County of Napa

Scope of Work - Program EIR Baseline Data Report

County of Napa

Program Environmental Impact Report (eir)

Baseline Data Report (mea)

-Scope of Work -

Overview:

The purpose of this ProgramEIR Baseline Data Report (aka; Master Environmental Assessment), hereafter referred to as the Baseline Data Report, is to document and describe the existing environmental characteristics of the County of Napa. Specifically, the Baseline Data Report will provide the most current condition for the following resource topics: geology and soils; mineral and rock resources; climate and air quality; surface hydrology; groundwater hydrology; surface water quality; biological resources; energy consumption; noise; public health and safety; population and housing; land use, agricultural resources; transportation and circulation; visual and aesthetic resources; public facilities and services; and cultural resources (includes historical and archeological resources).

When completed, the Baseline Data Report will provide the existing conditions data required for a number of planning efforts, including, but not limited to, a Program EIR on the Conservation Regulation Update currently underway, a possible County General Plan update, various specific plan efforts, and certain site-specific project reviews. However, due to the unknown nature of potential future projects, additional site-specific baseline data collection efforts may be necessary.

Project Management and Coordination:

Successful completion of this project will rely on a high degree of internal and external coordination. Project management responsibilities shall therefore include project coordination, budget expenditure review, and monthly invoicing. Coordination with the County shall include regular weekly communication and updates with the County Project Manager. Monthly invoice statements will include a brief status report describing progress to date during the invoiced period including discussion of any key technical accomplishments or challenges and conformance with the production schedule. Project status meetings (up to 10) with the County Project Manager will be conducted to coordinate work, discuss data issues, assess progress, solve problems, and keep the project generally on track. These meetings shall have an agenda. A meeting summary outlining key decisions and necessary follow-up shall be prepared and distributed to the participants and the County Project Manager.

A specific subset of project management and coordination responsibilities shall be focused on development of the GIS database. Key tasks shall include the following:

  1. development of a metadata template to ensure data integrity and track data processing;
  2. establishment of protocols to document edits and updates;
  3. definition in consultation with the County of appropriate mapping units;
  4. creation in consultation with the County of report-size and wall-size map layouts;
  5. coordination with County GIS staff;
  6. development of an appropriate attribute data database; and
  7. manage digitizing, data transformation, and data processing.

To manage and conduct the GIS data processing and analysis for the BDR, it is assumed that data being supplied to the consultant already meets the county's metadata and mapping accuracy requirements. The consultant will not be editing or cleaning up existing supplied data. A key data resource to initiate several topics within the BDR is the LIDAR based DEM that the County will be supplying to the consultant. The delay of access to this information will delay the initiation and delivery of resource topic sections of the BDR that are dependent on this information.

Individual Resource Topics:

The specific information, data, deliverables, and the models and geographic evaluation areas to be used for each of the resource topics identified above is presented below.

I.Geology and Soils

Information Required: This section shall provide information on physiography, geology, soils, slope stability, and the seismic environment in Napa County with an emphasis on conditions and hazards that are likely to affect urban and agricultural development patterns. Specifically, data collection shall include the following major earth resource-related topics:

  • Physical geographic features and their distribution;
  • Slopes and their distribution
  • Characteristics and geographic distributions of bedrock and near surface or “surficial” geologic units;
  • Characteristics and geographic distributions of soil types;
  • Nature and geographic distribution of geologic and soil-related hazards including severe erosion, expansive soils, settlement, landslides, earthflows, potentially unstable slopes, and land subsidence;
  • Location and activity of known faults in Napa County and vicinity; and
  • Seismic hazards including surface fault rupture, ground shaking, and earthquake-induced ground failures such as liquefaction, landslides, and earthflows.

Deliverables shall include a technical report with appropriate maps and graphics, both in hardcopy and on CD-ROM, of sufficient detail to illustrate the geographic distribution of the above-listed earth resources and related hazards and a summary suitable for use as the setting section in a Program EIR. The maps provided shall be at a scale of 1:24,000 and include, at a minimum, a Bedrock & Geologic Structure Map, a Surficial Deposits Map, a Landslides Map, a Faults Map, and a Dam/Levee Failure Inundation Map. Where available, Napa County’s Environmental Resource Maps shall be used as the base and starting point for further mapping. All information, data, and interpretations provided in this section shall be based entirely on published data and reports issued primarily by the U.S. Geological Survey, the Association of Bay Area Governments, the California Geological Survey, the Natural Resources Conservation Service, and Napa County. The compiling of existing data from disparate, site-specific sources not part of the Napa Co Environmental Resource Mapping System, such as project-level environmental studies, will not be undertaken. However, limited field work to spot check aerial photo analysis and resolve discrepancies between existing maps may be necessary.

Evaluation Areas(3):

  • Napa Valley (Western Mtns, Carneros Area, Napa River Marshes, Jamieson/American Canyon, Napa Valley Floor, Angwin Area, & Eastern Mtns)
  • Interior Valleys (Pope Valley, Central Interior Valleys, and Southern Interior Valleys)
  • Berryessa/Knoxville Area

II.Mineral/Rock Resources

Information Required: This section shall involve the collection and integration of existing and disparate data on mines, quarries and other economic rock activities in Napa County. It shall identify the geographic distribution of known mineral and rock resources and provide a discussion of the importance of these resources at the state, county, and local levels. If sufficient information exists, a discussion addressing the economic, regulatory, and political feasibility of extracting mineral resources from areas that are not currently part of ongoing mining operations shall also be included.

Deliverables shall include a technical report with appropriate maps and graphics, both in hardcopy and on CD-ROM, and a summary suitable for use as the setting section in a Program EIR. Maps shall be at a scale of 1:24,000 and include at a minimum a Mines, Quarries & Known Rock/Mineral Resource Areas Map showing the geographic distribution of these resources and the location of existing mines and quarries. The information and maps presented shall be based primarily on published data, reports, and maps issued by the U.S. Geological Survey, the California Geological Survey, and the County of Napa, but shall also draw from personal communications/interviews with staff from these agencies. Collection of new data or the compiling of existing data from disparate, site-specific sources not in the files of the County, such as project-level environmental studies, will not be necessary to complete this task. However, limited fieldwork to spot check aerial photo interpretations and existing mappings may be required.

Evaluation Area(1):

  • County (as a whole)

III.Climate and Air Quality

Information Required: This section shall provide an evaluation of the climatic conditions (temperature, wind, rainfall, humidity, inversions) that exist within Napa County and describe how topography and these factors potentially affect air quality. The collected climate data will be instrumental in developing the baseline hydrologic analysis. Climatic data in general and rainfall in particular will be assembled from many sources including, but not limited to, public sources (depending upon availability) such as the USGS, Napa Co RCD, Napa Co Airport, and NWS; and private sources such as private vineyard owners, and the Nexrain Corporation, (depending on availability and cost).

As the County is within the San Francisco Bay Area Air Basin (SFBAAB), and under the jurisdiction of the Bay Area Air Quality Management District (BAAQMD), applicable BAAQMD air quality rules, regulations, plans, policies, and significance criteria shall be summarized. In addition, local, state, and federal regulations relating to air quality shall be identified and summarized. A review and summary of existing climatic and air quality monitoring data from the California Air Resources Board and Bay Area Air Quality Management District monitoring stations in and near the County for the last three years shall be provided to characterize existing air quality conditions in the region. In addition, emissions from vehicular traffic along the major roadways in the County shall be calculated based on VMT and other traffic data (i.e., intersection V/C and LOS) provided by the County. The calculation of emissions from vehicular traffic shall be done using the EMFAC7Fcomputer model for localized CO modeling at up to 12 roadway segments and 4 intersections which will be selected based on the highest traffic data or highest probability for air quality exceedance. The most recent version of the Urbemis computer model for regional air quality modeling will be used. Particular attention shall be paid to particulate matter smaller than 10 microns in size (PM10) and diesel exhaust. However, site-specific diesel health risk assessments will not be performed. Identification of any areas that exceed state and/or federal standards shall be included. Fixed source and stationary source emissions, particularly dust from farming operations and active quarries, shall be estimated. The location of sensitive receptors (i.e., facilities that house persons who are particularly sensitive to air pollution such as hospitals, nursing homes, and schools) shall be mapped.

Deliverables shall include a technical report with appropriate maps and graphics, both in hardcopy and on a CD-ROM, and a summary suitable for use as the setting section in a Program EIR. Maps shall be at a scale of 1:12,000 and include, at a minimum, an accurate, updated, IsoplethAverage Annual Rainfall and Meteorological Stations Map of the County, a Rainfall Intensities Map (2-, 10- & 100-Year Storms), an Ambient Air Quality Standards Excedence Map, and a Sensitive Receptors Map. The number of available data points and the accuracy of the data from those points shall determine the accuracy of the maps. No new field measurements or development of new field data will be undertaken.

Air Quality Models

  • EMFAC7F
  • Urbemis 2001 ()

Evaluation Areas:

Climate (10):

  • Lower Napa Valley (Carneros, Napa River Marshes, & Jamieson/American Canyon)
  • Napa Valley Floor
  • Western Mountains
  • Angwin/Livermore Ranch Area
  • Eastern Mountains (excludes Angwin Area)
  • Pope Valley (includes adjoining uplands)
  • Central Interior Valleys (Chiles, Capel1, & Soda valleys and adjoining uplands)
  • Southern Interior Valleys (Wooden & Gordon Valleys and adjoining uplands)
  • Berryessa Area (includes adjoining uplands and subsidiary valleys to Berryessa Valley)
  • Knoxville Area (includes Upper Putah Creek Area)

Air Quality-Air “Basins” (5):

  • Lower Napa Valley (Carneros, Napa River Marshes, & Jamieson/American Canyon)
  • Upper Napa Valley (Napa Valley Floor, Angwin Area, Eastern Mtns, & Western Mtns)
  • Interior Valleys (Pope Valley, Central Interior Valleys, and Southern Interior Valleys)
  • Berryessa Area (includes adjoining uplands and subsidiary valleys to Berryessa Valley)
  • Knoxville Area (includes Upper Putah Creek Area)

Air Quality-Major Roads (9)

  • State Highways
  • Silverado Trail
  • Petrified Forest Rd
  • American Canyon Rd
  • Flosden Rd

IV.Surface Hydrology

Introduction: The baseline surface hydrology, groundwater hydrology and water quality analysis will support several county programs including:

  • Conservation Regulations: A more complete mapping and understanding of the County’s stream network identifying how stream classes and flow conditions relate to watershed characteristics.
  • Environmental/CEQA Compliance: Hydrologic and water quality information to support programmatic level CEQA type analysis of countywide planning initiatives. The baseline data will be used to guide/support the assessment of direct/indirect hydrologic impacts, development of alternatives, and most importantly evaluation of cumulative impacts. Within a programmatic CEQA approach, such analyses will generally occur at watershed to drainage scales, not at the scale of an individual parcel or site.

A MIKE-SHE Surface Hydrology-Groundwater-Water Quality Model (MIKE-SHE ISGW) shall be developed and used to provide the required information. Necessary input data to develop the MIKE-SHE ISGW model will be collected as well as processed from other relevant supporting resource topics specified under this scope-of-work, including GIS-based information on: topography, geology, soils, temperature, evaporation, wind, precipitation, vegetation, land-use, population; etc.

In areas where existing data is limited additional metadata and information describing soil, vegetation, water quality and other characteristics can be sought within the proposed level of effort for the other tasks within the BDR. General scientific information, accepted standards, and interpolation/extrapolation of existing data may therefore be required to supplement existing data.

No new data will be generated to support the hydrological models. The DEM information provided by the County (both traditional aerial photo and LIDAR-based) will have adequate geographic coverage to support the hydrologic analysis. The supplied DEM data shall be “clean” in that it requires no additional post processing. Based on the available DEM, the Consultant shall delineate 100 drainages within the County. The drainage basin delineation shall be approved by County and after approval be used by Consultant in the further hydrological analysis. Because the LIDAR-based DEM information is so critical to initiate the hydrology work plan, its delay will in turn delay the hydrology work plan. To advance the completion of the project, the consultant team is committed to initiating all possible tasks that are not dependent upon this data. Excessive delays of the LIDAR data (several months) may require additional budgeting and scheduling to successfully accomplish project objectives.

It is very important that the data collection and processing carried out for other resource topics will support the hydrological analysis; therefore close coordination with other resource studies is anticipated and important.

As noted previously where existing data is not available best engineering judgment will be applied to provide the best input data for the models. The models will be calibrated to the extent possible, however it should be noted that the model in areas with sparse or no data will be less accurate. The baseline hydrologic analysis will be capable of supporting specific project impact assessments at the drainage scale. The baseline hydrologic analysis will provide a basis for more detailed project level impact assessments, but such assessments are beyond the current work plan.

Task1. Baseline Surface Hydrology Assessment

Approach: A basic MIKE-SHE model shall be developed to permit assessment of runoff characteristics for drainages within Napa County. Due to budget constraints at this time, this scope of work will provide runoff characteristics for 100 drainages to be selected by the County (in consultation with the Resource Conservation District and the Flood Control District). However, during the execution of the project, the consultant team and the County Project Manager will strive to identify other funds and look for cost-saving efficiencies in order to permit the assessment of runoff characteristics for the remaining 45 drainages within the County. The MIKE-SHE model will be developed to allow runoff assessment for all drainages irrespective of whether or not the consultant team conducts the assessment as part of this project.

Only major streams in each drainage basin will be included in the models surface drainage network. The MIKE-SHE model will utilize the existing MIKE 11 and HECRAS models previously developed for Napa County. Cross sections for major stream reaches not included in existing MIKE 11 or HECRAS models will, to the extent possible, be extracted from the DEM. Channel routing in minor streams will be accounted for in the conceptual description of the runoff processes (i.e., the MIKE-SHE routing parameters). Flow conditions at the outlet of each drainage area will be the reference point for the particular drainage. While the MIKE-SHE model will be capable of supporting more detailed evaluations at project-scales within the designated drainages, such analyses will not occur within the work-plan of the current BDR project.