GARDEN BAR ROAD RAILCAR BRIDGE REPLACEMENT PROJECTdokkenbridges.com/nevada-county/envdoc/Railcar_2106_Draft_ISMND... · garden bar road railcar bridge replacement project nevada county

GARDEN BAR ROAD RAILCAR BRIDGE REPLACEMENT PROJECT

Nevada County

Bridge No. 17C-0068

INITIAL STUDY WITH PROPOSED MITIGATED NEGATIVE DECLARATION

Prepared by the: Nevada County Department of Public Works

December 2015

Garden Bar Road Railcar Bridge Replacement Project 4 of 53 November 2015

To: Nevada County Council CA Dept. of Fish & Wildlife Nevada County Transit Services Central Valley Water Quality Control Board Nevada County Transportation Commission Northern Sierra Air Quality Mgt. Dist. Nevada County Consolidated Fire District Native American Heritage Comm. Nevada County Clerk California State Clearinghouse Nevada Irrigation District* United Auburn Indian Community Ed Scofield District 2 Supervisor Sacramento District, U.S. Army Corps of Rural Quality Coalition

* Note: NOA and site plan only Date: December 7, 2015 Prepared by: David A. Garcia, Jr., Transportation Planner Nevada County Public Works

950 Maidu Avenue, Suite 170 Nevada City, CA 95959 (530) 265-7038 Email: [email protected]

Project Location: Garden Bar Road, 2 miles north of Bear River Project Description The Nevada County Department of Public Works, in cooperation with the California Department of Transportation (Caltrans), is proposing to replace the one lane Garden Bar Road Railcar Bridge (Bridge # 17C-0068) over the Little Wolf Creek with a one lane concrete slab bridge in Nevada County, California. The Garden Bar Road Railcar Bridge, which carries Garden Bar Road across Little Wolf Creek, approximately one mile west of Rosemary Lane, serves three properties in Nevada County (Figure 1 Project Vicinity and Figure 2 Project Location). As this bridge only serves three properties, the average daily traffic (ADT) is 60, which is considered very low by The American Associated of State Highway and Transportation Officials (AASHTO) Design Standards (AASHTO 2001).

The proposed bridge widening will replace the existing structure with a single span, 49 foot long by 15.5-foot wide, cast-in-place pre-stressed concrete slab bridge (Figure 3: Project Features). The bridge will accommodate one 12-foot lane, due to the very low ADT, and two 1.5-foot shoulders. Bridge railings will be mounted on the edge of deck. The bridge will be supported by two spread footing abutments.

Construction will include approximately 100 feet of roadway south of the bridge, and 250 feet of roadway north of the bridge. The roadway will be maintained at one travel lane (approximately 15.5 feet wide). A pull-out will be provided on the northwest side of the bridge. During construction, a temporary crossing will be created upstream of the existing alignment. This crossing will either consist of fill, with the creek being diverted through temporary culverts, or re-using the existing superstructure placed on temporary abutments and approach fill. Selection of either method will be at the option of the contractor.

All roadway and structure improvements fall within private right-of-way. It is anticipated that the project will require right-of-way to be acquired for the proposed bridge replacement.

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Auburn State Recreation AreaAuburn State Recreation Area

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Gold Bug ParkGold Bug Park

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Old Sacramento State Historic ParkOld Sacramento State Historic Park

Kings Beach State Recreation AreaKings Beach State Recreation Area

Tahoe State Recreation AreaTahoe State Recreation Area

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FIGURE 1Project Vicinity

Garden Bar Road Railcar Bridge Replacement ProjectNevada County, California

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FIGURE 2Project Location


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FIGURE 3Project Features


ProjectAreaProposed Bridge ReplacementPavement EdgesTemporary CrossingPotential Staging AreaParcels


Project Background The Garden Bar Road Railcar Bridge, constructed in 1950, spans the Little Wolf Creek in a north-south direction with the river flowing in an east to west direction. Garden Bar Road has one travel lane (11.8 feet wide). The existing bridge is a single-span, steel “railcar” structure with concrete abutments. The main span and total bridge length is 38 feet long.

Caltrans maintenance inspection records show that the bridge is structurally deficient due to its sub-standard width, deck condition, and deteriorating timber railing. In response, Nevada County Department of Public Works proposes to replace the bridge and secure a combination of local and Highway Bridge Program funds for preliminary engineering, environmental, right of way acquisition, construction, and construction engineering.

The purpose of the Garden Bar Road Railcar Bridge Replacement Project is to replace a structurally deficient and functionally obsolete bridge by replacing the bridge with a structure that can withstand modern traffic loading demands.

The bridge is in need of replacement as it has been determined to be structurally deficient due to inadequate deck capacity. In addition to the capacity deficiency, replacement is necessary as the bridge has been determined by Caltrans Structures Maintenance to be functionally obsolete due to the non-standard width and failing railing.

Other Permits Which May Be Necessary: Based on initial comments received, the following permits may be required from the designated agencies:

1. Section 401 Encroachment Permit – Central Valley Flood Protection Board 2. Section 404 Permit – US Army Corps of Engineers 3. Streambed Alteration Agreement – California Department of Fish and Wildlife 4. Dust control and operations permits - Northern Sierra Air Quality Management District

Environmental Factors Potentially Affected: All of the following environmental factors have been considered. Those environmental factors checked below would be potentially affected by this project, involving at least one impact that is "Less Than Significant with Mitigation" as indicated by the checklist on the following pages.

1. Aesthetics 2. Agriculture/ Forestry Resources

3. Air Quality

4. Biological Resources 5. Cultural Resources 6. Geology/ Soils

7. Greenhouse Gas Emissions

8. Hazards/ Hazardous Materials

9. Hydrology/ Water Quality

10. Land Use/ Planning 11. Mineral Resources 12. Noise

13. Population/ Housing 14. Public Service 15. Recreation

16. Transportation/ Circulation

17. Utilities/ Service Systems 18. Mandatory Findings of Significance


SUMMARY OF IMPACTS and PROPOSED MITIGATION MEASURES

3. AIR QUALITY: To offset the potential air quality impacts associated with the project construction and operational activities, the following avoidance and minimization measures will be implemented:

Measure 3A: Implement dust control measures. To reduce short-term construction impacts, permits will follow standards to the satisfaction of the Northern Sierra Air Quality Management District (NSAQMD) and the following standard measures will be implemented for dust control during construction, which will be noted on the construction plans:

AQ-1: Obtain appropriate permits from the NSAQMD for portable equipment.

AQ-2: The applicant will implement all dust control measures in a timely manner during all phases of project development and construction.

AQ-3: All material excavated, stockpiled or graded will be sufficiently watered, treated or covered to prevent fugitive dust from leaving the project boundaries and causing a public nuisance or a violation of an ambient air standard. Watering should occur at least twice daily, with complete site coverage.

AQ-4: All areas (including unpaved roads) within the project limits with vehicle traffic will be watered or have dust palliative applied as necessary for regular stabilization of dust emissions.

AQ-5: All land clearing, grading, earth moving, or excavation activities on the project will be suspended as necessary to prevent excessive windblown dust when winds are expected to exceed 20 mph.

AQ-6: All on-site vehicle traffic will be limited to a speed of 15 miles per hour (mph) on unpaved roads.

AQ-7: All inactive disturbed portions of the site will be covered, seeded or watered until a suitable cover is established. Alternatively, the applicant will be responsible for applying non-toxic soil stabilizers to all inactive construction areas.

AQ-8: All material transported off-site will be either sufficiently watered or securely covered to prevent public nuisance.

AQ-9: If serpentine or ultramafic rock is discovered during construction the Northern Sierra Air Quality Management District will be notified no later than the next business day and the California Code of Regulations, Title 17, Section 9315 applies.

Timing: During Construction Reporting: Nevada County Department of Public Works Measure 3B: Use alternative methods to open burning for vegetation disposal. The following measure will be implemented for air quality.

AQ-10: Open burning of site-cleared vegetation is prohibited.

Timing: During construction Reporting: Nevada County Department of Public Works 4. BIOLOGICAL RESOURCES: To offset the potential impacts to biological resources associated with the

project construction, the following avoidance and minimization measures will be implemented:

Measure 4A: Avoid impacts to sensitive biological habitats. This project will avoid impacts to sensitive biological habitats with the implementation of Environmentally Sensitive Area (ESA) fencing and Best


Management Practices (BMPs). The following measure will protect sensitive habitats during construction and noted on the construction plans for this project:

BIO-1: Prior to the start of construction activities, the project limits in proximity to jurisdictional waters (Little Wolf Creek) must be marked with high visibility ESA fencing or staking to ensure construction will not further encroach into waters. The project biologist throughout construction will periodically inspect the ESA to ensure sensitive locations remain undisturbed.

BIO-2: Contract specifications will include the following BMPs, where applicable, to reduce erosion during construction:

Existing vegetation will be protected in place where feasible to provide an effective form of erosion and sediment control;

Stabilizing materials will be applied to disturbed soil surfaces to prevent the movement of dust from exposed soil surfaces on construction sites as a result of wind, traffic, and grading activities.

Timing: Prior to construction Reporting: Nevada County Department of Public Works Measure 4B: Avoid impacts to aquatic wildlife. Construction activities associated with the proposed project may affect aquatic wildlife habitat. As a result, the project will implement the following measures into the project design to minimize and avoid potential effects to aquatic wildlife:

BIO-3: Erosion Control Measures must be implemented during construction. To minimize the mobilization of sediment into Little Wolf Creek, the following erosion-control and sediment-control measures will be included in the construction specifications, based on standard Caltrans measures and standard dust-reduction measures.

Soil exposure must be minimized through the use of temporary BMPs, groundcover, and stabilization measures;

The contractor must conduct periodic maintenance of erosion- and sediment-control measures.

BIO-4: Vegetation clearing will only occur within the delineated project boundaries. An ESA fence will be provided on the final plans to delineate which trees can be saved and which will be removed. Where possible, trees will be trimmed rather than removed fully with the guidance of a qualified biologist. In areas that will be subject to re-vegetation, plants will only be cleared where necessary and when feasible, will be cut above soil level.

BIO-5: If aquatic wildlife are found at any time during project work, construction will stop and the animal will be allowed to leave the project area unharmed. If a State or Federally listed species is discovered, the appropriate regulatory agency will be contacted immediately for further guidance.

BIO-6: Before any activities begin on the project, the project biologist will conduct environmental awareness training for all construction personnel. At a minimum, the training will include a description of sensitive species with potential to occur, their habitat, the project specific measures being implemented to conserve the species, and the boundaries within which the project may be accomplished.

BIO-7: Plastic mono-filament netting (erosion control matting) or similar material containing netting must not be used at the project area because the CRLF or other small animals may become entangled or trapped in it. Acceptable substitutes include coconut coir matting or tackified hydroseeding compounds.


BIO-8: A pre-construction clearance survey will be conducted by the project biologist to verify that no wildlife is located within the project area.

BIO-9: The County will not use herbicides to control invasive, exotic plants.

BIO-10: To allow subterranean wildlife enough time to escape initial clearing and grubbing activities, equipment used during initial clearing and grubbing will be operated at speeds no greater than three (3) miles per hour.

BIO-11: Narrow screened fencing (no greater than 3-inch) or impassible barriers will be installed where the project intersects riparian and wetland habitat to prevent western pond turtle and other wildlife access to the construction site.

Timing: Prior to construction Reporting: Nevada County Department of Public Works Measure 4C: Avoid impacts to California Black Rail. The project will avoid impacts to California black rail (Laterallus jamaicensis coturniculus) habitat through pre-construction surveys, and habitat restoration of temporarily disturbed habitats. The following measures will be implemented to protect California black rail.

BIO-12: If construction or restoration activities are necessary during the black rail breeding season (mid-March to early June), preconstruction surveys for California black rail will be conducted where suitable habitat for these species occurs within or adjacent to work areas. Surveys will be initiated between January 15 and February 1. A minimum of four surveys will be conducted evenly spaced prior to mid-April.

Should California black rail be identified within the project area during these surveys, the project biologist will coordinate with CDFW to determine appropriate avoidance and minimization measures to prevent project related impacts to the species.

Timing: Prior to and during construction Reporting: Nevada County Department of Public Works Measure 4D: Avoid impacts to the spread of invasive plant species. The following protective measures will be included in the construction plans to ensure that invasive species are not introduced or spread.

BIO-13: Prior to arrival at the project site and prior to leaving the project site, construction equipment that may contain invasive plants and/or seeds must be cleaned to reduce the spreading of noxious weeds.

Timing: Prior to and during construction Reporting: Nevada County Department of Public Works Measure 4E: Avoid impacts to nesting migratory birds and raptors. This project will avoid impacts to potential nesting migratory birds by coordinating work outside the breeding season (February15th-September 1st). The following avoidance and minimization measures will be incorporated to protect nesting birds and will be noted on the construction plans for this project.

BIO-14: If possible, vegetation removal should occur outside the breeding season (February 15th–September 1st) for all bird species.

BIO-15: If vegetation removal is to take place during the nesting season (February 15th –September 1st), a pre-construction nesting bird survey must be conducted within 7 days prior to vegetation removal. Within 2 weeks of the nesting bird survey, all vegetation cleared by the biologist will be removed by the contractor.


A minimum 100 foot no-disturbance buffer will be established around any active nest of migratory birds and a minimum 300 foot no-disturbance buffer will be established around any nesting raptor species. The contractor must immediately stop work in the nesting area until the appropriate buffer is established and is prohibited from conducting work that could disturb the birds (as determined by the project biologist and in coordination with wildlife agencies) in the buffer area until a qualified biologist determines the young have fledged. A reduced buffer can be established if determined appropriate by the project biologist and approved by CDFW.

Timing: Prior to and during construction Reporting: Nevada County Department of Public Works Measure 4F: Avoid impacts to local wildlife. To prevent harm to local wildlife, the project will implement the following measures.

BIO-16: The contractor must not apply rodenticide or herbicide within the project area during construction.

BIO-17: The contractor must dispose of all food-related trash in closed containers, and must remove it from the project area each day during construction. Construction personnel must not feed or attract wildlife to the project area.

Timing: During Construction Reporting: Nevada County Department of Public Works Measure 4G: Mitigation for Jurisdictional Waters. To minimize impacts to valley foothill riparian habitats, the following measure will be implemented.

BIO-18: The County will re-contour the temporary effects to pre-construction conditions and seed the area with a native seed mix. Exact mitigation ratios and locations will be determined during the environmental permitting phase of the project. No mitigation for the less than 0.01 acres of permanent impact is proposed.

Timing: Prior to issuance of the improvement plans Reporting: Nevada County Department of Public Works Measure 4H: Provide documentation of appropriate state and federal authorization for work within Little Wolf Creek.

BIO-19: Prior to issuance of improvement plans, the County will provide the appropriate authorization from California Department of Fish and Wildlife, the Central Valley Regional Water Control Board, and US Army Corps of Engineers for fill and disturbance of Little Wolf Creek. Permits that may apply include a Streambed Alteration Agreement from California Department of Fish and Wildlife, a Storm Water Pollution Prevention Plan from the Regional Water Quality Control Board, and a Section 404 permit from the US Army Corps of Engineers. If permits are not required from any of these agencies, the applicant will provide a written statement from the agencies to that effect. If permits are required, evidence of completion and approval of those permits will be submitted to the Planning Department prior to the issuance of improvement plans.

Timing: Prior to construction Reporting: Nevada County Department of Public Works


5. CULTURAL RESOURCES: To offset potentially adverse cultural or historical resources impacts associated with the proposed activities on site, the following mitigation measure will be required:

Measure 5A: Avoid impacts to sensitive cultural sites. Halt work and contact the appropriate agencies if cultural resources are discovered during project construction. To prevent cultural resource disturbance the following measures will be implemented.

CUL-1: All equipment operators and employees involved in any form of ground disturbance will be advised of the remote possibility of encountering subsurface cultural resources.

CUL-2: Section 5097.94 of the Public Resources Code and Section 7050.5 of the California Health and Safety Code protect Native American burials, skeletal remains and grave goods, regardless of age and provide method and means for the appropriate handling of such remains. If human remains are encountered, California Law requires that work should halt in that vicinity and the Nevada County Coroner should be notified immediately to assess the remains. If the coroner determines the human remains to be of Native American origin, the coroner must notify the Native American Heritage Commission (NAHC) within twenty-four hours of such identification. The NAHC shall then determine the Most Likely Descendant (MLD) of the human remains and contact the MLD immediately. The County, the MLD, and a professional archaeologist retained by the County shall then consult to determine the appropriate plans for treatment and assessment of the human remains and any associated grave goods.

CUL-3: If previously unidentified cultural materials are unearthed during construction, work shall be halted in that area until a qualified archaeologist can assess the significance of the find and develop a plan for documentation and removal of resources, if necessary. Additional archaeological survey will be needed if project limits are extended beyond the present survey limits.

Timing: During construction Reporting: Nevada County Department of Public Works 6. GEOLOGY/SOILS: To offset the potential for adverse soils or erosion impacts to result from project

grading and construction activities, the following measures will be required:

Measure 6A: Erosion and Sediment Control. Prior to issuance of permits or improvement plans for all project-related grading including road construction and drainage improvements, said permits or plans will incorporate, at a minimum, the following erosion and sediment control measures:

GEO-1: Contract specifications will include the following BMPs, where applicable, to reduce erosion during construction.

During construction, Best Management Practices (BMPs) for temporary erosion control will be implemented to control any pollutants that could potentially affect the quality of storm water discharges from the site.

Prior to commencement of site work, fiber rolls and silt fencing should be installed down slope of all proposed areas of disturbance to reduce migration of sediment from the site. Fiber rolls on slopes are intended to reduce sediment discharge from disturbed areas, reduce the velocity of water flow, and aid in the overall revegetation of slopes. The fiber rolls and silt fence should remain in place until construction activity is complete and vegetation becomes established;

All soil exposed in permanent slope faces should be hydroseeded or hand seeded/strawed with an appropriate seed mixture compatible with the soil and climate conditions of the site as recommended by the local Resource Conservation District, and;


Following seeding, jute netting or erosion control blankets should be placed and secured over the slopes steeper than 2:1, H.V.

Timing: During and post construction Reporting: Nevada County Department of Public Works 8. HAZARDS / HAZARDOUS MATERIALS. To offset the potential for impacts related to storage, use

and transport and hazardous materials, the following avoidance and minimization measures will be required:

Measure 8A: Properly dispose of treated wood waste (TWW) and other hazardous waste. The following measure has been incorporated into the project design to ensure that TWW generated by the project is properly disposed of.

HAZ-1: The chemically treated wood must be treated as TWW and disposed of as hazardous waste. Should additional timber used for construction of the bridge, i.e. buried creosote timber piles, be uncovered during bridge demolition and replacement, this timber would also be treated as TWW. For the TWW, the Department of Toxic Substances Control (DTSC) regulations §66261.9.5 provide alternative management standards (AMS) for TWW. Caltrans Special Standard Provision (SSP) for TWW, SSP 14-11.09, is based on DTSCs AMS regulations. This SSP directs the Contractor to follow the AMS including providing training to all personnel that may come in contact with TWW. This training must include, at a minimum, safe handling, sorting and segregating, storage, labeling (including date), and proper disposal methods.

HAZ-2: As is the case for any project that proposes excavation, the potential exists for unknown hazardous contamination to be revealed during project construction. For any previously unknown hazardous waste/ material encountered during construction, the procedures outlined in the Caltrans Unknown Hazard Procedures (as seen in Table 7-1.1 of the Caltrans 2014 Construction Manual) shall be followed (Caltrans 2014).

Timing: During construction Reporting: Nevada County Department of Public Works

9. HYDROLOGY/WATER QUALITY: To offset the potential for impacts related to alteration of drainage features and storm water quality from operational activities, the following measures will be required:

Measure 9A: Follow the established water quality plan. The proposed project has been designed to minimize all impacts to the maximum extent practicable through the use of BMPs and implementation of regulatory permit conditions. To ensure water quality the following measures will be followed:

WQ-1: BMPs will be incorporated into project design and project management to minimize impacts on the environment including the release of pollutants (oils, fuels, etc.):

The area of construction and disturbance would be limited to as small an area as feasible to reduce erosion and sedimentation.

Measures would be implemented during land-disturbing activities to reduce erosion and sedimentation. These measures may include mulches, soil binders and erosion control blankets, silt fencing, fiber rolls, temporary berms, sediment desilting basins, sediment traps, and check dams.

Existing vegetation would be protected where feasible to reduce erosion and sedimentation. Vegetation would be preserved by installing temporary fencing, or other protection devices, around areas to be protected.


Exposed soils would be covered by loose bulk materials or other materials to reduce erosion and runoff during rainfall events.

Exposed soils would be stabilized, through watering or other measures, to prevent the movement of dust at the project site caused by wind and construction activities such as traffic and grading activities.

All construction roadway areas would be properly protected to prevent excess erosion, sedimentation, and water pollution.

All vehicle and equipment maintenance procedures would be conducted off-site. In the event of an emergency, maintenance would occur away from the Little Wolf Creek.

All concrete curing activities would be conducted to minimize spray drift and prevent curing compounds from entering the waterway directly or indirectly.

All construction materials, vehicles, stockpiles, and staging areas would be situated outside of the stream channel as feasible. All stockpiles would be covered, as feasible.

Energy dissipaters and erosion control pads would be provided at the bottom of slope drains. Other flow conveyance control mechanisms may include earth dikes, swales, or ditches. Stream bank stabilization measures would also be implemented.

All erosion control measures and storm water control measures would be properly maintained until the site has returned to a pre-construction state.

All disturbed areas would be restored to pre-construction contours and revegetated, either through hydroseeding or other means, with native or approved non-invasive exotic species.

All construction materials would be hauled off-site after completion of construction.

WQ-2: Any requirements for additional avoidance, minimization, and/or mitigation measures will be in contained in the permits obtained from all required regulatory agencies.

WQ-3: The project limits in proximity to the Little Wolf Creek will be marked as an ESA or either be staked or fenced with high visibility material to ensure construction activities will not encroach further beyond established limits

WQ-4: Permanent treatment control BMPs will be evaluated based on effectiveness and feasibility and incorporated into the final design as applicable.

WQ-5: Storm water systems will be designed to prevent the release of toxins, chemicals, petroleum products, exotic plant materials or other elements that might degrade or harm biological resources.

Timing: Prior and during construction Reporting: Nevada County Department of Public Works 12. NOISE. To offset the potential for noise impacts on the nearest residence, the following avoidance and

minimization measures will be required: Measure 12A: Limit construction work hours. During grading and construction, the following measure will be implemented.

NOI-1: Construction work hours will be limited from 7:00 AM to 7:00 PM and will not exceed 75

dBA during construction hours.



Measure 12B: Limit construction noise levels. During construction, the following measure will be implemented.

NOI-2: During construction, all activities will be maintained below the average noise level (55 dBA) and the maximum event levels (75 dBA).

Noise standards for the rural zoning district will apply in the above table. If the County amends the noise standards in the future, any new noise standards will apply. Noise standards will be enforced through a complaint-driven process via the Nevada County Code Enforcement Division.



INITIAL STUDY AND CHECKLIST Introduction This checklist is to be completed for all projects that are not exempt from environmental review under the California Environmental Quality Act (CEQA). The information, analysis and conclusions contained in the checklist are the basis for deciding whether an Environmental Impact Report (EIR) or Negative Declaration is to be prepared. If an EIR is determined to be necessary based on the conclusions of the Initial Study, the checklist is used to focus the EIR on the effects determined to be potentially significant. This Initial Study uses the following terms to describe the level of significance of adverse impacts. These terms are defined as follows.

No Impact: An impact that would result in no adverse changes to the environment.

Less than Significant Impact: An impact that is potentially adverse but does not exceed the thresholds of significance as identified in the impact discussions. Less than significant impacts do not require mitigation.

Less than Significant with Mitigation: An environmental effect that may cause a substantial adverse change in the environment without mitigation, but which is reduced to a level that is less than significant with mitigation identified in the Initial Study.

Potentially Significant Impact: An environmental effect that may cause a substantial adverse change in the environment; either additional information is needed regarding the extent of the impact to make the significance determination, or the impact would or could cause a substantial adverse change in the environment. A finding of a potentially significant impact would result in the determination to prepare an EIR.

Project Location and Surrounding Land Uses The Garden Bar Road Railcar Bridge, which carries Garden Bar Road across Little Wolf Creek, approximately one mile west of Rosemary Lane, serves three large ranching properties in Nevada County (Figure 1 Project Vicinity and Figure 2 Project Location).

The area surrounding the project is primarily Rural-40 residential, as designated in the Nevada County General Plan (Nevada County, 2014). Parcels characterized as Rural-40 lands are have a minimum size of 40 acres.

1. AESTHETICS

Existing Setting: Garden Bar Road is not an official designated National Scenic Byways or a State Scenic Byways. Garden Bar Road provides views of Nevada County’s rangeland with natural oak woodland landscapes. The proposed project will require the removal of two trees and will widen the existing bridge by approximately three feet; however, no new vertical features will be added.

Would the proposed project:

Potentially Significant

Impact

Less Than Significant

with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in demonstrable, negative, aesthetic effects on scenic vistas or views open to the public? 25

b. Substantially damage scenic resources, including but not limited to trees, rock outcroppings,and historic buildings within a state scenic highway?

9, 21, 25, 30

c. Substantially degrade the existing visual character or quality of the site and its surroundings? 25


d. Create a new source of substantial light or glare, which would adversely affect day or nighttimeviews in the area?

--

e. Create a visually incompatible structure withina designated historic district? --

Impact Discussion 1a & 1c: The project site contains an unpaved roadway and a bridge structure with a natural stream and associated vegetation. The site is located on Garden Bar Road, an unpaved access thoroughfare for 3 residences, making the site visible to those travelers. The proposed project will require the removal of two trees and will widen the existing bridge by approximately one foot; however, no new vertical features will be added. Therefore, the project is anticipated to result in a less than significant impact to scenic vistas, views open to the public or the visual character of the site.

Impact Discussion 1b: The project site is not located on a state scenic highway and does not contain scenic resources (Caltrans 2011). Therefore, there would be no impact related to damaging scenic resources on a state scenic highway.

Impact Discussion 1d: The nearest residences sensitive to light and glare in the project area are approximately 1,000 feet away from the project site. This distance would preclude impacts to these receptors. The bridge would be made of similar materials as the existing bridge and no lighting will be added. Light and glare impacts from the proposed project is not anticipated; therefore, there would be no impact related to light and glare.

Impact Discussion 1e: There is no special historic zoning designation in place at or near this project site. The proposed project will result in no impact on any designated historic areas.

2. AGRICULTURAL/FORESTRY RESOURCES

Existing Setting: Agriculture and forest resources have been an integral part of Nevada County since the discovery of gold in California. Agriculture in Nevada County is a mosaic of farm land intermingled with other uses in the rural setting which typifies the County (Nevada County 2014, Nevada County 2014b). Forest resources within the County consist of timberlands and woodlands. These forest resources provide commercial timber production as well as wildlife habitat, vegetation diversity, watershed protection, and recreation.

As designated in the Nevada County General Plan, the area surrounding the project location is zoned as agriculture exclusive (Nevada County 2014b). Agriculture Exclusive provides for the preservation and protection of important agricultural lands that are being used for commercial agricultural production. It is consistent with all agricultural-oriented General Plan land use designations, as well as those designations that allow for more intensive uses (Nevada County 2014). The project area does not contain any Important Farmlands, nor is adjacent to any Important Farmlands. Agricultural uses do exist in the project area; however, the project area does not contain Williamson Act contracts (DOC 2015).



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Department of Conservation’s Divisionof Land Resource Protection, to non-agricultural use?

15, 25

b. Conflict with existing zoning for agricultural use or conflict with a Williamson Act contract?

15, 24, 25, 26


c. Conflict with existing zoning for, or cause rezoning of, forest land (as defined in Public Resource Code section 12220(g)), timberland zoned Timberland Production Zone (per Section L-II 2.3.C of the Nevada County Land Use and Development Code)?

25, 26

d. Result in the loss of forest land or conversion of forest land to non-forest use?

25, 26

e. Involve other changes in the existing environment, which due to their location or nature, could result in conversion of Farmland to nonagricultural use or conversion of forest land to non-forest use?

25

Impact Discussion 2a: The project site does not contain any Important Farmlands as identified by the Farmland Mapping and Monitoring Program. Therefore, there would be no impact to farmlands from the proposed project.

Impact Discussion 2b: The project site does contain agricultural use (cattle) and zoned as agriculture exclusive. Construction of the bridge and roadway will primarily be confined to existing roadway and is not anticipated to impact adjacent cattle ranching operations. The project area and adjacent lands are not under Williamson Act contracts and the project will not change local land use; therefore, there would be no impact to farmlands from the proposed project.

Impact Discussion 2c: The project site is not within a Timberland Production Zone. Therefore, there would be no impact.

Impact Discussion 2d: The project site and surrounding area consist of an oak woodland community and the project will require the removal of approximately 2 oak trees. Although the project will require the removal of trees, the project will not convert any existing forest land to another use. The project will result in no impact to existing forest land.

Impact Discussion 2e: Project implementation would neither directly nor indirectly result in the conversion of farmland to nonagricultural uses as noted above. There will be no impact to farmlands from this proposed project.

3. AIR QUALITY

Existing Setting: Nevada County is located in the Mountain Counties Air Basin. The overall air quality in Nevada County has improved over the past decade, largely due to vehicles becoming cleaner. State and Federal air quality standards have been established for specific “criteria” air pollutants including ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, lead, and particulate matter. In addition, there are State standards for visibility reducing particles, sulfates, hydrogen sulfide, and vinyl chloride. State standards are called California Ambient Air Quality Standards (CAAQS) (CEPA 2009) and federal standards are called National Ambient Air Quality Standards (NAAQS) (EPA 2014). NAAQS are composed of health-based primary standards and welfare-based secondary standards.

Western Nevada County designated Marginal Nonattainment for the 1997 ozone NAAQS, with a “Finding of Attainment” based on three years of “clean” data. The area is also designated Marginal Nonattainment for the 2008 ozone NAAQS and Nonattainment for the ozone CAAQS. Most of western Nevada County’s ozone is transported to the area by wind from the Sacramento area and, to a lesser extent, the San Francisco Bay Area. Ozone is created by the interaction of Nitrogen Oxides and Reactive Organic Gases (also known as Volatile Organic Compounds) in the presence of sunlight, especially when the temperature is high. Ozone is mainly a summertime problem, with the highest concentrations generally observed in July and August, especially in the late afternoon and evening hours.


Nevada County is also designated Nonattainment for the PM10 CAAQS, but Unclassified for the PM10 NAAQS due to lack of available recent data. The number after “PM” refers to maximum particle size in microns. PM10 is a mixture of dust, combustion particles (smoke) and aerosols, whereas PM2.5 is mostly smoke and aerosol particles. PM2.5 sources include woodstoves and fireplaces, vehicle engines, wildfires and open burning. PM10 sources include the PM2.5 plus dust, such as from surface disturbances, road sand, vehicle tires, and leaf blowers. Some pollen and mold spores are also included in PM10, but most are larger than 10 microns. All of Nevada County is Unclassifiable/Attainment for the PM2.5 NAAQS and Unclassified for the PM2.5 CAAQS.

Ultramafic rock and its altered form, serpentine rock (or serpentinite), both typically contain asbestos, a cancer-causing agent. Ultramafic rock and serpentine exist in several locations in Nevada County, mainly in the western half, but it is unlikely that these materials exist in the project area (USGS 2011, DOC 2000).

An evaluation of project impacts related to greenhouse gas emissions is provided in Section 7 of this Initial Study.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in substantial air pollutant emissions or deterioration of ambient air quality?

11, 18, 29

b. Violate any air quality standard or contribute to an existing or projected air quality violation?

11, 25, 29

c. Expose sensitive receptors to substantial pollutant concentrations?

--

d. Create objectionable smoke, ash, or odors? 8, 11 e. Generate dust? -- f. Exceed any potentially significant thresholds adopted in County Plans and Goals?

25, 29

g. Result in a cumulatively considerable net increase of any criteria pollutant for which the projectregion is in non-attainment under an applicable federal or state ambient air quality standard (including releasing emissions that exceed quantitative thresholds for ozone precursors)?

25, 29

Impact Discussion 3a, c &g: The project proposes to replace an existing bridge with a bridge of similar size and design and the proposed project would not conflict with the applicable air quality plan. Nevada County has two known air quality problems: ozone and PM10. The common source for PM10 violations in the winter is from inefficient wood burning devices. During the dryer months, wildfires also contribute to sources of PM10 violations. Ground level ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. The project is located within the NSAQMD. The NSAQMD administers air quality for all of Nevada County. The proposed project would result in a temporary and less than significant increase in vehicle and equipment during the construction phase of the project. The project will not be cumulatively considered a net increase of any criteria pollutant for which the project region is nonattainment under applicable federal (NAAQS) or state (CAAQS) ambient air quality standards (NSAQMD 2015). Improper disposal of removed vegetation, such as through open burning, would impact the local ambient air quality. Measure 3B prohibits the use of open burning and will ensure that project impacts will be less than significant with mitigation.

Impact Discussion 3b & e: Although unlikely, the project site has the potential to contain ultramafic rock. As noted above, ultramafic rock typically contains asbestos, a cancer-causing agent. Disturbance of this rock and nearby soil during project construction can result in the release of microscopic cancer-causing asbestos fibers into the air, resulting in potential health and safety hazards. Short-term project construction activities have the potential of generating dust and affecting the local ambient air quality with grading and excavation, vegetation


removal, and construction activities. If improperly managed or controlled, and depending upon the time of year and air conditions, the construction activities associated with this project may have the potential to produce off-site dust impacts and smoke impacts. Standard dust control measures included in Measure 3A and prevention of open burning in Measure 3B will reduce short-term construction impacts to a level that is less than significant with mitigation.

Impact Discussion 3d & f: Nevada County’s 1995 General Plan, Chapter 14 Air Quality Element, contains numerous policies to protect air quality in Nevada County. The proposed project is not expected to violate air quality thresholds including creating objectionable smoke, ash, or odors. No impact is anticipated to result from project implementation with regard to a Nevada County air quality code violation and the implementation of Measure 3B.

Mitigation: To further minimize the potential air quality impacts associated with the project construction activities, the following avoidance and minimization measures will be implemented:

Measure 3A: Implement dust control measures. To reduce short-term construction impacts, permits will follow standards to the satisfaction of the Northern Sierra Air Quality Management District (NSAQMD) and the following standard measures will be implemented for dust control during construction, which will be noted on the construction plans:

AQ-1: Obtain appropriate permits from the NSAQMD for portable equipment.

AQ-2: The applicant will implement all dust control measures in a timely manner during all phases of project development and construction.

AQ-3: All material excavated, stockpiled or graded will be sufficiently watered, treated or covered to prevent fugitive dust from leaving the project boundaries and causing a public nuisance or a violation of an ambient air standard. Watering should occur at least twice daily, with complete site coverage.

AQ-4: All areas (including unpaved roads) within the project limits with vehicle traffic will be watered or have dust palliative applied as necessary for regular stabilization of dust emissions.

AQ-5: All land clearing, grading, earth moving, or excavation activities on the project will be suspended as necessary to prevent excessive windblown dust when winds are expected to exceed 20 mph.

AQ-6: All on-site vehicle traffic will be limited to a speed of 15 miles per hour (mph) on unpaved roads.

AQ-7: All inactive disturbed portions of the site will be covered, seeded or watered until a suitable cover is established. Alternatively, the applicant will be responsible for applying non-toxic soil stabilizers to all inactive construction areas.

AQ-8: All material transported off-site will be either sufficiently watered or securely covered to prevent public nuisance.

AQ-9: If serpentine or ultramafic rock is discovered during construction the Northern Sierra Air Quality Management District will be notified no later than the next business day and the California Code of Regulations, Title 17, Section 9315 applies.

Timing: Prior to issuance of the improvement plans Reporting: Agency approval of plans Measure 3B: Use alternative methods to open burning for vegetation disposal. The following measure will be implemented for air quality.


AQ-10: Open burning of site-cleared vegetation is prohibited.

Timing: During construction Reporting: Nevada County Department of Public Works 4. BIOLOGICAL RESOURCES

Existing Setting: The 1.63-acre project area is characterized by dense riparian vegetation surrounded by oak woodlands and is moderately disturbed by cattle ranging. Little Wolf Creek flows east to west through the BSA, emptying to Bear River to ultimately drain into Camp Far West Reservoir. Vegetation adjacent to Little Wolf Creek includes dense understory of Pacific willow (Salix lasiandra), Himalayan blackberry (Rubus armeniacus), poison oak (Toxicodendron diversilobum), and California grape (Vitis californica). Vegetation along the unpaved roadway (Garden Bar Road) contains non-native grasses, and dispersed valley oak woodlands (see Figure 4: Waters and Vegetation Communities within the BSA). These areas also provide habitat for regional wildlife including coyote, bobcat, striped skunk, mule deer, western screech owl, great horned owl, pacific gopher snake, valley garter snake, and northern pacific rattlesnake.

A Natural Environmental Study (NES 2015) was prepared for this project and approved in 2015. The NES provides much of the information used in this section and may be consulted for further technical background.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special-status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service?

3, 5, 7, 10, 12, 13, 23, 33, 34,

36, 39

b. Have a substantial adverse effect on any riparianhabitat 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?

3, 5, 12, 23, 36

c. Result in a substantial reduction in the extent, diversity, or quality of native vegetation, includingbrush removal for fire prevention and flood controlimprovements?

23

d. Have a substantial adverse effect on 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?

23, 35

e. Interfere substantially with the movement of anynative 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?

10, 23, 39

f. Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance?

23, 25

g. Introduce any factors (light, fencing, noise, human presence and/or domestic animals), which could hinder the normal activities of wildlife?

--

I0 50 100 150 200Feet


Project Location

L i t t l e Wo l f C r e e k

Garde

n Bar

Road

Garden Bar Road

V:\21

06 G

arden

Bard

Rd Br

idge 2

Rep

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nviro

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ocum

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getat

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ommu

nities

with

in BS

A.mxd

FIGURE 4Vegetation Communities within the Biological Study Area

BRLO-5917(082)Garden Bar Road Railcar Bridge Replacement Project

Nevada County, Californiarnia

Biological Study AreaExisting Roadway (0.12 acres)Little Wolf Creek (0.09 acres)Tributary to Little Wolf Creek (0.06 acres)Valley Foothill Riparian (0.23 acres)Valley Oak Woodland (1.13 acres)


Impact Discussion 4a: A small number of mature oaks located on site could be used by federally protected nesting raptors and migratory birds during the nesting season. Construction activities should accordingly be scheduled for the non-breeding season or alternative steps taken to protect any nesting birds. Avoidance and minimization measures listed under 4E require a nesting survey prior to any disturbance to either offset or avoid impacts to potentially nesting raptors and migratory birds. Potential impacts on nesting raptors and migratory birds will be less than significant with mitigation.

While no candidate, sensitive, or special status species were observed during the biological surveys within the Biological Study Area (BSA) (see Figure 4: Waters and Vegetation Communities within the BSA), potential habitat exists and the following 7 regional special status species have potential to occur: brownish beaked-rush (Rhynchospora capitellata), Butte County fritillary (Fritillaria eastwoodiae), dubious pea (Lathyrus sulphureus var. argillaceus), California red-legged frog (CRLF) (Rana draytonii), foothill yellow-legged frog (Rana boylii), western pond turtle (Emys marmorata) and California black rail (Laterallus jamaicensis coturniculus) (CNDDB 2015, CNPS 2015, USFWS 2015b). Further information on each of these species is discussed below.

Brownish Beaked-Rush Brownish beaked-rush has been designated a rare plant rank of 2B.2 (rare, threatened, endangered eligible for state listing in California, but more common elsewhere) by the California Native Plant Society (CNPS) (CNPS 2015). Brownish beaked-rush is a perennial herb found in wet meadows, fens, seeps marshes, and riparian wetlands up to 6,600 feet in elevation. The blooming season only lasts 2 months from July to August (Baldwin 2012, CNPS 2015, Calflora 2015).

The proposed project will result in temporarily disturbing brownish beaked-rush potentially suitable riparian habitat but no direct impacts to the species are anticipated (Figure 5 Project Impacts to Special Status Species Habitat). With the incorporation of avoidance and minimization Measure 4A, project impacts to the species are anticipated to be less than significant with mitigation.

Butte County Fritillary Butte County fritillary is listed under CNPS as a 3.2 (plants about which more information is needed), species of concern. Butte County fritillary, a perennial bulbiferous herb is usually found on dry slopes but occasionally within moist areas of chaparral, cismontane woodland, and openings of lower montane coniferous forest between 164 to 4,921 feet elevation. The species sometimes prefers serpentine soil. The blooming season for the species occurs late spring through summer from March to June (Baldwin 2012, CNPS 2015, Calflora 2015).

The project will result in temporarily disturbance of approximately 0.03 acres of potentially suitable Butte County fritillary woodland habitat but no impact to the species is anticipated (Figure 5 Project Impacts to Special Status Species Habitat).

Dubious Pea Dubious pea is listed under CNPS as a 3.2 (plants about which more information is needed), species of concern. Dubious pea is a perennial herb inhabiting foothill woodlands to fir forests, cismontane woodlands, lower montane coniferous forests, and upper montane coniferous forests between 492 to 1,000 feet in elevation. The blooming season for the species occurs for only the month of April and May (Baldwin 2012, CNPS 2015, Calflora 2015).

The project will result in temporary disturbance of approximately 0.03 acres of dubious pea woodland habitat but no impact to the species is anticipated (Figure 5 Project Impacts to Special Status Species Habitat).

California Red-Legged Frog CRLF is a federally threatened species. Populations are known to exist in isolated localities in the Sierra Nevada, north Coast, and northern Transverse Ranges from sea level to elevations of 5,200 ft. (USFWS 2002). Historically, CRLF occurred from Point Reyes National Seashore on the coast, and inland from near Redding, Shasta County, south to northern Baja California, but the population has sustained a 70 percent reduction in its

I0 25 50 75 100Feet


Project Location

L i t t l e Wo l f C r e e k

Garden Bar Road

V:\21

06 G

arden

Bard

Rd Br

idge 2

Rep

lace\E

nviro

nmen

tal D

ocum

ent\F

5_Pr

ojectI

mpac

tsHab

itats.

mxd

FIGURE 7Project Impacts to Special Status Species Habitat

BRLO-5917(082)Garden Bar Road Railcar Bridge Replacement Project

Nevada County, Californiarnia

New Bridge DeckPermanent Cut/FillProject AreaOak Woodland Temporary Impacts (0.29 acres)Oak Woodland Permanent Impacts (0.03 acres)Waters of the U.S. and State Permanent Impacts (>0.01 acres)Waters of the State Permanent Impacts (>0.01 acres)Waters of the U.S. and State Temporary Impacts (0.06 acres)Waters of the State Temporary Impacts (0.10 acres)

Valley Oak Woodland- Butte County Fritillary Habitat- Dubious Pea Habitat

Valley Foothill Riparian- Brownish beaked-rush- FYLF upland habitat- Western pond turtle upland habitat- California black rail habitat

Stream Channel- FYLF habitat- Western pond turtle habitat


geographic range due to habitat loss, overexploitation, introduction of exotic predators, and a variety of other factors (USFWS 1996).

During the reconnaissance biological surveys, no CRLF were observed in Little Wolf Creek or in the adjacent riparian vegetation. Additionally, no ponds supporting CRLF habitat were observed within the project area. Trout, which are known to feed on CRLF eggs and tadpoles were also observed within Little Wolf Creek. For these reasons, Little Wolf Creek is not suitable breeding habitat for CRLF. Due to the lack of suitable habitat within the project area, no impact to the species is anticipated.

Foothill Yellow-Legged Frog Foothill yellow-legged frog (FYLF) is not a state or federally listed species, but is a CDFW Species of Special Concern. FYLF can be found in partly shaded, shallow streams and rocky riffles in a variety of habitats including valley-foothill hardwood, valley-foothill riparian, mixed conifer, coastal scrub, and mixed chaparral. The species requires some cobble-sized substrate for egg laying and a water source persisting for at least 15 weeks for larval metamorphosis. The main predators of FYLF are garter snakes, bullfrogs, and centrachid fish which were introduced into foothill streams. FYLF occurs from elevations near sea level to 6,370 feet and within 33 feet of a breeding water source (Zeiner 1990, CNDDB 2015, California Herps 2015).

Although no FYLF were observed during biological surveys, the species has a low/moderate potential to occur within the project area. The project is anticipated to permanently and temporarily affect potential FYLF breeding and dispersal habitat by removing a small portion of potentially suitable foraging habitat. The project is anticipated to permanently alter less than 0.01 acres of FYLF habitat. Additionally, the project will temporarily disturb approximately 0.06 acres of potential stream channel breeding and dispersal habitat and approximately 0.01 acres of riparian upland habitat. With the implementation of avoidance and minimization measures 4B, the project is anticipated to have a less than significant impact with mitigation to the species (Figure 5 Project Impacts to Special Status Species Habitat).

Western Pond Turtle The western pond turtle is not a state or federally listed species, but is a CDFW Species of Special Concern. The western pond turtle is a fully aquatic turtle, inhabiting ponds, marshes, rivers, streams and irrigation ditches with aquatic vegetation. The species requires suitable basking sites such as logs, rocks and exposed banks and associated upland habitat consisting of sandy banks or grassy open fields for reproduction. The species is omnivorous, consuming aquatic wildlife and vegetation for dietary requirements. The western pond turtle is known to hibernate underwater beneath muddy bottomed waters in colder climates, and reproduces from March to August (California Herps 2015, CDFW 2015, Zeiner 1990).

Although no western pond turtle were observed during the biological surveys, the species has a low/moderate potential to occur within the project area. The project is anticipated to temporarily and permanently disturb potential western pond turtle habitat. The project will temporarily disturb approximately 0.10 acres of potentially suitable upland habitat and approximately 0.06 acres of foraging habitat. Additionally the project will permanently disturb approximately 0.03 acres of potentially suitable upland habitat and less than 0.01 acres of foraging habitat. With the implementation of avoidance and minimization measures 4B, the project is anticipated to have a less than significant impact with mitigation to the species (Figure 5 Project Impacts to Special Status Species Habitat).

California Black Rail The California black rail is listed as Threatened under CESA and is Fully Protected by CFG code. The California black rail is the smallest rail in North America. The species feeds almost exclusively on small insects and forages by probing in saturated or flooded areas with 1 inch or less of standing water. The species was believed to be limited to tidal salt marshes within the San Francisco Bay until it was discovered in the Sierra Nevada foothills in 1994. California black rails are secretive birds and little is known about their total population distribution of the species but it is believed that less than 10% of the population resides outside of the San Francisco Bay.


The project will have a total of approximately 0.10 acres of temporary impact to California black rail habitat. With the implementation of avoidance and minimization measures 4C, the project is anticipated to have a less than significant impact with mitigation to the species (Figure 5 Project Impacts to Special Status Species Habitat).

Impact Discussion 4b & c: Field surveys identified approximately 0.23 acres of valley foothill riparian vegetation within the BSA located adjacent to Little Wolf Creek (Figure 4: Waters and Vegetation Communities within the BSA). This community has a developed tree layer consisting of valley oak (Quercus lobata), California sycamore (Platanus occidentalis), and Pacific willow with an understory of California grape, Himalayan blackberry, poison oak, and valley sedge (Carex barbarae). The project will permanently affect less than 0.01 acres and temporarily affect 0.10 acres of valley foothill riparian (Figure 5: Project Impacts to Special Status Species Habitat). An additional 0.29 acres of valley oak woodland vegetation will be temporarily impacted and approximately 0.03 acres will be permanently impacted. The proposed project will minimize impacts to these communities to the greatest extent practicable by incorporating Measures 4A, 4D, and 4G into the project design. Project impacts to sensitive vegetation communities will be less than significant with mitigation.

Impact Discussion 4d: No wetland features are found within the BSA (USFWS 2015, NES 2015). A total of 0.09 acres of Little Wolf Creek (federally protected by Section 404) and an ephemeral unnamed tributary to Little Wolf Creek are within the BSA. The proposed project permanent effects to Little Wolf Creek and tributary to Little Wolf Creek include deposition of fill material required to replace the bridge. No mitigation is required for permanent impacts less than 0.01 acres; therefore, the project impacts would be less than significant to federally protected Section 404 waters. Additionally, the proposed project would not result in the direct removal, fill or hydrological interruption of federally protected wetlands.

Impact Discussion 4e: Little Wolf Creek and tributary to Little Wolf Creek may serve as a migration corridor for aquatic and terrestrial species within the region. The project area is approximately 3.8 miles upstream from the confluence between Little Wolf Creek and Bear River. The creek may serve as an important dispersal corridor for aquatic animals such as fish, turtles, and amphibians. Although Environmentally Sensitive Area (ESA) fencing will be constructed along Little Wolf Creek and oak woodlands surrounding the bridge, the remainder of the project will remain open for wildlife movement. Multiple existing impassible barriers to migrating fish exclude anadromous fish from the project. Additionally, no new lighting on the bridge is anticipated. Therefore, the project affects to migratory wildlife corridors is less than significant.

Impact Discussion 4f: A number of local ordinances protecting biological resources exist in Nevada County; however, County transportation projects are exempt from these ordinances. The project will result in no impact to local policies.

Impact Discussion 4g: The proposed project would temporarily increase noise and human activity around the project, but these activities would occur generally during daylight hours. Daytime noise impacts on wildlife from construction activities are not anticipated to be substantial. Most construction activities would occur near existing roadway infrastructure where noise and human activity already commonly occurs. This impact would be less than significant.

Mitigation: To offset the potential impacts to biological resources associated with the project construction, the following measures will be implemented:

Measure 4A: Avoid impacts to sensitive biological habitats. This project will avoid impacts to sensitive biological habitats with the implementation of Environmentally Sensitive Area (ESA) fencing and Best Management Practices (BMPs). The following measure will protect sensitive habitats during construction and noted on the construction plans for this project:

BIO-1: Prior to the start of construction activities, the project limits in proximity to jurisdictional waters (Little Wolf Creek) must be marked with high visibility ESA fencing or staking to


ensure construction will not further encroach into waters. The project biologist throughout construction will periodically inspect the ESA to ensure sensitive locations remain undisturbed.

BIO-2: Contract specifications will include the following BMPs, where applicable, to reduce erosion during construction:

Existing vegetation will be protected in place where feasible to provide an effective form of erosion and sediment control;

Stabilizing materials will be applied to disturbed soil surfaces to prevent the movement of dust from exposed soil surfaces on construction sites as a result of wind, traffic, and grading activities.

Timing: Prior to construction Reporting: Nevada County Department of Public Works Measure 4B: Avoid impacts to aquatic wildlife. Construction activities associated with the proposed project may affect aquatic wildlife habitat. As a result, the project will implement the following measures into the project design to minimize and avoid potential effects to aquatic wildlife:

BIO-3: Erosion Control Measures must be implemented during construction. To minimize the mobilization of sediment into Little Wolf Creek, the following erosion-control and sediment-control measures will be included in the construction specifications, based on standard Caltrans measures and standard dust-reduction measures.

Soil exposure must be minimized through the use of temporary BMPs, groundcover, and stabilization measures;

The contractor must conduct periodic maintenance of erosion- and sediment-control measures.

BIO-4: Vegetation clearing will only occur within the delineated project boundaries. An ESA fence will be provided on the final plans to delineate which trees can be saved and which will be removed. Where possible, trees will be trimmed rather than removed fully with the guidance of a qualified biologist. In areas that will be subject to re-vegetation, plants will only be cleared where necessary and when feasible, will be cut above soil level.

BIO-5: If aquatic wildlife are found at any time during project work, construction will stop and the animal will be allowed to leave the project area unharmed. If a State or Federally listed species is discovered, the appropriate regulatory agency will be contacted immediately for further guidance.

BIO-6: Before any activities begin on the project, the project biologist will conduct environmental awareness training for all construction personnel. At a minimum, the training will include a description of sensitive species with potential to occur, their habitat, the project specific measures being implemented to conserve the species, and the boundaries within which the project may be accomplished.

BIO-7: Plastic mono-filament netting (erosion control matting) or similar material containing netting must not be used at the project area because the CRLF or other small animals may become entangled or trapped in it. Acceptable substitutes include coconut coir matting or tackified hydroseeding compounds.

BIO-8: A pre-construction clearance survey will be conducted by the project biologist to verify that no wildlife is located within the project area before the implementation of BIO-19.

BIO-9: The County will not use herbicides to control invasive, exotic plants.


BIO-10: To allow subterranean wildlife enough time to escape initial clearing and grubbing activities, equipment used during initial clearing and grubbing will be operated at speeds no greater than three (3) miles per hour.

BIO-11: Narrow screened fencing (no greater than 3-inch) or impassible barriers will be installed where the project intersects riparian and wetland habitat to prevent aquatic wildlife from entering the construction site.

Timing: Prior to construction Reporting: Nevada County Department of Public Works Measure 4C: Avoid impacts to California Black Rail. The project will avoid impacts to California black rail (Laterallus jamaicensis coturniculus) habitat through pre-construction surveys, and habitat restoration of temporarily disturbed habitats. The following measures will be implemented to protect California black rail.

BIO-12: If construction or restoration activities are necessary during the black rail breeding season (mid-March to early June), preconstruction surveys for California black rail will be conducted where suitable habitat for these species occurs within or adjacent to work areas. Surveys will be initiated between January 15 and February 1. A minimum of four surveys will be conducted evenly spaced prior to mid-April.

Should California black rail be identified within the project area during these surveys, the project biologist will coordinate with CDFW to determine appropriate avoidance and minimization measures to prevent project related impacts to the species.

Timing: Prior to and during construction Reporting: Nevada County Department of Public Works Measure 4D: Avoid impacts to the spread of invasive plant species. The following protective measures will be included in the construction plans to ensure that invasive species are not introduced or spread.

BIO-13: Prior to arrival at the project site and prior to leaving the project site, construction equipment that may contain invasive plants and/or seeds must be cleaned to reduce the spreading of noxious weeds.

Timing: Prior to and during construction Reporting: Nevada County Department of Public Works Measure 4E: Avoid impacts to nesting migratory birds and raptors. This project will avoid impacts to potential nesting migratory birds by coordinating work outside the breeding season (February15th-September 1st). The following avoidance and minimization measures will be incorporated to protect nesting birds and will be noted on the construction plans for this project.

BIO-14: If possible, vegetation removal should occur outside the breeding season (February 15th–September 1st) for all bird species.

BIO-15: If vegetation removal is to take place during the nesting season (February 15th –September 1st), a pre-construction nesting bird survey must be conducted within 7 days prior to vegetation removal. Within 2 weeks of the nesting bird survey, all vegetation cleared by the biologist will be removed by the contractor.

A minimum 100 foot no-disturbance buffer will be established around any active nest of migratory birds and a minimum 300 foot no-disturbance buffer will be established around any nesting raptor species. The contractor must immediately stop work in the nesting area until the appropriate buffer is established and is prohibited from conducting work that could disturb the birds (as determined by the project biologist and in coordination with wildlife


agencies) in the buffer area until a qualified biologist determines the young have fledged. A reduced buffer can be established if determined appropriate by the project biologist and approved by CDFW.

Timing: Prior to and during construction Reporting: Nevada County Department of Public Works Measure 4F: Avoid impacts to local wildlife. To prevent harm to local wildlife, the project will implement the following measures.

BIO-16: The contractor must not apply rodenticide or herbicide within the project area during construction.

BIO-17: The contractor must dispose of all food-related trash in closed containers, and must remove it from the project area each day during construction. Construction personnel must not feed or attract wildlife to the project area.

Timing: During Construction Reporting: Nevada County Department of Public Works Measure 4G: Mitigation for Jurisdictional Waters. To minimize impacts to valley foothill riparian habitats, the following measure will be implemented.

BIO-18: The County will re-contour the temporary effects to pre-construction conditions and seed the area with a native seed mix. Exact mitigation ratios and locations will be determined during the environmental permitting phase of the project. No mitigation for the less than 0.01 acres of permanent impact is proposed.

Timing: Prior to issuance of the improvement plans Reporting: Nevada County Department of Public Works Measure 4H: Provide documentation of appropriate state and federal authorization for work within Little Wolf Creek.

BIO-19: Prior to issuance of improvement plans, the County will provide the appropriate authorization from California Department of Fish and Wildlife, the Central Valley Regional Water Control Board, and US Army Corps of Engineers for fill and disturbance of Little Wolf Creek. Permits that may apply include a Streambed Alteration Agreement from California Department of Fish and Wildlife, a Storm Water Pollution Prevention Plan from the Regional Water Quality Control Board, and a Section 404 permit from the US Army Corps of Engineers. If permits are not required from any of these agencies, the applicant will provide a written statement from the agencies to that effect. If permits are required, evidence of completion and approval of those permits will be submitted to the Planning Department prior to the issuance of improvement plans.

Timing: Prior to construction Reporting: Nevada County Department of Public Works 5. CULTURAL RESOURCES

Existing Setting: The project vicinity was home to the Nisenan or Southern Maidu Native American people. The Nisenan had permanent settlements situated on natural ridges, knolls, and benches located near small streams and tributaries of major rivers. If suitable elevated land was not available in areas along the lower reaches of the American or Cosumnes rivers, artificial mounds were sometimes constructed to keep dwellings above the floodwaters. Such


intensive efforts were mostly reserved for permanent settlements located near reliable food and water supplies. During historic times, the discovery of gold caused an influx of miners into the Nevada County area. As a result, many agricultural communities emerged in part to sustain the growing number of residents moving into the area and as a way for some of the miners to sustain financial stability after the gold deposits were depleted. The project area and its vicinity continue to be used for agricultural purposes in modern times.

A Historic Property Survey Report (HPSR) and an Archeological Survey Report (ASR) were prepared to document cultural resources within the project’s Area of Potential Effects (APE). The HPSR/ASR provides much of the information used in this section; however due to sensitive and confidential information within the documents, they are not available for public review.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Cause a substantial adverse change in the significance of a historical resource as defined in Section 15064.5 of the CEQA Guidelines?

2, 21, 30

b. Cause a substantial adverse change in the significance of an archaeological resource pursuant to Section 15064.5 of the CEQA Guidelines?

2, 21

c. Directly or indirectly destroy a unique paleontological resource or site or unique geologicfeature?

2, 21

d. Disturb any human remains, including those interred outside of formal cemeteries?

2, 21

e. Cause a substantial adverse change in the significance of a tribal cultural resource as defined in Public Resource Code 21074 (i.e. AB-52)?

21

Impact Discussion 5a-c: Archaeological surveys and search of archaeological site records and survey reports on file at the North Central Information Center did not identify any historical resources or any archaeological resources, as defined in Section 15064.5 of the CEQA Guidelines. Further, the project will be situated entirely within an existing disturbed area. In addition, a search of the University of California Museum of Paleontology (UCMP) collection database and cursory pedestrian surface survey of the project area did not identify any evidence of significant paleontological resources. No impact is anticipated to result from project implementation to historical, archaeological or paleontological resources.

Impact Discussion 5d: Disturbance to human remains, including those interred outside of formal cemeteries is not anticipated because the project site is already highly disturbed from the construction of the existing roadway, bridge and roadway maintenance. This impact would be less than significant with mitigation identified in Measures 5A, which requires construction work to stop and appropriate steps taken if human remains are discovered.

Impact Discussion 5e: Tribal consultation under Public Resources Code 21074 was initiated as part of the project to determine potential impacts to tribal cultural resources (TRC). No TRCs were identified within the project area during the consultation period; however, as stipulated in Measure 5A, should any previously unidentified cultural resources be discovered during construction of the project, construction work shall be immediately halted and appropriate steps taken to assess the properly treat any uncovered cultural resources. Implementation of Measure 5A will reduce any construction impact to less than significant with mitigation.

Mitigation: To offset potentially adverse cultural or historical resources impacts associated with the proposed activities on site, the following avoidance and minimization measure will be implemented:


Measure 5A: Avoid impacts to sensitive cultural sites. Halt work and contact the appropriate agencies if cultural resources are discovered during project construction. To prevent cultural resource disturbance the following measures will be implemented.

CUL-1: All equipment operators and employees involved in any form of ground disturbance will be advised of the remote possibility of encountering subsurface cultural resources.

CUL-2: Section 5097.94 of the Public Resources Code and Section 7050.5 of the California Health and Safety Code protect Native American burials, skeletal remains and grave goods, regardless of age and provide method and means for the appropriate handling of such remains. If human remains are encountered, California Law requires that work should halt in that vicinity and the Nevada County Coroner should be notified immediately to assess the remains. If the coroner determines the human remains to be of Native American origin, the coroner must notify the Native American Heritage Commission (NAHC) within twenty-four hours of such identification. The NAHC shall then determine the Most Likely Descendant (MLD) of the human remains and contact the MLD immediately. The County, the MLD, and a professional archaeologist retained by the County shall then consult to determine the appropriate plans for treatment and assessment of the human remains and any associated grave goods.

CUL-3: If previously unidentified cultural materials are unearthed during construction, work shall be halted in that area until a qualified archaeologist can assess the significance of the find and develop a plan for documentation and removal of resources, if necessary. Additional archaeological survey will be needed if project limits are extended beyond the present survey limits.

Timing: During construction Reporting: Nevada County Department of Public Works 6. GEOLOGY/ SOILS

Existing Setting: The geology of the area consists of Mesozoic Meta-volcanic rocks and granitic formations. The soil in the project area is made primarily of Auburn-Rock Outcrop Complex (2 to 30% slopes). The Auburn-Rock complex is shallow loamy material weathered from diabase and/or metabasic rock with exposed outcrops of diabase and/or basic metamorphic rock (NRCS 2015). The County’s Master Environmental Inventory shows the project site as being in an area of low potential for landslide activity and does not map the site as being near a known earthquake fault (Nevada County 2012).

A Draft Geotechnical Engineering Report was prepared to document geologic and geotechnical information within the project area. The geotechnical report provides much of the information used in this section and may be consulted for further technical background.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in exposure to or production of unstable earth conditions such as landslides, earthquakes,liquefaction, soil creep, mudslides, ground failure (including expansive, compressible, collapsiblesoils), or similar hazards?

2, 16, 24, 28

b. Result in disruption, displacement, compaction, or over-covering of the soil by cuts, fills, or extensive grading?

--


c. Be located on a geologic unit or soil that is unstable, or that would become unstable as a resultof the project, and potentially result in on- or off- site landslide, lateral spreading, subsidence,liquefaction or collapse?

2, 16, 24, 28

d. Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater?

24, 25, 28

e. Result in any increase in wind or water erosion of soils, on or off the site?

--

f. Changes in siltation, deposition or erosion, which may modify the channel of a river, or stream, or the bed any bay, inlet or lake?

--

g. Result in excessive grading on slopes of over 30 percent?

--

Impact Discussion 6a & c: Ground or fault rupture is generally defined as the displacement that occurs along the surface of a fault during an earthquake. The Alquist-Priolo Earthquake Fault Zoning Act was adopted in 1972 to prevent the construction of buildings in areas where active faults have surface expression. The project site is not within an Alquist-Priolo Earthquake Fault Zone, and there are no known faults that cross through the project site. Generally, western Nevada County is located in the low intensity zone for earthquake severity. Due to the absence of any active faults onsite, the probability of damage due to surface rupture is low. Soils at the project site are composed of rock outcrop or weathered bedrock. The soil profile is typically 15 inches in depth and not subject to large amounts of spreading, subsidence, liquefaction or collapse. All bridge supports will be constructed on bedrock which will further reduce the risk of the project causing soil destabilization. The micro-topography at the project site is gently sloping and not conducive to landslides. Any potential adverse impact that would result from project implementation is determined to be less than significant, and no mitigation is required.

Impacts Discussion 6b: The project construction activities would likely necessitate the site grading to modify the existing road alignment in the vicinity of the bridge approaches, including fill slope grading, fill placement, and compaction. With implementation of Measure 6A, which requires the preparation of a soils or geotechnical report for project grading and structural work, impacts from excavation would be less than significant with mitigation.

Impact Discussion 6d: The project site lacks septic tanks and alternative wastewater disposal systems. No impact is anticipated to result from project implementation to soils supporting the use of septic tanks or wastewater disposal system.

Impact Discussion 6e & f: The project will primarily occur on already disturbed areas subjected to wind and water erosion. Construction activities associated with the project would include disturbances to the ground surface from existing bridge and abutment removal, grading, and new bridge construction. Removal of the existing riparian vegetation would increase the potential for slope erosion. These activities could potentially increase the amount of sediments entering Little Wolf Creek. Runoff during the winter season can result in potential erosion of unprotected or graded surfaces during rain events; therefore, Measure 6A is recommended to require the erosion control measures to ensure the disturbed areas are stablished during construction. Impacts related to erosion will be less than significant with mitigation.

Impact Discussion 6g: Slopes on the site are mostly gentle with small areas that exceed 30 percent slope. Fill and grading will primarily occur in areas less than 30 percent slope; however, there will be approximately 200 square feet of fill or grading located in areas that exceed 30 percent slope. Fill or grading in areas greater than 30 percent slope will be less than significant.

Mitigation: To offset the potential for adverse soils or erosion impacts to result from project grading and construction activities, the following measures will be implemented:


Measure 6A: Erosion and Sediment Control. Prior to issuance of permits or improvement plans for all project-related grading including road construction and drainage improvements, said permits or plans will incorporate, at a minimum, the following erosion and sediment control measures will be incorporated:

GEO-1: Contract specifications will include the following BMPs, where applicable, to reduce erosion during construction.

During construction, Best Management Practices (BMPs) for temporary erosion control will be implemented to control any pollutants that could potentially affect the quality of storm water discharges from the site.

Prior to commencement of site work, fiber rolls and silt fencing should be installed down slope of all proposed areas of disturbance to reduce migration of sediment from the site. Fiber rolls on slopes are intended to reduce sediment discharge from disturbed areas, reduce the velocity of water flow, and aid in the overall revegetation of slopes. The fiber rolls and silt fence should remain in place until construction activity is complete and vegetation becomes established;

All soil exposed in permanent slope faces should be hydroseeded or hand seeded/strawed with an appropriate seed mixture compatible with the soil and climate conditions of the site as recommended by the local Resource Conservation District; and

Following seeding, jute netting or erosion control blankets should be placed and secured over the slopes steeper than 2:1, H.V.

Timing: During and post construction Reporting: Nevada County Department of Public Works

7. GREENHOUSE GAS EMISSIONS

Existing Setting: Greenhouse gases (GHGs) are those gases that trap heat in the atmosphere. GHGs are emitted by natural and industrial processes, and the accumulation of GHGs in the atmosphere regulates the earth’s temperature. GHGs that are regulated by the State and/or EPA are carbon dioxide (CO2), methane (CH4), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6) and nitrous oxide (NO2). CO2 emissions are largely from fossil fuel combustion. In California, approximately 43 percent of the CO2 emissions come from cars and trucks. Electricity generation is another important source of CO2 emissions. Agriculture is a major source of both methane and NO2, with additional methane coming primarily from landfills. Most HFC emissions come from refrigerants, solvents, propellant agents and industrial processes, and persist in the atmosphere for longer periods of time and have greater effects at lower concentrations compared to CO2. The adverse impacts of global warming include impacts to air quality, water supply, ecosystem balance, sea level rise (flooding), fire hazards, and an increase in health related problems.

Assembly Bill 32 (AB 32), the California Global Warming Solutions Act, was adopted in September 2006 and requires that statewide GHG emissions be reduced to 1990 levels by the year 2020. This reduction will be accomplished through regulations to reduce emissions from stationary sources and from vehicles. The ARB is the State agency responsible for developing rules and regulations to cap and reduce GHG emissions. In addition, the Governor signed Senate Bill 97 in 2007 directing the California Office of Planning and Research to develop guidelines for the analysis and mitigation of the effects of greenhouse gas emissions and mandating that GHG impacts be evaluated in CEQA documents. CEQA Guidelines Amendments for GHG Emissions were adopted by Office of Planning and Research (OPR) on December 30, 2009. The Northern Sierra Air Quality Management District (NSAQMD) has prepared a guidance document, Guidelines for Assessing Air Quality Impacts of Land Use Projects. Therefore, in order to satisfy CEQA requirements, projects should make a reasonable attempt to quantify, minimize and mitigate GHG emissions as feasible.




Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment?

25, 29

b. Conflict with any applicable plan, policy or regulation of an agency adopted for the purpose of reducing the emissions of greenhouse gases?

25, 29

Impact Discussion 7a & b: Given the complex interactions between various global and regional-scale physical, chemical, atmospheric, terrestrial, and aquatic systems, it is not possible to determine to what extent this project’s CO2 emissions would result in any altered physical conditions. In considering this project’s GHG emissions within the context of statewide and regional emissions, it is assumed they will be minimal, given the small scale of the proposed project. Typically, cumulative impacts are analyzed and mitigated in the County’s General Plan and associated EIR. In this case, the General Plan for Nevada County does not address GHG emissions. Therefore, this analysis uses a conservative approach and acknowledges that the project will result in a less than significant impact to regional and statewide GHG emissions.

The proposed project is anticipated to result in temporary increases in CO2 levels from construction equipment emissions. The total site disturbance will be approximately 1.63 acres and will include grading for the roadway, fill for the bridge structure and storage areas. It is anticipated that at most 1 or 2 pieces of heavy equipment will be operated simultaneously during construction and construction is anticipated to last approximately 3 months. Given the small amount of equipment that will be operated and the short construction duration, the project emissions levels are anticipated to be within Northern Sierra Nevada Air Quality Management District thresholds. The project will not add travel lanes to the facility and operational CO2 emissions are anticipated to be less than significant.

8. HAZARDS/ HAZARDOUS MATERIALS

Existing Setting: The property is not within or adjacent to any hazardous materials sites compiled pursuant to Government Code Section 65962.5 (DTSC 2014), and is not located on an abandoned solid waste disposal site known to the County (Nevada County 2015). The project is within a High Fire Hazard Severity Zone as designated by the California Department of Forestry and Fire Protection (CAL-FIRE) Nevada County Fire Hazard Severity Zones map (CAL-FIRE 2007). As discussed in Section 3. Air Quality, ultramafic rock and its altered form, serpentine rock (or serpentinite), both typically contain asbestos, a cancer-causing agent. Ultramafic rock and serpentine exist in several locations in Nevada County, mainly in the western half, but it is unlikely that these materials exist in the project area (USGS 2011, DOC 2000).



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials?

22, 37

b. Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment?

14, 22, 25, 37

c. Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school?

17, 22, 25, 27


d. Be located on a site which is included on a list of hazardous materials sites compiled pursuant toGovernment Code Section 65962.5 and, as a result, create a significant hazard to the public or the environment?

6

e. For a project located within an airport land 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?

24, 25

f. For a project within the vicinity of a private airstrip, would the project result in a safety hazardfor people residing or working in the project area?

24, 25

g. Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan?

25

h. Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands?

4, 25

Impact Discussion 8a: The proposed project replaces an existing bridge without additional lanes. No additional transport, use, or disposal of hazardous materials is anticipated as a result of the project. The project will have no impact on the transportation of hazardous materials.

Impact Discussion 8b: The ISA evaluated the potential for hazardous materials or petroleum hydrocarbons to exist within the study area, and was based on a governmental records search, select agency interviews, aerial photograph and topographic map review and visual site survey. A review of the GeoTracker Database listed identical information provided in Department of Toxic Substances, EnviroStor Database. No cases were found within 1 mile of the project site.

A review of geologic mapping and field investigations did not find ultramafic rock or other sources of naturally occurring asbestos within the project area. In addition, during a site inspection with Caltrans on February 23, 2015, it was determined that the bridge was not constructed with asbestos containing materials. A visual survey of the project area was conducted on February 23, 2015. The site survey confirmed the current land uses and did not find indication of past spills requiring remediation. Additionally, the visual survey observed chemically treated wood that comprises the existing bridge deck. Treated wood may contain elevated levels of arsenic, chromium, copper, creosote, and pentachlorophenol. These chemicals are applied to the wood to prevent insect attack and fungal decay. Timber that is chemically preserved is handled as hazardous treated wood waste (TWW) when disposed of. Due to elevated levels of these hazardous chemicals, TWW is considered hazardous to human health and is subject to California’s hazardous waste control laws.

The project area was also tested for the presence of asbestos. No asbestos was detected in the concrete materials sampled. It was also determined during a site visit that no asbestos was contained in the bearing pads, or shims. No other potentially hazardous materials were observed within the project area. Measure 8A will reduce potential project impacts associated with hazardous waste disposal to less than significant with mitigation.

Impact Discussion 8c: The proposed project is not within ¼ mile of an existing or proposed school. Therefore, there would be no impact related to hazardous emissions or substances near a school.

Impact Discussion 8d: The proposed project is not located on a site included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 (CalEPA 2015). The proposed project will have no impact on hazard to the public or environment by disturbing the site during construction.


Impact Discussion 8e & f: The proposed project would not result in a safety hazard for people residing or working in the project area as the project is not within the vicinity of an airport land use plan or a private airstrip. Therefore, there would be no impact related to safety of the public in the project area.

Impact Discussion 8g: The proposed project will not alter any allowable residential density in the nearby area, or change any of the existing road networks or alter any existing emergency evacuation plans. The proposed project would not impair or physically interfere with the adopted emergency response and evacuation plans; therefore, no impact to emergency plans are anticipated.

Impact Discussion 8h: The project would not expose people or structures to a significant risk of loss, injury, or death involving wildland fires. The project will involve operating equipment in a wooded area but these activities will result in a less than significant increase in fire risk.

Mitigation: To offset the potential for impacts related to storage, use, and transport and hazardous materials, the following avoidance and minimization measures will be implemented:

Measure 8A: Properly dispose of TWW and other hazardous waste. The following measure has been incorporated into the project design to ensure that TWW generated by the project is properly disposed of.

HAZ-1: The chemically treated wood must be treated as TWW and disposed of as hazardous waste. Should additional timber used for construction of the bridge, i.e. buried creosote timber piles, be uncovered during bridge demolition and replacement, this timber would also be treated as TWW. For the TWW, the DTSC regulations §66261.9.5 provide AMS for TWW. Caltrans SSP for TWW, SSP 14-11.09, is based on DTSCs AMS regulations. This SSP directs the Contractor to follow the AMS including providing training to all personnel that may come in contact with TWW. This training must include, at a minimum, safe handling, sorting and segregating, storage, labeling (including date), and proper disposal methods.

HAZ-2: As is the case for any project that proposes excavation, the potential exists for unknown hazardous contamination to be revealed during project construction. For any previously unknown hazardous waste/ material encountered during construction, the procedures outlined in the Caltrans Unknown Hazard Procedures (as seen in Table 7-1.1 of the Caltrans 2006 Construction Manual) shall be followed (Caltrans 2006).

Timing: During construction Reporting: Nevada County Department of Public Works 9. HYDROLOGY/ WATER QUALITY

Existing Setting: The project area is located in the Camp Far West Reservoir-Bear River Hydrologic Unit. The Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM) does not indicate Little Wolf Creek or the tributary to Little Wolf Creek as water features of concern during a flood event (Figure 6: FEMA Flood Insurance Rate Map).

Little Wolf Creek and the tributary to Little Wolf Creek are located within the project site. The Little Wolf Creek originates approximately 2.8 miles northeast of the project at a detention pond within an unincorporated rural development. Little Wolf Creek passes through the project area to eventually the confluence with Bear River and ultimately to the Camp Far West Reservoir.

A Water Quality Assessment Report was prepared to document water quality information within the project area. Additionally, a Location Hydraulic Study was prepared for this project. The Water Quality Report provides much of the information used in this section and may be consulted for further technical background.

Source: FEMA; Dokken Engineering10/22/2015; Created By: scottsV:\21

06 G

arden

Bard

Rd Br

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Rep

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nviro

nmen

tal D

ocum

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6_FE

MA_F

loodM

ap.m

xd

FIGURE 6FEMA Flood Insurance Rate Map





Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Violate any water quality standards or waste discharge requirements?

25, 38

b. Substantially deplete groundwater supplies or interfere substantially with groundwater rechargesuch 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 nearbywells would drop to a level, which would not support existing land uses or planned uses for which permits have been granted)?

25, 38

c. Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a manner thatwould result in substantial erosion or siltation on- oroff-site?

8, 25, 38

d. Create or contribute to runoff water which would exceed the capacity of existing or planned storm water drainage systems or provide substantialadditional sources of polluted runoff?

8, 25

e. Otherwise substantially degrade water quality? 38 f. Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map?

19

g. Place within a 100-year flood hazard area structures that would impede or redirect flood flows?

19

h. Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam?

19

i. Create inundation by mudflow? --

Impact Discussion 9a: Project grading activities will require a County grading permit. Compliance with existing regulations and implementation of BMPs would reduce potentially significant impacts associated erosion or siltation on- or offsite. Measures 9A will minimize the water quality impacts associated with any erosion during and after project construction, the project impacts regarding water quality would be less than significant with mitigation.

Impact Discussion 9b: The proposed project would not directly or indirectly result in the construction of uses that would utilize groundwater supplies. Therefore, there would be no impact related to depletion of groundwater supplies or interference with groundwater recharge.

Impact Discussion 9c: No substantial alteration of the existing drainage patterns will occur. Drainage on the site will remain along natural drainage courses, similar to pre-construction conditions. The project storm water drainage would be designed consistent with the County requirements and Caltrans Project Planning and Design Guide and Storm Water Management Plan and will remain natural. Measures 6A and 9A would reduce the impacts related to erosion or siltation to less than significant with mitigation.

Impact Discussion 9d: Construction activities associated with the project would include ground disturbance including existing bridge and abutment removal, excavation, grading, and new bridge construction. Removal of the existing riparian vegetation would increase the potential for slope erosion. These activities could potentially


increase the amount of sediments entering Little Wolf Creek. Runoff during the winter season is of greater concern due to the potential erosion of unprotected or graded surfaces during rain events. Sediment could potentially harm aquatic resources and water quality.

Suspended material is considered a pollutant of primary concern for construction projects. Exposure of loose soil during excavation, grading, and filling activities during construction and its erosion is the primary source of suspended material. Construction activities inside or near the channel consist of removing the existing bridge, falsework placement, new bridge construction, and grading. A temporary diversion will be placed inside the channel underneath the bridge to constrict the channel for the duration of the project. These activities could temporarily increase the sediment load thus increasing the turbidity, and total dissolved solids present in stream water. Since a portion of the construction will take place within the streambed, it is important that the water in the creek be protected from increases in the sediment load, turbidity, total dissolved solids, fuels and lubricating oils generated during construction.

Accidental spills of petroleum hydrocarbons (fuels and lubricating oils) and or concrete waste are also a concern during construction activities and would be avoided and minimized through the implementation of BMPs. An accidental release of these wastes could adversely affect groundwater quality, vegetation, and wildlife habitat, but the impact is expected to be acute and not cause a long-term impact.

However, Little Wolf Creek is not 303(d) listed, but is a tributary to the Upper Bear River, from Combie Lake to Camp Far West Reservoir; which is 303(d) listed (Figure 7: 303(d) Listed Waters). Little Wolf Creek is approximate 4 miles upstream from the impaired/303(d) listed portion of the Upper Bear River. Permanent BMPs would be incorporated into the project as feasible and implementation of measures determined in the 401, 402, 404, and 1602 permits. Measure 9A would reduce the impacts related to erosion or siltation to less than significant with mitigation.

Impact Discussion 9e: The project may have short-term impacts associated with sediment and runoff during grading and construction. Materials imported during this process will be kept in piles of staged soil, and/or re-graded and distributed within the project site. Compliance with existing regulations and implementation of BMPs would reduce potentially significant impacts associated erosion or siltation on- or off-site to levels less than significant. Measure 6A, which requires the applicant to obtain an approved erosion and sediment control plan, will minimize the water quality impacts associated with any erosion. This impact would be less than significant with mitigation shown in Measure 9A, which requires BMPs.

Impact Discussion 9f-i: The FEMA FIRM does not indicate Little Wolf Creek or the tributary to Little Wolf Creek as water features of concern during a flood event (Figure 6: FEMA Flood Insurance Rate Map) (FEMA 2015). The proposed project would be designed to withstand a 100 year flood event, would not result in direct or indirect impacts to a levee or dam, and would not substantially contribute to storm water flows near a floodplain. The project would result in no impact related to flooding and mudflow.

Mitigation: To offset the potential for impacts related to amount and quality of storm water runoff from project development, the following avoidance and minimization measures will be implemented:

Measure 9A: Follow established water quality standards. The proposed project has been designed to minimize all impacts to the maximum extent practicable through the use of BMPs and implementation of regulatory permit conditions.

WQ-1: BMPs will be incorporated into project design and project management to minimize impacts on the environment including the release of pollutants (oils, fuels, etc.):

I0 1 2 3 4Miles

Source: USA Topo Map; Dokken Engineering11/10/2015; Created By: carolynnd

Camp Far West Reservoir

Bear River

Wolf Cree

k

)

Bear River

V:\21

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Bard

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Rep

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15_0

3_31

_210

6_30

3d.m

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FIGURE 7303(d) Listed Waters


Project Area303(d) Listed Little Wolf Creek


The area of construction and disturbance would be limited to as small an area as feasible to reduce erosion and sedimentation.

Measures would be implemented during land-disturbing activities to reduce erosion and sedimentation. These measures may include mulches, soil binders and erosion control blankets, silt fencing, fiber rolls, temporary berms, sediment desilting basins, sediment traps, and check dams.

Existing vegetation would be protected where feasible to reduce erosion and sedimentation. Vegetation would be preserved by installing temporary fencing, or other protection devices, around areas to be protected.

Exposed soils would be covered by loose bulk materials or other materials to reduce erosion and runoff during rainfall events.

Exposed soils would be stabilized, through watering or other measures, to prevent the movement of dust at the project site caused by wind and construction activities such as traffic and grading activities.

All construction roadway areas would be properly protected to prevent excess erosion, sedimentation, and water pollution.

All vehicle and equipment maintenance procedures would be conducted off-site. In the event of an emergency, maintenance would occur away from the Little Wolf Creek.

All concrete curing activities would be conducted to minimize spray drift and prevent curing compounds from entering the waterway directly or indirectly.

All construction materials, vehicles, stockpiles, and staging areas would be situated outside of the stream channel as feasible. All stockpiles would be covered, as feasible.

Energy dissipaters and erosion control pads would be provided at the bottom of slope drains. Other flow conveyance control mechanisms may include earth dikes, swales, or ditches. Stream bank stabilization measures would also be implemented.

All erosion control measures and storm water control measures would be properly maintained until the site has returned to a pre-construction state.

All disturbed areas would be restored to pre-construction contours and revegetated, either through hydroseeding or other means, with native or approved non-invasive exotic species.

All construction materials would be hauled off-site after completion of construction.

WQ-2: Any requirements for additional avoidance, minimization, and/or mitigation measures will be in contained in the permits obtained from all required regulatory agencies.

WQ-3: The project limits in proximity to the Little Wolf Creek will be marked as an ESA or either be staked or fenced with high visibility material to ensure construction activities will not encroach further beyond established limits

WQ-4: Permanent treatment control BMPs will be evaluated based on effectiveness and feasibility and incorporated into the final design as applicable.

WQ-5: Storm water systems will be designed to prevent the release of toxins, chemicals, petroleum products, exotic plant materials or other elements that might degrade or harm biological resources.

Timing: Prior and during construction Reporting: Nevada County Department of Public Works


10. LAND USE/ PLANNING

Existing Setting: The Garden Bar Road Railcar Bridge over Little Wolf Creek is located in the western portion of Nevada County, approximately 2.2 miles from Garden Bar Road terminus. Topographic features in the project area include rolling hills and water features. The areas surrounding the project includes rural housing, pastures, and oak woodlands. According to the Nevada County General Plan, land use surrounding the project is residential (Rural-40) with parcels having a minimum size of 40 acres (Nevada County, 2014). These areas are zoned as Agricultural exclusive (AE-40) in the Nevada County District Zoning Map (Nevada County 2014b) (Figure 8: Western Nevada County Land Uses).



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in structures and/or land uses incompatible with existing land uses? 25, 26

b. The induction of growth or concentration of population? 25, 32

c. The extension of sewer trunk lines or access roads with capacity to serve new development beyond this proposed project?

25

d. Result in the loss of open space? 24, 25 e. Substantially alter the present or planned landuse of an area, or conflict with a general plan designation or zoning district?

25, 26

f. Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan, specific plan, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect?

25, 26

g. Disrupt or divide the physical arrangement of an established community, including a low-income or minority community?

24, 25

Impact Discussion 10a & e: The proposed project consists of the replacement of an existing structure, which is compatible with the existing land use. As such, the project would not result in incompatible land uses and would have no impact related to current or future land use.

Impact Discussion 10b & c: The proposed project would not result in growth-inducing impacts because it would not construct any infrastructure or other physical development that could serve additional development. Land use in the project vicinity is defined as acreages of 40 or larger with no future plans to increase development (Nevada County, 2014). The project does not contain sewer trunk lines or additional access roads to attribute to future development or serve new development. Therefore, the project will have no impact related to future development potential offsite.

Impact Discussion 10d: The proposed project will not affect land use in the surrounding area. The proposed bridge and roadway improvements are approximately the same size as existing conditions. The project will have no impact on open space.

Impact Discussion 10f: The project area is not located within a Sphere of Influence of the City of Grass Valley and is mapped within the County’s General Plan planning area for agriculture use. There are currently no curbs, gutters, or sidewalks along Garden Bar Road; therefore, functionally classifying the road as a locals road providing primary access to individual properties. No conflicts with land use plans or functional classification of

Project Area

I Figure 8Western Nevada County Land Uses


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ProjectAreaOpen Space (OS)Planned Development (PD)Rural (RUR-5)Rural (RUR-10)Rural (RUR-20)Rural (RUR-30)Rural (RUR-40)

0 0.5 1 1.5 2Miles


the roadway will occur with the project. Therefore, the proposed project will have no impact to compatibility with adopted land use plans..

Impact Discussion 10g: The proposed project is surrounded by Rural-40 land and is not situated adjacent to or within any urban residential communities (Figure 7: Western Nevada County Land Use). The project would not disrupt or divide the physical arrangement of any established community and no impact would occur.

11. MINERAL RESOURCES

Existing Setting: The project area is not mapped within a Mineral Resource Zone (MRZ), or area of known valuable mineral deposits.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the state?

24, 25

b. Result in the loss of availability of a locally important mineral resource recovery site delineatedon a local general plan, specific plan or other land use plan?

24, 25

Impact Discussion 11a & b: Because the proposed project is not within a known mineral resource area and would not change existing land uses on the project site, there would be no impact to mineral resources.

12. NOISE

Existing Setting: The project area is within a rural area of Nevada County, which is an area with low levels of existing noise. There are no sensitive noise receivers within the immediate vicinity of the project area. The Nevada County Noise Standards (Nevada County Code, Section L-II 4.1.7) establish an Exterior Noise Limits ranging from 40-90 dBA (A-weighted decibel) depending on land use categories (rural, residential and public, commercial and recreation, business park and industrial) (see Table below).

Table 1. Nevada County Noise Standards Exterior Noise Limits

Land Use Category Zoning Districts Time Period

Noise Level, dBA Leq Lmax

Rural A1, TPZ, AE, OS, FR, IDR

7am - 7pm 7pm - 10pm 10pm -7 am

55 50 40

75 65 55

The General Plan has established daytime average noise levels and maximum event levels for residential uses. The nearest sensitive noise receiver is a residence approximately 2,000 feet south of the project area. This receiver is sufficiently far from the project area that no impact to this receiver is anticipated. While this receiver is situated in the vicinity to the project area, Measures 12A and 12B would ensure that noise related impacts are less than significant with mitigation.




Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Expose persons to or generate noise levels in excess of the County’s adopted standards established in the General Plan and Land Use and Development Code?

20, 25

b. Expose persons to or generate excessive ground borne vibration or ground borne noise levels (e.g., blasting)?

8, 20, 25

c. Result in a substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project?

8

d. Result in a substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project?

9, 20, 25

e. For a project located within an airport land 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?

24, 25

f. For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels?

24, 25

Impact Discussion 12a & d: The nearest sensitive receptor to the project area is a rural residence approximately 2,000 feet to the southeast of the project area. This receiver is protected from construction noise by rolling hills and dense trees surrounding the project area. Construction would result in temporarily low-level noise impacts to the nearest residences. Exposure of persons to noise levels in excess of the County’s adopted standards would therefore be less than significant with mitigation as described in Measure 12A and 12B, which limits constriction work to the hours of 7 AM to 7 PM or daylight hours and maintains noise levels below both the average noise level and the maximum event level.

Impact Discussion 12b: The proposed project would not result in blasting or other activities that could cause substantial vibration impacts. Therefore, there would be no impact related to ground borne vibration.

Impact Discussion 12c: The proposed project will not result in permanent increase to noise levels. Concrete bridge will decrease noise levels than the existing steel/wood bridge. Temporary increase in noise will occur during construction; however, construction will be restricted to daylight hours (7am – 7pm) as described in Measure 12A and maintains noise levels below both the average noise level and the maximum event level as described in Measure 12B. It is anticipated that impacts would be less than significant with mitigation as described in Measure 12A and 12B.

Impact Discussion 12e & f: The project is not located in or within 2 miles of an airport or private airstrip. The nearest airport is the Auburn Municipal Airport, approximately 9 miles from the project area. The project will result in no impacts to sensitive noise receivers of an airport or private airstrip.

Mitigation: To offset the potential for noise impacts on the nearest residence, the following avoidance and minimization measure will be required: Measure 12A: Limit construction work hours. During grading and construction, the following measure will be implemented.


NOI-1: Construction work hours will be limited from 7:00 AM to 7:00 PM and will not exceed 75

dBA during construction hours.

Timing: During construction Reporting: Nevada County Department of Public Works Measure 12B: Limit construction noise levels. During construction, the following measure will be implemented.

NOI-2: During construction, all activities will be maintained below the average noise level (55 dBA) and the maximum event levels (75 dBA).

Noise standards for the rural zoning district will apply in the above table. If the County amends the noise standards in the future, any new noise standards will apply. Noise standards will be enforced through a complaint-driven process via the Nevada County Code Enforcement Division.

Timing: During construction Reporting: Nevada County Department of Public Works 13. POPULATION/ HOUSING

Existing Setting: The project is within unincorporated Nevada County, which, according to the 2010 U.S. Census, has a total population of 98,764. The project area contains less than 20 persons per square mile, which exhibit low population densities within the area (U.S. Census, 2014). Population of the County is concentrated within the City of Grass Valley and the Town of Truckee, where population densities are between 2,711 and 500 persons per square mile, respectively. The population has grown 14% since 2000 (U.S. Census, 2014).

The project area and surrounding area is zoned Rural-40 in the Nevada County General Plan and as Agriculture-40 in the Nevada County District Zoning Map. This land use is characterized by very low density rural residences and small scale agriculture.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Induce substantial population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example,through extension of roads or other infrastructure)?

25, 32

b. Displace substantial numbers of existing housing, necessitating the construction of replacement housing elsewhere?

25, 32

c. Displace substantial numbers of people, necessitating the construction of replacementhousing elsewhere?

25, 32

Impact Discussion 13a-c: The project is located in rural Nevada County that supports low density housing. The project would not result in population growth or displacement of housing or people. Therefore, the proposed project would have no impact related to these issues.

14. PUBLIC SERVICES

Existing Setting: No public services are located within the project area..




Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in substantial adverse physical impacts associated with the provision of or 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 following the public services:

25

1. Fire protection? 25 2. Police protection? 25 3. Schools? 24, 25 4. Parks? 24, 25 5. Other public services or facilities? 24, 25

Impact Discussion 14a.1-5: The proposed project is located in undeveloped rural Nevada County which consists of agricultural lands and large residential parcels. No public services are located within the project. A temporary crossing over Little Wolf Creek will be placed south of the existing bridge to allow continuous access along Garden Bar Road throughout construction so that there will be no effect on service ratios or response times. Therefore, the proposed project would have no impact related to these issues.

15. RECREATION

Existing Setting: The project area is located approximately 5 miles east from the Camp Far West Reservoir, but no recreational facilities occur onsite or in close proximity to the project area.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Increase the use of existing neighborhood and regional parks or other recreational facilities suchthat substantial physical deterioration of the facility would occur or be accelerated?

25

b. Include recreational facilities or require theconstruction or expansion of recreational facilitiesthat might have an adverse physical effect on the environment?

25

c. Conflict with established recreation uses of the area, including biking, equestrian and/or hiking trails?

25

Impact Discussion 15a-c: The proposed project is located outside the Camp Far West Reservoir and all recreational facilities. The project would not result in affects to recreational uses or increase demand for recreational uses. Therefore, the proposed project would have no impact related to these issues.

16. TRANSPORTATION/ CIRCULATION

Existing Setting: The project is located along Garden Bar Road, which is designated as a minor collector in the Nevada County General Plan Circulation Element. Garden Bar Road is the primary access for three residences located past the project area. No public transportation occurs on Garden Bar Road.




Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in an increase in traffic that is substantial in relation to the existing traffic load and capacity of the street system (i.e., result in a substantial increasein either the number of vehicle trips, the volume-to-capacity ratio on roads, or congestion at intersections)?

25

b. Result in a need for private or public road maintenance, or new roads? 25

c. Result in effects on existing parking facilities, or demand for new parking? --

d. Substantially increase hazards due to a design feature (e.g., a sharp curve or dangerous intersection) or incompatible uses (e.g., farmequipment)?

--

e. Result in a substantial impact upon existing transit systems (e.g., bus service) or alteration of present patterns of circulation or movement of people and/or goods?

25

f. Result in an alteration of waterborne, rail, or air traffic patterns or levels? 25

g. Result in an increase in traffic hazards to motor vehicles, bicyclists, or pedestrians, including short- term construction and long-term operational traffic?

--

h. Result in inadequate: Sight distance? Ingress/egress? General road capacity? Emergency access (4290 Standard)?

--

i. Result in inconsistency with adopted policies supporting the provision of transit alternatives toautomobile transportation on an equitable basis with roadway improvements , e.g. clustered development,commuter-oriented transit, bus turnouts, sidewalks, paths, and bicycle racks?

25

Impact Discussion 16a-c: The project would not contribute to increased traffic during the operational phase of the project. Garden Bar Road at the project is a County maintained unpaved roadway allowing access to local residences. No parking facilities occur onsite or are necessary after construction. No roadway closure will occur during construction. A temporary creek crossing will be provided east of the existing roadway to allow traffic to cross Wolf Creek during construction; therefore, no additional permanent roadways are necessary. Traffic controls will be utilized to direct traffic to the temporary crossing during construction. Garden Bar Road currently is an access road for residences and will remain after construction. This project will have no impact on increased traffic and public or private road maintenance.

Impact Discussion 16d, e, g-i: Design features would comply with Caltrans and County standards. This will ensure than the replacement bridge and roadway facility has adequate sightlines, road capacity, ingress/egress and emergency access. The proposed project would not result in the development of uses that would substantially increase traffic or that would rely on transit services. The project is located well outside bus service areas and airport operations or other travel patterns. The project features will be consistent with existing features that do not result in traffic hazards or inadequacy of roadway travel. The project would not conflict with rideshare programs or other policies supporting alternative transportation, and there would be no impact related to these issues.


Impact Discussion f: The project is not located near any established waterborn, rail, or air traffic patterns. No impact to these transportation systems are anticipated.

17. UTILITIES/ SERVICE SYSTEMS

Existing Setting: No utilities or service systems are located within the project area. The proposed project will not require construction of additional utilities or service systems.



Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Result in a need for the extension of electrical power or natural gas? 25

b. Require the construction of new water or wastewater treatment facilities or expansion of existing facilities, the construction of which couldcause significant environmental effects?

25

c. Exceed wastewater treatment requirements of the applicable Regional Water Quality Control Board?

31

d. Have sufficient water supplies available to serve the project from existing entitlements and resources, or are new or expanded entitlements needed?

25

e. Require or result in the construction of newstorm water drainage facilities or expansion ofexisting facilities, the construction of which couldcause significant environmental effects?

--

f. Be served by a landfill or transfer station withsufficient permitted capacity to accommodate the project’s solid waste disposal needs?

25

g. Comply with federal, state, and local statutes and regulations related to solid waste? 18

h. Require a need for the extension of communication systems? --

Impact Discussion 17a-h: As a transportation project, the project would not result in a need for the extension of electrical power or communication systems, storm drainage facilities, or water or wastewater treatment facilities. No sewer or septic facilities are present on site; therefore, no exceedance of to wastewater treatment requirements will occur. The project would also not generate substantial solid waste during operation. Solid waste that will be disposed of in a landfill will include approximately 42 cubic yards of concrete and rock rubble from the old bridge abutments. It is anticipated that the rest of the existing bridge structure (i.e. wooden bridge deck and steel superstructure) will be recycled and repurposed. Additionally, federal, state, local statutes and regulation related to solid waste will be complied. Therefore, the project would have a no impact related to these issues.


18. MANDATORY FINDINGS OF SIGNIFICANT ENVIRONMENTAL EFFECT


Impact


with Mitigation


Impact

No

Impact

Reference Source

(Appendix A)

a. Does the project have the potential to degrade the quality of the environment, substantially reducethe 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 major periods of California'shistory or prehistory?

23

b. Does the project have environmental effects that are individually limited but cumulatively considerable? (“Cumulatively considerable” means that the incremental effects of the project are considered when viewed in connection with theeffects of past, current, and probable future projects.)

2, 21, 22, 23,

38

c. Does the project have environmental effects, which will cause substantial adverse effects onhuman beings, either directly or indirectly?

2, 18, 20, 21, 22, 24, 25,

38

d. Does the project require the discussion and evaluation of a range of reasonable alternatives,which could feasibly attain the basic objectives of the project?

--

Impact Discussion 18a: Development of the proposed project would comply with all local, state, and federal laws governing general welfare and environmental protection. The project will not substantially reduce habitat for fish or wildlife, cause wildlife populations to decrease, threaten plant and animal communities or restrict plant and animals range leading to California’s history or prehistory. Project implementation, during construction, will result in potential impacts. The project impacts have levels that are less than significant as outlined in the biological resources section.

Impact Discussion 18b: The proposed project is not growth inducing; thus, it would not contribute to the cumulative effects of population growth. Cumulative impacts to aesthetics, air quality, biological resources, cultural resources, geology and soils, hazards/ hazardous waste, and hydrology/ water quality would be reduced to less than significant levels by adhering to local, regional, state, and federal impact standards and by the adherence to the project-specific mitigation measures outlined in this Initial Study. Collectively, these potentially negative impacts to air quality, biological resources, cultural resources, geology and soils, hazards/hazardous materials, hydrology and water quality, and noise are not cumulatively considerable and will result in a less than significant with mitigation impact as outlined in each section.

Impact Discussion 18c: The proposed project will comply with all local, state, and federal laws governing general welfare and environmental protection. Project implementation would not substantially degrade the quality of the existing environment, since the proposed project is a replacement of an existing structure and would not result in any significant adverse and un-mitigatable impacts that could cause adverse effects to humans. Therefore, project impacts on human beings would be less than significant, and no additional mitigation is required.

Impact Discussion 18d: The proposed project will have no significant impacts; therefore, no project alternatives are required to be analyzed. This project will have no impact to basic objectives of the project.


RECOMMENDATION OF THE PROJECT PLANNER

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.

X 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 revisions in the project have been made by or agreed to by the project proponent. 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 "potentially significant impact" or a "potentially

significant unless mitigated" impact 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. 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,

because all potentially significant effects (a) have been analyzed adequately in an earlier EIR or NEGATIVE DECLARATION pursuant to applicable standards, and (b) have been avoided or mitigated pursuant to that earlier EIR or NEGATIVE DECLARATION, including revisions or mitigation measures that are imposed upon the proposed project, nothing further is required.

_______________________________ ______________________

David Garcia Jr., P.E. Project Manager Date

APPENDIX A - REFERENCES

1) AASHTO 2001. American Association of State Highway and Transportation Officials. Geometric Design of Very Low-Volume Local Roads (ADT ≤ 400).

2) ASR 2015. Archaeological Survey Report for Garden Bar Railcar Bridge Replacement Project.

3) Baldwin 2012. The Jepson Manual, Vascular Plants of California, second edition. University of California

Press. Oakland, CA. Available at: <http://ucjeps.berkeley.edu/IJM.html> (accessed 03/03/2015).

4) Calfire 2007. Nevada County-Fire Hazard Severity Zones in SRA. Adopted by Cal Fire November 7, 2007. Available at: <http://frap.fire.ca.gov/webdata/maps/nevada/fhszs_map.29.pdf> (accessed 08/10/2015).

5) Calflora 2015. California Digital Wild Plant Library. Available at: <http://www.calflora.org/> (accessed

03/03/2015).

6) CalEPA 2015. California Environmental Protection Agency. Cortese List: Section 65962.5(a). Hazardous Waste and Substance Site List. Available at: <http://www.calepa.ca.gov/SiteCleanup/CorteseList/SectionA.htm> (accessed 10/22/2015).

7) California Herps 2015. A Guide to the Amphibians and Reptiles of California. Available at:

<http://www.californiaherps.com/frogs/pages/r.boylii.html> (accessed 10/02/15).

8) Caltrans 2014. California Department of Transportation. Construction Manual. Available at: <http://www.dot.ca.gov/hq/construc/constmanual/chapter7/sec7-1.pdf> (accessed 10/20/2015).

9) Caltrans 2011. California Department of Transportation. California Scenic Highways. Available at:

<http://www.dot.ca.gov/hq/LandArch/scenic_highways/index.htm> (accessed 08/05/2015).

10) CDFW 2015. CWHR Life History Accounts and Range Maps. Available at: <http://www.dfg.ca.gov/biogeodata/cwhr/cawildlife.aspx> (accessed 03/03/2015).

11) CEPA 2009. California Environmental Protection Agency. Air Resources Board-California Ambient Air

Quality Standards (CAAQS). Available at: <http://www.arb.ca.gov/research/aaqs/caaqs/caaqs.htm> (accessed 07/22/2015).

12) CNDDB 2015. California Natural Diversity Database, Rarefind 5. Available at:

<http://www.dfg.ca.gov/biogeodata/cnddb/> (accessed on 03/03/2015).

13) CNPS 2015. California Native Plant Society. Inventory of Rare, Threatened and Endangered Plants of California. Available at: <http://www.rareplants.cnps.org/> (accessed 10/21/2015).

14) DOC 2000. Department of Conservation – Division of Mines and Geology. A General Location Guide for

Ultramafic Rocks in California – Areas More Likely to Contain Naturally Occurring Asbestos. Available at: <ftp://ftp.consrv.ca.gov/pub/dmg/pubs/ofr/ofr_2000-019.pdf> (accessed 10/21/2015).

15) DOC 2015. Department of Conservation. Important Farmland Categories. Available at: <http://www.conservation.ca.gov/dlrp/fmmp/mccu/Pages/map_categories.aspx> (accessed on 07/22/2015). D

16) DOC 2015b. Department of Conservation. Alquist-Priolo Earthquake Fault Zones. Available at:

<http://www.conservation.ca.gov/cgs/rghm/ap> (accessed on 10/21/2015).

17) DTSC 2014. Department of Toxic Substances Control. Available at: <https://www.dtsc.ca.gov/> (accessed 11/16/15).

18) EPA 2014. Environmental Protection Agency. Available at: <http://www.epa.gov> (accessed

08/03/2015).

19) FEMA 2015. Federal Emergency Management Agency. Available at: <http://www.fema.gov/> (accessed 08/10/2015).

20) FHWA 2011. Federal Highways Administration. Roadway Construction Noise Model –RCNM. Available

at: <http://www.fhwa.dot.gov/environment/noise/construction_noise/rcnm/> (accessed 10/22/2015).

21) HPSR 2015. Historic Property Survey Report for Garden Bar Railcar Bridge Replacement Project.

22) ISA 2015. Initial Site Assessment for the Garden Bar Railcar Bridge Replacement Project.

23) NES 2015. Natural Environment Study for the Garden Bar Railcar Bridge Replacement Project.

24) Nevada County. 2012b. Nevada County Interactive Map Gallery. Available at: <http://www.mynevadacounty.com/nc/igs/gis/Pages/NCMapGallery.aspx> (accessed 07/27/15).

25) Nevada County 2014. Nevada County General Plan. 1996 drafted and amended in 2014. Available at:

<http://www.mynevadacounty.com/nc/cda/planning/Pages/Nevada-County-General-Plan.aspx> (accessed 03/02/2015).

26) Nevada County 2014b. Western Nevada County District Zoning Map. Available at:

<https://www.mynevadacounty.com/nc/igs/gis/Pages/Zoning.aspx> (accessed 10/21/2015).

27) Nevada County 2015. Nevada County Solid Waste Division. Available at: <http://www.mynevadacounty.com/nc/cda/pw/sw/Pages/Home.aspx> (accessed 11/16/15).

28) NRCS 2015. Natural Resource Conservation Service Web Soil Survey. Available at:

<http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx> (accessed 03/02/2015).

29) NSAQMD 2015. Northern Sierra Air Quality Management District. Available at: <http://myairdistrict.com/index.php?Itemid=70> (accessed 08/04/2015).

30) OHP. 2015. Office of Historic Preservation-California Historical Landmarks. Available at:

<http://ohp.parks.ca.gov/?page_id=21387 > (accessed 08/05/15).

31) SWRCB. 2015. Central Valley Regional Water Quality Control Board. Available at: <http://www.swrcb.ca.gov/rwqcb5/> (accessed 08/10/15).

32) United States (U.S.) Census. 2014. American FactFinder for Nevada County, California. Available at:

<http://factfinder.census.gov/faces/nav/jsf/pages/community_facts.xhtml> (accessed 12/15/14).

33) USFWS. 1996. United States Fish and Wildlife: Endangered and Threatened Wildlife and Plants; Determination of Threatened Status for the California Red-Legged Frog. Federal Register. 5/23/1996. Volume 61, Number 101.

34) USFWS 2002. Recovery Plan for the California Red-legged Frog (Rana aurora draytonii). USFWS

Region1, Portland Oregon. Available at: <http://www.fws.gov/arcata/es/amphibians/crlf/documents/020528.pdf> (Accessed 03/03/2015).

35) USFWS 2015. National Wetlands Inventory. Available at:

<http://www.fws.gov/wetlands/data/mapper.HTML> (accessed 10/21/2015).

36) USFWS 2015b. Information for Planning and Conservation (IPaC). Available at: <http://ecos.fws.gov/ipac/> (accessed 10/21/2015).

37) USGS 2011. Reported Historic Asbestos Mines, Historic Asbestos Prospects, and Other Natural

Occurrences of Asbestos in California. Available at: <ftp://ftp.consrv.ca.gov/pub/dmg/pubs/ms/59/MS59_Plate.pdf> (accessed 08/02/15).

38) WQ. 2015. Water Quality Assessment Report for Garden Bar Road Railcar Bridge Replacement Project.

39) Zeiner 1988-1990. Zeiner, D.C., W.F.Laudenslayer, Jr., K.E. Mayer, and M. White, eds. 1988-1990.

California's Wildlife. Vol. I-III. CDFG, Sacramento, California.

APPENDIX B – ACRONYMS

AMS Alternative Management Standards APE Area of Potential Effects ARB California Air Resources Board ASR Archeological Survey Report

BMPs Best Management Practices BSA Biological Study Area

CAAQS California Ambient Air Quality Standards CAL-FIRE California Department of Forestry and Fire Protection

Cal-IPC California Invasive Plant Council Caltrans California Department of Transportation CESA California Endangered Species Act CEQA California Environmental Quality Act

CH4 Methane CNPS California Native Plant Society CO2 Carbon dioxide

CRLF California Red-Legged Frog dBA Weighted decibel

DTSC Department of Toxic Substance Control EIR Environmental Impact Report EPA United States Environmental Protection Agency ESA Environmentally Sensitive Area

FEMA Federal Emergency Management Agency FESA Federal Endangered Species Act FIRM Flood Insurance Rate Map FYLF Foothill yellow-legged frog GHG Greenhouse Gases HFCs Hydrofluorocarbons HPSR Historic Property Survey Report mph Mile per hour

NAAQS National Ambient Air Quality Standards NES Natural Environmental Study NO2 Nitrogen oxide

NPDES National Pollutant Discharge Elimination System NSAQMD Northern Sierra Air Quality Management District

PFC Perfluorocarbons PG&E Pacific Gas and Electric

PM (2.5 and 10) Particulate matter SF6 Sulfur hexafluoride SSP Special Standard Provisions

SWRCB State Water Resources Control Board TWW Treated Wood Waste VOC Volatile organic compounds

USACE United States Army Corps of Engineers USGS United States Geologic Survey

USFWS United States Fish and Wildlife Service

APPENDIX C – ENVIRONMENTAL COMTITMENTS RECORD

ENVIRONMENTAL COMMITMENTS RECORD

Minimization and Mitigation Summary for Garden Bar Road Railcar Bridge Replacement Project

* The Resident Engineer (RE) is responsible for all activities obligatory of the contractor.

The RE should sign off for the contractor on all measures listed in the table as being a responsibility of the contractor.

Mitigation Measure

Timing/

Reporting

Milestone

Reporting/

Responsible

Party*

Verification of Compliance

Name/

Initials Date Remarks

Air Quality – Measure 3A: Implement Dust Control Measures

AQ-1: Obtain appropriate permits from the NSAQMD for portable

equipment.

Prior to

Construction Contractor

AQ-2: The applicant will implement all dust control measures in a timely

manner during all phases of project development and construction.

During


AQ-3: All material excavated, stockpiled or graded will be sufficiently

watered, treated or covered to prevent fugitive dust from leaving the

project boundaries and causing a public nuisance or a violation of an

ambient air standard. Watering should occur at least twice daily, with

complete site coverage.

During


AQ-4: All areas (including unpaved roads) within the project limits with

vehicle traffic will be watered or have dust palliative applied as necessary

for regular stabilization of dust emissions.

Prior to


AQ-5: All land clearing, grading, earth moving, or excavation activities on

the project will be suspended as necessary to prevent excessive windblown

dust when winds are expected to exceed 20 mph.

During


AQ-6: All on-site vehicle traffic will be limited to a speed of 15 miles per

hour (mph) on unpaved roads.

During


AQ-7: All inactive disturbed portions of the site will be covered, seeded or

watered until a suitable cover is established. Alternatively, the applicant

will be responsible for applying non-toxic soil stabilizers to all inactive

construction areas.

During


AQ-8: All material transported off-site will be either sufficiently watered

or securely covered to prevent public nuisance.

During


AQ-9: If serpentine or ultramafic rock is discovered during construction

the Northern Sierra Air Quality Management District will be notified no

later than the next business day and the California Code of Regulations,

Title 17, Section 9315 applies.

During


Air Quality – Measure 3B: No Vegetation Burning

AQ-10: Open burning of site-cleared vegetation is prohibited. Prior to


Biological Resources – Measure 4A: Avoid Impacts to Sensitive Biological Habitats

BIO-1: Prior to the start of construction activities, the project limits in

proximity to jurisdictional waters (Little Wolf Creek) must be marked with

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high visibility ESA fencing or staking to ensure construction will not

further encroach into waters. The project biologist throughout construction

will periodically inspect the ESA to ensure sensitive locations remain

undisturbed.

BIO-2: Contract specifications will include the following BMPs, where

applicable, to reduce erosion during construction:

- Existing vegetation will be protected in place where feasible to

provide an effective form of erosion and sediment control;

- Stabilizing materials will be applied to disturbed soil surfaces to

prevent the movement of dust from exposed soil surfaces on

construction sites as a result of wind, traffic, and grading activities.

Prior to


Biological Resources – Measure 4B: Avoid impacts to aquatic wildlife.

BIO-3: Erosion Control Measures must be implemented during

construction. To minimize the mobilization of sediment into Little Wolf

Creek, the following erosion-control and sediment-control measures will

be included in the construction specifications, based on standard Caltrans

measures and standard dust-reduction measures.

- Soil exposure must be minimized through the use of temporary

BMPs, groundcover, and stabilization measures;

- The contractor must conduct periodic maintenance of erosion- and

sediment-control measures.

During


BIO-4: Vegetation clearing will only occur within the delineated project

boundaries. An ESA fence will be provided on the final plans to delineate

which trees can be saved and which will be removed. Where possible,

trees will be trimmed rather than removed fully with the guidance of a

qualified biologist. In areas that will be subject to re-vegetation, plants will

only be cleared where necessary and when feasible, will be cut above soil

level.

During


BIO-5: If aquatic wildlife are found at any time during project work,

construction will stop and the animal will be allowed to leave the project

area unharmed. If a State or Federally listed species is discovered, the

appropriate regulatory agency will be contacted immediately for further

guidance..

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BIO-6: Before any activities begin on the project, the project biologist will

conduct environmental awareness training for all construction personnel.

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At a minimum, the training will include a description of sensitive species

with potential to occur, their habitat, the project specific measures being

implemented to conserve the species, and the boundaries within which the

project may be accomplished.

BIO-7: Plastic mono-filament netting (erosion control matting) or similar

material containing netting must not be used at the project area because the

CRLF or other small animals may become entangled or trapped in it.

Acceptable substitutes include coconut coir matting or tackified

hydroseeding compounds.

During


BIO-8: A pre-construction clearance survey will be conducted by the

project biologist to verify that no wildlife is located within the project area.

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Construction County

BIO-9: The County will not use herbicides to control invasive, exotic

plants.

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Construction County

BIO-10: To allow subterranean wildlife enough time to escape initial

clearing and grubbing activities, equipment used during initial clearing and

grubbing will be operated at speeds no greater than three (3) miles per

hour.

During


BIO-11: Narrow screened fencing (no greater than 3-inch) or impassible

barriers will be installed where the project intersects riparian and wetland

habitat to deny western pond turtle and other wildlife access to the

construction site.

Prior to


Biological Resources – Measure 4C: Avoid Impacts to California Black Rail

BIO-12: If construction or restoration activities are necessary during the

black rail breeding season (mid-March to early June), preconstruction

surveys for California black rail will be conducted where suitable habitat

for these species occurs within or adjacent to work areas. Surveys will be

initiated between January 15 and February 1. A minimum of four surveys

will be conducted evenly spaced prior to mid-April.

Should California black rail be identified within the project area during

these surveys, the project biologist will coordinate with California

Department of Fish and Wildlife (CDFW) to determine appropriate

avoidance and minimization measures to prevent project related impacts to

the species.

Prior to

Construction County

Biological Resources – Measure 4D: Avoid Impacts to the Spread of Invasive Plant Species

BIO-13: Prior to arrival at the project site and prior to leaving the project During Contractor





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site, construction equipment that may contain invasive plants and/or seeds

must be cleaned to reduce the spreading of noxious weeds.

Construction

Biological Resources – Measure 4E: Avoid Impacts to Nesting Migratory Birds and Raptors

BIO-14: If possible, vegetation removal should occur outside the breeding

season (February 15th –September 1st) for all bird species.

During


BIO-15: If vegetation removal is to take place during the nesting season

(February 15th –September 1st), a pre-construction nesting bird survey

must be conducted within 7 days prior to vegetation removal. Within 2

weeks of the nesting bird survey, all vegetation cleared by the biologist

will be removed by the contractor.

A minimum 100 foot no-disturbance buffer will be established around any

active nest of migratory birds and a minimum 300 foot no-disturbance

buffer will be established around any nesting raptor species. The

contractor must immediately stop work in the nesting area until the

appropriate buffer is established and is prohibited from conducting work

that could disturb the birds (as determined by the project biologist and in

coordination with wildlife agencies) in the buffer area until a qualified

biologist determines the young have fledged. A reduced buffer can be

established if determined appropriate by the project biologist and approved

by CDFW.

Prior to

Construction County

Biological Resources – Measure 4F: Avoid Impacts to Local Wildlife

BIO-16: The contractor must not apply rodenticide or herbicide within the

project area during construction.

During


BIO-17: The contractor must dispose of all food-related trash in closed

containers, and must remove it from the project area each day during

construction. Construction personnel must not feed or attract wildlife to

the project area.

During


Biological Resources – Measure 4G: Mitigation for Jurisdictional Waters

BIO-18: The County will re-contour the temporary effects to pre-

construction conditions and see the area with a native seed mix. Exact

mitigation ratios and locations will be determined during the

environmental permitting phase of the project. No mitigation for the less

than 0.01 acres of permanent impact is proposed.

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Biological Resources – Measure 4H: Provide documentation of appropriate state and federal authorization for work within Rock Creek

BIO-19: Prior to issuance of improvement plants, the County will provide

the appropriate authorization from CDFW, the Central Valley Regional

Water Control Board, and US Army Corps of Engineers (USACE) for fill

and disturbance of Little Wolf Creek. Permits that may apply include a

Streambed Alteration Agreement from CDFW, a Storm Water Pollution

Prevention Plan from the Regional Water Quality Control Board, and a

Section 404 permit from the USACE. If permits are not required from any

of these agencies, the applicant will provide a written statement from the

agencies to that effect. If permits are required, evidence of completion and

approval of those permits will be submitted to the Planning Department

prior to the issuance of improvement plans.

Prior to

Construction County

Cultural Resources - Measure 5A: Avoid Impacts to Sensitive Cultural Sites

CUL-1: All equipment operators and employees involved in any form of

ground disturbance will be advised of the remote possibility of

encountering subsurface cultural resources.

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CUL-2: Section 5097.94 of the Public Resources Code and Section 7050.5

of the California Health and Safety Code protect Native American burials,

skeletal remains and grave goods, regardless of age and provide method

and means for the appropriate handling of such remains. If human remains

are encountered, California Law requires that work should halt in that

vicinity and the Nevada County Coroner should be notified immediately to

assess the remains. If the coroner determines the human remains to be of

Native American origin, the coroner must notify the Native American

Heritage Commission (NAHC) within twenty-four hours of such

identification. The NAHC shall then determine the Most Likely

Descendant (MLD) of the human remains and contact the MLD

immediately. The County, the MLD, and a professional archaeologist

retained by the County shall then consult to determine the appropriate

plans for treatment and assessment of the human remains and any

associated grave goods.

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CUL-3: If previously unidentified cultural materials are unearthed during

construction, work shall be halted in that area until a qualified

archaeologist can assess the significance of the find and develop a plan for

documentation and removal of resources, if necessary. Additional

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archaeological survey will be needed if project limits are extended beyond

the present survey limits.

Geology/Soils - Measure 6A: Erosion and Sediment Control

GEO-1: Contract specifications will include the following Best

Management Practices (BMPs), where applicable, to reduce erosion during

construction.

- During construction, BMPs for temporary erosion control will be

implemented to control any pollutants that could potentially affect

the quality of storm water discharges from the site.

- Prior to commencement of site work, fiber rolls and silt fencing

should be installed down slope of all proposed areas of disturbance

to reduce migration of sediment from the site. Fiber rolls on slopes

are intended to reduce sediment discharge from disturbed areas,

reduce the velocity of water flow, and aid in the overall revegetation

of slopes. The fiber rolls and silt fence should remain in place until

construction activity is complete and vegetation becomes

established;

- All soil exposed in permanent slope faces should be hydroseeded or

hand seeded/strawed with an appropriate seed mixture compatible

with the soil and climate conditions of the site as recommended by

the local Resource Conservation District, and;

- Following seeding, jute netting or erosion control blankets should be

placed and secured over the slopes steeper than 2:1, H.V.

During


Hazards/Hazardous Materials - Measure 8A: Properly Dispose of TWW and Other Hazardous Waste HAZ-1: The chemically treated wood must be treated as treated wood

waste (TWW) and disposed of as hazardous waste. Should additional

timber used for construction of the bridge, i.e. buried creosote timber piles,

be uncovered during bridge demolition and replacement, this timber would

also be treated as TWW. For the TWW, the DTSC regulations §66261.9.5

provide alternative management standards (AMS) for TWW. Caltrans

Special Standard Provision (SSP) for TWW, SSP 14-11.09, is based on

Department of Toxic Substances Controls AMS regulations. This SSP

directs the Contractor to follow the AMS including providing training to

all personnel that may come in contact with TWW. This training must

include, at a minimum, safe handling, sorting and segregating, storage,

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labeling (including date), and proper disposal methods. HAZ-2: As is the case for any project that proposes excavation, the

potential exists for unknown hazardous contamination to be revealed

during project construction. For any previously unknown hazardous waste/

material encountered during construction, the procedures outlined in the

Caltrans Unknown Hazard Procedures (as seen in Table 7-1.1 of the

Caltrans 2014 Construction Manual) shall be followed (Caltrans 2014).

During


Hydrology/Water Quality - Measure 9A: Follow The Established Water Quality Plan WQ-1: BMPs will be incorporated into project design and project

management to minimize impacts on the environment including the release

of pollutants (oils, fuels, etc.):

- The area of construction and disturbance would be limited to as

small an area as feasible to reduce erosion and sedimentation.

- Measures would be implemented during land-disturbing activities to

reduce erosion and sedimentation. These measures may include

mulches, soil binders and erosion control blankets, silt fencing, fiber

rolls, temporary berms, sediment desilting basins, sediment traps,

and check dams.

- Existing vegetation would be protected where feasible to reduce

erosion and sedimentation. Vegetation would be preserved by

installing temporary fencing, or other protection devices, around

areas to be protected.

- Exposed soils would be covered by loose bulk materials or other

materials to reduce erosion and runoff during rainfall events.

- Exposed soils would be stabilized, through watering or other

measures, to prevent the movement of dust at the project site caused

by wind and construction activities such as traffic and grading

activities.

- All construction roadway areas would be properly protected to

prevent excess erosion, sedimentation, and water pollution.

- All vehicle and equipment maintenance procedures would be

conducted off-site. In the event of an emergency, maintenance

would occur away from the Little Wolf Creek.

- All concrete curing activities would be conducted to minimize spray

drift and prevent curing compounds from entering the waterway

directly or indirectly.

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- All construction materials, vehicles, stockpiles, and staging areas

would be situated outside of the stream channel as feasible. All

stockpiles would be covered, as feasible.

- Energy dissipaters and erosion control pads would be provided at

the bottom of slope drains. Other flow conveyance control

mechanisms may include earth dikes, swales, or ditches. Stream

bank stabilization measures would also be implemented.

- All erosion control measures and storm water control measures

would be properly maintained until the site has returned to a pre-

construction state.

- All disturbed areas would be restored to pre-construction contours

and revegetated, either through hydroseeding or other means, with

native or approved non-invasive exotic species.

- All construction materials would be hauled off-site after completion

of construction.

WQ-2: Any requirements for additional avoidance, minimization, and/or

mitigation measures will be in contained in the permits obtained from all

required regulatory agencies.

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WQ-3: The project limits in proximity to the Little Wolf Creek will be

marked as an ESA and either be staked or fenced with high visibility

material to ensure construction activities will not encroach further beyond

established limits

During


WQ-4: Permanent treatment control BMPs will be evaluated based on

effectiveness and feasibility and incorporated into the final design as

applicable.

Prior to

Construction County

WQ-5: Storm water systems will be designed to prevent the release of

toxins, chemicals, petroleum products, exotic plant materials or other

elements that might degrade or harm biological resources.

Prior to

Construction County

Documents

GARDEN BAR ROAD RAILCAR BRIDGE REPLACEMENT PROJECTdokkenbridges.com/nevada-county/envdoc/Railcar_2106_Draft_ISMND... · garden bar road railcar bridge replacement project nevada county