding land uses consist of undeveloped and agricultural land. However, several marinas are located on Holland Tract and the Delta is heavily used by fishing and boating enthusiasts. Minor delay in access to these recreational areas may occur due to construction activities; however, the delay will be insignificant since, during the day, at least one lane will remain open for traffic until the replacement bridge is completed. Pile driving will occur at night, so the pile driving activities will not significantly impact boating uses in this area of the Delta. During other phases of the construction,boaters will be able to pass under the bridge without experiencing significant delays. Installation of the replacement bridge will not have a significant impact on recreational activities, since the Delta Road Bridge is already in place and the new bridge will have the same clearance as the existing bridge. XV. TRANSPORTATION/TRAFFIC-Would the project: a. Cause an increase in traffic which is _ X _ substantial in relation to the existing traffic load and capacity of the street system (i.e., result in a substantial increase in either the number of vehicle trips, the volume to capacity ratio on roads,or congestion at intersections)? (Source#1,2,6) b. Exceed,either individually or cumulatively, X a level of service standard established by the county congestion management agency for designated roads or highways? (Source#1,2,6) C. Result in a change in air traffic patterns, X including either an increase in traffic levels or a change in location that results in substantial safety risks? (Source#N/A) d. Substantially increase hazards due to a design _ _ X feature(e.g., sharp curves or dangerous inter- sections)or incompatible uses(e.g., farm equipment)? (Source#2,6) e. Result in inadequate emergency access? _ _ X _ (Source#2,6) f. Result in inadequate parking capacity? _ _ X (Source#N/A) g. Conflict with adopted policies,plans, or _ X programs supporting alternative transportation 23 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No m act Incoryoration Impact Impact (e.g.,bus turnouts,bicycle racks)? (Source#2) SUMMARY: Delta Road Bridge is a one-lane bridge that is the only access to Holland Tract and Quimby Tract. The average daily vehicle trips on Delta Road are estimated to be approximately 269. Adding an additional lane to the bridge will not increase the capacity of Delta Road. The project will bring the bridge up to current standards. Because an additional lane will be added,traffic crossing the bridge should flow more efficiently than it currently does once the bridge is completed. Although there will be additional traffic generated by construction of the new bridge due to construction vehicles, the existing bridge will be kept in service during the majority of the construction of the new two lane bridge. During pile driving activates and any other activites that will cause a delay of more than 15 minutes,the bridge may require temporary closure. In order to minimize traffic impacts, the temporary closure will occur at nighttime. The temporary closure is expected to occur over a maximum of four nights. Since this activity will isolate Holland Tract and Quimby Tract, a fire crew from the Oakley County Fire District will be located on Holland Tract to handle any potential emergencies. Utilization of the temporary crew has been coordinated with the Fire District. Coverage of the remainder of the Fire District's jurisdiction will not be impacted by the temporary utilization of the District's crew. Delta Road will be realigned for approximately 100 feet on the south side and 70 feet on the north side of the bridge in order to support the modified bridge alignment. The project will not alter waterborne, rail or air traffic as no water, rail or air transportation facilities are located in the immediate vicinity of the project area. Please see the Mitigation Summary for Best Management Practices that will be implemented as part of the contract. XVI. UTILITIES AND SERVICE SYSTEMS - Would the project: a. Exceed wastewater treatment requirements _ _ X of the applicable Regional Water Quality Control Board? (Source#N/A) b. Require or result in the construction of new — _ _ X water or wastewater treatment facilities or expansion of existing facilities, the construction or which could cause significant environmental effects?(Source#N/A) C. Require or result in the construction of new _ _ X storm water drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? (Source#6) d. Have sufficient water supplies available to _ X �9yt� 24 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No IMIZ—Act Incomoration I=ac Impact serve the project from existing entitlement and resources, or are new or expanded entitlement needed? (Source#6) e. Result in a determination by the wastewater _ _ — X treatment provider which serves or may serve the project that it has adequate capacity to serve the project's projected demand in addition to the provider's existing commitments? (Source#N/A) f. Be served by a landfill with sufficient — — — X permitted capacity to accommodate the project's solid waste disposal needs? (Source#N/A) g. Comply with federal,state and local statutes — — — X and regulations related to solid waste? (Source#N/A) SUMMARY: Relocation of one PG&E electric pole will be necessary to accommodate the new bridge. The relocation will be coordinated with representatives from PG&E. Ironhouse Sanitary District, Pacific Bell, TCI Cablevision and PG&E gas distribution have responded that they have no existing or proposed facilities that will be impacted by construction of the replacement bridge. Rock Slough contains San Joaquin Delta water supplies used by the Contra Costa Water District (CCWD) for treatment and distribution to 400,000 municipal and industrial customers in Contra Costa County. The Contra Costa Canal intake is located at the west terminus of Rock Slough, approximately 1.2 miles to the west of the project. The project is not within the existing Contra Costa Water District service area boundaries and CCWD does not have facilities on the existing bridge or plans for installation of facilities in connection with the bridge location. The project will not result in a substantial reduction of the amount of water available for this water supply. The Bureau of Reclamation and Contra Costa Water District are planning a joint project to install a fish screen on a Contra Costa Canal intake; however, coordination with the project manager for the fish screen project has indicated that access for that project will be from Cypress Road rather than Delta Road and the Delta Road Bridge project should therefore not impact the construction of the fish screen project. XVII. MANDATORY FINDINGS OF SIGNIFICANCE- -7 25 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No tmoact [ncomorationImact act a. Does the project have the potential to degrade _ X the quality of the environment, substantially reduce the habitat of a fish and wildlife species, cause a fish or wildlife population to drop below self-sustaining levels,threaten to eliminate a plant or animal community,reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? b. Does the project have impacts that are indiv- _ X _ idually limited,but cumulatively considerable? ("Cumulatively considerable"means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)? C. Does the project have environmental effects _ X _ which will cause substantial adverse effects on human beings,either directly or indirectly? SUMMARY: As discussed above under #IV Biological Resources, the project does have the potential to significantly impact plant or animal resources;however,direct impacts to wildlife and their habitat will be minimized by utilization of silt trapping devices during pile driving and other in-water work activities and by limiting in-water work to between August 1st and November 30'of any given year. Both of these measures were agreed to during informal consultation with USFWS. With these avoidance and minimization measures incorporated into the project,impacts to the listed fish species are expected to be insignificant. If necessary, some tree removal will occur;however, the trees will be replaced at a 3:1 ratio with like species. No impact to wetland vegetation is expected to occur as a result of the bridge construction. As agreed to during informal consultation with USFWS, no fill will be placed on emergent wetland vegetation. Both the Archaeological Survey Report and the Historic Architectural Survey Report findings were negative for the proposed project. Measures will be undertaken in the design and construction of the Delta Road Bridge project to avoid adverse impacts to water quality. New pilings installed for the replacement bridge will be steel encasing concrete and will not have toxic characteristics. The existing creosote pilings will be cut off at mudline and left in place below mudline to minimize water quality impacts due to total removal. In addition, as discussed above, a silt trapping device of the contractor's design will be utilized during pile driving activities in order to minimize impacts to water quality. To prevent any work materials from entering Rock Slough during removal of the old bridge and construction of the new bridge, debris containment methods (e.g., a net barrier) of the contractor's design will be 26 Potentially Significant Potentially Unless Less than Significant Mitigation Significant No rryact Incomgration Impact Irnpact required by the contract specifications. Standard construction safety practices will be followed to ensure no accidental release of hazardous substances as a result of construction activities. Booms and absorbent materials shall be on site in the event of an accidental release. Temporary closure of the bridge may occur over a maximum of four nights. During the closure, a fire crew from the Oakley County Fire District will be located on Holland Tract to handle any potential emergencies. Although the new bridge will not increase ambient noise levels associated with utilization of the bridge; noise levels in the vicinity of the bridge will be temporarily increased due to construction activities. Pile driving activites are expected to occur over a maximum of four nights. The nearest sensitive receptors are located approximately half a mile away from the construction activities. The residents,business owners, and property owners will be notified one week in advance of the potential for night work to occur and the expected dates and duration. Based on the temporary nature of the noise and the distance of the nearest sensitive receptors, impacts due to noise are not expected to be significant. During pile driving activates and any other activites that will cause a delay of more than 15 minutes, the bridge may require temporary closure. In order to minimize traffic impacts,the closure will only occur at nighttime and it is expected to occur over a maximum of four nights. Residents and property owners on Holland Tract, Quimby Tract and Veale Tract will be notified of the potential for closure and the expected dates and duration. Standard specifications will require installation of sufficient warning sign regarding the construction and work hours. Due to the nature of the project and the area in which it is proposed,the project will not have impacts that are individually limited but cumulatively considerable. The bridge will be located in a previously disturbed area in the approximate location of the existing bridge. Installation of the replacement bridge will not increase the capacity of Delta Road. As discussed in Sections I(Aesthetics),II(Agricultural Resources), III(Air Quality),IX(Land Use and Planning), X(Mineral Resources), XII(Population and Housing), XIV (Recreation), and XVI (Utilities and Service Systems), the proposed project will not result in substantial adverse effects on human beings, either directly or indirectly. g\enviro\99 Pro j ects\beltandBridge\M itigatedNECDEC CALIFORNIA ENVIRONMENTAL QUALITY ACT NOTICE OF DETERMINATION CONTRA COSTA COUNTY COMMUNITY DEVELOPMENT DEPARTMENT 651 PINE STREET 4TH FLOOR NORTH WING MARTINEZ, CALIFORNIA 84553-0095 Telephone: (925)313-2296 Contact Person: Cece Seligren, Environmental Planner Project Description,Common Name(if any)and Location:Delta Road Bridge Replacement Project,County File#CP 00-02. The Contra Costa County Public Works Department proposes to replace the existing deteriorating one-lane timber decked Bailey-style bridge over Rock Slough with a 26-foot wide two-tane'bridge. The new bridge abutments will be Installed on the upland portion of the levee farther back from the edge of the slough than the existing abutments are located.No grading of the banks of the slough will be necessary. in the area below the existing bridge abutments,rock slope protection armors the banks of the slough. The existing dprap will remain In place and no new riprap will be placed. The project also includes realigning Delta Road approximately 100 feet on the south side and 70 feet on the north side of the bridge to conform to the new wider bridge. A retaining structure will be built on the southeast side of the bridge to support the realigned bridge approach. The alignment of the new bridge will be similar to the original configuration. Minor fill will be placed on the top of the levee to widen the northern levee approach;however,this fill will be placed In an upland area and will not Impact the slough. With the exception of the new piles,there will be no fill within the slough. A house with associated agricultural buildings is located adjacent to the bridge;however,the house is currently abandoned. The existing bridge will remain open during the majority of the construction of the replacement bridge. Once the eastern half of the replacement bridge is complete.It will be opened for traffic while the existing bridge Is removed and the western half of the replacement bridge completed. The bridge will be closed during Installation of the piles or during any other activites that would cause delays of more than 15 minutes. These activities will be conducted at night to avoid disruption to daily traffic patterns.If the bridge requires closure,a fire crew from the Oakley County Fire Protection District will be positioned on Holland Tract to handle any emergencies. All work associated with the bridge pilings will be conducted either from a barge or from the existing bridge(if the contractor Is able to demonstrate that the bridge will be able to sustain the weight of the heavy equipment). Contract specifications will require the Installation of silt trapping devices of the contractor's design to ensure that siltation In the slough as a result of the pHs driving and any other In water work is kept to a minimum. To prevent work materials from entering Rock Slough during removal of the old bridge and construction of the new bridge,debris containment methods (e.g., a net barrier)of the contractor's design will be required per contract specifications. The existing creosote-coated piles will be cut off at mudline in order to remove them as a navigational hazard yet minimize the potential Impacts to water quality due to total removal.The new piles installed for the replacement bridge will consist of steel encasing concrete. The piles will not have potential toxic characteristics. All in-water work will occur between August 1" and November 301 unless otherwise agreed to by the resource agencies and the County. Project Location: The Delta Road Bridge is located over Rock Slough In the Knlghtsen area of east Contra Costa County. The bridge Is the only access to Holland and Quimby Tracts. The project was approved on Pursuant to the provisions of the California Environmental Quality Act: ( } An Environmental Impact Report was prepared and certified(SCH# } { ) The Project was encompassed by an Environmental Impact Report previously prepared for (SCH# ). ( X ) A Mitigated Negative Declaration was prepared following identification of a potentially significant Impact that was not Identified In the original Negative Declaration(CDD CP#96-1). Copies of the record of project approval and the Negative Declaration or the final EIR may be examined at the office of the Contra Costa County Community Development Department. ( X } The Project will not have a significant environmental effect with the incorporation of mitigation Into the project description. ( } The Project will have a significant environmental effect. { } Mitigation measures were made a condition of approval of the project. ( } A statement of overriding considerations was adopted. { ) Findings were adopted pursuant to Section 15091 of the State CEQA Guidelines. Date: By: Community Development Department Representative AFFIDAVIT OF FILING AND POSTING I declare that on 1 received and posted this notice as required by California Public Resources Code Section 21152(c). Said notice will remain posted for 30 days from the filing date. Signature Title Applicant Department of Fish and Game Fees Due Public Works Department EIR-$850 Total Due: $ 255 Glacier Drive X— Neg.Dec.-$1,250 Total Paid $ Martinez,CA 84553 DeMinlmis Findings-$0 Attn:Leigh Chavez �X� County Clerk-$50 Reoelpt#: G:1GrpD&ts\EngSvclENVIRO\99pmjccts\DeltaRoad$ridge\NOD.doc Dennis AICP Community Contra GoommUAy1)6vel�o erne nt Director �y`11YDevelopment Costa Department ounty � VIJo 7. County Administration Buildings 851 Pine Street ,g'' STACOUNTY ICK 4th Floor,North Wing i'.}` +._ DEPUTY Martinez,California 94553-0095 '- "''-F6 rUa ;.-2000 ..-_. Phone: NOTICE OF PUBLIC REVIEW A INTENT TO ADOPT A PROPOSED MITIGATED NEGATIVE DECLARATION County File # CP 00-02 Pursuant to the State of California Public Resources Code and the "Guidelines for Implementation of the California Environmental Quality Act of 1970" as amended to date, this is to advise you that the Community Development Department of Contra Costa County has prepared an initial study on the following project: DELTA ROAD BRIDGE REPLACEMENT. County File # CP00-02: The Contra Costa County Public Works Department proposes to replace the existing deteriorating one- lane timber decked Bailey-style bridge over Rock Slough with a 26-foot wide two-lane bridge. The new bridge abutments will be installed on the upland portion of the levee farther back from the edge of the slough than the existing abutments are located. No grading of the banks of the slough will be necessary. In the area below the existing bridge abutments, rock slope protection armors the banks of the slough. The existing riprap will remain in place and no new riprap will be placed. The project also includes realigning Delta Road approximately 100 feet on the south side and 70 feet on the north side of the bridge to conform to the new wider bridge. A retaining structure will be built on the southeast side of the bridge to support the realigned bridge approach. The alignment of the new bridge will be similar to the original configuration. Minor fill will be placed on the top of the levee to widen the northern levee approach; however, this fill will be placed in an upland area and will not impact the slough. With the exception of the new piles, there will be no fill within the slough. The existing bridge will remain open during the majority of the construction of the replacement bridge. Once the eastern half of the replacement bridge is complete, it will be opened for traffic while the existing bridge is removed and the western half of the replacement bridge completed. The bridge will be closed during installation of the piles or during any other activites that would cause delays of more than 15 minutes. These activities will be conducted at night to avoid disruption to daily traffic patterns. If the bridge requires closure, a fire crew from the Oakley County Fire Protection District will be positioned on Holland Tract to handle any emergencies. All work associated with the bridge pilings will be conducted either from a barge or from the existing bridge (if the contractor is able to demonstrate that the bridge will be able to sustain the weight of the heavy equipment). Contract specifications will require the installation of silt trapping devices of the contractor's design to ensure that siltation in the slough as a result of the pile driving is kept to a minimum. To prevent work materials from entering Rock Slough during removal of the old bridge and construction of the new bridge, debris containment methods (e.g., a net barrier) of the contractor's design will be required per contract specifications. The existing creosote-coated piles will be cut off at mudline in order to remove them as a navigational hazard yet minimize Page 1 of 2 Office Hours Monday- Frday:8:00 a.m.-5:00 p.m. Office is closed the 1 st, 3rd & 5th Fridays of each month the potential impacts to water quality due to total removal. The new piles installed for the replacement bridge will consist of steel encasing concrete. The piles will not have potential toxic characteristics. All in water work will occur between August lot and November 30th unless otherwise agreed to by the resource agencies and the County. A house with associated agricultural buildings is located adjacent to the bridge; however, the house is currently abandoned. Project Location: The Delta Road Bridge is located over Rock Slough in the Knightsen area of east Contra Costa County. The bridge is the only access to Holland and Quimby Tracts. The proposed project will not result in any significant impacts. A copy of the mitigated negative declaration and all documents referenced in the mitigated negative declaration may be reviewed in the offices of the Community Development Department, and Application and Permit Center at the McBrien Administration Building, North Wing, Second Floor, 651 Pine Street, Martinez, during normal business hours. Public Comment Period — The period for accepting comments on the adequacy of the environmental documents extends to March 16, 2000. Any comments should be in writing and submitted to the following address: Debbie Chamberlain, Principle Planner Community Development Department Contra Costa County 651 Pine Street, North Wing, 4t' Floor Martinez, CA 94553 Any questions regarding the project itself, should be directed to: Leigh Chavez (925) 313-2366 Public Works Department 255 Glacier Drive Martinez, CA 94553 Lett gAEngSvc\ NVlR0\99projecW DeltaRoadBridgMatice of Public Review.doc Cc: County Clerk's Office (2 copies) Public Works—L. Chavez, Engineering Services Page 2 of 2 TO: BOARD OF SUPERVISORS FROM: J. MICHAEL WALFORD, PUBLIC WORKS DIRECTOR DATE: March 21, 2000 SUBJECT: Approve Addendum No. 1 for the Lone Tree Way Right Turn Lana Project, in the Brentwood Area. Project No. 0662-6R4006-99 Specific Request(s) or Recommendation(s) & Background & Justification Io RECOMMENDED ACTION: APPROVE prior issuance of Addendum No. 1 for the Lone Tree Way Right Turn Lane Project. II. FINANCIAL IMPACT: This Addendum has no financial effect on the project budget or the General Fund and is funded by Hazard Elimination and Safety (HES) (100%). Fla j+ Continued on Attachment: X SIGNATURE: RECOMMENDATION OF COUNTY ADMINISTRATOR _RECOMMENDATION OF BOARD COMMITTEE —APPROVE —OTHER SIGNATURE(S): ACTION OF BOARD ON MARCH 21, 2000 APPROVED AS RECOMMENDED OTHER VOTE OF SUPERVISORS _ UNANIMOUS (ASSENT_ DONE AYES: NOES: ABSENT:__- _ ABSTAIN: 1 hereby certify that this is a true and correct copy of an action taken and entered on the Md:ad minutes of the Board of Supervisors on the \\PWS4\SHARDATA\OrpData\Design\Board Orders\ date shown. BO 2000\Lons Tree Way Right Turn Lane Add 1 3-21.doc Ong.Div: Public Works(Design Division) ATTESTED: 21 t 2000 Contact Mark de is O(313-2355) cc: County Administrator,E.Kuevor PHIL BATCHELOR, Clerk of the Board Auditor-Controller PWAcccourding of Supervisors and County Administrator Construction Community Development-A.Woods By ✓ �}epUty 140 SL'3JECT: Approve Addendum No. 1 for the Lone Tree Way Right Turn Lane Project, in the Brentwood area. Project No. 0662-684006-99 DATE: March 21, 2000 PANE: 2 III. REASONS FOR RECOMMENDATIONIBACKGROUND: On February 1, 2000, the Board of Supervisors approved plans and specification for this project. Addendum No. 1 is needed to reflect the changes in Federal Minimum Wages that took effect February 11, 2000. IV. Consequences of Negative Action: If Addendum No. 1 is not approved, our bidding requirements would be in conflict with current federal mandates. ct+ THE BOARD OF SUPERVISORS OF CONTRA COSTA COUNTY, CALIFORNIA Adopted this Order on March 21, 2000,by the following vote: AYES: SUPERVISORS GIOIA, UILKEKA, DESAULNIER, CANCIAMILLA AND GERBER NOES: NONE ABSENT: NONE ABSTAIN: NONE SUBJECT: Ratify previous permission by Public Works Director to completely Close a portion of Waterfront Road,for the Purpose of constructing a pipeline bridge across Walnut Creek Channel, in the Martinez area. (RC 00-3) The Public Works Director having reported that prior approval has been granted to Tosco Refining Company to completely close Waterfront Road,except for emergency traffic, on Wednesday, March 1, 2000 to Wednesday, March 8,2000, subject to the following conditions: 1. Traffic will be detoured via Solano Avenue from State Highway 4 per the plan approved by Public Works. 2. All signing to be in accordance with the State of California Manual of Traffic Controls. 3. Tosco Refining Company shall comply with the requirements of the Ordinance Code of Contra Costa County. 4. Provide the County with a Certificate of Insurance in the amount of $1,000,000.00 for Comprehensive General Public Liability which names the County as an additional insured prior to permit issuance. 5. Obtain approval for the closure from the Sheriff's Department,the California Highway Patrol and the Fire District. IT IS BY THE BOARD ORDERED that the action taken by the Public Works Director is approved. I hereby certify that this is a true and correct copy of an action taken and entered on the minutes of the Board of Supervisors on the date shown. BH:mw G:\GrpData\Bngsvc\BO\2000\BO 3-21-00.doc Originator: Public works{APC) ATTESTED: MARCH 21, 2000 Contact: Bob Hendry(646-1607) PHIL BATCHELOR, Clerk of the Board of Supervisors cc: CHP and County Administrator Sheriff-Patrol Div.Commander By , Deputy TO: BOARD OF SUPERVISORS FROM: J. MICHAEL WALFORD, PUBLIC WORKS DIRECTOR DATE: MARCH 21, 2000 SUBJECT: AMEND CONSULTING SERVICES AGREEMENT FOR MISCELLANEOUS SOILS INVESTIGATIONS SPECIFIC REQUEST(S)OR RECOMMENDATION(S)&BACKGROUND AND JUSTIFICATION 1. Recommended Action: APPROVE and AUTHORIZE the Public Works Director to execute, on behalf of Contra Costa County a Consulting Services Agreement Amendment with Hultgren-Tlllis Engineers increasing the limit from $48,000 to $98,000 for various services in connection with soils investigation matters. 111. Financial lmpact: Payments under this contract are charged directly to various road, flood control and other projects which require consulting services on an "as needed" basis. No general funds will be required. Continued on Attachment:x SIGNATURE:�Zlz��ImZ� —KrECOMMENDATION OF COUNTY A15MIRISTRATOR RECOMMENDATION OF BOARD COMMITTEE ®APPROVE OTHER SIGNATURE(S): ACTION MARCH 21, 2000 VOTE OF SUPERVISORS X UNANIMOUS(ABSENT NONE ) AYES: NOES: ABSENT: ABSTAIN: — I hereby certify that this is a true and correct copy of an action taken and entered on the cps:eh minutes of the Board of Supervisors on the G:1GrpData\RealProp\2000-Files\BOs&RES\BOHultgren.doc date shown. Orig.Div:Public Works(RIP) Contact: C.Pina-Sandoval(313-2306) cc: County Administrator ATTESTED: MARCH 21, 2000 Auditor-Controller(via RIP) PHIL BATCHELOR,Clerk of the Board of P.W.Accounting Supervisors and County Administrator By Deputy Hultgren-Tillis Engineers Amendment to Consulting Services Agreement for Misc. Soils Investigations March 21, 2000 Page 2 111. Background and Reasons for Recommendations: Hultgren-Tillis Engineers is a Small Business Enterprise environmental firm which various County agencies use from time to time to provide soils investigations and analyze for the presence of hazardous materials. In order to conserve time and reduce paperwork, a single "standing" Consulting Services Agreement with a $35,000 limit was initially approved and later amended for an additional $10,000 and $13,000 so that the firm's services could be obtained quickly on an as-needed basis. In the interim, various projects have drawn down the funds available through these agreements. County staff members wish to continue to use this firm because of its quick response time and reliable performance. Therefore, staff is requesting approval of a third amendment for an additional $50,000 for future services as needed. Agreement extends through the completion of all assigned projects. IV. Consequences of Negative Action: Negative action will result in an incomplete assessment of property and possibly substantial financial risks associated with contamination problems.