5. Environmental Analysis - Mt. San Jacinto College. Environmental Analysis San Gorgonio Pass Master...

5. Environmental Analysis

San Gorgonio Pass Master Plan Draft EIR Mt. San Jacinto CCD Page 5.6-1

5.6 HAZARDS AND HAZARDOUS MATERIALS

This section evaluates the potential impacts of the proposed project on human health and the environment due to exposure to hazardous materials or conditions associated with the project site, project construction, and project operations. Potential project impacts and appropriate mitigation measures or standard conditions are included as necessary. The analysis in this section is based, in part, upon the following source:

Pipeline Safety Hazard Assessment, The Planning Center|DC&E, February 2012

A complete copy of this study is included in the Technical Appendices to this Draft EIR (Volume II, Appendix G).

5.6.1 Environmental Setting

The project site is in the City of Banning in Riverside County on the south side of Westward Avenue, between Sunset Avenue to the west and Woodland Avenue to the east. Pershing Creek borders the site to the south. The project site consists primarily of undeveloped land covered with both native and nonnative vegetation. Of the 50.1 acres of land, approximately 2.7 acres in the northwestern corner of the project site have been developed. In November 2010 the District constructed a 1,920-square-foot administration building, four 3,840-square-foot classroom buildings, a 960-square-foot toilet/utility building, shade structures, a paved parking area for 117 cars, and sustainable landscaping.

The site has a rolling topography that generally slopes toward the southeast. The site elevation ranges from approximately 2,380 feet above mean sea level in the southern portion to approximately 2,420 feet above mean sea level in the northwest portion. An unnamed tributary to the Pershing Creek bisects the project site in a southeasterly direction, while the Pershing Creek borders and encroaches onto the site on its southern border.

Surrounding land use consists of residential properties and vacant land. The proposed campus is bounded on the north by W. Westward Avenue, on the east and south by vacant land, and on the west by Sunset Avenue.

There are three natural gas pipelines and one petroleum product pipeline within 1,500 feet of the school site. No chemical pipelines were reported within a 1,500-foot radius. The locations of the pipelines are shown on Figure 5.6-1.

Two natural gas transmission pipelines operated by the Southern California Gas Company are within a 1,500-foot radius: A 30-inch pipeline (designated L-2000 or the Texas Line) is beneath Lincoln Street approximately 1,332 feet north of the property boundary. It was installed in 1947 and is constructed of Grade X-52 steel with a wall thickness of 0.344 inch. The maximum allowable operating pressure (MAOP) of this pipeline is 650 pounds per square inch (psig). There is an isolation valve at the intersection of Lincoln Street and Hathaway Street.

A second 36-inch natural gas transmission pipeline is beneath Bobcat Road approximately 1,268 feet south of the proposed campus site. This pipeline (designated L-5000) was installed in 1971 and also has a MAOP of 650 psig. The pipeline is constructed of Grade X-60 steel with a wall thickness of 0.392 inch.

Both of these natural gas pipelines are wrapped and equipped with an induced current cathodic protection system to minimize corrosion. Natural gas transmission pipelines that operate at pressures greater than 20 percent of the specified minimum yield strength (SMYS), are inspected annually. Both pipelines have at least 36 inches of cover, and no incidents have been reported along either.

Questar Southern Trails Pipeline Company owns a 16-inch transmission pipeline beneath Westward Avenue that is approximately 19 feet north of the campus. This pipeline is currently idle and filled with an inert gas; it previously was used for the transport of crude oil. Questar is currently going through the regulatory approval process to have it converted for natural gas use.

5. Environmental Analysis HAZARDS AND HAZARDOUS MATERIALS

Page 5.6-2 The Planning Center|DC&E January 2013

The pipeline was installed in 1957 and is constructed of ductile, electric resistance welded (ERW) Class X-52 steel with a wall thickness of 0.25 to 0.281 inch and a coal tar coating to minimize corrosion. The entire length of the pipeline was inspected with “smart pig” in 1996 to document the pipeline’s physical condition and integrity. Pressure testing of the pipeline specified by 49 CFR 192 will be conducted to determine the proposed MAOP for the natural gas pipeline. According to Questar, the MAOP in this area will be 975 psig. Sectionalizing block valves will be installed at spacings that meet Department of Transportation (DOT) requirements and typically will be four miles apart.

Kinder Morgan owns and operates a 20-inch petroleum product pipeline (LS-111) that is approximately 25 feet north of the campus property boundary (Kinder Morgan 2012). The pipeline, which transports petroleum products from Colton to Yuma, was formerly owned and operated by Santa Fe Pacific Pipeline. The pipeline was installed in 1985 and is constructed of Grade X-60 steel with a wall thickness of 0.281 inch. It has a 50 mil Polytape Polyken YG III external coating to minimize corrosion. The pipeline depth varies but is a minimum of three feet below ground surface (bgs). Due to recent company restrictions on providing pipeline information, the operating pressure was not provided. However, previous information obtained for this pipeline stated that the operating pressure of the pipeline was 1,250 psi.

There also are two large volume (>12 inches) water pipelines within 1,500 feet of the project site. A 12-inch water main is beneath Sunset Avenue, which is adjacent and west of the property. There also is an 18-inch water main beneath Westward Avenue that begins west of Sunset Avenue and the project site.

There are no buildings or structures that could partially block or buffer jet flames, vapor releases, or burning pools if an incident were to occur involving natural gas pipelines or petroleum product pipelines located beneath W. Westward Boulevard. Intervening structures and residences would partially block releases from the 30-inch natural gas pipeline beneath Lincoln Avenue, but there are currently no structures between the 36-inch natural gas pipeline beneath Bobcat Road and the campus. Potential ignition sources may include motor vehicles traveling along the adjacent streets, overhead high voltage lines, and residential gas heating units.

5.6.2 Thresholds of Significance

According to Appendix G of the CEQA Guidelines, a project would normally have a significant effect on the environment if the project would:

H-1 Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials.

H-2 Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment.

H-3 Emit hazardous emissions or handle hazardous or acutely hazardous materials, substance, or waste within one-quarter mile of an existing or proposed school.

H-4 Be located on a site which is included on a list of hazardous materials compiled pursuant to Government Code Section 65962.5 and, as a result, would create a significant hazard to the public or the environment.

H-5 For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would result in a safety hazard for people residing or working in the project area.

H-6 For a project in the vicinity of a private airstrip, result in a safety hazard for people residing or working in the project area.

H-7 Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan.

Source: Google Earth Pro 2011

San Gorgonio Pass Campus Master Plan Draft EIR The Planning Center • Figure 5.6-1

Pipeline Location Map

0 1,500

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36-inch Natural GasTransmission Pipeline

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20-inchKinder Morgan

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HAZARDS AND HAZARDOUS MATERIALS

San Gorgonio Pass Campus Master Plan Draft EIR Mt. San Jacinto Community College District .6-5

H-8 Expose people or structures to a significant risk of loss, injury, or death involving wildland fires, including where wildlands are adjacent to the urbanized areas or where residences are intermixed with wildlands.

The Initial Study, included as Appendix A, substantiates that impacts associated with the following thresholds would be less than significant:

Threshold H-1 Threshold H-3 Threshold H-4 Threshold H-5 Threshold H-6 Threshold H-7 Threshold H-8

These impacts will not be addressed in the following analysis.

5.6.3 Environmental Impacts

The following impact analysis addresses thresholds of significance for potentially significant impacts. The applicable thresholds are identified in brackets after the impact statement.

IMPACT 5.8.1: CREATE A SIGNIFICANT HAZARD TO THE PUBLIC OR THE ENVIRONMENT THROUGH REASONABLY FORESEEABLE UPSET AND ACCIDENT CONDITIONS INVOLVING THE RELEASE OF HAZARDOUS MATERIALS INTO THE ENVIRONMENT. [THRESHOLD H-2]

Impact Analysis: The Initial Study identified potentially significant hazards from the operation of offsite high pressure pipelines located within 1,500 feet of the project site. In order to evaluate the potential impacts, a pipeline safety hazard assessment (PSHA) was prepared by The Planning Center|DC&E. The results of the study are summarized below:

Assessment Methodology

The California Department of Education (CDE) recently developed and published guidance procedures for evaluating safety hazards associated with natural gas and hazardous liquid releases from underground and aboveground pipelines. A detailed description of the procedures is provided in the California Department of Education Guidance Protocol for School Site Pipeline Risk Analysis. These procedures were used in conducting the PSHA.

The PSHA process has of two steps: The first (Stage 1) is a risk screening analysis based on the distance of the pipeline(s) from the site and operating characteristics of the pipeline(s). If the screening criteria are met, the level of risk is acceptable and no further analysis is required.

If the screening criteria are not met, then the second step of the PSHA process is completion of a Stage 2 quantitative risk analysis. The Stage 2 risk analysis considers pipeline accident rates, site dimensions, conditional probabilities for ignition, time, and fatality probabilities for different exposure scenarios (pool fire, flash fire, and explosion) to estimate individual risk (IR). Pipelines located within 50 feet of a project site are also subject to a Stage 3 (more comprehensive) analysis to verify the results of the Stage 2 evaluation.

Individual fatality risk is compared to the significance threshold level of one in one million (1.0 x 10-6). If the estimated risk is less than one in one million, then no significant safety hazard is predicted for the project site. If the estimated risk is greater than one in one million, mitigation measures are required to reduce risk to within acceptable limits or a more detailed Stage 3 risk analysis can be conducted.



In addition to individual risk, an estimate of the potential risk for the population present at the school site is determined by calculating the total individual risk (TIR) indicator ratio and the population risk indicator. These parameters add an additional perspective by taking into account the site configuration and project site population. There is no significance threshold established by the CDE for this evaluation, and this does not replace the IR estimate as the primary decision criteria for evaluating risk at the school site. However, it does provide additional information regarding the magnitude of risk at the project site.

The CDE also has developed risk analysis procedures for evaluating flooding associated with releases from large diameter water pipelines, as described in CDE’s Guidance Protocol for School Site Pipeline Risk Analysis. Also, releases from underground water pipelines can cause subterranean erosion of saturated soil, leading to subsidence or formation of a sinkhole. The most likely cause of failure is a large magnitude earthquake and associated strong ground shaking.

Although no specific criteria have been established by the CDE as a threshold of significance for flooding at a project site, a water depth of 12 inches or greater is a trigger that could warrant further evaluation.

Risk Analysis Results

Stage 2 Results

The calculated IR results for the high pressure pipelines are:

30-inch Natural Gas Transmission Pipeline in Lincoln Avenue: 3.0 x 10-9 36-inch Natural Gas Transmission Pipeline in Bobcat Road: 4.0 x 10-9 16-inch Natural Gas Transmission Pipeline in Westward Avenue: 8.8 x 10-8 20-inch Petroleum Product Pipeline in Westward Avenue: 3.7 x 10-9

The cumulative TIR for all pipelines is 9.9 x 10-8. Since the calculated risk is less than one in a million (1.0 x 10-6), which is the TIR criterion specified in the CDE manual, the risk is considered to be less than significant.

As part of the Stage 2 analysis, population risk indicators were also determined for the school site, based on the protocol presented in the CDE manual. The project site was divided into three zones; each zone was approximately 500 feet wide. The TIR was calculated for each zone and compared to the TIR calculated for the nearest school boundary to the pipeline (i.e., TIR Indicator Ratio).

Also, the relative risk to the project site population in terms of mortality for a jet fire or pool fire release scenario was determined, as per the CDE manual. An average mortality value for each zone was multiplied by the zone population (i.e., the number of people that could potentially be outdoors and within the zone area). The CDE default value assumes that 30 percent of the total campus population of 5,200 students and staff are outdoors at any one time. The outdoor occupancy of each zone was based on the proposed site plan for San Gorgonio Pass Campus. Because Zones 1 and 3 contained primarily parking areas and open space, these zones were assumed to have an outdoor occupancy value of 40 percent. Zone 2 contains most of the buildings and was assumed to have an outdoor occupancy value of 20 percent. The calculations for TIR ratios and population risk indicators for all the pipelines were nil with the exception of the 16-inch natural gas pipeline along Westward Avenue. The aggregate population threat (potential number of people on campus who could suffer mortalities) in the unlikely event that a pipeline release and subsequent jet fire or pool fire were to occur was 312. There are no significance thresholds established by CDE for the population risk indicator. The value is simply used as an indicator of the relative potential risk at a school site.

Stage 3 Results

Because the 16-inch natural gas pipeline and 20-inch petroleum product pipeline along Westward Avenue are less than 50 feet from the school property boundary, a Stage 3 analysis was conducted to verify and validate the Stage 2 results, using different calculation methods. The CDE manual states that near-field modeling may not accurately apply within a


HAZARDS AND HAZARDOUS MATERIALS

San Gorgonio Pass Campus Master Plan Draft EIR Mt. San Jacinto Community College District Page 5.6-7

distance of 50 feet and that “additional modeling should be applied, with checks by more than one estimation method.” For the natural gas pipeline, the Los Angeles Unified School District’s pipeline risk protocol was used, which has more conservative results than the CDE protocol.

For the Stage 3 analysis for the petroleum product pipeline, the potential impact from the detonation of gasoline vapors in the storm drain beneath Westward Avenue was evaluated. In the unlikely event of a pipeline break, the released petroleum product would flow to the east along the north side of Westward Avenue and enter the storm drain inlet near the intersection of Westward Avenue and Woodland Avenue.

The closest location of a school building to the storm drain is approximately 500 feet. At this distance, the aboveground blast overpressure was estimated to be 0.34 psi. This is a “safe distance” pressure at which there is a 95 percent probability of no serious damage and 10 percent probability that windows could be broken. This overpressure estimate is conservative, because it assumes that the explosion occurs aboveground, when the explosion actually would take place in a vented, confined space below ground. With belowground explosions, a substantial portion of energy released from the blast would be absorbed into the surrounding ground. In addition, the analysis assumes that the storm drain is entirely enclosed, when in reality, there are storm drain inlets or vents along the line at intervals that relieve the pressure buildup and result in lower peak overpressures. Therefore, it is determined that in the unlikely event that vapors could accumulate in the storm drain and result in an explosion, the impact to students and staff at the campus would be less than significant.

Water Pipeline Flooding Analysis

The CDE Guidance Protocol for School Pipeline Risk Analysis provides a methodology for evaluating the potential for flooding. For the 12-inch water main beneath Sunset Avenue and the 18-inch water main beneath Westward Avenue west of the site, a pipeline flooding analysis was conducted to determine the depth and location of water flow within the street in the event of a pipeline leak or rupture.

For this worst-case analysis, it was conservatively assumed that all of the water flowing through these pipelines at its maximum capacity would reach the surface. In addition, no credit was taken for the presence of a concrete drainage ditch or curbing along the east side of Sunset Avenue. It is probable that both Sunset Avenue and Westward Avenue west of Sunset Avenue will be paved and curbed in the future as more development occurs in the area.

Release impacts were calculated based on the procedures specified in the CDE manual. The results from the analysis indicate that releases from either of these pipelines could result in water entering the project site. The results show that water could extend approximately 19 feet onto the campus from a break in the 12-inch water main and 8 feet from a break in the 18-inch water main. However, these results are conservative because they do not take into account the curbing at the intersection of Sunset Avenue and Westward Avenue. Also, the future plan for the campus includes a detention basin in the northwest corner of the project site that would retain water from any pipeline releases, and the western edge of the project site includes a 100-foot-wide strip of undeveloped, open space that would prevent any released water from impacting the campus. If curbing is installed along Sunset Avenue in the future, then any releases from broken water mains would be entirely contained within the confines of the street. Given the proposed Phase III development plan for the campus, the likelihood of future curbing along Sunset Avenue, and the calculations that water would extend only up to 19 feet onto the campus into green open space if curbing was not installed, releases from broken water mains would not result in adverse impacts to students or staff at the site.

5.6.4 Cumulative Impacts

The PSHA evaluated the cumulative impact of all high pressure pipelines that carry hazardous materials within 1,500 feet of the project site. The cumulative risk was determined to be 9.9 x 10-8 for all pipelines. Since the calculated risk is less than one in a million (1.0 x 10-6), which is the TIR criterion specified in the CDE manual, the cumulative risk is considered to be less than significant.



5.6.5 Existing Regulations and Standard Conditions

Natural gas pipelines are regulated under Section 49 of the Code of Federal Regulations, Parts 190-192 and 199. Additionally, natural gas pipelines in California are regulated under General Order 112-E. Hazardous liquid pipelines are regulated under Section 49 of the Code of Federal Regulations, Part 195, and in California additionally under Section 51010 of the California Government Code. Pipelines in California are regulated by the following three agencies: 1) the State Fire Marshal’s Office; 2) the California Public Utilities Commission (CPUC); and 3) USDOT, Office of Pipeline Safety. The State Fire Marshal’s Office has jurisdiction over hazardous liquid pipelines in California, the CPUC has jurisdiction over natural gas pipelines in California, and the Office of Pipeline Safety provides federal regulation for both hazardous liquid and natural gas pipelines.

Although the California Department of Education (CDE) requires a Pipeline Risk Assessment to be conducted for all high-pressure pipelines within 1,500 feet of a proposed elementary or secondary school, the California Postsecondary Education Commission (now defunct), which covered state universities and community colleges, did not have any comparable requirement.

5.6.6 Level of Significance Before Mitigation

Upon implementation of regulatory requirements and standard conditions of approval, the following impacts would be less than significant: 5.8-1.

5.6.7 Mitigation Measures

A less than significant impact with respect to hazards and hazardous materials was identified and no mitigation measures are necessary.

5.6.8 Level of Significance After Mitigation

A less than significant impact with respect to hazards and hazardous materials was identified and no mitigation measures are necessary. No significant unavoidable adverse impacts related to hazards have been identified.

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