Chapter 6 Natural Resources and Conservation 6.1 Introduction This chapter analyzes the impacts associated with implementation of the proposed general plan on the following natural resources in the planning area (sections 6.2–6.7, respectively): water resources, agriculture, biological resources, air quality, visual resources, and cultural resources. The impacts of the four alternatives evaluated in this program EIR are qualitatively compared to those impacts of the proposed general plan at the end of each section. Flooding and other hazards are addressed in chapter 7, and storm drainage and conveyance facilities are addressed in chapter 5. 6.2 Water Resources 6.2.1 Environmental Setting Regulatory Setting Beneficial uses and water quality objectives for surface water and groundwater resources in the planning area are established in a Water Quality Control Plan (Basin Plan) by the San Francisco Bay RWQCB, as mandated by the state Porter-Cologne Act and federal Clean Water Act (CWA) (San Francisco Bay Regional Water Quality Control Board 1995). The San Francisco Bay RWQCB is also responsible for administering and enforcing the National Pollutant Discharge Elimination System (NPDES) permit program to manage and monitor point and nonpoint source pollution. NPDES stormwater permits are required for Draft Program Environmental Impact Report August 2001 Comprehensive Amendment to the J&S 01-078 City of Fairfield General Plan 6-1 City of Fairfield Natural Resources and Conservation projects that disturb more than 5 acres of land. Individual NPDES stormwater permits are required for urban areas with populations greater than 100,000, and self-implemented general NPDES stormwater permits are required for most industrial facilities and for construction sites exceeding 5 acres of disturbance. The FSSD administers the Urban Runoff Management Program that was developed for the Cities of Fairfield and Suisun City to comply with the urban NPDES permit requirements (EOA 2000). The general NPDES stormwater permits for general industrial and construction activities require an applicant to file a public notice of intent (NOI) with the applicable RWQCB to discharge stormwater and prepare and to implement a storm water pollution prevention plan (SWPPP). The SWPPP includes a site map, description of stormwater discharge activities, and best management practices (BMPs) that would be employed to prevent water pollution. The SWPPP for general construction activity permits must describe BMPs that would be used to control soil erosion and discharges of other construction-related pollutants (e.g., petroleum products, solvents, paints, cement) that could contaminate nearby water resources. Inspection of BMPs is required to ensure compliance with the SWPPP. The FSSD reviews major development proposals to ensure compliance with the industrial and construction NPDES permit requirements. Surface Water Surface Water Resources Fairfield has a mild Mediterranean climate characteristic of central California, with hot, dry summers and cool, wet winters. Average annual precipitation is approximately 21 inches at the lower elevations in the Fairfield municipal area. Approximately 85% of this precipitation occurs as moderate to intense rainfall from November–March (California Department of Water Resources 2001). Watersheds encompassing the Fairfield area are small, ranging in size from 1.1– 49.5 square miles with a combined drainage area of 142 square miles (90,880 acres). The intermittent or perennial stream systems drain south or east through the study area into Suisun Marsh, the dominant surface water feature of the region. Figure 5-2 shows the major named streams draining the study area from north to south, including McCoy, Laurel, Union Avenue, Pennsylvania Avenue, Ledgewood, Suisun, Dan Wilson, and Green Valley Creeks. Jameson Canyon and American Canyon Creeks drain the area from west to east. The upper reaches of Suisun and Green Valley Creeks originate in the Vaca Mountains and are the largest streams in the area. Water in these streams is impounded with dams at various locations and provides more than 13,000 acre-feet (af) of water to Vallejo. Suisun and Green Valley Creeks are major streams used for irrigation that flow through fertile stream valleys with excellent soil. McCoy, Laurel, Union Avenue, and Pennsylvania Avenue Creeks drain the watersheds north of Travis AFB and Fairfield, discharging through minor sloughs into Suisun Slough. Suisun, Dan Wilson, and Green Valley Creeks Draft Program Environmental Impact Report August 2001 Comprehensive Amendment to the J&S 01-078 City of Fairfield General Plan 6-2 City of Fairfield Natural Resources and Conservation originate in the Vaca Mountains and drain upper and lower Suisun and Green Valleys between Cordelia and Fairfield before emptying into Cordelia Slough. Ledgewood Creek also drains Suisun Valley into Suisun Marsh. Jameson Canyon and American Canyon Creeks collect runoff from part of the Coast Ranges southwest of Cordelia and discharge into Cordelia Slough. Many modifications of the natural stream alignments have been constructed at the lower elevations leading to Suisun Marsh to increase flow capacity in channels and reduce flooding hazards. The Putah South Canal traverses the study area from northeast to southwest, delivering water from Lake Berryessa for agricultural and municipal purposes in the study area. The North Bay Aqueduct generally parallels the Putah South Canal through Fairfield to the south and conveys water from the Delta to Fairfield. The SID provides irrigation water from Lake Berryessa to agricultural lands in the vicinity of Fairfield, primarily in the Suisun Valley. A portion of the water that is imported into the Fairfield watersheds ultimately drains into Suisun Marsh as treated municipal wastewater or irrigation return flows. Surface Water Quality Fairfield streams have been used primarily for fish and wildlife habitat, recreation, groundwater recharge, and agricultural water supply. City water supplies are provided entirely from imported surface water. The San Francisco Bay RWQCB has designated beneficial uses for Suisun, Green Valley, Laurel, and Ledgewood Creeks that include cold and warm water fish habitat, recreation, migration and spawning, and wildlife habitat (San Francisco Bay Regional Water Quality Control Board 1995). The U.S. Environmental Protection Agency (EPA) has also listed Laurel and Ledgewood Creeks as “water quality limited” on the list of impaired water bodies because of elevated levels of diazanons in Section 303(d) of the federal CWA. The Suisun Marsh wetlands are listed as being impaired by metals, nutrients, organic enrichment, dissolved oxygen, and salinity (EOA 1999). Background water quality monitoring data for area streams is limited, but previous investigations include a water quality study of the Fairfield streams and sloughs in connection with the Fairfield Vicinity Streams Project that found high levels of nutrients and pesticides and low levels of heavy metals in most streams (U.S. Army Corps of Engineers 1975). Nutrient levels were attributable to agricultural runoff, while the pesticides stemmed primarily from urban runoff. Oxygen content and acidity were within acceptable ranges for aquatic life. Total suspended solids were high, possibly indicating upstream erosion problems. Suspended solids act as carriers for other pollutants such as bacteria and heavy metals and increase stream turbidity and sedimentation. More recently, the FSSD has conducted specific monitoring for the Urban Runoff Management Program (EOA 2000), an ongoing program being conducted to comply with the regulatory requirements of the NPDES stormwater permit program for urban areas that exceed a population of 100,000. Dry-season monitoring of total and dissolved metals, total suspended solids, coliform Draft Program Environmental Impact Report August 2001 Comprehensive Amendment to the J&S 01-078 City of Fairfield General Plan 6-3 City of Fairfield Natural Resources and Conservation bacteria, and 2 pesticides (diazanon and chlorpyrifos) in McCoy, Laurel, Ledgewood, Green Valley, and American Canyon Creeks was conducted on 4 dates during summer 1999 and summer 2000 (EOA 2000). The data indicated that water quality in general was very good given the urban environment through which the streams flow. Arsenic was elevated in McCoy Creek and was hypothesized to result from extended detention of the flows in a large upstream detention basin that allowed sufficient time for natural arsenic to leach from the soil into the water. The FSSD is continuing to investigate the arsenic problem with University of California, Davis staff. Maintaining and enhancing water quality in the area streams is important because all runoff and wastewater from the study area eventually discharges into Suisun Marsh. Suisun Marsh is protected under state law (the Suisun Marsh Preservation Act of 1977) in recognition of its irreplaceable value as a wildlife and aquatic habitat. The water quality of Suisun Marsh is influenced mainly by temperature, turbidity, contaminants, and salinity. Salinity is steadily increasing because of fresh water diversions from the Delta, increasing the importance of local freshwater inflow from groundwater, runoff, and wastewater discharge (California Department of Water Resources 1991). The CDWR, in accordance with the Suisun Marsh Preservation Act, installed control structures on Montezuma Slough to control salinity intrusions into Suisun Marsh. Treated wastewater