Loading...
HomeMy WebLinkAboutMINUTES - 07082003 - SD5 TO: BOARD OF SUPERVISORS FROMI: MAL-RICE M. SHIU, PUBLIC WORKS DIRECTOR DATE: JULY 8, 2003 SUBJECT: ADOPT the Vasco Road and Camino Diablo Intersection Improvements Project Negative Declaration in compliance with the California Environmental Quality Act and APPROVE the project, Byron area. [CDD-CP #03-17] (District III) Project No. 0662-684097 Specific Request(s) or Recommendatian(s} & Background & Justification L RECOMMENDED ACTION: FIND on the basis of the Vasco Road and Camino Diablo Intersection Improvements Project Negative Declaration initial study and all comments received,there is no substantial evidence the project will have a significant effect on the environment, and ADOPT the Negative Declaration which is in compliance with the California Environmental Quality Act (the custodian of which is the Community Development Director who is located at 651 Pine,Martinez),and state and county guidelines, and DIRECT the Director of Community Development to file a Notice of Determination with the County Clerk, and fl r e� Coxitirruetl an Attachment: X SIGNATURE' - SIGN s ECOMMENDATION OF COUNTY ADMINISTRATOR RECOMMENDATION OF BOARD COMMITTEE � AP'PROVE _ OTHER .t r SIGNATURE(S): ACTION OF BO ON J11177, ZW3 APPROVED AS RECOMMENDED OTHER VOTE OF SUPERVISORS X UNANIMOUS(ABSENT 1V } AYES: NOES: I hereby certify that this is a true and correct copy of an action ABSENT: ABSTAIN: taken and entered on the minutes of the Board of Supervisors on *District III Stet VACANT* the date shown. LC:sr G:\GrpData\EngSvc\E,NVIRO\BO\2003\ (06-24-03)CEQA-vascoCaminoDiabloAoc July 8, 2003 Orig.Div: Public Works(Eng Sery Division) ATTESTE : Contact: Leigh Chavez,(925)313-2366 JOHN SWEETEN,Clerk of the Board of Supervisors and County cc: Administrator-Atte. E.Kuevor Administrator Auditor-Controller r Community Development—K.Piona Public works: Accounting By �. � �`'` i� �� `� ''� ,Deputy Construction4R,Bruno E..' Design-M.Sen TE—S.Kowalewski SUBJECT: ADOPT the Vasco Road and Camino Diablo Intersection Improvements Project Negative Declaration in compliance with the California Environmental Quality Act and APPROVE the project, Byron area. [CDD-CP #03-17] (District III)Project No. 0662-584097 DATE: July 8, 2003 PAGE: 2 I. RECOMMENDED ACTION(continued): 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 ding the Notice of Determination, and APPROVE the Vasco Road and Camino Diablo Intersection Improvements Project. IL FISCAL IMPACT: The estimated project cost is $2.1 million funded by Local Road Funds ($200,000), City of Brentwood ($200,000) and the East County Transportation Improvement Authority($1.7 million). III. REASONS FOR RECOMMENDATION/BACKGROUND: The project is needed in order to allow for improved efficiency and reduced congestion at the Vasco Road and Camino Diablo intersection. The project will consist of intersection improvements including traffic signal installation, minor roadway widening, installation of standard lane addition tapers and drop tapers, and re-striping to provide for protected left turn pockets. A Negative Declaration of environmental significance pertaining to the project was published on May 7, 2003. The Public Works Department received two comments regarding the project. The first comment was submitted by the California Department of Transportation(Caltrans). This comment indicated satisfaction following a review of the Initial Study and Negative Declaration that the project will not have a significant impact to State transportation facilities (no response necessary). The second comment was from an Alameda County resident(Mr. Dick Ward)who lives at 3884 N. Vasco Road. Mr. Ward is concerned that the intersection improvement project will exacerbate the problems he experiences accessing his property as a result of added traffic volume. The Department responded to Mr. Ward's comment as follows: the volume of traffic using Vasco Road will not change as a result of the project. The project has been designed to improve the efficiency of existing traffic movement through the localized intersection of Vasco Road and Camino Diablo. The project will not increase the number of vehicles using Vasco Road; rather it will increase the speed at which existing vehicles move through the intersection. Based on literature research,in-house expert opinion,and the professional opinion of a traffic engineering consultant,the groupings of vehicles passing in front of Mr.Ward's property will not be dictated by a signal located approximately 10 miles from Mr. Ward's residence. Although it is clear that access to SUBJECT: ADOPT the Vasco Road and Camino Diablo Intersection Improvements Project Negative Declaration in compliance with the California Environmental Quality Act and APPROVE the project, Byron area. [CDD-CP#03-17] (District III)Project No. 0662-68.4097 DATE: July S, 2003 PAGE: 3 III. REASONS FOR.RECOMMENDATION/BACKGROUND: (continued) and egress from Mr.Ward's driveway is difficult due to long groupings of vehicles passing his driveway,the Department believes the groupings are the result of a number of factors including driver behavior, road geometrics, vehicle mix, and weather conditions rather than the signal located several miles north of his property. The Board has considered the Negative Declaration together with all comments received during the public review period. IV. CONSEQUENCES OF NEGATIVE ACTION: Delay in approving the project will result in a delay of design and construction and may jeopardize funding. CONTRA PUBLIC WORKS DEPARTMENT COSTA INITIAL STUDY COUNTY OF ENVIRONMENTAL SIGNIFICANCE PROJECT # 0676-6P4097 CP# 03-17 PROJECT NAME: Vasco Road and Camino Diable Intersection Improvements PREPARED BY: Leigh Chavez DATE: 3/17/03 APPROVED BY: 00" DATE: ''- Z-d_ RECOMMENDATIONS: {) Categorical Exemption .(Class ) ( X ) Negative Declaration { } Environment Impact Report Required { ) Mitigated Negative Declaration The project will not have a significant effect on - the environment. The recommendation is based on the following: There is no substantial evidence that the project or any of its aspects may cause a significant effect on the environment {Sec. 15063(b)(2)). What changes to the project would mitigate the identified impacts: N/A USGS Quad Sheet: Byron Hot Springs Base Map Sheet #: Q26 Parcel # N/A GENERAL CONSIDERATIONS: 1. Location: The project is located at the intersection of Vasco Road and Camino Diablo Road in the eastern Contra Costa County area near the Town of Byron (Figures 1-3) 2. Project Description: The project consists of improvements to the Camino Diablo and Vasco Road intersection to allow for improved efficiency and reduced congestion. Improvements will consist of (Figure 3): 1) on the north leg: widening the west side of Vasco Road by approximately 12 feet for an approximate distance of 600 feet and installing a standard lane addition taper to allow for a southbound through lane, 2) on the south leg: widening the west and east side of Vasco Road by approximately 12 feet for an approximately distance of 600 feet and installing a standard lane addition taper on the east side for an additional northbound through lane and a standard lane drop taper on the west side for additional southbound through lane, 3) on the east leg: re-striping of the existing lane configuration to provide a protected left-turn packet and a single lane in each direction as well as minor widening of approximately 4 feet on the north side of Camino Diablo for an approximate distance of 115 feet, and 4) on the west leg: re-striping the existing lane configuration to provide a protected left-turn lane and single lane in each direction as well as minor widening of approximately 4 feet on the north and south side of Camino Diablo for an approximate distance of 770 feet north and 760 feet south. Signal poles will be relocated and/or replaced to accommodate the new lane configuration. In order to accomplish the improvements, some cut and fill will be required on some of the roadway shoulders, The most substantial area of cut will occur along the southern leg of Vasco Road on the east side of the roadway. The project may include installation of a retaining wall varying from ' to 6' tall at this location; however, grading the existing slope back rather than installing a retaining wall is likely, to be the chosen construction method. Roadway drainage facilities associated with the improvements will tie into existing drainage utilized for the roadway, and the existing v-ditch along the southeastern side of Vasco Road will be re-established. Curing construction, lanes will be narrowed and shoulders utilized for through traffic in order to accommodate the necessary construction activities while still allowing for efficient traffic flow. No lane closures will be necessary. Although unlikely, some nighttime work may be conducted in order to minimize traffic impacts as a result of construction activities. Right of way acquisition may be necessary in order to accommodate the cut slopes and/or the retaining wall. Additional real property transactions may be necessary. 3. Does it appear that any feature of the project will generate significant public concern? ] yes JX] no [ ] maybe (Nature of concern). 4, Will the project require approval or permits by other than a County agency? X ] yes [ ] no Agency Name(s); No 5. Is the project within the Sphere of Influence of any city"? No t\1' ul i ,✓ ,,+'''fin ��'' �. �,,,.: '''•,., �� r —'" "���,. Q �ti . 637 SEE 6I7 MAP Figure {+tom �"�.'- ."' ::,�,rr'3 -mrs.—'n ; „� a .,` ,..n,.5t'?�x'_ �t�;' y.a". .t.1j g^ �s^i•,„'� .',.7;r,b� �:: ,,c .:..0 "':....:, ,1 dg�L.l L.. 2 . N 32 33 34 HOFFMAN LN t —I . T1 N _ ---'-ICF'rMA _ ..__ _...__..-_..._ a � ' 4513 \HANNONR I * BYER RU ri B ft 4 CN 3 E O C a t1 ii. SAN ~� I 3OAOUIN p, g A MA Y� Q Cm NO SIA LO LE GRAND M ' _ CAMI zeaoy• 3zad� _-1ST ST cox FS vi 1 w ..................8 -------- lo -- -- 1G} �' 1 716 ... z t _..._..._...a.--_..._... - — J' k i 1 t 97-5 ARMST,RU4,G RQ ..�`• . � I — �Edd�d��,�Mxr '',rs �k..�r�'+� ���,} 52^d�3"���,` 77 ,. � ....... •'' � ��`CGN7"RAt °��,�tJS �fCDU�M' r }} F i"iV ..._ R o t � +` s�s k' r*ef�'.� -eta va .34. '°'ui-rte ��' r.�"3ss� ,�„•n f'�""�,s,' '`.� �ra€"�..�s��$ s. - - �' '�' ' fir' a w�... t��k}t^' �7f s„'�'�-�'�9°�' •�,•ww`-�",,�, , -�* ��� �ax„*�t y+t�* as maw w.�t.: � 9 ,#k' "^ skt '�: <.t�',✓ .ss ' #�� k Ij' a wa�++�"7r;`✓s� t � {a '��" •�'a .+r.,tKA�r�y��'" t �;Zi. Ml ^r '.. ` 4`" '� sa'a; �57 sum W Mr m, s'r* `;,pq rS%�,,w.>s y., ,�3* G ✓ "S,,s- ?i ." WN �#'eR"'�z' t� C„�,✓� �'tb ^:-mN-K ^t'��"z "f Cc°l, {. `' p'� '" K,,. .ri •7' ^,: %' Y�.> 5 �5�. , ' }� �'�s.' i'i"' &:iv zt.4+� 5,"�a"'*�,'+�' x r ' r¢.'^X� ,ry `a,,° � w. 't �� ��� a ta: a h� �• „'k.. '.• &.g�.a�F���b'" ';`y�,' _c�v 'm5°'����"k-ft,�� �, 3� +�.'f'eG.n.�y,�"`at.�Qg{�a�d's,x�` "tam KN,till ? AN a �`"# °`°r f` �,,.,7x t Us # - 0p ARV Wr MINT! 'iCi to +G >4 � ��14',� &d��+ .� �y ,k•h`y^e�T t F{' "�' eW�Y,.A.S 4 { 4�+*'�� �.a�R""� .�q�;_V ��4�a, .�.,a�` h�wk Asea..r`-�', }/,�- Environmental Checklist Form 1. Project Title: Vasco Road and Camino Diablo Intersection Improvements Project 2. Lead Agency Nan-se 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) 313-2365 Contra Costa County Public Works Department 4. Project Location: The project is located at the intersection of Masco Road and Camino Diablo in the eastern Contra Costa County area near the Town of Byron. 5. Project Sponsor's Name and Address: Contra Costa County Public Works 255 Glacier Drive Martinez, CA 94553.4897 6. General Plan Designation: Agricultural Land 7. Zoning: Public Right-of-way(Camino Diablo Road— Arterial Roadway, Vasco Road— Expressway) 8. Description of Project: The project consists of improvements to the Camino Diablo and Vasco Road intersection to allow for improved efficiency and reduced congestion. Improvements will consist of: 1) on the north leg: widening the west side of Vasco Road by approximately 12 feet for an approximate distance of 600 feet and installing a standard lane addition taper to allow for a southbound through lane, 2) on the south leg: widening the west and east side of Vasco Road by approximately 12 feet for an approximately distance of 600 feet and installing a standard lane addition taper on the east side for an additional northbound through lane and a standard lane drop taper on the west side for additional southbound through lane, 3) on the east leg: re-striping of the existing lane configuration to provide a protected left-turn pocket and a single lane in each direction as well as minor widening of approximately 4 feet on the north side of Camino Diablo for an approximate distance of 115 feet, and 4) on the west leg: re- striping the existing lane configuration to provide a protected left-turn lane and single lane in each direction as well as minor widening of approximately 4 feet on the north and south side of Canino Diablo for an approximate distance of 770 feet north and 760 feet south. Signal poles will be relocated and/or replaced to accommodate the new lane PAGE 1 configuration. In order to accomplish the improvements, some cut and till will be required on some of the roadway shoulders. The most substantial area of cut will occur along the southern leg of Vasco Road on the east side of the roadway. The project may include installation of a retaining wall varying from 3' to 8' tall at this location; however, grading the existing slope back rather than installing a retaining wall is likely to be the chosen constriction method. Roadway drainage facilities associated with the improvements will tie into existing drainage utilized for the roadway, and the existing concrete v-ditch along the southeastern side of Vasco Road will be re-established. During construction, lanes will be narrowed and shoulders may be utilized for through traffic in order to accommodate the necessary construction activities while still allowing for efficient traffic flow. No lane closures will be necessary. Although unlikely, some nighttime work rra..ay be conducted in order to minimize traffic impacts as a result of construction activities. Right of way acquisition may be necessary in order to accommodate the cut slopes and/or the retaining wall. Additional real property transactions may be necessary. 9. Surrounding Land Uses and Setting: Land uses in the vicinity of the proposed project include open agricultural fields (principally used for livestock grazing) and a sand-mining facility. 10. Other public agencies whose approval is required (e.g., permits, financing approval, or participation agreement): None 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 Planning Transportation/ _Public Services Population&Housing Circulation ,,.,_Utilities &Service Geological Problems _Biological Resources Systems Water Energy&Mineral ,,Aesthetics Air Quality ResourcesCultural Resources Mandatory:Findings of Hazards -Recreation Significance ` Noise X No Significant Impacts Identified PAGz-2 DETERMINATION On the basis of this initial evaluation: X 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 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?v1AY have a significant effects)on the environment,but at least one effect (1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and( )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 avoided or mitigated pursuant to that earlier EIR,including revisions or mitigation measures that are imposed upon the proposed project. Signature Date �+vo - -�,� CCC Community Development Department Printed Name For PAGE 3 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 Byron Hot Springs Quadrangle, CA 2. The(Reconsolidated) County General Plan(July 1996) and Draft EIR on the General Flan (September 1990) Contra Costa County Important Farmland Map 1998, California Department of Conservation Division of Land Resources Protection, 1999 4. Field reviews and/or Project Description(including coordination with Design, Transportation, and Traffic Engineers) 5. Soil Survey of Contra Costa County, Soil Conservation Service, 9/77 6. Contra.Costa County Flood.Insurance Rate Zone Information Map,FIRM panel 063025 0525E 7. Contra Costa County General Plan 1995 -2010, Contra Costa County Community Development Department, July 1996 8. Final Environmental Impact Report Vasco Road and Utility Relocation Project, Contra Costa Nater District, SCH#: 890'2123, Jones & Stokes Associates, Inc., September 1990 9. State Route 4 Bypass Project Environmental Impact Report, State Route 4 Bypass Authority, SCH#: 89032824, Environmental Science Associates, October 1993 10. State Route 4 Bypass Project, Biological Assessment, State Route 4 Bypass Authority, Environmental Science Associates,November 1993 11. Coordination with California Department of Fish and Game Biologist Janice Gan 12, Cultural Resources Investigation for the Vasco Road and Camino Diablo Intersection Improvement Project, David Chavez &Associates, February 2003. 13. Habitat Assessment for the Vasco Road—Camino Diablo Intersection Project, Essex Environmental, February 2003 PAGE 4 EVALUATION OF ENVIRONMENTAL C TACTS: Potentially Significant Potentially Unless Less n,an Significant Mitigation Significant No imp-aetnogr.9r ted Imnact ct I. AESTHETICS. Would the proposal: a. Have a substantial adverse effect on a X scenic vista? b. Substantially damage scenic resources, _ _ X including, but not limited to, trees, rack outcroppings, and historic buildings within a state scenic highway? C. Substantially degrade the existing _ X visual character or quality of the site and its surroundings? d. Create a new source of substantial light X or glare which would adversely affect day or nighttime views in the area? SUMMARY: Less Than Significant Impact. The Contra Costa County General Plan categorizes Camino Diablo as a scenic route and Vasco Road as a scenic expressway. The existing visual setting of the Vasco Road and Camino Diablo intersection area consists of gently rolling terrain, primarily consisting of adjacent agricultural (livestock grazing) fields and a sand mining facility relatively near the southwest and northwest corners of the intersection. Improvements to the roadway will not significantly change the visual quality of the area, and based on the limited and very localized nature of the work and the consistency of the improvements with the existing roadway facility, intersection improvements will not impact the scenic classification of these two roadways. Some cut and fill will be required in order to construct the roadway improvements. The majority of the cut will occur on the eastern side Of the southern leg of Vasco Road. The hillside in this area was cut and graded back at a 2:1 slope when Vasco Road was originally relocated to its current location. With the new improvements, it is likely that the hillside will be laid back at a 2:1 slope similar to the existing conditions at the project site. It is possible, although unlikely, that a retaining wall may instead be installed in this area. If design plans ultimately call for a retaining wall rather than simply grading back the slope, the wall will vary in height between 3 and 8 feet. Above the wall the hillside will be laid back at a 2:1 slope. . There are several sedimentary rock outcroppings located on the east side of the southern leg of Vasco Road. Although the roadways are not classified as state scenic highways and the outcroppings are not highly visible from the roadways, the outcroppings could be considered a scenic resource. The project is being specifically designed to avoid impact to these rock. outcroppings. Minor grading and possibly installation of a retaining will occur adjacent to two of the rock outcroppings. Regardless of the slope treatment in this area(grading or retaining wall installation), the work will occur just below the lowest rack outcropping and will likely serve to improve the viewshed to the rock outcroppings since soil that partially blocks the view of the ?AGE 5 outcroppings will be removed with installation of the improvements. In order to ensure that construction activities cause no impact to the aesthetic integrity of the rock outcroppings,project plans and specifications will require fencing of the outcroppings with highly visible Environmentally Sensitive Area(ESA) fencing. Construction activities associated with improvements to the intersection will impact the minimum amount of vegetation feasible. No trees will require removal as a result of the project. Vegetation in the vicinity of the project consists of non-native annual grassland. At the conclusion of construction, all disturbed areas will be hydroseeded with a Immix of native grasses and wildflowers to provide erosion control and to ensure that the grassland nature of the project site is returned. Improvements to the intersection will not result in an increase in light and glare coming from the site, since no additional lighting will be added to the intersection. Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No Impact cororatcd ac T�tlpeat 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 Prune Farmland, Unique Farmland, _ X or Farmland of Statewide linportance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use? b. Conflict with existing zoning for X agricultural use, or a Williamson Act contract? 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? SUMMARY: Less Than Significant Impact. Project construction will not affect any areas that have been identified as Prime Farmland, Unique Farmland or Farmland of Statewide Importance. The Contra Costa County Important Farmland 1998 map identifies the Vasco Road and Camino PAGE 6 Diablo Intersection Improvement project area as being located within the "Other Land" and "Farmland of Local Importance" designations. With only minor exception(on the east side of the south leg of Vasco Road), the project will be constructed entirely Within existing County road right of way. Other Land is defined by the Important Farmland snap as land that does not meet the criteria of any other category on the snap. The"other land"identified on the map refers to the sand mining operation that is located to the northwest and southwest of the project area. Project construction will not affect land identified as "other land" since all construction on the western half of the project, adjacent to the sand mining operation, will occur within existing County road right of way. Farmland of Local Importance is defined by the;Important Farmlands map as land that is typically used for livestock grazing, is capable of producing dryland grain, and typically lacks irrigation water. The area surrounding the project appears to be used primarily for livestock grazing. Although minor property acquisition will be necessary in an area defined as Fannland of Local Importance (on the east side of the south leg of Vasco Road) in order to accommodate the cut slope or retaining wall as necessary, the area to be acquired is a fairly steep existing roadcut that does not provide appropriate grazing area. This roadcut area is fenced, effectively keeping livestock off the steep area; therefore, the project will not significantly impact Farmland of Local Importance. Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No t7i fact k&otorated inn ac 1310act 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? b. Violate any air quality standard or _ X contribute to an existing or projected air quality violation? 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)? PAGE 7 Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No bp—ac! Incorporated Irnyaci —Y-22aw d. Expose sensitive receptors to substantial X pollutant concentrations? e. Create objectionable odors affecting a __ X substantial number of people? SUMMARY: Less Than Significant Impact. According to the CEQA Guidelines, a project will normally have a significant adverse impact on air quality if it will violate any ambient air quality standard, contribute substantially to an existing or projected air quality violation, or expose sensitive receptors to substantial pollutant concentrations. The project is not intended to, nor is it expected to, increase the number of cars utilizing either Vasco Road or Camino Diablo since roadway capacity will not be increased beyond the immediate intersection area. The lane widths will only be modified in the immediate vicinity of the intersection to allow for efficient operation of the intersection, rather than being widened for any substantial length of either roadway. The improvements will correct a design deficiency at the intersection, allowing vehicles that currently cause gridlock in their attempt to make left and right turns, to make turns without backing up the through-traffic queued behind them. The project is expected to have a beneficial effect on air quality in the immediate project vicinity since traffic will flow more freely through the intersection, minimizing the amount of idling, stopping, and starting typical at the intersection during heavy backup conditions. Short-tern emissions and objectionable odors may be generated during project-related construction activity, however these effects will be minor and temporary. In order to minimize impacts due to construction activities associated with the intersection improvements, contract specifications will stipulate the use of properly tuned and muffled equipment and the elimination of unnecessary idling of equipment when not in use. The implementation of dust control practices including general watering of exposed areas and<'or use of chemical stabilizers will also minimize project-related air quality impacts during construction. With the implementation of these best management practices, the minor, temporary deterioration of ambient air quality during construction at the project site will have no potentially adverse long-term impacts to air quality. The intersection improvement project will not create any adverse change in air movement, winds, temperature or other climatic conditions. PAGF 8 Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No hmact Inccroorated imp---t iw= rV. 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? 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 Servicer C. Have a substantial adverse effect onX 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? d. .Interfere substantially with the movement � � X of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? e. Conflict with any local policies or X ordinances protecting biological resources, such as tree preservation policy or ordinance? f. Conflict with the provisions of an _ X adopted Habitat Conservation Flan, Natural Community Conservation Plan, or,other approved local, regional, or state habitat conservation plan? SUMMARY: Less Than. Significant Impact. In order to ensure that the project would not cause impacts to sensitive habitats or rare species, the County hired.Essex Environmental to conduct research and survey the project site. The majority of the impact area consists of paved roadways with highly disturbed, unvegetated road shoulders, which are routinely sprayed with herbicide. The paved roadway is bordered by ruderal and nonnative grassland vegetation. Ruderal plant PAGE 9 communities found along the roadsides are dominated by weedy species in areas that have been significantly disturbed by agriculture, grazing, and sand mining operations. Yellow star-thistle (Centauraea solstitialis)is the dominant species within the plant community. Other species present include wild mustard (Brassica sp.) and wild radish(Raphanus sativus). Ston-native grassland communities border the ruderal/disturbed vegetation lining Vasco Road and the majority of Camino Diablo. Plant species in the community consist primarily of annual grasses such as nonnative brome (.Bromus sp.). Several sedimentary rock outcroppings are located in the rolling hills on the southern leg of the project east of Vasco Road. The closest of these outcroppings is located approximately 25 vertical feet above the roadway. At the base of these outcroppings are small depressions that appear capable of ponding water as a result of their topography yet appear to drain rapidly based on an obvious lack of ponding during the rainy season when other depressions in the area are inundated.. The vegetation within the depressions does not vary from the surrounding nonnative annual grassland. Based on the vegetative composition and sandy substrate, the depressions do not support vernal pools or other wetlands (Essex Environmental, 2/03). Grading activities will occur near two of the rock outcroppings. Regardless of the slope treatment in this area(,grading or retaining wall installation), the work will occur below the lowest rock outcropping and grading activities will not significantly encroach into the depressional areas at the base of the outcroppings. In order to ensure the rock outcroppings are not impacted by the project,project plans and specifications will require fencing of the outcroppings with highly visible Environmentally Sensitive Area(ESA) fencing. There is a sparsely vegetated depression that ponds water during the rainy season located outside the project area within a heavily grazed field. The depression is highly disturbed by cattle and has limited vegetation consisting primarily of annual grasses with limited mounts of curly dock (Rumex crispus). The depression is located behind existing barbed-wire fencing that will remain in place throughout construction; therefore impacts as a result of the project are not expected. Standard construction BMPs (e.g., dust control, installation of silt fencing, hay bales, etc.)will be utilized to ensure no indirect impacts occur to the ponded area. According to the biological consultant, the project area is highly disturbed and provides low to no suitable habitat for sensitive species. Therefore, impacts to listed species as a result of the project are not expected. Public Works Environmental staff met with Ms. Janice Gan (CDFG Biologist) at the project site to review the habitat in the project area and tip discuss potential impacts due to the project. Ms. Gan concurred with the consultant's determination regarding the quality of the habitat in the project area(January 2003) and indicated that no permits would be necessary to move forward with the construction. In order to ensure that potential impacts to sensitive species (e.g., San Joaquin kit fox) possibly moving through the work site are minimized, preconstruction surveys will be conducted to ensure that no sensitive wildlife species occur in the project area prior to construction. In addition, avoidance and minimization measures including the following will be incorporated into the project specifications: 1) off-road traffic will be prohibited outside of designated project areas, 2) all food-related trash items will be removed on a daily basis, 3) firearms, pets, and rodenticides will be prohibited in the project area, 4) a worker education program will be PAGE 10 conducted prior to construction initiation, and 5) a representative will be appointed for contact with the resource agencies regarding project-related impacts to kit fox. Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No 1=a&t InecrooratedIrnact )fact 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? b. Cause a substantial adverse change in the X significance of an archaeological resource pursuant to §15064.5? C. Directly or indirectly destroy a unique X paleontological resource or site or unique geologic feature? I Disturb any human remains, including X those interred outside of formal cemeteries? SL.}.} 3ViARY: Less Than Significant Impact. A review of the County Resource Mapping System indicated no historical or archaeological sites exist within the project area. The project is proposed in a location that has already been significantly disturbed due to the installation of the existing realigned Vasco Road; therefore, the probability of finding unknown cultural resources is minimal. However, contact with Sonoma State's Northwest Information Center indicated that there is a moderate possibility of identifying Native American archaeological resources and a moderate possibility of identifying historic-period archaeological resources in the.project area. In order to address potential cultural resources in the vicinity that could be adversely impacted by project-related construction activities, the County hired a cultural resources consultant to review the project site (David Chavez &Associates). Staff from David Chavez &Associates researched cultural and historical records in the vicinity of the project and conducted a pedestrian survey of the project area in February, 2003. According to the report prepared by Mr.-Chavez, no cultural resources were observed during the survey and no impacts to known or suspected archaeological or historical resources are expected as a result of the project. Contact with the Native American Heritage Commission was made to ensure that local tribal representatives had the opportunity to comment on the potential project impacts. One representative (Ms. Katherine Perez) expressed concern regarding potential resources in the region but was not aware of any specific locations within or immediately adjacent to the project area. Mr. Chavez coordinated with Ms. Perez to ensure her concerns were noted and addressed within the analysis. PAGE 11 There is a possibility that previously unknown historic or prehistoric resources could be discovered during grading and excavation work associated with the intersection improvements. Contract specifications will include the following language: "in accordance with CEQA. Subsection 15064.5(f), should any previously unknown historic or prehistoric resources, including but not limited to charcoal, obsidian or chert flakes, grinding bawls, shell fragments, bone, pockets of dark, friable soils, glass, metal, ceramics, wood or similar debris,be discovered during grading, trenching or other on-site excavations), earthwork within 100 feet of these materials shall be stopped until a professional archaeologist certified by the Registry of Professional Archaeologists (RPA)has had an opportunity to evaluate the significance of the find and suggest appropriate rnitigation(s), as determined necessary" Implementation of these best management practices will 'limit the potential archaeological resource impacts associated with construction to a level of less than significant. Potentially Signif ican, Potentially Unless Less Than Significant Mitigation Significant No fact Tncoroorated nact act CJI. 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. 2. Strang seismic ground.shaking? X 3. Seismic-related ground failure, including X liquefaction? 4. Landslides? _ . X - b. Result in substantial sail erosion or the loss X of topsoil? 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? d. Be located on expansive soil, as defined in X Table 18-1-B of the Uniform,wilding Code (1994), creating substantial risks to life or property? PACE 12 Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No kmRac bl;gmpmted Impact Inipact 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? SU MARY% Less Than Significant Impact. The terrain surrounding the project site consists of low and gently sloping hills. According to the Soil Survey of Contra Costa County(Soil Conservation Service, 1977), soils found in the area include Linne Clay Loam (5-15% slope), Rincon Clay Loam (2-9%) and Clear Lake Clay. These soils tend to have relatively low potential for erosion and are typically used for dryland grain production and rangeland. The Vaqueros, Kellogg, and Brentwood Faults are located in the vicinity of the project area (roughly 3, 4, and 4.5 miles from the project site, respectively). The faults are inferred active based on a number of scattered small magnitude earthquakes near the trace of the fault. However, activities associated with the project, including grading, will not result in an increase of exposure to geologic hazards,nor will they result in unstable earth conditions or changes to the ,geologic substructure. All roadway facilities including the potential retaining wall will be designed and constructed to account for site-specific soils conditions and potential geologic hazards. Slope stability will not present a substantial hazard along the route. All necessary cut and fill slopes will be designed to specific soil conditions defined during project design. The majority of ,the cut activities necessary for the improvements will occur on roughly level grade in areas that will be cut and recopacted in order to create an adequate roadbed. In the area of the majority of the cut (i.e... the eastern side of the south leg of Vasco Road), slope cuts and/or the retaining.wall necessary will be designed and constructed to accommodate soils and geologic conditions present at the site. Approximately 2000 cubic yards of material will require removal from this location. Grading of the improvements will result in a minor change in topography and will temporarily increase the exposure of soils to wind erosion. Adherence to standard dust and erosion control practices, including, but not limited to, general watering of exposed areas and/or use of chemical stabilizers, covering storage piles and any necessary haul trucks, and suspending excavation activities during periods of high winds will minimize dust and erasion impacts. All areas left exposed along the project will be seeded with a mix including native grasses and wildflowers upon completion of the project in order to stabilize exposed soil. These best management practiceswill be incorporated into the construction specifications. Superficial grading of the project area is not expected to result in unstable earth conditions or change geologic substructures. PAGE 13 Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No Irnryact Inco orated impact Impact `VIII. HAZARDS ANT 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? 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? C. Emit hazardous emissions or handle X hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? 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? 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. f. For a project within the vicinity of a private X airstrip, would the project result in a safety hazard for people residing or working in the project area? g. Impair implementation of or physically X _ interfere with an adapted emergency response plan or emergency evacuation plan? 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? SUMMARY.- Less Than Significant Impact. The potential for a release of hazardous substances (e.g., accidental petroleum spills) exists at the project site during construction. Contract specifications will require that standard safety practices and standard best management practices PAGE 14 be followed during construction to ensure no accidental release of hazardous substances and no increase in the potential for exposure to these substances. The County Resource Mapping System does not identify any facilities in the vicinity of the project with the potential for contamination of toxic materials or hazardous waste. Contract specifications will require the contractor to contact Underground Service Alert (USA)prior to conducting any work that could potentially impact utilities. The intersection improvement project has the potential for interfering with an emergency response due to construction activities. However, in order to ensure that potential impacts are minimized, the general public will be notified prior to the onset of construction via signage regarding construction schedule, construction detours, and associated work hours. In addition, local law enforcement will be notified of the initiation of project construction. During construction, lanes will be narrowed and shoulders may be utilized for through traffic to accommodate the construction activities, however, no lane closures will be necessary; therefore, emergency vehicle access will be maintained at all times. The project site is located more than one-quarter mile from the nearest school and is not within two miles of any public airport or any private airstrip (Byron Airport is located nearby but outside the two-mile radius). Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No k.ulact Incorporated act Impact VIII. HYDROLOGY AND WATER QUALITY - Would the project: a. Violate any water quality standards or X waste discharge requirements? 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)? 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? 'AGE 15 Potentially Significant Potentially Unless Less Tan Significant Mitigation Significant No kmLaot inggr2orated hip—act ;rM.D.2Ct 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? 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? f. Otherwise substantially degrade water X quality? 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? h. Place within a 100-year flood hazard area X structures which would impede or redirect flood flows? 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? j. Inundation by seiche, tsunami, or udflow? X SUMMARY: Less Than Significant Impact. During project-related construction, the potential exists for spills of gasoline,oil or other pollutants that may have a significant impact on water quality. Standard safety practices and best management practices will be followed in order to reduce the possibility of spills and minimize the potential for water quality impacts to a level that is less than significant. Construction activities at the project site may temporarily increase the potential for erosion of newly exposed sediments. Runoff and discharges from construction areas could potentially be transported into nearby storm drains. These potential temporary impacts will be addressed through the implementation of best management practices and erosion control measures required by contract specifications. The intersection improvements will 'increase the impervious surface within the construction area slightly; however, this increase in impervious surface area is negligible based on the limited amount of developed area in the vicinity of the project and will not substantially increase the rate and amount of runoff. In order to comply with the State Water Resources Control Board PAGE 16 National Pollutant Discharge Elimination System (NPDES) General Construction Perriit requirements, a Stormwater Pollution Prevention Plan (SWPPP) will be prepared and implemented for the project site-to ensure erosion and sediment control is adequately addressed. Roadway drainage facilities associated with the improvements will tie into existing drainage utilized for the roadway. According to the FEMA Flood Insurance Rate Map the project is located within Zone C which is defined as an area of minimal flooding. Project construction will not affect this designation and will not modify the .flooding potential in the area. Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No im nct 'ncocvorated SmDaCY ^t aqt IX LAND USE AND PLANNNG-Would the project; a. Physically divide an established community? X 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? C. Conflict with any applicable habitat X conservation plan or natural community conservation plan? SUMMARY: Less Than Significant Impact. The County General Plan defines the project as located within a land use area including agriculture, open space and other non-urban uses. Land uses surrounding the project site include a sand mining facility and rangeland for livestock grazing. These land use characteristics will not change as a result of the proposed intersection improvements. Camino Diablo and Vasco Road are existing roadways; therefore improvements to these roadways will not physically divide an established community. The County General Plan defines Camino Diablo as an existing arterial roadway and Vasco Road as an existing expressway. The project is consistent with the County General Plan Transportation and Circulation Element Roadway and Transit Goal#5-A (to provide a safe, efficient and balanced transportation system), and Policy 95-9 (Existing circulation facilities shall be improved and maintained by eliminating structural and geometric design deficiencies). Intersection improvements will correct a design deficiency at the immediate intersection, . allowing vehicles that currently cause gridlock as a result of their attempts to make left and right turns to make these turns without backing up the through-traffic queued behind them. The project is not intended to, nor is it expected to,increase the number of cars utilizing either Vasco Road PAGE 17 or Camino Diablo since roadway capacity will not be increased beyond the immediate intersection area. Therefore, land use will not be impacted by roadway improvements. Right of way may need to be purchased along the east side of the south leg of Vasco Road to accommodate grading required by the road widening. Alternately, a retaining wall may be constructed at the same location to accommodate roadway widening. Purchase of right of way will occur immediately adj a.cent to the existing roadway and will not lead to a modification in the land use in the area surrounding the project. Potentially Significant Potentially Unless Less Than Significant Mitigation Significant NO act bac DW-0rTat@L� Ixntract Ir gacS 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? b. Result in the lass of availability of a locally- — _ m X important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan? SUMMAR ': Less Than.Significant Impact. Construction of the improvements will require the use of paving materials (i.e., asphalt),wood products, concrete and other materials derived from natural resources. The use of these materials for construction of these structures will not significantly impact these resources. The use of oil and gasoline to operate machinery for construction purposes is negligible and of a short-term,temporary nature. In order to minimize impacts due to construction activities, contract specification will stipulate the elimination of unnecessary idling of equipment when not in use. The intersection is located near an area of domengine sandstone. According to the County General Plan, this mineral resource is a valuable commodity for the continued economic vitality of Contra Costa County, as it is the sole deposit of this material in the State of California and it is an important national resource. Domengine sandstone is used by PG&E as trench backfill and is a primary ingredient in the manufacture of heat-resistant glass used in the national space program. The General Plan calls for the protection of the entire sandstone resource area. The majority of project construction will occur in the existing County road right of way. However, some property acquisition will be necessary in order to construct the improvements on the east side of Vasco Road. This right of way acquisition will occur immediately adjacent to the road right of way on the east side of the south leg of Vasco Road on property that is not used for sand mining and is not owned by the t.lnimin Saeid Mining Company; therefore, no impact to the sandstone resource is expected as a result of the project. PAGE 18 Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No Lnpact lriq=orated Lmoactact XI. NOISE - Would the project result in: a. Exposure of persons to or generation of _ — X — noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? b. Exposure of persons to or generation of X — excessive ground borne vibration or ground borne noise levels? C. A substantial permanent increase in X — ambient noise levels in the project vicinity above levels existing without the project? d. A substantial temporary or periodic increase X in ambient noise levels in the project vicinity above levels existing without the project? e. For a project located within an airport land � o 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? 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? SUMMARY: Less Than Significant Impact. The dominant source of noise in the project area is. vehicles already using the existing roadways. Since the project will not add additional vehicles to the roadways, the noise level following construction is expected to remain the same as current conditions. Construction associated with the project will increase the noise levels in the area temporarily. However, based on the lack of sensitive receptors in the area, the project is not expected to result in significant noise impacts during construction. Nevertheless, contract specifications will require the use of properly tuned and muffled equipment to minimize noise due to construction. PAGE 19 Potentially Significant Potentially unless Less Than Significant Mitigation Sign ficant No Impact 1ncolt red =act IMMOt XE. POPULATION AND HOUSING- Mould 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)? b. Displace substantial numbers of existing X housing, necessitating the construction of replacement housing elsewhere? C. Misplace substantial numbers of people, X necessitating the construction of replacement housing elsewhere? SUMNIA,RY: Less Than Significant Impact. The purpose of the proposed intersection improvement is to allow an existing intersection to function as was intended when originally designed. Although the roadway will be widened in the very localized intersection area,the number of lanes on Camino Diablo and Vasco Road leading to the intersection will not change. The intersection improvements are not expected to add to either the available capacity of the roadway or the vehicle trips generated on Vasco Road or Camino Diablo Road. Therefore the project is not expected to induce population growth. XM. PUBLIC SERVICES 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: 1. Fire Protection? X 2. Police Protection? X _ 3. Schools? X a Parks? ..�. �.. ._..._ X S. Other Public facilities? X PAGE 20 SUMMARY: Less Than Significant Impact. Although minor traffic impacts typical of a construction project can be expected as a result of the project, these impacts are not expected to be significant since the majority of the work will occur on the roadway shoulders and no lane closures are expected to be necessary. The general public will be notified prior to the onset of construction via signage along Camino Diablo and Vasco Road in order to minimize inconvenience due to construction. In addition, in order to minimize potential delays in emergency response during construction activity at the project site, emergency services providers and local law enforcement agencies will be notified prior to initiation of construction. The completed roadway improvements are expected to improve emergency vehicle access to the intersection area as well as destinations that utilize the intersection for access. Completion of the project is not expected to impact educational facilities, public services, emergency fire or medical services, water or waste water systems or supply, or recreational or community services or facilities. Bath Vasco Road and Camino Diablo are currently maintained by the County, and routine maintenance of roadway improvements will continue to be performed by the County. Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No Impact Incorporated €mpact Impact 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? b. Does the project include recreational __ X facilities or require the construction or expansion of recreational facilities which aright have an adverse physical effect on the environment? SUMMARY: Less Than Significant Impact. Surrounding land uses consist of livestock grazing and sand mining facilities. The County Resource Mapping System and the field reviews did not identify any public recreational opportunities in the project area. Although there is use of both Camino :Diablo and Vasco Road by bicyclists, the temporary reduction in accessibility as a result of the project will be balanced by a long-term improvement to the facility. PAGE 21 Potentially Significant Potentially Unless Lass Than Significant Mitigation Significant No fact Inco ori rated kug6it h=Ct XV. TRANSPORTATIONITRAFFIC i 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)? b. Exceed, either individually or cumulatively, X a level of service standard established by the county congestion management agency for designated roads or highways? 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? 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)? e. Result in inadequate emergency access? X _ f: Result in inadequate parking capacity? X g. Conflict with adopted policies,plans, or X programs supporting alternative transportation (e.g., bus turnouts,bicycle racks)? SUNEVLk .'Y: Less Than Significant Impact. The County General Plan defines Camino Diablo as an Existing Arterial roadway and Masco Road as an Expressway. The intersection improvements are intended to correct design deficiencies associated with an existing intersection. As originally designed, the intersection was expected to allow for free flow of traffic. However, based on the unexpected amount of queuing as a result of vehicles attempting to make left or right turns, the intersection is not currently functioning as originally intended. The proposed improvements are expected to modify the intersection such that it will function appropriately. The project is consistent with the County General Plan Transportation and Circulation Element Roadway and Transit Goal#5-A (to provide a safe, efficient and balanced transportation system) and Policy#5-9 (Existing circulation facilities shall be improved and maintained by eliminating structural and geometric design deficiencies). PAGE 22 Impacts to traffic due to construction of the improvements are expected to be less than significant. Although traffic through the area will be somewhat slowed by typical construction activity and narrowed lanes in the construction zone, the work will occur primarily in the shoulder areas of both roadways and no lane closures will be necessary, therefore construction work is not expected to significantly impede normal flow of traffic. The number of lanes available during construction will remain consistent with the number of lanes currently available to traffic. In order to allow for construction work necessary, lanes will be narrowed and roadway shoulders may be utilized for through traffic. Approximately 2000 cubic yards of material will require removal on the east side of the southern leg of Vasco Road. In order to remove the material, approximately five truck trips per hour over approximately five days are expected to be necessary. In order to minimize any potential impact due to tracks entering and leaving the project site, excavation necessary on all legs of Vasco Road and Camino Diablo will be timed to occur during non-peak hours. used on the relatively brief nature of the off-haul and the timing to avoid peak hours, impacts associated with truck traffic for the excavation are expected to remainat a level that is less than significant. Although unlikely, some construction work may be conducted at night. No road closures are expected to be necessary to complete the project. In order to minimize potential delays in emergency response during construction activity at the project site emergency services providers and local law enforcement agencies will be notified prier to construction. The project would not result in any change in air traffic patterns, and would improve roadway design by allowing through traffic to move through the intersection without getting backed up by vehicles attempting to turn left or right. Once constructed, the project would enhance the ability of emergency vehicles to access areas serviced by both roadways. Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No tmvact Dwomorated lrnuaarrt lawag :?BVI. UTILITIES AND SERVICE SYSTEMS Would the project: a. Exceed wastewater treatment requirements X of the applicable Regional Water Quality Control Board? 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? 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? MAGE 23 Potentially Significant Potentially Unless Less Than Significant Mitigation Significant No n ct I corpoMAd IMACt kn,_2 t d. Have sufficient water supplies available to i _ X serve the project from existing entitlement and resources, or are new or expanded entitlement needed? 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? f Be served by a landfill with sufficient X permitted capacity to accommodate the project's solid waste disposal needs? g. Comply with federal, state and local statutes _ _ X and regulations relates'to solid waste? TJ Y: The project will result in the relocation of some of the existing signal light poles. County staff will coordinate any necessary utility relocation activities with the appropriate utility agencies. The project will not result in a wasteful or inefficient use of energy for construction. XVII. MANDATORY FUNDINGS OF SIGNIFICANCE - 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? PAGE 24 Potentially Significant Potentially unless Less Than Significant Mitigation Significant No !Lijact TIji , mate Fmtract Smtact b. Does the project have impacts that are individually- X _ 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: The project does not have the potential to impact the quality of the environment, substantially reduce the habitat of a fish or 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 maj or periods of California history or prehistory;nor will the project have cumulative, direct or indirect effects that could cause substantial adverse effects on human beings. Intersection improvements will correct a design deficiency at the immediate intersection and will not modify the existing level of use of either roadway. PAGE 25 C o m m u n j tyDennis M. 9arM AMP Col itra Community Development Directo, Development C7r - Departmentn , a County Administration Building 651 Pine Street 4th Floor,North Wing .5y !'" 2003_ Martinez,California 94553-0095 4 a - .><. WEIR, COUNTY CLERK Phone: �� T -111 T, EPUTY, NOTICE OF PUBLIC.REVIEW AND INTENT TO ADOPT A PROPOSED NEGATIVE DECLARATION County File # CP 03-17 Pursuant to the State of.California. Public resources Code and the "Guidelines for implementation of the California Envirlonmen.tal Quality Act of 1970" as mended to, date, this is to.advise you thatthe Community Development be, of Contra Costa County has prepared an initial study on the following project: Vasco Road and Camino Diablo Intersection improvements Proiect, CP#• 03-17 The project consists of improvements to the Camino.Diablo and Vasco Road intersection to allow for improved efficiency and reduced congestion. Impiovements will consist of: 1) on the north leg: widening the west side of Vasco Road by approximately 12 feet for an approximate distance of 600 feet and installing a standard lane addition taper to allow for a southbound through lane, 2) on the south leg: widening the west and east side of Vasco Read by approximately 12 feet for an approximately distance of 6007 feet and installing a standard lane addition taper on the east side for an additional northbound through lane and a standard lane drop taper on the west side for additional southbound through lane, 3) on the.east leg: re-striping of the existing lane configuration to provide a protected left-tu m..pocket and a single lane in each direction as well as'minor widening of approximately 4 feet on the north side of Camino Diablo for an approximate distance of 115 feet, and 4) on the west leg: re-striping the existi ig,lane configuration to'provide a protected left-turn lane and single lane in each direction as well as minor-widening of approximately 4 feet on the north and south side of Camino Diablo for an approximate distance of 770 feet north and 760 feet south. Signal poles will be relocated and/or replaced to accommodate the new lane configuration. .In order to accomplish the improvements, some cut and fill will be required on some of the roadway shoulders. The most substantial area of cut will occur along the southern leg of Vasco Road on the east side of the roadway. The project may include.installation of a retaining wall varying from 3' to 8'tall at this. location; however, grading the existing slope. back rather.than installing a retaining waIUs.likelyAo.be-the:chosen.construction meth od;:vRoadway-rainage:facilities .:. . associated with the improvements will tie into existing drainage utilized for the roadway, and the existing concrete v-ditch along the southeastern side of Vasco Road willbe re-established. Durinc construction, lanes will be narrowed and shoulders maybe utilized for through traffic in order to V accommodate the necessary construction activities while still allowing for efficient traffic flow. No lane closures will be necessary. Although unlikely, some nighttime work maybe conducted in order to minimize traffic impacts as a result of construction activities. Right of way acquisition may be necessary in order to accommodate the cut slopes and/or the retaining wall. Additional real property transactions may be necessary. Project location: The project is located at the intersection of Vasco Road and Camino Diablo in the eastern Contra Costa County area near the Town of Byron. , n anY si�nifcnt impacts proposed project will notresuifi . A copy of the negative declaration and all documents referenced in the negative declaration may be reviewed :in the ofces.of.the Public Works Department,.255 Glacier Drive. Martinez, during normal business hours. .Public Comment Period The period for accepting comments on the adequacy of the environmental document axtends to June 9, 2003. Any comments .should be in writing and submitted to the following address: .Leigh Chavez, Planner 111 Contra Costa County Public Works Department 255 Glacier Drive .Martinez, Cts 94553 The. environmental document is expected to gra before. the County Board of Supervisors on or .around June 17, 2003. To confirm the Board date, please contact Leigh Chavez at (925) 313- 2356. Any questions regarding the project itself, should be directed to: Monish Sen at {925) 313-2187 Contra Costa.County Public Works Department 255 Glacier Drive Nairtinez, CA 04553 G:\Grp[dat2\Engsvc\Enviro\2002Pojects\Vasco-CamincOiabloWatice of Public Review Vases C : county Clark's Office Public Works--L.Chavez,Engineering Services CEWED STATE OI±CALIFQfiT33A—BUS NESS TRMSPORT'ATION AND HOUSING AG--NCY JUN 3 2anj G } Y DAMS :apy mor DEPARTMENT OF TRANSPORTATION t P. 0. BOX 23660V IRONMENTA�, OAKLAND, CA 94625-0660 �""`� - (510) 286-4444 Flex your power! (510) 286-4454 TDD Be energy e uient! May 29, 2003 CCO04713 SCH2003052016 Ms. Leigh Chavez, Planner III Contra. Casts, County Public Warks Department 255 Glacier Drive Martinez, CA 94553 Dear Ms. Chavez_ Vasco Road and Camino Diablo Intersection Improvements Project — Initial Study and Negative Declaration Thank you for including the California Department of Transportation in the environmental review process for the proposed project. We have examined the Initial Study and Negative Declaration and are satisfied that the project will not have a significant 'impact to State transportation facilities. Should you have any questions regarding this letter, please call Lisa Carboni of my staff at (5 10) 622-5491. Sincerely, T'4'� TL\40THY C. SABLE District Branch Chief p IGR/CEQA c: Philip Crimmins (State Clearinghouse) 'Caltrans improves mbility across California' RECD J U N - 9 2003 Leigh Chavez , Planner 111 Contra Costa County Public Works Dept. 255 Glacier Drive Martinez, Ca 94553. Richard F. (Dick) Ward 3884 N. Vasco Road Livermore Area , Ca 94551 6/5/O5 925-443-4598 Ms, Chavez Per my short telephone discussion with you on 6/4/03 , I am submitting this letter as a commentary on the proposed Project to Improve the Camino Diablo Intersection with N.Vasco Road. This intersection is located approximately 10 miles north of my home on N.Vasco Road in the unincorporated area of Alameda north of the City of Livermore. My concerns with this project are the effect it will have on the volume of traffic using N.Vasco Road in the Southbound direction especially during the weekday morning commute. Currently , southbound traffic during the morning commute period is very heavy in front of my home typically from 5-9 am weekdays. The traffic usually flows in groups with short breaks between the groups. Some of the groups take 5-10 minutes to cross in front of my property. Breaks between groups are generally short , perhaps 15 —30 seconds. This results in extremely long waiting periods to either exit or enter my property during these commute hours. It is my opinion that the improvement planned for the Camino Diablo intersection will have the effect of creating even longer groups of vehicles crossing in front of my property perhaps making it practically impossible to Safely enter or exit during the morning commute. The project will add a second southbound lane at the intersection which will allow double the number of vehicles to cross the intersection during each cycle of the traffic signal. This will double the density of traffic flowing on Vasco Road southbound hence increasing the lengths of the groups passing my property. It is even possible that the traffic line could become continuous and this would be an unacceptable condition. It is understood that traffic conditions are currently difficult at this intersection. However , it does not appear that shifting the problem further south on Vasco Road is an adequate solution to the problem. The rural residents of Vasco Road have rights as well as the drivers who use the road. It is unfair to us as residents to continue to raise the traffic volume using the road without solving the problems created for the residents. N. Vasco Road is not a freeway and was never intended to be. t r It is noted here for reference the project proposed to straighten approximately l.0 miles of Vasco Road from the Alameda J Contra Costa County Line south will not help my situation in regards to the Camino Diablo Project. The Alameda County Project ends approximately 304 yards North of my property. This project will serve only to increase roadway speeds in front of my property creating even more safety problems. It is requested that the environmental document not be certified and the project placed on indefinite hold. It should not be considered except as part of a regional solution for the Vasco Corridor problem. We as residents of N. Vasco Road do not want to end up as traffic statistics. Richard 1~', W Mrd adeliene E. Ward Other Vasco Road residents: i A, Contra Public Works DepartmentMaurice siDi Public Works Director Costa 255 Glacier Drive R.ditch Avalon Martinez,CA 94553-4825 Deputy Director County Telephone: (925)313-2000 Julia R.Bueren FAX: (925)313-2333 Deputy Director Web site:www.co.contra-costa.ca.us/depart/pw June Patricia R.McNamee ' Deputy Director Richard Ward 3884 N. Vasco Road Livermore, CA 94551 RE: Vasco Road/Camino Diablo Intersection Dear Mr. Ward: Thank you for your letter regarding the Vasco Road/Camino Diablo Intersection Improvements project (CP ##03-17). The following response to your comments is being provided pursuant to Section 21091 of the Public Resources Code and Section 15088 of Title 14 of the California Code of Regulations. We understand you have concerns regarding the impact the project will have on your ability to enter and exit your property located at 3884 N. Vasco Road in Alameda County, however we believe sufficient analysis has been conducted to conclude the proposed intersection improvements will not affect your access. We hope the fallowing addresses your concerns regarding the issues raised in your letter. Your first concern is the effect the project will have on traffic volumes using Vasco Road. You indicate the project improvements will increase the volume of traffic on Vasco Road. However, the volume of traffic using Vasco Road will not change as a result of completion of the project. The project is designed to improve the efficiency of existing traffic moving through the localized intersection of Vasco Road and Camino Diablo. The intersection improvements will correct a design deficiency at the immediate intersection, allowing vehicles that currently cause gridlock as a result of their attempts to make left and right turns to negotiate these turns without backing up the through- traffic queued behind them. The project is not intended to, nor is it expected to, increase the number of vehicles utilizing the two roadways since roadway capacity will not be increased beyond the localized intersection area. The number of lanes on Camino Diablo and Vasco Road leading to the intersection will be unaffected by the intersection improvements and the same number of vehicles will use the two roadways, they simply will not have to wait as long at the Vasco Road/Camino Diablo signal. In short, the project will not increase the number of vehicles using Vasco Road; rather it will increase the speed at which existing vehicles move through the Vasco Road/Camino Diablo intersection. Your second concern is the effect the additional lanes at the intersection will have on your ability to enter and exit your driveway on Vasco Road about 10 miles south of the subject improvements due to an increased number of vehicles. You indicated that by adding the lanes at the intersection, twice as many vehicles will be allowed through on a green light thereby increasing your waiting time to enter Vasco Road from your driveway as a result of longer groupings of vehicles. Richard Ward June 26, 2003 Page 2 While we agree that there will be an increase in vehicles through each green light at the intersection, the improvements will not add more vehicles to the roadway. Based on literature research (Highway Capacity Manual, Special Report 209, Third Edition; Signalized Intersection Spacing, Oregon Department of Transportation, 9996), in-house expert opinion, and the professional opinion of a traffic engineering consultant (Fehr and Peers), we believe the effect of groupings of vehicles (known as platooning) dissipates within one-half to one-mile of an intersection as a result of varying driver characteristics and road conditions. Because your property is located 10 to 12 miles south of the intersection, the grouping effect caused by the signal will be negligible. We do agree that grouping of vehicles occurs on Vasco Road in the vicinity of your residence; however, we believe the grouping of vehicles is the result of a number of factors including driver behavior, road geometrics, vehicle mix, and weather conditions rather than the signal located several miles north of your property. Vasco Road provides one lane in each direction with truck climbing lanes. Gaps in traffic flow for this facility type are formed by the variance of individual vehicle speeds. Vehicles moving at higher speeds overtake slower moving traffic and are then required to follow the slower vehicle (resulting in groupings of vehicles). The distance between groupings of vehicles represents the gaps in traffic flow that you experience as you attempt to exit your driveway. Although we understand your frustration with the existing conditions along Vasco Road, we believe the intersection improvement project will not change these existing conditions since they are the result of varying driver characteristics and road conditions rather than platooning due to signal facilities along Vasco Road. The project will simply serve to improve the operation of Vasco Road at the intersection by limiting the amount of time vehicles are queued at the signal light. We are of the opinion the existing CEQA documentation adequately addresses concerns related to vehicle volume increases on Camino Diablo and Vasco Road. We hope our response further clarifies the issues associated with your concerns. For your information, the environmental document will go before the Contra Costa County Board of Supervisors for consideration on July 8, 2003. If you have any additional questions, please contact me at (925) 313-2225. Very truly yours, � t Stephen Kowalewski Assistant Public Works Director Transportation Engineering GAGrpDatal7ranaEnplProiectalVasm Rd-Camino Diablo Intersection irtVrovemantsXCEOA Response Letter.doc C-1 M.Shiu,Director J.Sueren,Deputy H.Ballenger,Engineering Services D.Dennis,SR4 Bypass Authority N.Wain,Transportation Engineering L.Chavez,Environmental Resident,9850 N.Vasco Road Resident,2757 N.Vasco Road Resident,3350 N.Vasco Road