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3A. AIR QUALITY
3B. GEOLOGY & SOILS
3C. HAZARDS AND HAZARDOUS MATERIALS
3D. HYDROLOGY & WATER QUALITY
3E. LAND USE
3F. NOISE
3G. PUBLIC SERVICES AND UTILITIES
3H. TRANSPORTATION/ TRAFFIC
This section, Environmental Analysis, examines the environmental consequences associated with the construction and operation of the Valley New High School No. 1. Section 2 offers a complete and detailed description of the proposed project.
The NOP/ IS for this project identified air quality, noise, and traffic as the potentially significant environmental impacts associated with the construction and operation of the proposed high school. The other environmental issues were identified as less than significant or no impact. The list of environmental issues considered in this section was expanded to include issues presented in the March 20, 2001 public scoping meeting and issues identified through project technical reports. Therefore, eight environmental issue areas are evaluated in this section. These environmental issues are listed below:
3A Air Quality 3E Land Use 3B Geology and Soils 3F Noise 3C Hazards and Hazardous Materials 3G Public Services and Utilities 3D Hydrology and Water Quality 3H Transportation/ Traffic
Within each issue area, the project is discussed in the following order: · Introduction · Setting · Applicable Regulations · Impacts and Mitigation -Methodology -Criteria for Determining Significance -Project Impacts -Mitigation Measures -Cumulative Impacts -Mitigation Measures.
Impact Significance Categories
While the criteria for determining significant impacts are unique to each issue area, the classification of the impacts was uniformly applied in accordance with the following definitions:
· A beneficial impact would result when the proposed project would have a positive effect on the natural or human environment, and no mitigation would be required.
· A designation of no impact is given when no adverse changes in the environment are expected. · A less-than-significant impact would cause no substantial adverse change in the environment. · A significant (but mitigable) impact would have a substantial adverse impact on the environment, but could be reduced to a less-than-significant level with mitigation.
· A significant unavoidable impact would cause a substantial adverse effect on the environment, and no feasible mitigation measures would be available to reduce the impact to a less-than-significant level. To index
3A.1 Introduction
3A.2 Existing Setting
3A 2.1 Climate and Meteorology
3A.2.2 Existing Air Quality
3A.2.3 Sensitive Receptors
3A.3 Applicable Regulations
3A.4 Impacts and Mitigation
3A.4.1 Methodology
3A.4.2 Project Impacts
3A.4.3 Cumulative Impacts
3A. 1 INTRODUCTION This section presents information on ambient air quality conditions in the vicinity of the project site, and also identifies potential impacts to air quality as a result of the construction and operation of the proposed project. Sections 3A. 2 and 3A. 3 describe the existing setting as it relates to air quality and applicable regulations, respectively. Section 3A. 4 describes impacts and mitigation measures including the methodology and criteria for determining significance. Mitigation measures are proposed for any impact determined to be significant. To index
3A. 2.1 Climate and Meteorology The study area lies within the South Coast Air Basin (SCAB) (see Figure 3A-1), which is characterized as a Mediterranean climate with mild winters, when most rainfall occurs, and hot, dry summers. The regional climate is dominated by a strong and persistent high-pressure system that frequently lies off the Pacific coast (generally known as the Pacific High). The Pacific High shifts northward or southward in response to seasonal changes or the presence of cyclonic storms. Besides the influence from the Pacific High, other important meteorological characteristics influencing air quality in the study area are the persistent temperature inversions, predominance of onshore winds, mountain ridge and valley topography, and prevalent sunlight.
Temperature and Precipitation. A monthly climate summary for a monitoring station in Canoga Park (approximately 3 miles southwest of the proposed project) was selected to characterize the climate of the study area. As described in Table 3A-1, average summer (July) high and low temperatures in the study area are 94.8 ° ° F (34.9 ° ° C) and 57.0 ° ° F (13.8 ° ° C), respectively. Average winter (January) high and low temperatures in the study area are 67.6 ° ° F (19.8 ° ° C) and 39.2 ° ° F (4.0 ° ° C). Rainfall averages approximately 17 inches (43 centimeters) per year in the study area. Most of the annual rainfall occurs between November and April, with negligible precipitation during summer months.
Winds. Wind patterns in the project vicinity display an unidirectional on-shore flow from the southwest that is strongest during the summer, with a weaker off-shore return flow; return flow is strongest in the winter nights when the land is colder than the ocean. Local topography in the project area may modify these wind patterns to an extent, but the day-night difference is still very noticeable. The on-shore winds that sweep across the region average from seven to nine miles per hour (mph) with stronger winds occurring during the summer. The offshore flow is often calm or drifts slowly southwesterly at two to six mph, with winter nights showing the strongest effects. Aspen Environmental Group Figure 3A-1 South Coast Air Basin
STUDY AREA
Source: CARB, 2000 Riverside Co.
San Bernardino Co. Orange Co.
Los Angeles Co. North Long Beach-G, P Lynwood-G, P Diamond Bar-G (opened 5/ 94) Pomona-G Pico Rivera-G, P Hawthorne-G, P
Los Angeles-G, P Glendora-G Azusa-G, P Pasadena-G, P West Los Angeles-G, P Burbank-G, P Reseda-G
Santa Clarita-G, P
Costa Mesa-G El Toro-G, P
Anaheim-G, P Los Alamitos-P (closed 2/ 94) La Habra-G Norco-G, P Ontario-P
Upland-G, P Fontana-G, P Lake Gregory-G, P San Bernardino-G, P
Redlands-G, P
Rubidoux-G, P Magnolia-G, P Riverside (2)
Perris-G, P Hemet-G Lake Elsinore-G
Temecula-P (closed 3/ 94)
N 1 0 ½ ¼ Scale in Miles
P G Monitoring Particulate Monitoring Gaseous California Air Basin
Valley New High School 1
Table 3A-1 Monthly Average Temperatures and Precipitation Temperature
Precipitation
Maximum Minimum Month o F o C o F o C Inches Centimeters
January 67.6 19.8 39.2 4.0 3.79 9.63
February 70.1 21.2 40.7 4.8 3.66 9.30
March 72.1 22.3 41.7 5.4 2.87 7.29
April 77.0 25.0 44.7 7.1 1.13 2.87
May 80.6 26.9 48.9 9.4 0.26 0.66
June 87.2 30.7 52.8 11.6 0.05 0.13
July 94.8 34.9 57.0 13.8 0.01 0.03
August 95.3 35.2 57.4 14.1 0.11 0.28
September 91.5 73.7 54.6 12.6 0.17 0.43
October 84.1 28.9 48.8 9.3 0.43 1.09
November 74.8 23.8 42.6 5.9 1.90 4.83
December 68.8 20.4 38.8 3.8 2.27 5.77
Note: Period of Record is July 1, 1949 to July 31, 2000. Source: Western Regional Climate Center Internet site (http:// www. wrcc. sage. dri. edu, 5-17-01) To index
3A. 2.2 Existing Air Quality Criteria Pollutants. The quality of the surface air (air quality) is evaluated by measuring ambient concentrations of pollutants that are known to have deleterious effects. The degree of air quality degradation is then compared to the current National and California Ambient Air Quality Standards (NAAQS and CAAQS). Because of unique meteorological problems in the State, and because of differences of opinion by medical panels established by the California Air Resources Board (CARB) and the USEPA, there is considerable diversity between State and Federal standards currently in effect in California. In general, the CAAQS are more stringent than the corresponding NAAQS. Those standards currently in effect in California are shown in Table 3A-2.
Air quality standards are designed to protect those people most susceptible to further respiratory distress, such as asthmatics, the elderly, very young children, and people already weakened by other disease or illness. Table 3A-3 provides a summary of the health effects from the major criteria air pollutants. It should be noted that healthy adults can tolerate occasional exposure to air pollutant concentrations above these minimum standards before adverse effects are observed.
Attainment Status. A summary of the air quality status of the SCAB, relative to meeting the National and State AAQS is provided in Table 3A-4. Non-attainment is a term used to indicate violations of the standard. As listed in Table 3A-4, air quality in the SCAB is non-attainment of the NAAQS and CAAQS for ozone (O3 ), carbon monoxide (CO), and fine particulate matter (PM10 ). With regard to NO2 , the USEPA and CARB are currently in the process of changing the attainment status of the SCAB for NO2 from non-attainment to attainment.
Table 3A-2 National and California Ambient Air Quality Standards Pollutant Averaging Time California Standards 1 National Standards 2 8-hour NS 0.08 ppm 3 Ozone (O3) 1-hour 0.09 ppm 0.12 ppm 8-hour 9.0 ppm 9.0 ppm Carbon Monoxide (CO) 1-hour 20 ppm 35 pm Annual Arithmetic Mean NS 0.053 ppm Nitrogen Dioxide (NO2) 1-hour 0.25 ppm NS Annual Arithmetic Mean NS 0.03 ppm 24-hour 0.04 ppm 0.14 ppm Sulfur Dioxide (SO2) 1-hour 0.25 ppm NS Monthly 1.5 ug/ m 3 NS Lead (Pb) Quarterly NS 1.5 ug/ m 3 Sulfates (SO4) 24-hour 25 ug/ m 3 NS Hydrogen Sulfide (H2S) 1-hr 0.03 ppm NS Annual Arithmetic Mean NS 50 ug/ m 3 Annual Geometric Mean 30 :g/ m 3 NS Fine Particulate Matter (PM10) 24-hour 50 :g/ m 3 150 ug/ m 3 Annual Arithmetic Mean NS 15 ug/ m 3 Very Fine Particulate Matter (PM2.5) 3 24-hour NS 65 ug/ m 3 Notes: ppm= parts per million; ug/ m 3 = micrograms per cubic meter; NS= no standard 1. California standards for ozone, carbon monoxide (except Lake Tahoe), sulfur dioxide (1-hour and 24-hour), nitrogen dioxide, and PM10 are values that are not to be exceeded. If the standard is for a 1-hour, 8-hour, or 24-hour average, then some measurements may be excluded. In particular, measurements are excluded that California Air Resources Board determines would occur less than once per year on the average. 2. National standards other than for ozone and those based on annual averages or annual arithmetic means are not to be exceeded more than once a year. The ozone standard is attained if, during the most recent three-year period, the average number of days per year with maximum hourly concentrations above the standard is equal to or less than one. 3. In 1997, USEPA established an 8-hour standard for ozone, and annual and 24-hour standards for very fine particulate matter (PM2.5). The USEPA's new standards were challenged in court, and as of April 2001, their status was uncertain. Source: SCAQMD, 1993 and USEPA, 2001a.
Table 3A-3 Summary of Health Effects of the Major Criteria Pollutants Air Pollutant Adverse Effects
Ozone · Eye irritation · Respiratory function impairment · Aggravation of respiratory and cardiovascular diseases
Carbon Monoxide · Impairment of oxygen transport in the bloodstream, increase of carboxyhemoglobin · Aggravation of cardiovascular disease · Impairment of central nervous system function · Fatigue, headache, confusion, dizziness · Death at high levels of exposure · Aggravation of some heart diseases (angina)
Nitrogen Dioxide · Risk of acute and chronic respiratory disease Suspended Particulates · Increased risk of chronic respiratory disease · Reduced lung function · With SO2, may produce acute illness · Particulate matter 10 microns or less in size (PM10) may lodge in and/ or irritate the lungs Source: SCAQMD, CEQA Air Quality Handbook, 1993.
Table 3A-4 Attainment Status of South Coast Air Basin O3 CO NO2 SO2 PM10 Air Basin State Federal State Federal State Federal State Federal State Federal
South Coast N Extreme Non-Attainment N N T T A A N Serious Non-Attainment Note: A= Attainment of Standards; N= Non-Attainment; T= Non-Attainment (Transitional) Source: SCAQMD, 2001a and USEPA, 2001b.
Indications of criteria pollutant levels near the project area can be obtained by reviewing recent data collected at nearby SCAQMD monitoring stations. Two monitoring stations in the study area were selected to provide a general profile of the air quality within the study area. Table 3A-5 provides the monitoring data from 1996 to 1999 for the Reseda (O3, NO2, and CO data) and Burbank (PM10 data only) monitoring stations.
Table 3A-5 Project Area Air Quality Summary Standard 1996 1997 1998 1999 OZONE (1-Hour) STANDARD Maximum Concentration (ppm) Days >CAAQS (0.09 ppm)
Days > NAAQS (0.12 ppm) 0.20 50 11 0.12 12 0 0.16 23 7 0.10 10 0 NO2 (1-Hour) STANDARD a Maximum Concentration (ppm) Days > CAAQS (0.25 ppm) 0.16 0 0.13 0 0.14 0 0.11 0
PM10 (24-Hour) STANDARD b Maximum Concentration (ug/ m 3 ) Days > CAAQS (50 ug/ m 3 )
Days > NAAQS (150 ug/ m 3 ) 110 15/ 59 0/ 59 92 17/ 56 0/ 56 75 9/ 59 0/ 59 82 21/ 60 0/ 60 CO (8-Hour) STANDARD Maximum Concentration (ppm) Days > CAAQS (9.0 ppm)
Days > NAAQS (9.0 ppm) 8.7 0 0 9.5 1 1 9.3 1 1 7.5 0 0 Source: CARB, 2000. California Ambient Air Quality Data, 1980 to 1999. Notes: ppm= parts per million; ug/ m 3 =micrograms per cubic meter a No Federal (1-hour) NO2 standard. b "Days" for PM10 are given as exceedences/ number of annual measurements.
As described in Table 3A-5, the maximum one-hour concentration for ozone during 1996 was 0.20 ppm. There were 50 exceedances of the CAAQS and 11 exceedances of the NAAQS for the one-hour concentration of ozone during 1996. In the years 1997 through 1999, the average one-hour ozone concentration ranged from 0.10 in 1999 to 0.16 in 1998, with 45 exceedances of the CAAQS and 7 exceedances of the NAAQS during the three year time period. Ambient NO2 levels at the Reseda monitoring station were below the CAAQS during the four-year study period. The PM10 concentrations exceeded the CAAQS (24-hour) of 50 micrograms per cubic meter (50 ug/ m 3 ) at the Burbank station between 9 and 21 times a year during the four year period, averaging approximately 16 exceedances a year. It should be noted that no exceedances of the NAAQS for PM10 were recorded during the four-year period. Maximum 8-hour CO concentrations at the Reseda monitoring station ranged from 7.5 parts per million (ppm) to 9.5 ppm during the four year period for an average of 8.8 ppm. There were two exceedances of the CAAQS during the study period: one during 1997 and one during 1998. To index
3. A. 2.3 Sensitive Receptors Some land uses are considered more sensitive to air pollution than others due to the types of population groups or activities involved. Sensitive population groups include children, the elderly, the acutely ill and the chronically ill, especially those with cardio-respiratory diseases.
Residential areas are also considered to be sensitive to air pollution because residents (including children and the elderly) tend to be at home for extended periods of time, resulting in sustained exposure to any pollutants present. Recreational land uses are considered moderately sensitive to air pollution. Although exposure periods are generally short, exercise places a high demand on respiratory functions, which can be impaired by air pollution. In addition, noticeable air pollution can detract from the enjoyment of recreation. Industrial and commercial areas are considered the least sensitive to air pollution. Exposure periods are relatively short and intermittent, as the majority of the workers tend to stay indoors most of the time. In addition, the working population is generally the healthiest segment of the public.
A land use survey was conducted to identify sensitive receptors (e. g., schools, hospitals, churches, recreational facilities) in the general vicinity of the proposed project. Refer to Figure 3F-1 in the Noise Section for the location of the sensitive receptors within the study area. Sensitive receptors identified include: three student dorm buildings, the closest of which are approximately 200 feet north and northwest from the project site; Rosecrown Hall (first floor is the headquarters for CSUN's Public Safety, the upper floors are residences for students and staff), approximately 150 feet north of the project site; a multifamily residential complex north of Superior Street and east of Zelzah Avenue, approximately 350 feet from the project site; a Child and Family Guidance Center on the corner of Superior Street and Zelzah Avenue, approximately 150 feet northeast from the project site; single and multifamily residential complexes north of Halsted Street, approximately 100 feet west from the project site; CSUN student housing on Zelzah Avenue bounded by Halsted Street and Plummer Street, approximately 300 feet southeast from the project site; a fraternity house and single family residences on the south side of Halsted Street, approximately 350 feet east from the project site; the CSUN Hillel Jewish Student Center on the north side of Plummer Street, approximately 350 feet southeast from the project site; a church and single family residences on the south side of Plummer Street approximately 600 feet southeast from the project site; and a church on the southeast corner of Zelzah Avenue and Prairie Street, over 1,000 feet south from the project site. To index
3A. 3 APPLICABLE REGULATIONS Federal, State, and regional agencies have established air quality standards and regulations that affect proposed projects. The following regulatory considerations may apply to the project and alternatives.
Federal Regulations · The Federal Clean Air Act of 1970 directs the attainment and maintenance of National Ambient Air Quality Standards (NAAQS). The 1990 Amendments to this Act determine attainment and maintenance of NAAQS (Title I), motor vehicles and fuel reformulation (Title II), hazardous air pollutants (Title III), acid deposition (Title IV), operating permits (Titles V), stratospheric ozone protection (Title VI), and enforcement (Title VII).
· The U. S. Environmental Protection Agency (USEPA) implements New Source Review (NSR) and Prevention of Significant Deterioration (PSD). PSD applies to major sources with annual emissions exceeding either 100 or 250 tons per year (TPY) depending on the source, or that cause or contribute adverse impacts to any Federally classified Class I area.
· The USEPA implements the NAAQS and determines attainment of Federal air quality standards on a short- and long-term basis.
State Regulations and Laws · The California Air Resources Board (CARB) has established the California Ambient Air Quality Standards (CAAQS) and determines attainment status for criteria air pollutants.
· The California Clean Air Act (CCAA) went into effect on January 1, 1989 and was amended in 1992. The CCAA mandates achieving the health-based CAAQS at the earliest practicable date.
· The California Health and Safety Code, Division 26 Air Resources, Part 6 Air Toxics Hot Spots Information and Assessment, Section 44300, requires an inventory of air toxics emissions from individual existing facilities, an assessment of health risk, and notification of potential significant health risk when found to be present.
· California Health and Safety Code, Division 26 Air Resources, Chapter 6 Facility Toxic Air Contaminant Risk Reduction Audit and Plan, Section 44390, provides guidelines to identify a more realistic health risk, requires high risk facilities to submit an air toxic emission reduction plan, holds air districts accountable for ensuring that the plans will achieve their objectives, and that high risk facilities will be required to achieve their planned emission reduction.
· California Health and Safety Code, Division 26 Air Resources, Chapter 3.5 Toxic Air Contaminants, Article 2.5 Coordination with the Federal Act, Section 39656, sets forth provisions to implement the Federal program for hazardous air pollutants.
· California Health and Safety Code, Division 26 Air Resources, Part 4 Nonvehicular Air Pollution Control, Chapter 4 Enforcement, Section 42301.6, requires new or modified sources of air contaminants located within 1,000 feet from the outer boundary of a school to give public notice to the parents of school children before an air pollution permit is granted.
· Section 21151.4 of the California Public Resources Code, Division 13 Environmental Quality, Chapter 4 Local Agencies, addresses Hazardous Air Pollutant releases within one-fourth mile of a school site.
SCAQMD Rules and Regulations Emissions that would result from the Proposed Project are subject to the rules and regulations of the South Coast Air Quality Management District (SCAQMD). Rules and regulations of this agency are designed to achieve defined air quality standards that are protective of public health. To that purpose, they limit the emissions and the permissible impacts of emissions from projects, and specify emission controls and control technologies for each type of emitting source in order to ultimately achieve the air quality standards. The following discussion outlines various SCAQMD rules and regulations that could be applicable to the proposed project.
· Rule 403 -Fugitive Dust. Requirements that minimize emission of fugitive dust for any active operation, open storage pile, or disturbed area (see Tables 3A-8 and 3A-9 for text of requirements).
· Rule 403 – Asbestos Emissions from Demolition/ Renovation Activities requires that the owner or operator of any demolition or renovation activity have the affected facility or facility components thoroughly surveyed for the presence of asbestos prior to such activity occurring. The survey will include the inspection, identification, and quantification of all friable, and Class I and Class II non-friable asbestos-containing material, and any physical sampling of materials.
· Regulation II. SCAQMD Regulation II contains a series of rules specifying requirements for permits to construct and operate stationary equipment capable of emitting air contaminants, including air emissions control equipment.
· Regulation IV. Regulation IV defines the allowable concentration and emission levels for pollutants, as well as inspection and maintenance requirements for hydrocarbon emissions sources. Rules bearing upon the proposed project include Rule 463, Organic Liquid Storage.
· Regulation XI. Regulation XI contains a series of rules governing emissions from specific sources. Those bearing upon the proposed project include: Rule 1113, Architectural Coatings; Rule 1146.1, Emissions from Small Boilers and Process Heaters; Rule 1149, Storage Tank Degassing; Rule 1166, volatile organic compounds (VOC) Emissions from Soil Decontamination; and Rule 1173, Fugitive VOC Emissions.
· New Source Review (Regulation XIII). Regulation XIII requires that all new and modified stationary emissions sources must use best available control technology (BACT) to control emissions of all affected pollutants. In addition, if there is a net emission increase of any size, emission offsets will be required to counteract the effects of emissions growth. These offsets must be achieved through contemporaneous or third party emissions reduction. Some credit remains available in the form of "banked" emissions.
In addition to the rules and regulations sited above, the SCAQMD is required to produce plans to show how air quality will be improved. The 1989 Air Quality Management Plan (AQMP) was the first AQMP to define a comprehensive control strategy, achievable attainment dates, and an aggressive rulemaking schedule for implementation of the Plan. The AQMP has been revised several times since it was originally adopted in 1989, the most recent of which to be adopted by the Governing Board was the Final 1999 Amendments to the 1997 Ozone AQMP.
To accomplish the task of improving air quality in the SCAB, the AQMP relies on a multi-level partnership of governmental agencies at the Federal, State, regional, and local level. These agencies (USEPA, CARB, local governments, Southern California Association of Governments [SCAG], and SCAQMD) are the cornerstones that implement the AQMP programs. The AQMP provides an attainment planning framework that sets specific dates by which the SCAB will achieve the Federal and State air quality standards. To index
3A. 4.1 Methodology Projected air emissions were calculated using the URBEMIS emissions model approved by CARB, and SCAQMD and USEPA emission factors. The URBEMIS model uses EMFAC7G emissions factors for vehicle traffic. The calculated emissions of the project are compared to thresholds of significance for individual projects using the SCAQMD Air Quality CEQA Handbook. The SCAQMD CEQA Air Quality Handbook recommends assessing emissions of reactive organic compounds (ROC) and nitrogen oxides (NOx) as indicators of O3 .
The potential for the project to contribute to CO hotspots is assessed using the CALINE4 model developed by the California Department of Transportation.
CRITERIA FOR DETERMINING SIGNIFICANCE The SCAQMD has established thresholds of significance for construction activities and for project operations. See Table 3A-6 below for SCAQMD's thresholds of significance.
Table 3A-6 SCAQMD's Thresholds of Significance for Proposed Projects Pollutant Project Construction lbs/ day Project Operation lbs/ day Carbon Monoxide 550 550 Reactive Organic Compounds 75 55 Nitrogen Oxides 100 55 Sulfur Oxides 150 150 Particulate Matter 150 150 Note: the SCAQMD no longer requires construction activities to be evaluated by quarterly significance thresholds (SCAQMD, 2001b).
With regard to CO emissions emitted by vehicle trips associated with project operations, the SCAQMD considers the following concentration increases to be significant:
· 1 hour = 20 parts per million · 8 hour = 9 parts per million.
This evaluation will also consider the following criteria:
§ Construction of the proposed project would generate emissions of air pollutants. § Operation of the project could result in increased air pollutant emissions. § The project would be consistent with the Air Quality Management Plan. § Project-generated carbon monoxide (CO) concentrations at intersections with unacceptable levels of service. To index
3A. 4.2 Project Impacts Impact A1: Construction of the proposed project would generate emissions of air pollutants.
Construction activities would result in the generation of air pollutants. Construction-related emissions would primarily be (1) dust generated from earthmoving, excavation, and other construction activities, (2) reactive organic compounds (ROC) from paints, (3) exhaust emissions from diesel powered construction equipment, and (4) motor vehicle emissions associated with construction equipment, worker commute, and debris hauling activities.
Emission levels for construction activities vary with the type of equipment, duration of use, operation schedules, and the number of construction workers. Table 3A-7 presents the estimated construction emissions for the proposed project. Project construction emissions were estimated using methods from the SCAQMD's CEQA Air Quality Handbook and Appendix J of USEPA's AP-42. Please refer to Appendix C for all assumptions used in estimating emissions.
Since all construction activities don't occur simultaneously, the worst case scenario using construction equipment associated with earth moving activities such as trenching and excavating, combined with haul
trips and commuting worker trips was considered for the maximum daily concentrations. The maximum daily ROC emissions are based on estimates associated with architectural coating applications and commuter trips. Pursuant to Section 41.40 of the Los Angeles Municipal Code, construction activities shall be limited to between 7 a. m. to 9 p. m. or any weekday (Monday through Friday), and 8 a. m. to 6 p. m. on Saturday or a national holiday. Construction is prohibited on any Sunday. The operation repair or servicing of construction equipment and the job-site delivering of construction materials in residential areas shall be prohibited on Saturdays and Sundays.
Table 3A-7 Estimated Maximum Daily Construction Emissions Estimated Emissions lbs/ day Activity/ Source ROC NOx CO PM10 SOx Onsite Trenching/ Excavating ---69.7 43.1 4.3 5.9 Haul Trips ---24.5 17.0 1.1 0.8 Commuting Worker Trips 4.4 2.8 30.6 0.2 0.1 Fugitive Dust ---------47.5 --- Architectural Coatings 68.57 ------------Total Emissions 72.97 97.0 90.7 53.1 6.8 Significance Thresholds 75 100 550 150 150 Significant Construction Impact? No No No No No
Notes: Emissions sources associated with onsite trenching and excavating activities are: two excavators, one loader, two backhoes, and a water truck. Emission estimates for fugitive dust assume 70 percent reductions associated with implementation of Rule 403.
During construction, the project would be subject to SCAQMD Rule 403 (Fugitive Dust). SCAQMD Rule 403 does not require a permit for construction activities, per se, but rather, sets forth general and specific requirements for all construction sites (as well as other fugitive dust sources) in the South Coast Air Basin. The general requirement prohibits a person from causing or allowing emissions of fugitive dust from construction (or other fugitive dust source) such that the presence of such dust remains visible in the atmosphere beyond the property line of the emissions source. SCAQMD Rule 403 also prohibits a construction site from causing an incremental PM10 concentration impact at the property line of more than 50 micrograms per cubic meter as determined through PM10 high-volume sampling, but the concentration standard and associated PM10 sampling do not apply if specific measures identified in the rule are implemented and appropriately documented.
SCAQMD Rule 403 identifies two sets of specific measures: one for high wind conditions and the other for more normal wind conditions. When wind gusts exceed 25 miles per hour, neither the sampling requirement nor the general requirement applies so long as the measures presented in Table 3A-8 are implemented and appropriately documented.
During normal wind conditions (i. e., with wind gusts less than 25 miles per hour), the sampling requirement does not apply so long as the measures presented in Table 3A-9 are implemented and appropriately documented.
Table 3A-8 Rule 403 Measures for High Wind Conditions Source Control Measure Earthmoving Cease all active operations, or apply water to soil not more than 15 minutes prior to moving such soil. On the last day of active operations prior to a weekend, holiday, or any other period when active operations will not occur for not more than four consecutive days, apply water with a mixture of chemical stabilizer diluted to not less than 1/ 20 of the concentration required to maintain a stabilized surface for a period of six months; or Apply chemical stabilizers prior to wind event, or Apply water to all unstabilized disturbed areas 3 times per day. (If there is any evidence of wind driven fugitive dust, watering frequency is increased to a minimum of four times per day); or Establish a vegetative ground cover within 21 days after active operations have ceased. (Ground cover must be of sufficient density to expose less than 30 percent of unstabilized ground within 90 days of planting, and at all times thereafter); or
Disturbed Surface Areas
Utilize any combination of the three measures immediately preceding such that, in total, these actions apply to all disturbed surface areas. Unpaved Roads Apply chemical stabilizers prior to wind event, or apply water twice per hour during active operation, or stop all vehicular traffic. Open Storage Piles Apply water twice per hour, or install temporary coverings. Paved Road Track-out Cover all haul vehicles, or comply with the vehicle freeboard requirements of Section 23114 of the California Vehicle Code for both pubic and private roads.
Table 3A-9 Rule 403 Measures for Normal Wind Conditions Source Control Measure Earthmoving (not for including construction lines, conduct cut and fill) Maintain soil moisture content to a minimum of 12 percent when earthmoving, as necessary to prevent visible dust emissions from exceeding 100 feet in length in any direction.
Earthmoving areas (construction fill areas) Maintain soil moisture content at a minimum of 12 percent. For soils that have an optimum moisture content for compaction of less than 12 percent, complete the compaction process as expeditiously as possible after achieving at least 70 percent of the optimum soil moisture content. Earthmoving (construction cut areas) Conduct watering as necessary to prevent visible emissions extending more than 100 feet beyond the active cut area unless the area is inaccessible to watering vehicles due to slope conditions or other safety factors. Disturbed Surface Areas (except completed stabilized, grading areas) Apply dust suppression in sufficient quantity and frequency to maintain a stabilized surface. Any areas, which cannot be stabilized as evidenced by wind driven fugitive dust, must have an application of water at least twice per day to at least 80 percent of the unstabilized area. Disturbed Surface Areas Apply chemical stabilizers within five working days of grading completion; or apply water to at least 80 percent of all inactive surface areas on a daily basis when there is evidence of wind driven fugitive dust, except any areas which are inaccessible to watering vehicles due to excessive slope or other safety conditions; or establish a vegetative ground cover within 21 days after active operations have ceased. Ground cover must be of sufficient density to expose less than 30 percent of unstabilized ground within 90 days of planting, and at all times thereafter. Inactive Disturbed Surface Areas Apply water to at least 80 percent of all inactive disturbed areas on a daily basis when there is evidence of wind driven fugitive dust, except any areas which are inaccessible to watering vehicles due to excessive slope or other safety conditions; or apply dust suppressants in sufficient quantity and frequency to maintain a stabilized surface; or establish a vegetative ground cover within 21 days after active operations have ceased (ground cover must be of sufficient density to expose less than 30 percent of unstabilized ground within 90 days of planting, and at all times thereafter); or utilize any combination of the above three measures such that, in total, these actions apply to all inactive disturbed surface areas. Unpaved Roads Water all roads used for any vehicular traffic at least once per every two hours of active operations; or water all roads used for any vehicular traffic once daily and restrict vehicle speeds to 15 miles per hour; or apply a chemical stabilizer to all unpaved road surfaces in sufficient quantity and frequency to maintain a stabilized surface. Open Storage Piles Apply chemical stabilizers; or apply water to at least 80 percent of the surface area of all open storage piles on a daily basis when there is evidence of wind driven fugitive dust; or install temporary coverings; or install a three-sided enclosure with walls with no more than 50 percent porosity which extend, at a minimum, to the top of the pile.
Finally, SCAQMD Rule 403 requires applicants whose projects engage in hauling operations to take actions necessary to prevent or remove (within one hour) the track-out of bulk material onto public paved roadways. Alternatively, one may implement these specific actions:
· Pave or apply chemical stabilization at sufficient concentrations and frequency to maintain a stabilized surface starting from the point of intersection with the public paved surface, and extending for a centerline distance of at least 100 feet and a width of at least 20 feet; or
· Pave from the point of intersection with the public paved road surface, and extending for a centerline distance of at least 25 feet and a width of at least 20 feet, and install a track-out control device immediately adjacent to the paved surface such that exiting vehicles do not travel on any unpaved road surface after passing through the track-out control device.
Under either specific alternative course of action, the following additional requirements apply: · Removal of track-out material at anytime it extends for a cumulative distance of greater than 50 feet onto any public paved road during active operations; and
· Remove all visible roadway dust track-out upon public paved roadways as a result of active operations at the conclusion of each workday when active operations cease.
Given the connection between SCAQMD's Rules and Regulations (particularly Rule 403), and the regional air quality planning efforts, the project would not conflict with or obstruct implementation of the air quality plan as long as the project sponsor complies with all applicable SCAQMD Rule 403 requirements in connection with project construction. The District has incorporated the measures required under SCAQMD Rule 403 (as described above) for high wind and normal wind conditions as part of the project description to reduce PM10 emissions (from the various fugitive dust sources associated with construction) and would document all actions that demonstrate compliance with all the rules.
With regard to NOx emissions, the LAUSD requires its contractors to implement the following measures to reduce daily NOx emissions associated with construction activities. The LAUSD's application of these measures will ensure that NOs emissions do not exceed the SCAQMD threshold of 100 pounds:
· Limit the amount of on-site heavy-duty construction equipment and off-site number of haul trips to the amounts that were used for the estimation of pollutant emissions or an alternative mix of equipment that does not result in emissions exceeding the threshold of significance.
· All equipment shall be properly tuned and maintained in accordance with manufacturer's specifications. · General contractors shall maintain and operate construction equipment so as to minimize exhaust emissions. During construction, trucks and vehicles in loading and unloading queues would be kept with their engines off, when not in use, to reduce vehicle emissions. Construction emissions should be phased and scheduled to avoid emissions peaks and discontinued during second-stage smog alerts.
To ensure that daily ROC emissions associated with architectural coating operations remain below the SCAQMD threshold of 75 pounds, LAUSD requires its contractors to use an approved list of paints with specific volatile organic compound (VOC) limits. All primer paints shall contain VOCs of 1.25 pounds per gallon or less, and all topcoat paints shall contain VOCs of 0.83 pounds per gallon or less. In addition, the architectural coating schedule shall span a period of at least 35 days. 5
As presented in the Table 3A-7, the estimated daily construction emissions are not elevated above the significance thresholds for any of the criteria pollutants. Therefore, potential construction impacts are considered to be less than significant.
Mitigation Measures. No mitigation measures are required since estimated daily construction emissions are not elevated above the significance thresholds.
Impact A2: Operation of the project could result in increased air pollutant emissions. Significant air quality impacts are identified for projects that would exceed thresholds of significance established by the SCAQMD. Stationary on-site emissions are generated as a result of the combustion of natural gas to meet the demand generated by the proposed project. In addition, stationary emissions associated with the electrical energy consumption of the project would occur off-site at electrical power generating plants located throughout the utility's generating network. Stationary-source emissions generally contribute an insignificant amount to total operational emissions when compared to mobile-source emissions, which would be the largest source of pollutants resulting from implementation of the proposed project. Mobile source emissions would include worker and student commute trips, school bus trips, and daily delivery truck trips.
Operational mobile source emissions that would be generated by the proposed project were estimated using URBEMIS7G (version 5.1.0), a computer program developed by the CARB. Emissions associated with stationary natural gas and power sources were estimated using emission factors from SCAQMD's Air Quality CEQA Handbook. Estimated total daily operational emissions are presented in Table 3A-10. As presented in Table 3A-10, total daily operational emissions are projected to be below SCAQMD's operational significance criteria for criteria pollutants. Therefore, potential impacts associated with project emissions generated during operations are considered less than significant.
Table 3A-10 Total Daily Operational Emissions (pounds per day) Air Pollutant Mobile Source Emissions Natural Gas and Power Emissions Total Operational Emissions Thresholds of Significance Exceedance of Thresholds?
CO 143.7 2.0 145.75 550 No ROC 17.6 0.3 17.9 55 No NOx 21.7 11.3 33.0 55 No SOx ---0.6 0.6 150 No PM10 7.3 0.2 7.5 150 No Notes: Emissions are predicted using URBEMIS7G (Version 5.1.0) and SCAQMD emission factors. Sources: California Air Resources Board, URBEMIS7G: Version 5.1.0 and SCAQMD Air Quality CEQA Handbook
Providing additional schools within the City of Los Angeles would not increase overall net air emissions. Rather, providing new local schools closer to the communities they serve would reduce overall commute emissions. Although potential operation impacts are estimated to be less than significant, LAUSD will implement the following measures to further reduce emissions caused by mobile sources.
· The LAUSD shall promote ride-sharing programs for both students and teachers. · The LAUSD shall maintain fleet vehicles including school buses, maintenance vehicles, and other service fleet vehicles in good condition.
Mitigation Measures. No mitigation is required since estimated total daily operational emissions are projected to be below SCAQMD's operational significance criteria.
Impact A3: The project would be consistent with the Air Quality Management Plan. A project is deemed inconsistent with air quality plans if it would not result in population and/ or employment growth that exceeds growth estimates included in the applicable air quality plan. Therefore, proposed projects need to be evaluated to determine whether they would generate population and employment growth and, if so, whether that growth would exceed the growth rates included in the relevant air plans.
The proposed Valley New High School No. 1 project would not result in an increase in population since it is designed to accommodate current populations and to alleviate overcrowding in current schools. The project would be placed within an area that is in a high population area and is designed to serve the local areas, thus minimizing busing requirements.
The proposed additions would cause a net increase of full-time and part-time employees, consisting of teachers, administrators, and support staff. Some of these teachers and support staff may be reassigned from other schools since the students would be from other local schools. This increase is consistent with the employment growth estimates used to develop the SCAQMD's Air Quality Attainment Plan. Based on this analysis, the proposed project would not conflict with or obstruct implementation of SCAQMD's Plan. Therefore, the project does not impact SCAQMD's Air Quality Attainment Plan since the project is not regionally significant (less than significant).
Mitigation Measures. No mitigation is required. Impact A4: Project-generated carbon monoxide (CO) concentrations at intersections with unacceptable levels of service.
Curbside CO concentrations were estimated using the CALINE4 dispersion model developed by the California Department of Transportation, using peak-hour a. m. traffic volumes and worst-case meteorological assumptions. Worst case meteorological conditions include low wind speed, stable atmospheric conditions, and the wind angle producing the highest CO concentrations for each case. CO concentrations were modeled for three intersections: Zelzah Avenue/ Lassen Street (north of the project site), Reseda Boulevard/ Lassen Street (northwest of the project site); and Zelzah Avenue/ Nordhoff Street (south of the project site) because the existing Level of Service (LOS) at these intersections is F, which is very low. The other intersections in the vicinity of the project area currently operate between
an LOS of E and C (see Section 3H, Traffic/ Transportation for more on the LOS of roads in the vicinity of the project area). Curbside CO concentrations were modeled under the following scenarios:
· Future conditions (2004) without the proposed project · Future conditions (2004) with the proposed project.
Existing and projected worst-case curbside CO concentrations at the Zelzah Avenue/ Lassen Street, Reseda Boulevard/ Lassen Street, and Zelzah Avenue/ Nordhoff Street intersections are shown in Table 3A-11. The concentrations correspond to a location of approximately 50 to 70 feet from the center of a given intersection.
Table 3A-11 Estimated Future Maximum CO Concentrations (2004) Modeled Intersection Averaging Period Existing Conditions a Increase due to Future traffic levels Without Project (2004) b
Increase due to Future traffic levels With Project (2004) c Net Increase Project Impact
1-hr. 10.5 5.1 5.2 0.1 No Reseda Blvd./ Lassen St. 8-hr. 8.8 3.6 3.6 0.1 No 1-hr. 10.5 6.4 6.5 0.1 No Zelzah Ave./ Nordoff St. 8-hr. 8.8 4.5 4.6 0.1 No 1-hr. 10.5 4.3 4.1 0.2 No Zelzah Ave./ Lassen St 8-hr. 8.8 3.0 2.9 0.1 No Notes: Modeled with the CALINE4 dispersion model using EMFAC7G composite emission factors and assuming worst-case meteorological conditions. Concentrations correspond to a location between 50 to 70 feet from the edge of the given intersection. The state one-hour average CO standard is 20 ppm; the state and federal eight-hour average CO standard is 9.0 ppm. No exceedances of applicable standards were estimated. These estimated concentrations are based on the traffic impact analysis prepared by Meyer, Mohaddes Associates, Inc. a. The existing conditions are based on a 4-year (1996 through 1999) running average of maximum CO concentrations at the Reseda monitoring station. b. The 1-hr average concentrations are modeled using a. m. peak hour future traffic estimates without project related trips. The 8- hr standard is estimated by multiplying the 1-hr standard by a factor of 0.7. c. The 1-hr average concentrations are modeled using a. m. peak hour future traffic estimates with the addition of projected project related trips. The 8-hr standard is estimated by multiplying the 1-hr standard by a factor of 0.7.
The SCAQMD CEQA Handbook indicates that a significant impact would be identified if modeled CO concentrations would increase by 1.0 parts per million (ppm) under the 1-hour standard or 0.45 ppm under the 8-hour standard. In addition, if the project would cause an exceedance of either standard, a significant CO Hot Spot would be created.
The results of CO modeling, as provided in Table 3A-11, indicate that traffic generated by the project would increase local 1-hour and 8-hour CO concentrations immediately adjacent to the subject intersections by up to approximately 0.2 and 0.1 ppm, respectively. This increase in CO concentrations represents a less than significant impact to air quality.
Mitigation Measures. No mitigation is required. To index
3A. 4.3 Cumulative Impacts The CEQA Guidelines require that projects be evaluated with respect to their contribution to the cumulative baseline. This contribution with respect to air emissions would include both construction
and operational emissions. Cumulative projects are described in Section 2.5 of this report, and include 11 projects that encompass proposed residential, commercial, and academic uses in the project area.
The project would contribute air emissions to the region that would add to the cumulative baseline. Construction emissions of the cumulative projects would be short term, but similar to the construction of the project. It is unlikely that all of the cumulative projects would be constructed at the same time. As mitigation measures would be applied to these projects to reduce construction related air emissions, cumulative impacts are expected to be less than significant.
Operational emission sources are not expected to be significant with the implementation of mitigation measures to reduce emissions. Rather, placing schools closer to the communities they serve would tend to reduce overall vehicle commute emissions. Therefore, the Project would not contribute considerably to the cumulative baseline with respect to air quality.
Mitigation Measures. For construction impacts, the LAUSD requires its contractors to implement measures to reduce PM10 and NOx . For the operation emissions, LAUSD will also require specific ride-sharing and vehicle maintenance measures.
With implementation of these project features, no additional measures would be needed to address potential cumulative impacts. To index
3B.1 Introduction
3B.1.1 Overview of Geologic Processes and Hazards
3B.1.2 Purpose and Scope
3B.2 Existing Setting
3B.2.1 Field Investigation Methodology
3B.2.2 Faults and Seismically Induced Groundshaking
3B.3 Applicable Regulations.
3B.4 Impacts and Mitigation.
3B.4.1 Methodology
3B.4.2 Project Impacts
3B.4.3 Cumulative Impacts.
3B. 1.1 Overview of Geologic Processes and Hazards Geologic and soil hazards that result from geologic processes include: surface rupture; ground shaking; ground failure; tsunamis; seiches; landslides; mudflows; and subsidence of the land. Because the project area is generally considered to be geologically active, most projects would be potentially exposed to some risk from geologic hazards, such as earthquakes. Thus, significant geologic and soil impacts exceed the typical risk of hazard for the region.
Surface ruptures are the displacement and cracking of the ground surface along a fault trace. Surface ruptures are visible horizontal or vertical displacements, or a combination of the two, typically confined to a narrow zone along a fault. The damaging effects of ground shaking and the actual trembling or jerking motion of the ground during an earthquake can vary significantly across an area and depends on factors such as earthquake intensity, duration of shaking, soil conditions, type of building, and other factors. Ground failure results from the cyclical ground acceleration generated during an earthquake and can produce landslides, ground cracking, subsidence, and differential settlement. Liquefaction is a
form of earthquake-induced ground failure that occurs primarily in loose, granular, and water-saturated soils.
Tsunamis are large ocean waves that are most often generated by large-scale, short-duration submarine earthquakes. Tsunami waves are capable of traveling great distances (over 1,000 miles) and damaging low-lying coastal regions. Seiches are waves formed from oscillations in enclosed or restricted bodies of water (e. g., harbors, lakes). Seiches can cause water to overtop reservoirs and lakes.
Mudflows and landslides are the down slope movement of soil and/ or rock under the influence of gravity. Mudflow and landslide processes are influenced by factors such as thickness of soil or fill over bedrock, steepness and height of slope, physical properties of the fill, soil or bedrock materials, and moisture content. These factors may increase the effective force of gravity upon a slope and decrease the ability of the sloped soil or fill to resist gravitational influence, leading to mudflows and landslides.
Subsidence is a localized movement that involves the gradual settling or sinking of the earth's surface, resulting from the extraction of mineral resources, subsurface oil, groundwater, or other subsurface nonsolid resources, such as natural gas. Settlement is the gradual downward movement of a structure due to compression of the soil below the foundation. The principal cause of subsidence is the extraction of subsurface nonsolids, whereas settlement results from the compression of soils due to the weight of a structure on the ground surface. To index
3B. 1.2 Purpose and Scope This report presents the results of the Report of Comprehensive Geotechnical Investigation for the Valley New High School No. 1 (Geotechnical Report) completed in January 2001 by URS/ Dames & Moore. The purpose of the investigation was to explore and evaluate the subsurface conditions at the site, identify the key geotechnical and geologic issues that could potentially impact the proposed project, and develop geotechnical recommendations for design and construction of the project. The scope of the investigation included the following tasks:
· Reviewed aerial photographs, geological and geotechnical data pertinent to the project site · Reviewed and analyzed seismic information for the project site · Conducted a site reconnaissance by a field geologist that observed the existing conditions and laid out the location of proposed borings
· Contacted Underground Services Alert (USA) of Southern California to identify subsurface utilities and obtained clearance for drilling at the site
· Explored the subsurface conditions at the site by drilling and sampling seven geotechnical borings to depths ranging from 21 feet to 102 feet
· Performed a shearwave velocity measurement in the borehole with a depth of 102 feet · Performed laboratory tests on selected soil samples obtained from the borings to evaluate index and compressibility properties of the soils
· Performed engineering analyses to develop geotechnical recommendations for design and construction of the proposed project
· Prepared a report summarizing findings, conclusions, and recommendations. To index
The proposed school site is currently vacant with sparse vegetation and some old asphalt paving at isolated locations, possibly as parts of an old walkway. The site has an approximate square shape and is bounded on the north, west, and south by properties and facilities of California State University at Northridge (CSUN), and on the east by Zelzah Avenue. The area of the project site is approximately 360 feet by 360 feet.
The Geotechnical Report for the project describes the site as located within the western portion of the San Fernando Valley, which consists of a broad alluvial valley bounded on the north by the Santa Susana and San Gabriel Mountains, and on the south by the Santa Monica Mountains. Specifically, the site is within the northern portion of the alluvial basin forming the San Fernando Valley. The area is characterized by relatively flat terrain with a slight southward sloping gradient. To the north of the site is a series of low hills commonly referred to as the Northridge Hills. Movement along the Northridge Hills Fault, which underlies this area, is believed to be responsible for uplifting the hills and has resulted in continuing erosion and subsequent alluvial deposition within the valley areas. The Northridge Hills are composed of relatively older alluvial deposits that have been uplifted through the surrounding younger alluvium that overlies much of the basin. Based on exploratory wells and cross-sections prepared through the area north of the site, depth to bedrock of the underlying Saugus Formation is believed to be greater than 100 feet below ground surface (bgs) (URS, 2001a).
Regionally, the site is within the Transverse Ranges geomorphic province in Southern California. The area is characterized by a series of east-west trending mountain ranges and intervening valleys. This east-west trending fabric is a result of a combination of north-south compressional forces interacting with the "Big Bend" along the San Andreas Fault Zone. Complex tectonic interactions within this area have resulted in numerous east-west trending mountain ranges and intervening valleys, which are evidence of these compressional forces (URS, 2001a). To index
3B. 2.1 Field Investigation Methodology The geotechnical field exploration program was initiated on January 23 and completed on January 24, 2001 under the technical supervision of a representative from URS/ Dames & Moore. The subsurface conditions at the site were explored by drilling and sampling seven borings to a depth of about 21 feet to 102 feet bgs. These borings were geotechnically logged and sampled using a Modified California Split-spoon Ring (Ring) and/ or a Standard Penetration Test (SPT) sampler at selected intervals. In addition, bulk samples of the surface soils were collected from some of the borings. Each collected sample was inspected and described in general accordance with the Unified Soil Classification System (USCS).
As a part of the field investigation, downhole seismic measurements were obtained in order to evaluate the seismic velocity profile for this site. The results of these measurements are presented in the Geotechnical Report. Laboratory tests were performed on representative samples to verify the field classifications and determine the geotechnical properties of the sample materials as they relate to the proposed construction of the Valley New High School No. 1 Project. Details of the exploration, including the logs of the borings and the results of the laboratory tests, are presented in the Geotechnical Report. All laboratory tests were performed in general conformance with the American Society for Testing and Materials (ASTM). The following tests were performed:
· Moisture content and density · Additional sieve analyses · Consolidation · Expansion Index · Corrosivity · Direct shear · Percent passing the No. 200 sieve · R-value To index
3B. 2.2 Faults and Seismically Induced Ground Shaking The two principal seismic considerations for most properties in Southern California are surface rupturing along fault traces and damage to structures due to seismically induced ground shaking. The numerous faults in Southern California include active, potentially active, and inactive faults. The criteria for these major groups are based on criteria developed by the California Division of Mines and Geology (CDMG) for the Alquist-Priolo Earthquake Fault Zoning Program. By definition, an active fault is a fault that has ruptured within the Holocene Epoch (within the last 11,000 years). A potentially active fault is a fault that has demonstrated surface displacement of Quaternary age deposits (last 2 million years). Inactive faults are faults that have not moved in the last 2 million years.
The site is not located within an Alquist-Priolo Earthquake Fault Zone, and active or potentially active faults with the potential for surface fault rupture are not known to be beneath or within 50 feet of the new school site. The site is outside of the liquefaction hazard zones designated by CDMG (URS, 2001a). Based on the current understanding of the geologic framework of the site area, severe ground shaking as a result of an earthquake occurring along any of several major active and potentially active faults in Southern California is expected to have the highest probability of affecting the site. Known active faults in the region that could cause significant ground shaking based on their proximity to the site include the Sierra Madre, Santa Susana, Oakridge, and Northridge Hills faults. Active and potentially active faults in the region of the proposed project are identified in Table 3B-1 and on Figure 3B-1.
The mapped surface traces of the largest Transverse Ranges faults within the vicinity of the site include the Sierra Madre Fault and Santa Susana Fault, approximately 4 km and 6 km north of the site, respectively. The Hollywood Fault is approximately 23 km south of the site. These faults have been designated as active by the State of California, the closest of which is the Sierra Madre Fault. It should be noted that the Northridge Hills Fault was not the fault on which the 1994 Northridge Earthquake
Table 3B-1 Characterization of Faults Considered Significant Seismic Sources to the Site Fault System Fault Activity Fault Type Length (km) Assumed Slip Rate (mm/ yr) Estimated Upper Bound Magnitude (Mw) Approximate Distance to Site (km) Northridge Hills Potentially Active Reverse 23 0.2 – 1.2 6 ½ 1 Sierra Madre Active Reverse 109 0.36 – 4 6 ½ to 7 4 Santa Susana Active Oblique 38 5 – 7 6 ½ to 7 6 Verdugo-Eagle Rock Active Reverse 29 0.2 – 2 6 ¾ 10 Oakridge/ Northridge Potentially Active Reverse 53 3.5 – 6 7 12 Northridge Blind Thrust Active Thrust 27 1 – 5 7 12 San Gabriel Potentially Active Strike-Slip 99 0.01 – 5 6 ½ to 7 16 Simi – Springville – Camarillo Potentially Active Oblique 47 2 – 3 6 ¾ 16 Santa Monica Mountains Potentially Active Oblique/ Thrust 184 0.2 – 4 6 ½ to 7 19 Newport – Inglewood Active Strike-Slip 73 0.1 – 1 6 ½ to 7 23 Hollywood Fault Left-Reverse 15 0.3 6 ½ 23 Puente Hills – Peralta Hills Potentially Active Thrust 59 0.5 – 2 6 ½ t o 7 27 Compton/ Los Alamitos/ Pelican Hills Potentially Active Thrust/ Oblique 72 0.1 – 1.4 6 ½ to 6 ¾ 29
Elysian Park-Monterey Park Potentially Active Oblique 19 0.1 – 0.2 6 ½ 30 Palos Verdes – Coronado Bank Active Oblique/ Strike-Slip 115 1 – 4 7 to 7 ¼ 32 San Andreas Active Strike-Slip 300 25 – 35 6 ¾ to 7 ¾ 47 Whittier Active Oblique 47 2 – 3 6 ¾ 53
Source: Southern California Earthquake Center (SCEC), et al., 2001; URS/ Dames & Moore, 2001a.
occurred. That was a south-dipping blind thrust fault, cut off at a depth of roughly 6 km by the Santa Susana fault zone, and probably connected at depth with the Oak Ridge fault (SCEC, 2001). The historically active San Andreas Fault, which accounts for most of the seismic strain in the region, is located approximately 50 km northeast of the site.
Two less prominent faults have been mapped within close proximity to the site. A buried trace of the Northridge Hills Fault has been mapped approximately 2,000 feet northeast of the site. The Mission Hills Fault, as a part of the Sierra Madre Fault system, is located approximately 3 km north of the site. Although not currently designated as active by the State of California, these faults have been inferred to be active by others (URS, 2001a).
The seismicity of the region surrounding the site, including the epicenter and magnitude of past earthquakes, is described in the Geotechnical Report. Examples of past earthquakes that have produced significant seismic shaking at the site include the 1994 Northridge Earthquake with a moment magnitude of 6.7 (Mw), and the 1971 San Fernando Earthquake with a moment magnitude of 6.6 (Mw). The epicenters of these earthquakes were 5 km to the south and 20 km to the northeast of the site, respectively. Both of the faults that produced these earthquakes, and a number of other faults in the area, are considered capable of producing strong seismic shaking at the site in the future.
6 Ventura Co. Los Angeles Co.
Orange Co. Riverside Co.
San Bernardino Co.
Kern Co. Santa Barbara Co.
P a c i f i c
O c e a n
1952 M 7.5 1857 M 8+ 1916 M 6.0
1971 M 6.6 1994 M 6.7 1941 M 6.0
1933 M 6.4 1987 M 5.9 1991 M 5.8 1899 M 7.0 1812 M 6.9
1923 M 6.3 1992 M 6.4 1907 M 6.0
1890 M 7.0
M 6.5 M 7.0 San Fernando Fault
San Fernando Fault
Northridge Hills
Hollywood Fault
Figure 3B-1 Regional Faults and Seismicity Map
Valley New High School 1
Project Site Project Site Fault Data Source: Law/ Crandall, 2001 URS, 2001
San Andreas Fault
Big Pine Fault
Santa Ynez Fault Santa Susana Thrust Fault San Gabriel Fault
San Gabriel Fault
Newport- Inglewood Fault
Banning Fault Mission Creek Fault
San Jacinto Fault
Helendale Fault
Lenwood Fault
Blackwater Fault Calico Mesquite Fault
Garlock Fault
Cucamonga Fault Palos Verdes Fault
Simi-Springville Camarillo Fault
Mission Hills Fault
Chatsworth Fault
San Sierra Madre Fault
Verdugo Fault
San Andreas Fault
(Year of Earthquake) (Magnitude of Earthquake) 1987 M 5.9 (Year & Magnitude Data Unavailable)
Oakridge Santa Monica Mountains Fault
Ground motions were postulated corresponding to the Upper Bound Earthquake (UBE), having a 10 percent probability of exceedence during a 100-year time period. A site-specific Probabilistic Seismic Hazard Analysis (PSHA) was performed in order to estimate the Peak Ground Acceleration (PGA) for the UBE, based on recurrence interval. The probabilistic analysis considered various magnitudes of earthquakes that active or potentially active faults in the vicinity of the site could produce along their respective fault lengths. The estimated peak ground acceleration for the UBE is 0.71g (URS, 2001a).
Liquefaction is a seismic phenomenon in which loose, saturated, fine-grained soils behave similarly to a fluid when subject to high-intensity ground shaking. Liquefaction occurs when three general conditions exist: 1) shallow groundwater depth; 2) low density, fine, clean sandy soils; and 3) high-intensity ground shaking. Studies indicate that saturated, loose and medium dense, near-surface cohesionless soils exhibit the highest liquefaction potential, while dry, dense, cohesionless soils and cohesive soils exhibit low to negligible liquefaction potential. Effects of liquefaction on level ground can include sand boils, settlement, and bearing capacity failures below structural foundations. Lateral spreading can also occur in areas of sloping ground. Seismic dynamic settlement is a typical term applied to settlement of loose to medium dense granular soils above groundwater. The site is not within a State of California defined liquefaction hazard zone. Site-specific simplified liquefaction evaluations were performed and found that the granular sand and silty sand soils encountered in the borings are generally dense to very dense throughout the depths explored. Also, groundwater was not encountered within the 102-foot depth explored (URS, 2001a). To index
3B. 3 APPLICABLE REGULATIONS California Building Code, Section 4-317( e) requires geological and soil engineering studies to be made for the construction of any school building or for the reconstruction or alternation or addition to any school building for work which alters structural elements if the site of the project is within the boundaries of any special studies zone (Alquist-Priolo Zones).
California Department of General Services, Division of the State Architect, Interpretation of Regulatory Documents IR A-4 (Geological Hazard Studies For Schools) has a requirement (third paragraph under Section 1) that no school building is to be constructed, reconstructed, or relocated in the trace, or within 50 feet either side, or a geological fault along which surface rupture can reasonably be expected to occur within the expected life of the school building.
California Education Code Section 17212 requires that a geological and soil engineering study be prepared if the prospective school site is located within the boundaries of any special studies zone or within an area designated as geologically hazardous in the safety element of the local general plan. The geological and soil engineering studies are to provide an assessment of the nature of the site and the potential for earthquake or other geological hazard damage. The geological and soil engineering studies of the site shall be of such a nature as to preclude siting of a school in any location where the geological and site characteristics are such that the construction effort required to make the school building safe for occupancy is economically unfeasible.
California Education Code Section 17212.5 requires that geological and soil engineering studies, as described in Section 17212, shall be prepared for the construction of any school building or if the estimated cost exceeds twenty thousand dollars ($ 20,000) for the reconstruction or alteration of or addition to any school building for work which alters structural elements. No school building shall be constructed, reconstructed, or relocated on the trace of a geologic fault along which surface rupture can reasonably be expected to occur within the life of the school building.
California Code of Regulations (CCR), Title 5. Education, Section 14010. Standards for School Site Selection requires that pursuant to Education Code Sections 17212 and 17212.5, the site shall not contain an active earthquake fault or fault trace, and shall not be subject to moderate to high liquefaction or landslides.
California Code of Regulations (CCR), Title 5. Education, Section 14011. Procedures for Site Acquisition– State-Funded School Districts requires that in compliance with Education Code Sections 17212 and 17212.5, the geological and soil engineering study shall address all of the following: a. Nature of the site, including a discussion of liquefaction, subsidence or expansive soils, slope, stability, dam or flood inundation, and street flooding; b. Whether the site is located within a special study zone as defined in Education Code Section 17212; c. Potential for earthquake or other geological hazard damage; d. Whether the site is situated on or near a pressure ridge, geological fault, or trace fault that may rupture during the life of the school building and the student risk factor; and e. Economic feasibility of the construction effort to make the school building safe for occupancy.
Uniform Building Codes (UBC) define criteria to be used in construction of structures based on the level of seismic activity in the region. All of Western California is within the area defined as UBC Seismic Zone 4, which is the highest seismic zone in the country. To index
3B. 4.1 Methodology The environmental baseline for the proposed project and project alternatives is based on the field investigation and laboratory testing conducted for this project and information taken from Internet sites of the United States Geological Survey (USGS), the California Department of Conservation (DOC), and the Southern California Earthquake Center (SCEC). The construction of the Valley New High School No. 1 project may potentially expose people to earthquakes, slope instability, subsidence, liquefaction, or other seismic hazards. Mitigation measures to reduce potential impacts are recommended and assessed for expected effectiveness and potential impacts if implemented.
Criteria for Determining Significance The criteria used to determine the significance of impacts are based on the model initial study checklist in Appendix G of the State CEQA Guidelines. Although the Los Angeles Unified School District is not a City of Los Angeles agency, and the District's boundaries extend outside of the Los Angeles city limits, the draft Los Angeles CEQA Thresholds Guide: Your Resource for Preparing CEQA Analyses in Los Angeles (Thresholds Guide) (City of Los Angeles, 1998a) was also considered in identifying significance criteria or thresholds. The Thresholds Guide is a draft guidance document that is useful in the environmental review of projects in the City of Los Angeles that are subject to CEQA.
For this analysis, the proposed project may result in significant impacts if it would expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving:
· Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault
· Strong seismic ground shaking · Seismic-related ground failure, including liquefaction · Landslides. To index
3B. 4.2 Project Impacts Impact B1: Expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving an earthquake fault, strong seismic ground shaking, seismic-related ground failure, or landslides.
Ground Rupture. As indicated above, the project site is not located within an Alquist-Priolo Earthquake Fault Zone or within 50 feet of an area of known surface rupture. Based on a review of available geologic data, active faults do not cross through the proposed site (URS, 2001a). As such, it is not expected that the proposed school would be exposed to significant impacts from ground rupture in an earthquake.
Ground Shaking. With regard to potential impacts from seismic ground shaking, all structures on site would be constructed in accordance with Uniform Building Code (UBC) Extreme Construction Standards and state seismic safety standards. Detailed recommendations for appropriate foundation systems, together with the necessary design parameters for floor slab, for excavation and shoring, and for grading, are addressed in the Geotechnical Investigation by URS.
Other Seismic Ground Failure. The potential for seismic-related ground failures such as liquefaction, seismically induced settlement, tsunamis, inundation, seiches, flooding, and subsidence affecting the project site has been determined to be low.
The potential seismically induced total and differential settlement is estimated to be on the order of about one inch, under the seismic loading of upper-bound peak ground acceleration (URS, 2001). Thus, proposed buildings could be susceptible to some distress caused by seismically induced settlement that could occur as the result of a significant earthquake on a nearby fault. It is expected that the estimated potential magnitudes of differential settlement would result in some cosmetic damage and possible structural damage, but not structural collapse of a building designed in accordance with current building codes. The Geotechnical Report's recommendation for support of buildings on shallow foundations have been prepared in order to reduce, but not eliminate, the risk associated with the potential for seismically-induced settlement.
Landslides. The site is nearly level; therefore landsliding is not considered to present a hazard. The following discussion summarizes the recommendations presented in the Geotechnical Report. Please refer to this document for a more detailed description of the recommendations outlined below.
Foundations: · Recommendations on the load pressure, depth, and compaction for spread footings during construction in natural soils for the subterranean parking garage, for at-grade buildings to structures, and for other minor structures that are structurally separate from the main buildings
Make bearing value of compacted fill depend on the materials used and the compaction methods employed · Footing excavations should be approved by personnel of the Geotechnical Engineer of Record and any applicable government agency.
Floor Slab Support: · A field representative should observe the condition of the final subgrade soils immediately prior to slab-on-grade construction and, if necessary, perform further density and moisture content tests to determine the suitability of the final prepared subgrade.
A moisture barrier is recommended under all floor slabs to be overlain by moisture sensitive floor covering. A plastic or vinyl membrane may be used for this purpose and should be placed between two layers of moist sand, each at least 2 inches thick.
Excavation and Slopes: · Excavation should extend laterally outside the proposed foundation footprint, a distance equal to the depth of excavation or at least 5 feet, whichever is greater
· Excavations should be observed by personnel of the Geotechnical Engineer of Record and all applicable safety requirements and regulations, including OSHA regulations, should be met
· All cuts greater than 4 feet in depth should be sloped and/ or shored · Berms should be placed along the tops of slopes to prevent runoff from entering the excavation and eroding the slope faces.
Shoring: · Where there is no sufficient space for sloped embankments, shoring will be required · Design and installation of the shoring should be followed as discussed in the Geotechnical Report. The shoring system should be monitored and consist of periodic surveying.
Retaining Walls and Walls Below Grade: · The pressure distribution recommendation is diagrammed in the Geotechnical Report · Backfill should be compacted to at least 90percent of the maximum density obtainable by the ASTM Designation D1557-91 method of compaction.
Paving: · Pavement adjacent to the building should be sloped away from the buildings in all directions and ponding of water should not be allowed
· The base course for both asphaltic and concrete paving should the specifications for Class 2 Aggregate Base as defined in Section 26 of the latest edition of the State of California, Department of Transportation, Standard Specifications or the specifications of untreated base in Section 200-2 of the Standard Specifications for Public Works Construction
· Inspection is recommended to verify that the recommended thickness or greater thickness is achieved and that proper construction procedures are used for asphaltic paving.
Grading: · All existing fill and disturbed natural soils should be excavated and replaced as properly compacted fill · Any additional fill required within the areas of the proposed school buildings should be properly compacted · After clearing the site, the exposed soils should be carefully observed for the removal of all unsuitable deposits
· Exposed soils within the building areas should be compacted to at least 95 percent of the maximum density obtainable by the ASTM Designation D1557-91 method of compaction
· Where some settlement, associated cracking, and greater than normal maintenance of the asphaltic paved areas is acceptable, the over-excavation of only the upper 2 feet of existing fill soils would be required, with the lower portion of the existing fill being left in place
· The moisture content of the on-site soil at the time of compaction should vary not more than 2 percent below or above optimum moisture content
· The on-site soils, less debris, or organic materials within any existing fill soils, may be used in required fills · All required fill should consist of relatively non-expansive soils.
These recommendations (as presented in the Geotechnical Report) have been incorporated in the design of the project. The LAUSD's incorporation of these recommendations in the project would result in less than significant potential impacts.
Mitigation Measures: No mitigation is required.
3B. 4.3 Cumulative Impacts Geology and soils impacts are site-specific and are typically addressed and mitigated to acceptable levels on a case-by-case, site-by-site basis. No cumulative impacts are expected to occur.
Mitigation Measures. No mitigation is required. To index
3C.1 Introduction
3C.2 Setting
3C.3 Draft Phase I Environmental Site Assessment (ESA)
3C.4 Draft Final Preliminary Endangerment Assessment Report
(PEA)
3C.5 Applicable Regulations
3C.6 Impacts and Mitigation
3C.6.1 Methodology
3C.6.2 Project Impacts
3C.6.3 Cumulative Impacts
3C. 1 INTRODUCTION Hazardous materials are generally substances that by their nature and reactivity have the capacity to cause harm or health hazards during normal exposure, an accidental release, or other mishap. Hazardous materials are characterized as being toxic, corrosive, flammable, reactive, an irritant, or strong sensitizers. The term "hazardous substances" encompasses chemicals regulated by both the United States Department of Transportation's (DOT) "hazardous materials" regulations and the U. S.
response. Hazardous wastes require special handling and disposal because of their potential to impact public health and the environment. A designation of "acutely" or "extremely" hazardous refers to specific listed chemicals and quantities.
Activities and operations that use or manage hazardous or potentially hazardous substances could create a hazardous situation if release of these substances occurs. Individual circumstances, including the type of substance, quantity used or managed, and the nature of the activities and operations, affect the probable frequency and severity of consequences from a hazardous situation. Federal, State, and local laws regulate the use and management of hazardous or potentially hazardous substances.
Creation of human health hazards or exposure of people to existing sources of potential health hazards, including asbestos-containing material (ACM), is also considered in this section. To index
3C. 2 SETTING According to the Northridge Community Plan (revised in 1998) and Plan Map, the project site is designated as a PF zone (public facilities). The site is vacant and is surrounded primarily by athletic facilities, residences, and commercial uses (see Figure 3E-2 in Land Use). The nearest public or private airport is Van Nuys Airport located approximately three miles southeast from the project site.
In accordance with Section 15186 of the CEQA Guidelines (see section 3E. 3, Applicable Regulations), Public Resources Code Section 21151.8, and Education Code Section 17213, research and consultation were conducted to identify facilities located within one-quarter mile of a proposed school site that might
reasonably be anticipated to emit hazardous emissions or handle hazardous or acutely hazardous materials. A survey conducted by Parsons Engineering Science, Inc. did not identify facilities within one-quarter mile that might reasonably be anticipated to emit hazardous air contaminants (Appendix D).
In accordance with Section 21092.6 of CEQA, a review of specific State databases pertaining to hazardous wastes was conducted to determine if the project site is listed. Environmental Data Resources, Inc. (EDR) conducted a search of environmental database records and facilities were not listed in the Federal databases within one-half mile of the site or within one-quarter mile of the project site in the State databases for facilities (URS, 2000). Additional regulatory agencies were directly contacted for any files or records on historic or current uses of the proposed site. According to records at the California Department of Oil & Gas, there is one plugged and abandoned oil well located 400 feet west of the site. URS obtained a letter from the California Department of Oil and Gas verifying that the well was properly abandoned on March 23, 1954 (URS, 2001b). To index
3C. 3 DRAFT PHASE I ENVIRONMENTAL SITE ASSESSMENT (ESA) The LAUSD Office of Environmental Health and Safety completed a draft Phase I Environmental Site Assessment (ESA) in November 2000. The ESA included a site reconnaissance, a records review and interviews, a historical information review, an environmental setting, and interviews with applicable personnel for the project site. During the September 2000 Site reconnaissance visit, the proposed site was observed as a vacant, undeveloped lot. The only features observed on the lot were some water pipes extending out of the ground, two surface grates which drain to the curb on Zelzah Avenue, a small unused transformer area, several small asphalt-paved walkways, a fence, some signage, utility poles lying on the ground in the southwestern portion of the site, and a Los Angeles Department of Water and Power (LADWP) wooden shed housing temporary electrical power equipment. In addition, there was a large mound of dirt mixed with sparse grass clippings, tree limb chips, and asphalt pieces on the western portion of the site. According to CSUN personnel, the dirt mound was generated when soil was removed from areas where the portable buildings were to be placed at a level surface (URS, 2000).
Historical topographic maps and aerial photographs indicate that the land was used for agricultural purposes prior to the late 1950s. Development of the university on land surrounding the project site began in the late 1950s, and development on the project site did not begin until 1994 with installation of 24 portable buildings. According to the search conducted by EDR, there were no documented environmental concerns on or within close proximity to the project site (URS, 2001b). To index
3C. 4 DRAFT FINAL PRELIMINARY ENDANGERMENT ASSESSMENT REPORT (PEA) The LAUSD Office of Environmental Health and Safety completed a Draft Preliminary Endangerment Assessment (PEA) Report in April 2001. The April 2001 Draft PEA was submitted to the DTSC. After reviewing the Draft PEA Report, the Department of Toxic Substances Control (DTSC) recommended that a Focused Site Investigation (FSI) be conducted to further characterize the extent of
elevated levels of pesticides (toxaphene and DDE) in their May 14, 2001 letter. A FSI Work Plan was submitted to DTSC on June 1, 2001 and the DTSC issued a letter approving the FSI Work Plan on June 12, 2001. The FSI was conducted on June 20, 2001. The results of the FSI and the revised human health screening evaluation were presented in the July 2001 Draft Final PEA. The DTSC issued a "Further Action" notice on August 15 requesting preparation of a Removal Action Work Plan for this site (Appendix D). Revisions to the July 2001 report based on the comments received from this August letter were submitted in a supplemental document dated September 14, 2001.
The following sections present results of the soil sampling conducted as part of the PEA investigations. All results reported were taken from the Draft PEA Report submitted in April 2001, the Draft Final PEA submitted in July 2001, and revisions submitted in a supplemental document on September 14, 2001 by the LAUSD Office of Environmental Health and Safety.
Sampling Activities and Results As a result of the background information gathered on the project site as part of the April 2001 report, potential source areas were identified and recommended for sampling. Soil gas sampling was not conducted. Vadose zone soil sampling was conducted at 28 on-site locations on February 16, 2001 in accordance with the DTSC Interim Guidance for Sampling Agricultural Soils, dated June 28, 2000. The sampling strategy was developed with input from DTSC as follows:
· Fifteen locations were randomly placed throughout the site to assess residual pesticides and metals from historic agricultural activities at the site
· Two locations to assess the vicinity of the wooden shed housing unused electrical equipment and an abandoned transformer unit
· Two locations to assess the storage area of the former utility poles · Nine locations to assess the stockpile of soil that had been spread along the western portion of the site.
Background soil samples were not collected at the site. Background data gathered for another school site, Van Nuys Elementary School No. 1 located 5 miles southeast of the proposed site at the southeast corner of Vanowen and Columbus, was considered to be representative of background conditions at the proposed site.
Organochlorine Pesticides Organochlorine pesticides were detected in 34 soil samples. Table 3C-1 summarizes the reported concentrations.
With the exception of five soil samples, organochlorine concentrations detected at the site were below their respective residential Preliminary Remediation Goals (PRGs) (URS, 2001b).
Table 3C-1 Organochlorine Pesticide Concentrations Organochlorine Pesticide Minimum Concentration [µg/ kg] Maximum Concentration [µg/ kg] 4,4'-DDD in 18 samples 1.8 (at 4.0 feet bgs) 400 (at 1.0 foot bgs) 4,4'-DDE in 33 samples 0.69 (at 4.0 feet bgs) 1,900 (at 1.0 foot bgs)
4,4'-DDT in 21 samples 1.5 (at 1.5 feet bgs) 920 (at 1.0 foot bgs) Dieldren in 6 samples 1.1 (at 1.0 feet bgs) 3.9 (at 1.0 foot bgs) Toxaphene in 8 samples 170 (at 1.0 foot bgs) 1,200 (at 1.0 foot bgs) Source: URS, 2001b.
Semi-Volatile Organic Compounds (SVOCs) SVOCs were detected in 1 of 23 samples collected for analysis. Table 3C-2 summarizes the SVOC detections in the soil sample collected at 1.0-foot bgs.
The single soil sample containing SVOC concentrations was located in the former area of the stockpiled soil. The concentrations detected were all below their respective PRGs for residential soil (URS, 2001b).
Table 3C-2 SVOC Concentrations SVOC Concentration [mg/ kg] Anthracene 0.14 Benzo (a) anthracene 0.42 Benzo (a) pyrene 0.28 Benzo (b) fluoranthene 0.18 Benzo (g, h, I) perylene 0.12 Chrysene 0.46 Fluoranthene 0.79 Indeno (1,2,3-c, d) pyrene 0.11 Phenanthrene 0.63 Pyrene 0.99 Source: URS, 2001b.
Polynuclear Aromatice Hydrocarbons (PAHs) PAHs were detected in two of three soil samples collected for analysis. Table 3C-3 summarizes the PAH detections in the soils samples.
Table 3C-3 PAH Concentrations PAHs Concentrations [µg/ kg] Benzo (b) fluoranthene 16 (at 1.0 foot bgs) Chrysene (in 2 samples) 5 and 4 (at 1.0 foot bgs) Fluoranthene 10 (at 1.0 foot bgs) Phenanthrene (in 2 samples) 3 and 17 (at 1.0 foot bgs) Pyrene 20 (at 1.0 foot bgs) Source: URS, 2001b.
The two soil samples with detected PAH concentrations were from two boring locations in the vicinity of the storage area of the former utility poles. The soil samples were analyzed by USEPA Method 8310.
Metals (including Lead and Arsenic) Fifteen Title 22 metals were detected in soils at the proposed site. Table 3C-4 summarizes the results of the analysis.
Table 3C-4 Title 22 Metals Concentrations Metal Number of Detections Minimum Concentration [mg/ kg] Maximum Concentration [mg/ kg] Range of Background Concentrations [mg/ kg] Arsenic 32 2.02 7.15 6.69 to 8.12 Barium 28 77.7 125 145 to 191
Beryllium 28 0.154 0.259 0.121 Cadmium 28 1.03 2.32 ND* to 0.485 Chromium (Total) 28 9.66 22.6 17.5 to 23.5 Cobalt 28 2.03 2.94 9.44 to 12.8 Copper 28 9.03 28.9 18.8 to 25.4 Lead 32 1.23 20.6 4.39 to 31.6 Mercury 26 0.0159 0.118 0.0153 to 0.0301 Molybdenum 28 1.98 9.95 1.08 to 2.26 Nickel 28 14.6 28.4 16.3 to 26.1 Selenium 1 6.13 6.13 3.57 to 4.44 Silver 22 0.0241 0.171 0.0252 to 0.0736 Vanadium 28 29.7 55.5 30.8 to 42.1 Zinc 28 28.4 82.9 61.1 to 98.1 *ND= Not detected above the indicated laboratory reporting limit. Source: URS, 2001b.
With the exception of arsenic, the maximum metal concentrations from the 26 soil borings were below the PRGs for residential soils (URS, 2001b).
Focused Site Investigation In DTSC's Further Action letter of May 14, 2001, DTSC indicated that elevated levels of toxaphene and DDE were identified on the project site. DTSC requested that the LAUSD conduct further sampling in the areas where elevated levels of toxaphene and DDE were detected in order to determine the lateral extent of these compounds in the subsurface soil. Step-out soil sampling was conducted in the immediate vicinity of four boring locations as part of the Focused Site Investigation (FSI).
At each sampling location, soil samples were collected from depths of 0.5 to 1.0 feet below ground surface (ft-bgs) and 2.5 to 3.0 ft-bgs. Fifty (50) soil samples (48 field samples and 2 field duplicates) were collected. Some of these samples were archived for future analyses based on the results of the sampling effort. Out of these 50 samples, 35 samples (33 field samples and 2 duplicate samples) were analyzed as part of the FSI. The samples were collected in June 20, 2001 and analyzed by EPA Method 8081A.
Elevated concentrations of DDE, DDT, and toxaphene were detected in the five-foot step-out soil samples in three of the four boring locations. At each of these locations, DDT concentrations decreased to regulatory screening levels in the soil samples collected at the 10-foot step-out locations. DDE and toxaphene decreased to regulatory screening levels in the soil samples collected at almost all (except three) of the 10-foot step-out locations, although the detections were above the regulatory screening levels. At each step-out location, organochlorine pesticide concentrations decreased significantly with increasing depth (URS, 2001b). Table 3C-5 presents the pesticide concentrations for soil samples that exceeded the DTSC screening criteria.
Table 3C-5 FSI Summary Results: Soil sample locations containing pesticide concentrations that exceed DTSC Screening Criteria Step-Out Sample
Locations Depth (ft) DDE m mg/ kg 1 DDT m mg/ kg 1 Toxaphene m mg/ kg 2 5 ft step-out locations SS03B 1 2000 1500 2100 SS06A 1 3000 2200 1500 SS06B 1 3300 1600 640 SS06C 1 2500 1400 630 SS08A 1 3800 1800 1100 SS08A 1 3500 1500 920 SS08B 1 6400 1400 1800 SS08C 1 4000 1200* 1200 10 ft step-out locations SS03E 1 1900 840* 910 SS06E 1 2300 1300 1100
SS06F 1 1400 480* 390 SS08E 1 4300 850* 1400 SS08F* 1 1300 120* ND Sources: URS 2001b and Richey 2001. 1 DTSC Screening Criteria for DDE and DDT -1200 mg/ kg 2 DTSC Screening Criteria for Toxaphene -340 mg/ kg
* Concentrations below DTSC Screening Criteria ND (Not Detected)
Human Health Screening Evaluation The human health screening evaluation examines the chemicals of potential concern (COPCs) at the proposed site and compares the calculated dose for these chemicals to health-based levels deemed acceptable by DTSC. The potential dose for the proposed site is calculated for a residential land-use scenario with exposure of 350 days per year for more than 30 years. Metals that were found at the proposed site at a concentration significantly higher than their corresponding background concentrations were considered COPCs. Table 3C-6 lists the eight chemicals identified as COPCs at the proposed site.
Table 3C-6 Identified COPCs for the Proposed Site Metals Beryllium Cadmium Molybdenum Pesticides 4,4'-DDD 4,4'-DDE 4,4'-DDT Dieldrin
Toxaphene
The baseline risk assessment for the proposed site assumes that the site is uncovered with bare soils available for contact. Once the proposed site is developed, it is anticipated that the ground surface would be covered with grass and pavement; therefore, future school attendees would be exposed to site chemicals via the following pathways: incidental ingestion, dermal contact, and inhalation of particulates from chemicals in soils. The maximum detected concentrations were used for the comparison in the evaluation.
The toxicity assessment characterizes the relationship between the magnitude of exposure to a COPC and the nature and magnitude of adverse health effects that may result from such exposure. Adverse health effects are classified into two broad categories: noncarcinogens and carcinogens. The chronic toxicity criteria used for this assessment were selected from the following sources, in order of preference: Cal/ EPA Cancer Potency Factors, toxicity values from the online CalTOX database, USEPA's Integrated Risk Information System (IRIS), and USEPA (2001) Health Effects Assessment Summary Tables (HEAST) (URS, 2001b).
The results of the human health screening evaluation indicate that DDE, DDT, and toxaphene concentrations, using maximum detected concentrations, are high enough to pose a potential incremental cancer risk above the regulatory benchmark level of 1E-06 (1 x 10 -6 ), but within the USEPA acceptable risk range of 1E-06 (1 x 10 -6 ) to 1E-04 (1 x 10 -4 ) (see Table 3C-7).
Table 3C-7 Summary of Estimated Risks and Hazards Estimated Risks and Hazards Using Maximum Soil Concentrations Estimated Risks and Hazards Using 95% UCL Concentrations Chemicals of Potential Concern (COPCs) Maximum Soil Concentration (mg/ kg) Cancer Risk Adult/ Child Maximum Soil Concentration (mg/ kg) Cancer Risk Adult/ Child
Metals Beryllium 0.259 5.4E-10 0.205 4.3E-10 Cadmium 2.32 8.7E-09 1.94 7.2E-09
Molybdenum 9.95 --4.56 --Pesticides 4,4'DDD 0.88 5.3E-07 0.19 1.1E-07 4,4'-DDE 6.4 5.4E-06 0.99 8.4E-07 4,4'-DDT 2.2 1.9E-06 0.39 3.3E-07 Dieldrin 0.013 5.2E-07 0.0029 1.2E-07 Toxaphene 2.1 6.3E-06 0421 1.2E-06 Source: URS, 2001b.
The conservative assumptions in the health risk calculation utilized by URS are likely to lead to an overestimation of the health risks posed by the COPCs at the proposed site. The frequency and duration of soil contact activities would be significant factors affecting the potential for adverse human health impacts from the proposed site. The risks for all pathways were based on a residential exposure of 350 days per year for more than 30 years. A more realistic school-based scenario would assume an exposure frequency of 250 days per year for 30 years for school staff and 180 days per year for 4 years for students, and would reduce the assessment's exposures and risks by one or two orders of
magnitude. In addition, the risk estimates would decrease if the actual land use of the proposed site were accounted for versus the baseline setting. To index
3C. 5 APPLICABLE REGULATIONS CEQA Guidelines Section 15186, School Facilities requires that a lead agency of a school project, as well as a project proposed to be located near schools, examine potential health impacts resulting from exposure to hazardous materials, wastes, and substances. Such impacts are to be examined and disclosed in a negative declaration or EIR. CEQA Guidelines Section 15186 describes three types of sites for which specific findings must be made. When the project involves the purchase of a school site or the construction of a secondary or elementary school, the negative declaration or EIR prepared for the site must provide information sufficient to determine whether the property is: (1) the site of a current or former hazardous waste or solid waste disposal facility and, if so, whether wastes have been removed; (2) a hazardous substance release site identified by DTSC in a current list adopted pursuant to Section 25356 of the Health and Safety Code for removal or remedial action pursuant to Chapter 6.8 (commencing with Section 25300) of Division 20 of the Health and Safety Code; or (3) the site of one or more buried or above ground pipelines which carry hazardous substances, acutely hazardous materials, or hazardous wastes, as defined in Division 20 of the Health and Safety Code.
In developing such information, the lead agency is to consult with the county or city administering agency (as designated pursuant to Section 25502 of the Health and Safety Code), and with any air pollution control district or air quality management district having jurisdiction, to identify facilities within one-quarter mile of the proposed school site that might reasonably be anticipated to emit hazardous emissions or handle hazardous or acutely hazardous material, substances, or waste. Based on this consultation, the school board or district will determine whether such facilities exist and, if so, whether: (1) the health risks from the facilities do not and will not constitute an actual or potential endangerment of public health to persons attending or working at the proposed school; or (2) if corrective measures required under an existing order by another agency having jurisdiction over the facilities will, before the school is occupied, mitigate all chronic or accidental hazardous air emissions to levels that do not constitute any actual or potential public health danger to persons attending or working at the proposed school.
CEQA Statute (California Public Resources Code, Division 13 Environmental Protection) Section 21092.6 List Relating to Hazardous Waste directs the Lead agency to consult the lists compiled pursuant to Section 65962.5 of the Government Code to determine whether the project and any alternatives are located on a site that is included on any list.
California Education Code Section 17213.1 requires that DTSC be involved in the environmental review process for the proposed acquisition and/ or construction of school properties utilizing State funding. Prior to acquiring a school site, the governing board would contract with an environmental assessor to supervise the preparation of a Phase I environmental assessment of the proposed school site
unless the governing board decides to proceed directly to a preliminary endangerment assessment (PEA). The Phase I environmental assessment will contain one of the following recommendations: (1) further investigation of the site is not required; (2) a PEA is needed to determine if a release of hazardous material has occurred and, if so, the extent of the release; (3) there is the threat of a release of hazardous materials; or (4) if a naturally occurring hazardous material is present.
If it were concluded that a PEA is needed, the school district would prepare or direct the preparation of a PEA of the proposed school site and enter into an agreement with DTSC to oversee the preparation of the PEA. The PEA will contain one of the following conclusions: (1) further investigation of the site is not required; (2) a release of hazardous materials has occurred, and if so, the extent of the release; (3) that there is a threat of a release of hazardous materials; or (4) that a naturally occurring hazardous material is present; or any combination thereof.
The school district would submit a preliminary draft of the PEA to DTSC for its review and approval and to the State Department of Education for its files. Following any necessary revisions to the PEA in order to respond to DTSC comments, provided that these revisions are satisfactory to DTSC, the PEA is required to be made available to the public along with the draft EIR or negative declaration.
The school district would then hold a public hearing on the PEA and the draft EIR or negative declaration at the same time, pursuant to CEQA. All comments on the PEA would be forwarded to DTSC.
If DTSC disapproves the PEA, it would inform the district of the decision, the basis for the decision, and actions necessary to secure DTSC approval of the PEA. The school district would take actions necessary to secure the approval of the PEA from DTSC or elect not to pursue the acquisition or construction project. If the PEA determines that a further investigation of the site is not required and DTSC approves this determination, it would notify the State Department of Education and the school district of its approval. The school district may then proceed with the acquisition or construction project.
If the approved PEA concludes that the property has contamination that requires additional investigation and cleanup, the school district could either investigate and cleanup the property under DTSC oversight or it can elect not to proceed with the acquisition or construction of the project. Should the former be pursued, the school district is required to enter into a Cleanup Agreement with DTSC to oversee the effort.
California Education Code Section 17215 requires that before acquiring title to property for a new school site, the governing board of the school district will give the State Department of Education written notice of the proposed acquisition if the proposed site is within two miles, measured by air line, of an airport runway or a potential runway included in an airport master plan that is nearest to the site. The Department of Transportation, who would be notified by the Department of Education of the
proposed acquisition, will investigate the proposed site, and within 30 days should submit to the State Department of Education a written report of its findings, including recommendations concerning acquisition of the site. As part of the investigation, the owner and operator of the airport would be granted the opportunity to comment upon the proposed school site. If the written report does not favor the acquisition of the property for a school site, state funds or local funds cannot be used for acquisition of, or school construction at, the subject site.
South Coast Air Quality Management District Rule 1403: Asbestos Emissions from Demolition/ Renovation Activities requires that the owner or operator of any demolition or renovation activity have the affected facility or facility components thoroughly surveyed for the presence of asbestos prior to such activity occurring. The survey will include the inspection, identification, and quantification of all friable and Class I and Class II non-friable asbestos-containing material, and any physical sampling of materials. To index
3C. 6.1 Methodology The environmental baseline for the proposed project is based on the Phase I ESA and a PEA Work Plan conducted for this project. The construction of the proposed Valley Area New High School No. 1 project could potentially disturb or release hazardous materials. The potential impacts would be described in terms of the likelihood and severity of public contact with hazardous materials and whether this level of contact would be considered to result in a significant, adverse impact. The potential for environmental damage would also be considered for impacts, such as deterioration to air and/ or water quality, etc. Mitigation measures to reduce potential impacts would be recommended and assessed for expected effectiveness if implemented.
Criteria For Determining Significance The criteria used to determine the significance of an impact are based on the model initial study checklist in Appendix G of the State CEQA Guidelines. Although the LAUSD is not a City of Los Angeles agency and the District's boundaries extend outside of the Los Angeles city limits, the draft Los Angeles CEQA Thresholds Guide: Your Resource for Preparing CEQA Analyses in Los Angeles (Thresholds Guide) (City of Los Angeles, 1998a) was also considered in identifying significance criteria and thresholds. The Threshold Guide is a draft guidance document that is useful in the environmental review of projects in the City of Los Angeles that are subject to CEQA.
The proposed project may result in significant impacts if it would: · Create a significant hazard to the public or environment through the routine transport, storage, use, or disposal of hazardous materials
· Create a significant hazard to the public through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment
· Be located within one-quarter mile of a site that emits hazardous emissions or handles hazardous or acutely hazardous materials, substances, or waste
· Be located on a site that is known to contain hazardous materials or is listed on a site compiled pursuant to government code section 65962.5, and as a result could create a significant hazard to the public or the environment Impair or interfere with the implementation of an adopted emergency response plan or emergency evacuation plan. To index
3C. 6.2 PROJECT IMPACTS Impact C1: Create a significant hazard to the public or environment through routine transport, storage, use, or disposal of hazardous materials.
Long-term operation of the proposed school would involve very little transport, storage, use, or disposal of hazardous materials. The types of hazardous materials associated with operation of the school would generally be limited to those associated with janitorial, maintenance, and repair activities, such as commercial cleansers, lubricants, paints, etc. Additionally, certain courses such as chemistry and shop may involve small quantities of chemicals, fuels and other petroleum products, solvents, and paints. Notwithstanding, the amounts and use of these hazardous materials would be very limited during school operations. The transport, storage, use, and disposal of these materials would be subject to Federal, State, and local health and safety requirements. Such requirements would be incorporated into the design and operation of the school such as providing for, and maintaining, appropriate storage areas for hazardous materials, installing or affixing appropriate warning signs and labels, using commercial services that specialize in the recycling of used automotive fluids (i. e., collect such fluids on a regular basis to minimize the quantity stored on campus), installing emergency wash areas for flushing irritating automotive fluids from eyes and exposed skin areas should such contact occur, providing for well-ventilated areas in which to use paints and solvents, and maintaining adult supervision during students' use of hazardous materials. As such, it is anticipated that no significant impacts related to this issue area are expected to occur during project operation.
Grading and construction activities may involve the transport, storage, use, or disposal of hazardous materials, such as in the fueling/ servicing of on-site construction equipment. Such activity would be short-term or one-time in nature and would be subject to Federal, State, and local health and safety requirements.
Mitigation Measures. No mitigation is required. Impact C2: Located within one-quarter mile of a facility that emits hazardous emissions or handles hazardous or acutely hazardous materials, substances, or waste.
Parsons Engineering Science, Inc. conducted a survey of the project area to determine if there were facilities within one-quarter mile of the project site that emit hazardous emissions or handle hazardous
or acutely hazardous materials, substances, or waste. The survey did not identify any such facilities (see Appendix D). According to the California Division of Oil and Gas records, one plugged and abandoned oil well is located approximately 400 feet west of the site. The Texaco 'Seaboard" well was properly abandoned in 1954 (URS, 2001b). Therefore, potential impacts associated with facilities that emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or wastes are considered to be less than significant.
Mitigation Measures. No mitigation is required. Impact C3: Located on a site that is known to contain hazardous materials or is listed on a site compiled pursuant to Government Code Section 65962.5, and as a result could create a significant hazard to the public or the environment.
Selected regulatory agency databases were reviewed for documented environmental concerns on the site, or in close proximity to the site, as part of the URS PEA study. The review of environmental agency databases indicated that the site was not identified in any of the agency databases that were reviewed.
According to a recently implemented State law AB 387, SB 162, and AB 2644 as reflected in Education Code Section 17210 – 17224, a PEA was prepared by URS Corporation with agency oversight provided by California Department of Environmental Protection Agency (Cal-EPA) DTSC. Results from the Draft Final PEA were presented in the Section 3C. 4.
During preparation of the PEA, site-specific background research was conducted to identify areas where operations involving hazardous materials/ wastes could have resulted in impacts to the property. Four areas were identified including the following:
· Former stockpile of soil that had been spread · Former utility poles had been stored on the ground and were removed · Wooden shed housing where unused electrical equipment and abandoned transformer unit are located · The overall site area where agricultural activities were conducted prior to the late 1950s.
Each of these areas was investigated during the field investigation phase conducted as part of the PEA. As such, vadose zone soil sampling was collected and analyzed for COPCs. A total of eight chemicals were identified as COPCs at the proposed site (see Table 3C-6).
The human health screening evaluation identified DDE, DDT and toxaphene maximum concentration levels are high enough to pose a potential incremental cancer risk above the regulatory benchmark level of 1E-06, but within the USEPA acceptable risk range 1.0E-06 and 1.04-04 (see Table 3C-7). As a result, the DTSC issued a Further Action letter on August 15, 2001. The DTSC has requested that the
LAUSD conduct further investigation to delineate the pesticide contamination and to develop a Removal Action Work Plan (RAW) to address the potential risk posed by hazardous substances detected at the site. As a result, soil contamination on the project site is potentially significant but mitigable.
Mitigation Measures. C-1 The site investigation to further delineate the extent of the impacted areas and evaluate potential removal/ remediation action alternatives shall be completed under DTSC's Removal Action Workplan (RAW) program. While the RAW has not yet been fully developed, as a result of the PEA investigation, removal action will be required by DTSC at this project site. The removal action includes excavation and off-site disposal.
C-2 To reduce the potential for significant hazardous emissions during the removal action, the following measures will be taken:
-Maintain slow speeds with all vehicles -Load impacted soil directly into transportation trucks to minimize soil handling -Water/ mist soil as it is being excavated and loaded onto the transportation trucks -Water/ mist and/ or apply surfactants to soil placed in transportation trucks prior to exiting the site -During dumping, minimize soil drop height into transportation trucks or stockpiles -During transport, cover or enclose trucks transporting soils, increase freeboard requirements, and repair trucks exhibiting spillage due to leaks -Cover the bottom of the excavated area with polyethylene sheeting when work is not being performed -Place stockpiled soil on polyethylene sheeting and cover with similar material -Place stockpiled soil in areas shielded from prevailing winds.
C-3 The education code requires that the DTSC be involved in the assessment, investigation, and cleanup to ensure that this property is cleaned up to a level that is protective of the students and faculty who will occupy the new school. DTSC will also ensure that any precautions (see measure C-2) are implemented during the removal action. LAUSD shall enter into a Cleanup Agreement with the DTSC for their oversight of the removal of the contaminated soils (AB387 and SB162). As specified by the DTSC, the removal action may occur during construction with an approved work plan, delineation of contamination, confirmation sampling and a commitment to implement all required elements of the plan. The LAUSD shall obtain a letter from DTSC certifying that the cleanup of the site is complete.
Level of Significance After Mitigation. With the incorporation of the above measures, the hazards associated with the site are expected to be less than significant.
Impact C4: Create a significant hazard to the public through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment.
This impact is considered unlikely. Based on the nature and use of hazardous materials at the proposed school, as described previously, there are no reasonably foreseeable upset and accident conditions that would create a significant hazard to the public due to the release of hazardous materials. In the unlikely event of such an occurrence, school administrators would immediately contact the local police and/ or fire department( s) for appropriate emergency response. As a school facility, procedures for systematic evacuation of students from classrooms and other school facilities are established and practiced regularly. No significant impacts related to release of hazardous materials from upset and accident conditions are anticipated to occur.
Mitigation Measures. No mitigation is required. Impact C5: Impair or interfere with the implementation of an adopted emergency response plan or emergency evacuation plan.
This impact is considered unlikely, as schools do not impair or interfere with emergency response plans or emergency evacuation plans.
Mitigation Measures. No mitigation is required. To index
3. C. 6.3 Cumulative Impacts Compliance with the Education Code including AB387, SB162, and AB 2644 would provide for the oversight of DTSC for contaminated soils identified at the project site. DTSC has issued a Further Action letter on this project, which means that the LAUSD needs to take further action to address contaminated soils on the project site. By removing contaminated soils from the site, LAUSD is minimizing hazardous materials impacts in the project area.
As noted in Section 3C. 6.2 Impacts, there are no existing facilities within one-quarter mile of the project area that emit hazardous materials. The cumulative projects identified in Section 2.5 include the potential development of a fast food restaurant at a former gas station. Because this new facility may be required to remediate the site under current state and local regulations that require management of hazardous materials and wastes, it is not anticipated that this site would add considerably to hazards and hazardous materials impacts in the project area.
In addition, the new high school would use very limited quantities of hazardous materials during construction (e. g., vehicle equipment fuels) or operation of the school (e. g., laboratory and janitorial supplies) and would not emit hazardous emissions during operation; therefore, the project's contribution to cumulative hazards and hazardous emissions is considered less than significant.
Mitigation Measures. No mitigation is required. To index
3D.1 Introduction
3D.2 Existing Setting
3D.2.1 Surface Water Hydrology
3D.2.2 Surface Water Quality
3D.2.3 Groundwater Hydrology
3D.2.4 Groundwater Quality
3D.3 Applicable Regulations
3D.4 Impacts and Mitigation
3D.4.1 Methodology
3D.4.2 Project Impacts
3D.4.3 Cumulative Impacts
3D. 1 INTRODUCTION This section describes the existing conditions and potential impacts to surface water hydrology and quality and groundwater hydrology and quality due to implementation of the proposed Valley Area New High School No. 1 project. To index
3D. 2 EXISTING SETTING The City of Los Angeles overlies eight groundwater basins as identified in the Los Angeles Region Water Quality Control Plan, adopted by the Los Angeles Regional Water Quality Control Board (LARWQCB), and designated by the California Department of Water Resources (DWR). The Los Angeles Coastal Plain includes the West Coast Basin, the Central Basin, the Santa Monica Basin, and the Hollywood Basin. The San Fernando Valley overlies the San Fernando Basin and portions of the Eagle Rock, Verdugo, and Sylmar Basins. The Los Angeles Region Water Quality Control Plan identifies several beneficial uses common to all of these basins including municipal and domestic supply, industrial process and service supply, and agricultural supply.
According to the review of historical aerial photographs, the site was used for agricultural purposes from the late 1920s to the 1950s. Development of the university on land surrounding the project site began in the late 1950s, and development on the project site did not begin until 1994 with installation of 24 portable buildings used as an earthquake recovery village for 4 to 5 years after the 1994 Northridge earthquake (URS, 2001b).
The project site is within one of four distinct groundwater basins of the Upper Los Angeles River Area (ULARA) known as the San Fernando Basin (SFB). Table 3D-1 below summarizes hydrologic activity in the ULARA during the 1998-1999 water year.
Table 3D-1 Summary of Water Supply, Operations, and Hydrologic Conditions of the ULARA Activity Amount
Average Rainfall 9.81 inches Total Spreading Operations 14,662 acre-feet Total Extractions 156,487 acre-feet Gross Imports (including pass-through water) 533,855 acre-feet Total Exports 317,958 acre-feet Total Treated Wastewater 90,062 acre-feet Total Recycled Water 6,771 acre-feet Sewage Export (does not include treated wastewater) 93,454 acre-feet Source: ULARA Watermaster, 2000.
The SFB is the largest of the four basins. It consists of 112,000 acres and comprises 91.2 percent of the total San Fernando Valley fill (ULARA Watermaster, 2000). To index
3D. 2.1 Surface Water Hydrology Surface water hydrology impacts may occur when a project results in either increased on-or off-site storm water flows, changes in absorption rates, alterations to existing surface water flow patterns or directions (including the intake and use of water from a surface water body), or other factors which result in a changed rate of flow. Surface waters include lakes, rivers, streams, reservoirs, the ocean, and similar water bodies. Flood hazard is defined as flooding which occurs during a storm event, particularly the 50-year developed storm event. 1 Impacts may also occur when development of a project results in the depletion of natural flood plain values through development of land within a flood plain area, which is accounted for in the 50-year developed storm event. These impacts typically result in an increased potential for flood hazard.
Water flows from the project's region in a south/ southeasterly direction toward the Los Angeles River. Surface water bodies in the vicinity of the proposed project site are the Chatsworth Reservoir approximately 5 miles west/ southwest of the site and the Sepulveda Basin and Dam approximately 5 miles southeast of the site. Three waterways are within the project site's region. Aliso Canyon Wash is approximately one-half mile northwest of the project site. This south flowing wash converges with Wilbur Wash approximately one mile west of the site. Bull Creek is approximately one and three-quarter miles east of the project site and flows south. To index
3D. 2.2 Surface Water Quality Surface water quality may be impacted by pollutants discharged directly into receiving water from municipal wastewater treatment plants (treated effluent), industrial flows from water required for manufacturing, cleaning, or cooling, and activities such as dewatering of groundwater encountered during construction activities. These types of discharges can usually be directed to an outfall or pipe and are therefore categorized as "point sources."
As observed during a November 2000 site inspection, two surface grates, which drain to the curb on Zelzah Avenue east of the site, were present at the project site (URS, 2001b). The surface runoff in the area contains salts dissolved from rocks in the tributary areas of the SFB and is sodium-calcium, sulfate-bicarbonate in character (ULARA Watermaster, 2000).
1 The 50-year developed storm event is the maximum predicted rainfall event used by the City and County of Los Angeles for determining stormwater runoff quantities utilized in the design of the local storm drain system. This specification has been incorporated in the Bureau of Engineering Manual Part G, Storm Drain
Design. The year refers to a calculated storm magnitude that would occur with an approximate frequency of every 50 years. "Developed" refers to hydrology calculations that assume that all land is developed according to its general plan/ zoning designation. A "developed condition" permeability factor is assigned to each parcel, even if it is currently vacant, in order to design adequate storm drain facilities for future conditions. To index
3D. 2.3 Groundwater Hydrology Groundwater hydrology impacts may occur from extracting groundwater for water supply needs or, increasing or decreasing groundwater recharge, intercepting and removing groundwater from cuts or excavations, or remediation of contaminated groundwater. Earthwork cuts or excavations in areas of shallow groundwater may necessitate the use of temporary or permanent removal of groundwater by dewatering systems.
Groundwater recharge may be reduced if an area currently available for spreading of stream runoff is reduced, if permeable streambeds are lined, or if permeable areas located above groundwater basins are replaced by hard surfaces (paving, buildings, etc.). Groundwater recharge may be increased if larger permeable areas are created.
Underlying the project site is a thick sequence of relatively younger alluvial deposits consisting of medium dense sandy silts and silty sands, followed by more consolidated older alluvium consisting of dense to very dense sands and sandy silts (URS, 2001b).
The groundwater storage capacity of the SFB is estimated to be 3,200,000 acre-feet (ULARA Watermaster, 2000). The depth to groundwater near the project site (Well No. 4785 at the corner of Plummer Street and White Oak Avenue, which is approximately 0.15 mile south of the site) as of November 21, 2000 was 197.6 feet below ground surface (bgs) with a groundwater surface elevation of 884.5 feet above mean sea level (LA County Flood Control District, 2000). The groundwater generally flows from west to east across the San Fernando Valley, following the path of the Los Angeles River. To index
3D. 2.4 Groundwater Quality Degradation of groundwater quality may result from a variety of activities, including: the discharge or application of wastewater, groundwater, or solid waste to the land surface or subsurface areas; groundwater injections or withdrawals, or other activities that could result in a change in the flow direction of existing plumes of groundwater contamination or saltwater intrusion; drilling that intercepts areas of groundwater contamination; leaking underground or above-ground storage tanks; or accidental spills or releases or other hazardous materials on permeable soils.
According to the ULARA 2000 Watermaster Report, there have been several groundwater contamination investigations in the ULARA, but no major sites are identified within the proposed project area. There are no leaking underground storage facilities identified on or within the project area. To index
3D. 3 APPLICABLE REGULATIONS Federal Federal Water Pollution Control Act (Clean Water Act -CWA) (33 U. S. C. 1251) Including Clean Water Act Amendments of 1972, PL 92-500, Amendments of 1977, PL 95-217 and amendments of 1987, PL 100-4. The objective of the CWA is to restore and maintain the chemical, physical, and biological integrity of the Nation's waters.
NPDES (40 CFR Sec. 122.1). The NPDES program requires permits for the discharge of pollutants from any point source into waters of the United States. These point sources include: concentrated animal feeding operations, concentrated aquatic animal production facilities, discharges into aquaculture projects, and discharges of stormwater.
Safe Drinking Water Act Amendments of 1996. Safe Drinking Water Act of 1974, PL 93-523; Safe Drinking Water Act of 1986, PL 99-339, which establishes a Federal program to monitor and increase the safety of all commercially and publicly supplied drinking water.
State California Water Code (CWC), Division 7 Water Quality. This division of the Code addresses: the conservation, control, and utilization of water resources; water quality; and charges the State and regional water boards with coordination and control of water quality. Section 13050 defines pollution, contamination and nuisance, as well as other terms used in the water code.
Regional NPDES General Permit for Stormwater Discharges Associated with Construction Activity – Water Quality Order 99-08-DWQ. This permit, established by USEPA in 1990 and administered by LARWQCB, establishes requirements for discharges of stormwater to waters of the U. S. from construction projects that encompass five (5) acres or more of soil disturbances.
Regulatory Framework In 1948, Congress enacted the Water Pollution Control Act, which has since been amended significantly on several occasions, and is now commonly referred to as the Clean Water Act (CWA). The CWA delineates a national permitting system for point discharges known as the National Pollutant Discharge Elimination System (NPDES). NPDES is the basic regulatory and enforcement tool available under the CWA. NPDES permits typically incorporate specific discharge limitations for point source discharges to ensure that dischargers meet permit conditions and protect State-defined water quality standards.
California is authorized to administer key components of the Federal water quality management program in the State. The California Water Code (CWC) establishes nine administrative areas in the State, each of which are administered by their respective RWQCBs that adopt Water Quality Control Plans for their regions. The Water Quality Control Plans designate beneficial uses for each receiving water body and establish water quality objectives to ensure reasonable protection of the beneficial uses. The primary method of plan implementation for point discharges is through the issuance of permits.
The existing NPDES framework was expanded in 1987 to regulate stormwater runoff (discharges) originating from municipal, industrial, and construction stormwater discharges. LARWQCB, as an agent of the State Water Resources Control Board (State Board), is authorized to issue these permits as part of its general NPDES authority.
In general, environmental impacts to surface water quality are assessed in relation to the existing characteristics of the body of water that would receive the discharge (receiving water body), including its size, flows, designated beneficial uses, and present concentrations of pollutants. Increased concentrations of toxic metals, organic compounds, suspended solids, nutrients, pathogenic microorganisms and other pollutants, or changes in temperature may result in sedimentation, eutrophication, habitat degradation, and/ or threats to public health.
For point source discharges from proposed projects, the nature of the discharge is directly related to the process that produces the discharge. Non-point source impacts to receiving waters during project operation are related to such factors as land use type, size, design, and intensity. Construction activities may also result in the discharge of stormwater runoff pollutants, including dissolved solids, to receiving waters.
The owner or operator of any facility discharging or proposing to discharge waste to surface waters (typically from a point source) is required to apply for an NPDES permit with the appropriate RWQCB. The RWQCB sets effluent limits for each potential pollutant in accordance with applicable State and Federal water quality criteria for the receiving water body.
Within the City of Los Angeles, the criteria are contained in the Los Angeles Region Basin Plan. The owner or operator of any facility discharging or proposing to discharge waste that may affect groundwater quality or from which waste may be discharged in a diffused manner (e. g., erosion from soil disturbance) must first obtain Waste Discharge Requirements (WDR) from the appropriate RWQCB.
The State Water Quality Control Board has also issued two general stormwater discharge permits to cover industrial and construction activities. LARWQCB oversees implementation and enforcement of the general permits. The City's Bureau of Engineering, Stormwater Management Division is the agency responsible for overseeing implementation of permit responsibilities for the City. Presently, under the General Construction Stormwater Permit, projects greater than five acres are required to
incorporate, to the maximum extent possible, permanent or post-construction Best Management Practices (BMPs) in project planning and design.
On July 15, 1996, LARWQCB issued a NPDES Permit (Permit) for municipal stormwater and urban runoff discharges to Los Angeles County and 85 cities (Permittees). The Standard Urban StormWater Mitigation Plan (SUSMP) was developed as part of the municipal stormwater program to address stormwater pollution from new private sector development and redevelopment projects. The SUSMP contains a list of the minimum required BMPs that must be used for a designated project.
The SUSMP was designed and intended for private sector development projects and not directed towards State agencies such as School Districts. However, if a LAUSD school facility project is five (5) acres or greater, a NPDES General Construction Stormwater Permit is required. Permanent or post-construction BMP's are similar to the BMP requirements of the SUSMP. To index
3D. 4.1 Methodology The environmental baseline for the proposed project is based on the review of existing hydrological data from local and regional agencies including the LA County Flood Control District, LARWQCB, and the LA Department of Water and Power. Seven potential impacts are analyzed in terms of the standards of significance criteria, as outlined below. Impact conclusions are then based on comparison of the level of impact assuming implementation of recommended mitigation measures presented below.
Criteria for Determining Significance The proposed project would have a significant impact on surface hydrology, water quality, and/ or groundwater if any of the following were to occur:
· Violation of any water quality standards or waste discharge requirement · Substantial depletion of groundwater supplies or substantial interference with groundwater recharge · Substantial alteration of existing drainage patterns resulting in substantial erosion and/ or flooding on or off site
· Substantial degradation of overall water quality · Placement of structures within a 100-year flood hazard zone that would impede or redirect flood flows · Exposure of people or structures to significant risk of loss, injury, or death involving flooding, including flooding from failure of a dam or levee
· Exposure of people or structures to significant risk of loss, injury, or death involving inundation by seiche, tsunami, or mudflow. To index
3D. 4.2 Project Impacts Impact D1: Violation of any water quality standard or waste discharge requirement.
Sediment from project-induced on-site erosion could accumulate in the downstream drainage facilities, which could interfere with flow, aggravating downstream flooding conditions. Operation of the school is anticipated to produce minimal surface runoff and therefore would not likely violate any water quality standards in waterways and water bodies downstream of the project site.
Storm events could cause the movement of loose soils during the construction activities (e. g., soils from the excavation for the underground garage) into street gutters and ultimately storm drainages. However, proper compliance with the required NPDES General Construction Stormwater Permit would result in a less than significant impact.
Mitigation Measures. No mitigation measures are required. Impact D2: Substantial depletion of groundwater supplies or substantial interference with groundwater recharge.
Development of the proposed project would not result in any substantial changes in the quantity of groundwater on site. There would be a decrease in percolation of water into groundwater associated with the proposed project compared to the current conditions (a vacant lot with few impermeable surfaces), because of construction of new impermeable surfaces (e. g., building, parking lot). However, a small area of the site would remain pervious as lawns and open space. It is anticipated that this increase in impervious surfaces would not substantially interfere with recharge of the San Fernando Basin (SFB). Therefore, potential impacts are considered to be less than significant.
Construction of the underground parking garage would include excavating to an estimated depth of between 10 to 15 feet bgs. The depth to groundwater near the project site is approximately 198 feet bgs; therefore, excavation and construction of the garage would not impact the groundwater supply. However, there is the potential to accumulate water in the excavation pit during construction. Implementation of Mitigation Measure 3D-1 would reduce potential impacts associated with improper discharge of accumulated water to a less than significant level.
Mitigation Measure D-1 Water accumulation within the excavation pit shall be properly discharged in accordance with Best Management Practices and a dewatering plan that must be developed and approved prior to construction as part of the NPDES General Construction Stormwater Permit.
Level of Significance after Mitigation. The impact would be less than significant after mitigation.
Impact D3: Substantial alteration of existing drainage patterns resulting in substantial erosion and/ or flooding on or off site.
The project site is within an urbanized area with existing infrastructure for drainage flows and flood control. The construction of impermeable surfaces on approximately 60 percent of the site would slightly increase stormwater flows but impacts are anticipated to be less than significant. See Section 3G, Public Services and Utilities, for a more detailed analysis on potential stormwater impacts.
Mitigation Measure. No mitigation required. Impact D4: Substantial degradation of overall water quality. Altering surface runoff could potentially cause a decrease in water and sediment quality in the Sepulveda Basin. Development of the proposed school could result in a higher surface runoff than currently leaves the project site. Covering the existing soil surface with impermeable materials would decrease the amount of water that infiltrates the ground and increase the net surface runoff from the site. Implementation of Mitigation Measures D-2 and D-3 below would minimize the effects of increased surface runoff, reducing potentially significant impacts to a less than significant level.
Mitigation Measures D-2 Surface runoff shall be collected in a storm water collection system. The design of the storm drain system (i. e., drain inlets and conveyances) must be adequate to prevent localized flooding due to foliage and debris entrapment from increased storm runoff, and prevent contamination of the SFB. In order to accommodate the additional storm water runoff and annual water yield resulting from the construction, storm drain improvements shall provide capacity to carry 25-year peak runoff rates and insure a flood protection to proposed buildings in the project site for a 100-year flood.
As required, an NPDES stormwater permit application shall be submitted for the proposed project. The effluent quality criteria shall be specified in the permit, as determined by LARWQCB based on receiving water guidelines and waste load allocations. Monitoring of the outflow from the collection system may be required in the permit to ensure that the requirements and water quality criteria specified by the permit are achieved.
D-3 Prior to the stabilization of the construction site area, sediment flows shall be prevented from entering storm drainage systems by the construction of temporary filter inlets around existing storm drain inlets. The sediment trapped in these impounding areas shall be removed after each storm.
Level of Significance after Mitigation. Impacts would be less than significant after mitigation.
Impact D5: Placement of structures within a 100-Year Flood Hazard Zone that would impede or redirect flood flows.
The project site is not located in a 100-Year Flood Hazard Zone (City of Los Angeles, 1999). The project would not impede or redirect flood flows and there would be no potential impacts.
Mitigation Measure. No mitigation required. Impact D6: Exposure of people or structures to significant risk of loss, injury, or death involving flooding, including flooding from failure of a dam or levee.
According to the City of Los Angeles General Plan, the project site is not located in a potential inundation area. Therefore, the project would not create a risk of loss, injury, or death involving flooding, including flooding from failure of a dam or levee (City of Los Angeles, 1996), and there would be no potential impacts.
Mitigation Measure. No mitigation required. Impact D7: Exposure of people or structures to significant risk of loss, injury, or death involving inundation by seiche, tsunami, or mudflow.
According to the City of Los Angeles General Plan, the project site is not located in a potential inundation area and does not have the potential to be impacted by a tsunami (City of Los Angeles, 1996). The project would not create risk of loss, injury, or death involving inundation by seiche, tsunami, or mudflow. Therefore, there would be no potential impacts.
Mitigation Measure. No mitigation required. To index
3D. 4.3 Cumulative Impacts The development of cumulative projects in the project area could increase the amount of surface runoff. Similarly, water quality impacts would be impacted with the development of projects. BMPs and SUSMP are developed by the RWQCB on a regional basis to address cumulative impacts from surface runoff. Therefore, implementation of BMPs and SUSMP on a project-by-project basis would not cause cumulatively considerable impacts to hydrology or water quality (less than significant).
Mitigation Measures. No mitigation is required. To index