Devil's Slide Improvement Project

Route 1 from Half Moon Bay Airport to Linda Mar Boulevard in Pacifica,

San Mateo County, California

DRAFT

SECOND SUPPLEMENTAL ENVIRONMENTAL IMPACT STATEMENT/

SECOND SUPPLEMENTAL ENVIRONMENTAL IMPACT REPORT

ALL COMMENTS ON THIS DOCUMENT MUST BE MADE IN WRITING TO:

Robert Gross, Chief
Office of Environmental Planning, South
Caltrans District 4
P.O. Box 23660
Oakland, CA 94623-0660

5.0 ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES


This section describes the environmental consequences for the build alternatives and the no-project alternative. The discussion regarding each area of potential impact has been revised where appropriate to reflect the results of any new and updated information. Issues which remain unchanged from the information presented in the 1986 FEIS, are indicated under each environmental topic and are incorporated in this draft second SEIS/R by reference.

 

5.1 AESTHETICS

Setting

The proposed Martini Creek alignment alternative now incorporates a revised 4.5 meter (15 foot) higher profile grade. These design changes do not result in any additional adverse visual changes, and the visual setting previously described in the 1986 final EIS/EIR generally reflects the current existing conditions (1998). The following information supplements the 1986 Aesthetics Setting discussion by providing more detail with regard to the proposed tunnel alignment alternative.

The project area is in San Mateo County on State Route 1, approximately 3.2 km (two miles) south of Rockaway Beach and the town of Pacifica. It is two miles north of the community of Montara, and five miles north of the northern end of Half Moon Bay. State Route 1 in this section of the highway is eligible to become a Designated Scenic Route (see Aesthetics discussion, page 71 of the 1986 FEIS for further information).

The project area is within the Coast Range, with the proposed tunnel to be located through a portion of San Pedro Mountain. The vegetation blanketing the hillsides on the northern and southern portals is comprised of coastal scrub (Ceanothus sp., Baccharis pilularis, Rhamnus sp.), with tree species both native and exotic, sprinkled amongst the coastal scrub in concentrated patches of forest. Tree species include Coastal Live Oak (Quercus agrifolia) , Monterey Pine (Pinus radiata), and Eucalyptus.

In the southbound direction, existing Route 1 approaches the northern end of the project area by means of a long uphill grade, adjacent to the green hillsides and valleys of the Shamrock Ranch area along the southeast side of the highway. The roadway grade continues through road cuts, with the vista opening west out to a vast, sweeping view of the Pacific Ocean. Existing Route 1 hugs steep, rocky and barren hillsides, with coastal bluffs and hills interspersed along the highway. Route 1 continues south, with views broadening towards the southeast to the communities of Montara and Moss Beach situated at the base of the upsweeping Coast Range.

The northbound approach to the proposed tunnel’s southern portal area allows motorists along Route 1 to transition from the residential neighborhoods and small commercial areas of Moss Beach and El Granada, up a gradual grade to the coastal scrub-covered hills and rocky coastal bluffs. The open valley of Green Valley on the eastern side of the highway comes into view. Steep bluffs on the west side of the highway drop to the ocean’s edge, with boulders and outlying rocks lying in the path of incoming waves. The ocean spray from the waves is sometimes visible.

Impacts

The following summarizes the visual impacts that would result from construction of a tunnel through San Pedro Mountain, east of Devil’s Slide on Route 1 in San Mateo County. The impacts of two tunnel design options proposed for crossing the Shamrock Ranch valley from the existing Route 1 to the proposed North Portal (‘Fill Option’ and ‘Bridge Option’) were evaluated. Since the fill option is no longer being considered as part of the tunnel project, the aesthetic impacts of this option are not discussed.

The bridge option provides a concrete cast-in-place bridge spanning the Shamrock Ranch valley. This option would also provide for two lanes of traffic, separating at the approach to the portal. With the bridge option, all the fill material would be placed at the South Disposal Site. Although the removal of excess material could be accomplished by hauling the material off-site, the associated costs and time constraints are not as practical as the south disposal site option.

Two tunnel design variations, ‘A’ and ‘B’, were analyzed in the Visual Assessment Report. Both design variations include two bores each with a single lane of traffic in one direction with an outside shoulder, and raised sidewalks for emergency / maintenance personnel access. The design variations differ in that design variation ‘B’ is wider in cross-section to include a concrete barrier separating a proposed bike lane from the outside shoulder, and would result in 763,071 cubic meters (998,000 cubic yards) of excess material. Design variation ‘A’ would produce in 724,076 cubic meters (947,000 cubic yards) of excess material. The visual impacts at the North and South Portal Areas are similar in nature but more severe under design variation ‘B’ than ‘A’ due to the wider cross-sectional area (and thus the greater amount of fill material at the disposal site) associated with variation ‘B’.

North Portal Area

The proposed bridge structure would span the small valley at Shamrock Ranch and connect the highway at its existing alignment with the North Portal. It is estimated to be 320 meters (1,050 feet) in total length. The bridge would present a negative visual impact on this small valley which currently enjoys minimal intrusions from development.

Trees and hillside vegetation would be cleared and grubbed for construction of the tunnel portal approach as well as the portal itself. A negative visual impact would be the result of the contrast between the cleared area and the chaparral-blanketed hillsides.

An access road and water tank, on the hillside above the portal, would be visible in long range views resulting in a negative visual impact. The North Portal facade presents a structure on a heavily vegetated hillside that would be visible for a short duration for motorists and bicyclists.

The elements of the North Portal, including the rock cut, tunnel portal, guardrail, and small structures would create an aggregate visual change and would have a negative impact on the existing visual environment for motorists and bicyclists.

A safety fence proposed for the top of the rock cut also presents a potential negative visual impact. This transition area, from natural hillside to built structure, would be defined by the fence.

South Portal Area

The South Disposal Site would be the only area where all the excavated material from the tunnel construction would be disposed of within the project limits. The site would undergo negative visual changes with the placement of fill in a coastal scrub-covered valley located close to the coastal bluffs. Under design variation "B-Bridge option", the south disposal site would receive an estimated 763,072 cubic meters (998,000 cubic yards) of excavated material. Under design variation "A", the south disposal site would receive an estimated 724,076 cubic meters (947,000 cubic yards) of excess material. The fill area would create a hill with 2:1 slopes, 180 meters (590’) in diameter and reaching 90 meters (295’) in height.

 

The South Portal would be visible from a short distance for motorists on the highway, and from a long-distance for boaters on the ocean’s surface. There are no residents within the immediate vicinity of the South Portal who would experience long exposure views to the South Portal.

The large rock cut proposed at the South Portal Area is necessary to align the highway and to provide adequate sight distance and radius curve. A smaller rock cut will top the South Portal with the proposed designs. Rock cuts could be visually prominent.

The South Portal Electric Building proposed for this area may be considered a neutral or negative visual impact. An Operations and Maintenance Center is also proposed to be located a short distance from the portal itself. This building may be a visually intrusive feature in the environment.

The rock fence proposed at the base of the rock cut (to catch rock crumbling off the face of the rock cut) could be a visually contrasting element in the environment as well. Other elements of the South Portal Area include drainage features, a turnaround area, and a guardrail.

Mitigation Measures

North Portal Area

The overall appearance of the bridge would have a negative visual impact on the Shamrock Ranch valley and the surrounding area. Mitigation for this visual impact would include consideration of aesthetics as an integral part of the bridge design. A well-designed bridge which includes consideration of form, pattern, color, etc., as well as structural elements integrated with the natural surroundings would mitigate the visual impact of the bridge. Standard monolithic concrete structures with no form, pattern or articulation would not provide adequate mitigation for this impact.

The mitigation proposed for the negative visual impact includes a major revegetation effort. The revegetation strategy includes site-specific measures for erosion control of fill slopes; collection, propagation and planting of native plant species; and installation of automatic irrigation systems. Mitigation and monitoring measures include a plant establishment period of ten years.

Construction clearing and grubbing activities should have clearly defined limits. The negative visual impact for vegetation removal could be mitigated with revegetation. With sufficient quantities, the passage of time, and successful establishment of trees, shrubs and other materials, it is possible to provide a new landcover to mitigate the associated visual impact.

Mitigation for the impacts of construction of the access road and water tank includes screening of the water tank with vegetation. Preliminary studies identified gravel as the surface material for the access road. This is visually appropriate for the chaparral-covered hillside.

Mitigation for the potential negative visual impact of the North Portal facade includes an architectural treatment for the tunnel portal in order to lend a cohesive, substantive design for the tunnel entrance that blends with the environment. The North Portal would be viewed by motorists for a longer duration than the South Portal. The architectural aesthetic treatment would provide the predominating design theme for the other built elements of the North Portal Area to key off of. Architectural treatment for the North Portal is necessary in order to mitigate negative visual impacts.

Design of the North Portal Area should also include aesthetic considerations. Architectural surface treatment (for visual continuity) of the proposed facilities for the entire portal area should be carefully considered, planned for, and included in project cost estimating. Aesthetic treatment includes landscaping for softening and transition of the built elements into the hillside.

The proposed safety fence should visually blend into the background. The choice of fence material should be carefully considered for this element of the Portal. Plain fabric fence (chain-link) or barbed wire is inappropriate. Vinyl cladding or paint for fence fabric is recommended for mitigation if fabric fence is the chosen material.

South Portal Area

The proposed mitigation for the visual impact of the placement of fill material in the South Disposal Site would include contour grading of the fill to blend into the adjacent hillsides and the floor of the valley. Mitigation would also include revegetation to further blend the fill material into the surroundings.

The South Portal should present an aesthetically pleasing exterior and should match the North Portal’s aesthetic treatment. Architectural surface treatment would be included in the project cost estimate.

If possible, the face of the rock cuts should not be left with a machined or unnatural appearance. Existing rock cut faces in this area present a natural, rough appearance which duplicates the natural rock faces.

Architectural treatment of the proposed South Portal Electric Building would help reduce the associated potential visual impacts of the structure. The Operations and Maintenance Center would also be shielded from view of the highway through the use of earthen berms. Small-scale screen planting would also aid in visual mitigation.

The proposed safety fence may be epoxy-coated to reduce corrosion. A color for the epoxy coating could be specified to blend the fence into its surroundings and to visually mitigate its appearance.

Mitigation measures for the proposed drainage features, turnaround area, and guardrail facilities include the consideration of these elements as a whole, to present a comprehensive, unified design effort for the South Portal Area. Architectural treatments, surface treatments, scale, and positioning considerations would be included in the design, along with functional considerations, in order to reduce visual impacts.

Martini Creek Alignment Alternative

Potential visual impacts and proposed mitigation measures associated with the Martini Creek alignment alternative were addressed in the 1986 FEIS. The revised project proposal includes extending certain bridge structures, thus reducing the amount of cut and fill material identified in that document. It is expected, however, that the extensive revegetation effort described as mitigation for that project would still be necessary to reduce any potential impacts.

 

 

5.2 AIR QUALITY

Setting

Air pollution in the Bay Area has been determined to be a serious health problem by the EPA (Environmental Protection Agency), the California Air Resources Board (ARB), and the Bay Area Air Quality Management District (BAAQMD). Since a major share of this pollution is caused by motor vehicles, Caltrans addresses the impact of highway projects on air quality in accordance with the following legislation: the Clean Air Act and its amendments, the EPA Final Regulations (November 1997), NEPA and CEQA.

The project is in an air quality maintenance area for all criteria pollutants, including carbon monoxide. However, due to seventeen exceedances of the one hour ozone standard in 1995 and 1996, the Bay Area's status has been changed from an ozone attainment area to an ozone non-attainment area without assigning it a specific classification (i.e. marginal, moderate, serious, severe or extreme), since the existing Clean Air Act classification system does not specifically apply to the Bay Area. This proposed change to 40 CFR Section 81.305 was announced in the Federal Register on July 10, 1998 (63 Fed. Reg. 37258-37280) and became effective August 10, 1998.

California has adopted its own ambient standards for air pollutant concentrations, which are more stringent than Federal standards. The San Francisco Bay Area has been designated as a non-attainment zone for state ozone and PM-10 standards. The California Clean Air Act (CCAA) required non-attainment areas to develop plans aimed at reducing emissions of non-attainment pollutants or their precursors by 5 percent per year. Alternatively, if an air district is unable to achieve a 5 percent reduction, the adoption of all feasible measures on an expeditious schedule is acceptable. The California Legislature, when it passed the CCAA in 1988 (amended in 1992), recognized that PM-10 attainment was not realistic and excluded it from the requirements in CCAA.

Because the San Francisco Bay Area cannot achieve the 5 percent reductions required under the 1988 CCAA, the 1991 Clean Air Plan (CAP) for the San Francisco Bay Area was developed to implement all feasible measures. The CAP is updated every three years. The 1997 CAP consists of twenty Transportation Control Measures (TCM) and is divided into three phases for implementation. Many of the Phase III control measures are not currently funded. Although the 1997 CAP is intended to satisfy State standards, many elements of the 1997 CAP will also satisfy Federal air quality planning requirements. The requirements for quantitative analysis contained in 40 CFR 93.123(b)(4) Transportation Conformity Rule, published in the Federal Register August 15, 1997 states:

The requirements for quantitative analysis contained in this paragraph (b) will not take effect until EPA releases modeling guidance on this subject and announces in the Federal Register that these requirements are in effect.

Pollutants

Carbon Monoxide

Carbon Monoxide (CO) is almost exclusively emitted by motor vehicles. This pollutant binds the oxygen-carrying protein in blood to hemoglobin, reducing the amount of the oxygen reaching the heart and brain. Exposure to CO, even at low levels, can endanger people with coronary artery disease. It can also cause headaches, fatigue, and slow reflexes, even among healthy people.

Ozone

Ozone (O3) is the primary constituent of photochemical smog. It is not emitted directly into the atmosphere, but is produced through a complex series of chemical reactions involving hydrocarbons (HC) and oxides of nitrogen (NOx) in the presence of sunlight. Vehicle exhaust emissions contribute slightly less than half of the pollutants that form ozone. High ozone levels occur primarily in the summer and early fall. The Federal standard for ozone is .12 part per million (ppm) for one hour. The State of California has a .09 ppm one hour ozone standard. High ozone levels aggravate asthma, bronchitis, and other respiratory ailments, as well as cardiovascular disease. High concentrations of ozone may also cause dizziness, headaches, burning of eyes and throat, and nausea. The EPA is phasing out and replacing the previous one-hour primary ozone standards with a new eight hour standard of .08 ppm (3-year average of the annual 4th highest daily maximum 8-hour concentrations) to protect against longer exposure periods. The Bay Area did not experience a single exceedance of the new national ozone standard.

Small Particulates (PM-10)

Ambient air quality standards for PM-10 were announced in the July 1, 1987 Federal Register. These standards took effect August 15, 1997. PM-10 is the term used to describe the small particles, of any composition and origin, with nominal size of 10 micrometers or less. Such particles are so small that, individually, they would not be visible. The fine particles are a threat to health, however, because they penetrate deep into the lungs during breathing and lodge there. (Large particles, by contrast, are filtered out in the upper respiratory passages, or are cleared by coughing, sneezing, etc.)

PM-10 standards are 150 micrograms/cubic meter for the 24-hour average and 50 micrograms/cubic meter for the annual average.

Oxides of Nitrogen

Nitrogen oxides (NOx) are produced by motor vehicles (particularly heavy duty vehicles) and high-temperature industrial operations, but have not posed a separate, serious health problem in the Bay Area in the past several years.

Impacts

Recent traffic projections were completed utilizing the MTC travel demand forecasting model and incorporating ABAG's land-use projections. The results compare similarly to the original traffic projections used in the 1986 FEIS. Therefore, the traffic projections used in the air quality study for the 1986 FEIS are still valid.

Factors used in calculating ambient air quality have changed since air quality studies were conducted for the approved FEIS in 1986. Present calculations would include a "roll back" factor which is defined as the ratio of expected future year emissions to the estimated base year emissions and refers to the dropping out of older, higher polluting vehicles from the overall highway vehicle fleet, creating a percentage reduction in air pollution every year.

Computer programs used to estimate present and future vehicle emissions and to predict pollution concentrations adjacent to the roadway have been revised since the project calculations were performed for the 1986 FEIS. Using the current emission factors, projections for the year 2010 are lower than those derived from previous calculations using the former emission factors.

In the 1986 FEIS, it was determined that air quality standards for carbon monoxide would not be exceeded for the design year for any of the alternatives. Although air quality regulations and measurement methodologies have been revised since project approval in 1986, the proposed Martini Creek alignment project design has not essentially changed. The proposed tunnel project does not add any additional capacity beyond that of the Martini Creek alignment alternative project and since neither build alternative increases roadway capacity nor moves the roadway closer to receptors, there will be no violation of the State or Federal CO standards.

One issue still under consideration as part of the proposed tunnel project is whether or not bicycle travel will be restricted through the tunnel. The EPA and FHWA requirements are not clearly established with regard to tunnel ventilation and potential tunnel air quality impacts to bicyclists. The proposed tunnel design includes a "real time" air quality monitoring system that includes variable message signs that can advise bicyclists when unacceptable air quality conditions exist in the tunnel. It is anticipated that adverse conditions would be infrequent (Woodward-Clyde Consultants, 1997).

 

With regard to construction-related impacts, either build alternative would generate air pollutants during the construction stages. The exhaust and odors from trucks and other construction equipment would contain hydrocarbons, oxides of nitrogen, carbon monoxide, and particulates, especially PM-10's. The largest percentage would be windblown dust generated by excavation, grading, hauling, and various other activities. The impacts from the above activities would vary from day to day as construction progresses, and would depend on the proximity of the receptors to the construction activities.

Mitigation Measures

To reduce dust generated by construction, hauling and grading activities, as well as any others that might raise dust, Caltrans construction specifications for dust control would include standard emission controls on construction vehicles, and sufficient watering of the area to accompany such activities. This watering will be included in the contract provisions for this project. This would effectively mitigate most particulate air quality impacts for the build alternatives.

 

5.3 CONSTRUCTION

Setting

Except for the following new tunnel-related information, the setting information remains unchanged from that described in the 1986 FEIS. With regard to the tunnel alternative (bridge option), the bridges are proposed to be constructed using the segmental balanced cantilever method to minimize impacts to pre-designated environmentally sensitive areas (ESA) within the Shamrock Valley. It should be noted that considerable site disturbance will be necessary to the area around the piers outside the ESA in order to position a crane and other equipment needed for pier construction. Also, a portion of the end spans of the bridge may require falsework for construction.

Impacts

Construction-related impacts are typically short-term in nature and are discussed under each impact section of this document (e.g. aesthetics, air quality, water quality, etc.) as applicable.

Mitigation Measures

Construction-related impacts will be minimized under either the tunnel or Martini Creek alignment alternatives by the use of various noise and dust controls, traffic restrictions, erosion control measures, work-hour guidelines, and the delineation of Environmentally Sensitive Areas off-limits to construction activities. Again, there is a discussion of construction-related mitigation measures within each impact section of this document as necessary.

5.4 CONSISTENCY WITH LOCAL AND REGIONAL PLANS

The California Coastal Commission (CCC) reviews federal assistance activities within or affecting the coastal zone to make a determination regarding its consistency with the Coastal Zone Management Program (CZMP). Although required permits are issued by the County, the Coastal Commission determines consistency. If the finding of consistency is denied, the action is not eligible for Federal funding unless it is modified to remove the inconsistency finding.

In November, 1996, the voters of San Mateo County passed the Devil’s Slide Tunnel Initiative known as Measure T. Passage of the Measure initiated the process to amend the County’s land use plan portion of the San Mateo County certified LCP to provide "a tunnel for motorized vehicles only behind Devil’s Slide through San Pedro Mountain" as the preferred alternative for Highway 1 around Devil's Slide, and to delete references to a two-lane bypass along the Martini Creek alignment.

The Initiative requires that the tunnel be designed consistent with the Coastal Act limits restricting Route 1 to a two-lane scenic highway using minimum Federal and State tunnel standards, and that a separate trail for pedestrians and bicycles be provided outside the tunnel. The Measure also requires voter approval of any other alternative to the tunnel, except repair of the existing highway. In January, 1997, the California Coastal Commission voted to certify the LCP amendment as submitted by the County.

The Metropolitan Transportation Commission (MTC) establishes regional transportation policies for the Bay Area. The current draft of the Regional Transportation Plan (RTP) includes a Devil's Slide tunnel as a project within San Mateo County (MTC, 1998). It also identifies emergency relief funding and funds originally earmarked for the Martini Creek alignment alternative as potential funding sources for a tunnel project.

The California Coastal Commission (CCC) determines Federal Coastal Zone Management Program consistency of the final EIS. The consistency determination will be documented in the record of decision (ROD). During the final design phase of the project, a permit application will be submitted to San Mateo County to obtain the required LCP permit.

 

5.5 CULTURAL RESOURCES

Setting

Section 106 of the National Historic Preservation Act and its implementing regulations Title 36, Code of Federal Regulations (CFR), section 800 require federal agencies to take into account the effect of their undertakings on historic properties. Historic properties are properties which meet the criteria for listing on the National Register of Historic Places.

A previous archeological survey of the Martini Creek alignment alternative was described in the 1984 Historic Properties Survey Report (HPSR), and a report of negative findings was submitted and cited in the 1986 FEIS. The setting remains unchanged from that described in the 1986 FEIS with regard to the Martini Creek alignment. An additional survey was conducted in October 1997 at the locations of the proposed tunnel alignment portals, and at an excess soil disposal site located at the south portal.

Eleven prehistoric sites have been recorded within 1 mile of the Route 1 right of way between PM 34.0 and 41.0 (KP 54.7-6.0). There are no previously recorded sites within the Area of Potential Affect (APE) of the proposed tunnel portal locations and excess soil depository site. The 1997 archeological survey did not find any new resources.

Impacts

Tunnel Alternative

No significant historic properties or archeological sites, which are eligible or potentially eligible for the National Register, would be affected by this alternative.

Martini Creek Alignment Alternative

The cultural resources investigations for the 1986 FEIS concluded that there is no evidence of cultural resources that meet the National Register of Historic Places criteria within the APE for the Martini Creek Alignment Alternative. The State Historic Preservation Officer (SHPO) was consulted and concurred with these findings. The revised alternative includes extended structures on essentially the same alignment and therefore is adequately covered by the previous evaluation of cultural resources within the established APE.

Of the 32 properties evaluated in the original Historic Architecture Survey Report (HASR), three have passed the 50-year threshold for National Register listing since 1986.

All three properties were given consideration for California Register and National Register listing, but determined to be ineligible due to lack of integrity, or lack of architectural significance. Based upon a recent review of the HASR, and the files relating to the Section 106 process for this project, there does not appear to be any need to reevaluate any of the properties documented in the original HASR.

Similarly, the series of roads and trails in the vicinity of the proposed Martini Creek alignment alternative are thought to lack the proper integrity to be eligible for listing on the National Register.

Mitigation Measures

No previously recorded archeological sites are known to exist at the locations of the two portals and excess soil disposal site for the proposed tunnel alternative alignment of the Devil’s Slide project. However, because a number of sites exist in the vicinity of the project any work outside of the APE that might involve subsurface construction within the Shamrock Ranch Valley would require further archaeological evaluation.

Excess spoils from tunnel borings will be deposited at a location south of the portal. Electrical utility linkages supporting the tunnel facility will connect through overhead power lines utilizing existing underground facilities at the Shamrock Ranch. The routing of electrical utilities will thereby avoid subsurface construction activities within areas that may contain buried archeological sites.

In the unlikely event that cultural resources are encountered during project construction, all work in the vicinity of the find must temporarily halt until a qualified Caltrans archeologist has evaluated the site and determined appropriate mitigation measures. As there are no anticipated project impacts to cultural resources, no mitigation measures are currently proposed.

 

 

5.6 FARMLANDS

Setting

As was described earlier in this document, the terrain throughout the vicinity of the proposed tunnel project is characterized by steep, eroded slopes with natural gradients ranging between 30% and 70%. Dense northern coastal scrub covers most of the project area. Please see previous Environmental Setting discussions in this report (especially section 4.1) and the Farmland Setting section in the 1986 FEIS for more detailed information.

Impacts

No prime farmland will be removed from production as a result of the proposed tunnel alternative. The Martini Creek alignment alternative would permanently remove 4.2 ha (10.4 acres) of prime farmland from production.

The impacts and mitigation measures identified in the 1986 FEIS for the Martini Creek alignment alternative are still applicable. While the southerly portion of the revised project includes a slight shift in alignment to the north (to avoid impacts to wetlands and Hickman's Cinquefoil, an endangered plant species), this change will not reduce the impacts to prime farmland as identified in the previous document.

Mitigation Measures

No mitigation measures are proposed for the tunnel alternative. Mitigation for the Martini Creek alignment alternative is discussed in the 1986 FEIS (pp. 92-93).

 

5.7 FOG

Setting

Extended periods of coastal fog are quite common along the northern California coast, primarily during the summer months, and tend to be heaviest during the morning hours of those months.

Impacts

Information in the 1986 FEIS shows that the higher elevations along the coast in the Devil’s Slide area are more affected by fog than the lower elevations. The majority of areas where there were reductions in sight distance due to fog occur at elevations above 198 meters (650 feet).The north and south entrances of the proposed tunnel are at approximate elevation 107 meters (350 feet) and 91 meters (300 feet), respectively. With the tunnel bore inside the mountain where it is less exposed to fog, potential visibility problems are not expected to occur.

The impacts and mitigation measures identified in the 1986 FEIS (pp. 95-97) for the Martini Creek alignment alternative still apply to the revised project alternative. The maximum alignment elevation for the Martini Creek alternative reaches 222 meters (730 feet). Based on the assumption that there is a linear increase of 5.5% fog occurrence per 30.4 meters (100 Feet) rise in elevation, the Martini Creek alignment alternative would result in an increase in fog frequency and duration

Mitigation Measures

Exterior night-time lighting at the tunnel approaches would be provided to improve visibility. The entire lighting system would be computer controlled with an uninterruptable power supply.

 

5.8 GEOLOGY

Setting

The proposed tunnel project area is located along the western edge of the Coast Ranges province of California. This province is characterized by a general northwest trending structural grain (mountains, valleys, regional faults), and the existence of two entirely different core complexes existing side-by-side (the Jurassic-Cretaceous Franciscan sedimentary rocks, and the Jurassic to Cretaceous granitic rocks).

In many locations, including at the project site, the sedimentary and granitic core complex rocks are overlain by later Cretaceous to Cenozoic clastic sedimentary rocks. Unconformable sedimentary contacts between rock units, folds, thrust faults, steep reverse faults, and strike slip faults are all evidence of the complex tectonics that have deformed the rocks and shaped the terrain in the study area through geologic time.

Montara mountain and San Pedro Mountain (through which the proposed tunnel pass) are underlain at depth and locally at the surface, by the granitic core complex rocks. Over most of the tunnel alignment, the granitic rocks are overlain by Paleocene to Cretaceous sedimentary rocks. The granitic mass comprising Montara Mountain covers about 30 square miles along the coast, the northernmost outcrop occurring on the cliff face below the existing landslide mass north of Devil's Slide. The Franciscan core complex rocks are found about a mile to the northeast, separated from the granitic complex by the Montara and Pilarcitos faults.

The site is within a seismically active region, and while the site is not known to be crossed by any holocene-active faults, the San Andreas fault (the longest and most notable fault in California) is located about 6.4 km (4 miles) east of the site.

The proposed tunnel alignment crosses at least two geologic formations: the Montara granodiorite; and a series of folded and faulted Paleocene sedimentary rocks that overlie the granodiorite. The granitic rocks will be encountered at the south end of the tunnel for about 457 to 487 meters (1,500 to 1,600 feet). The remainder of the tunnel would encounter the Paleocene sedimentary rocks. Depending on the geologic structure at depth beneath the central portion of the alignment, the tunnel may also encounter Cretaceous sedimentary rocks. While not penetrated by the proposed tunnel alignment, alluvial deposits exist within the valley north of the North Portal, and would be crossed by the proposed roadway between the North Portal and where the new roadway would join the existing Route 1.

Small local slides have occurred in the vicinity of the North and South Portals. Please refer to the 1986 FEIS for a description of the geologic setting for the proposed Martini Creek alignment alternative.

Impacts

The Devil's Slide area at San Pedro Mountain is located within a seismically active area. The San Andreas Fault is less than four miles east of the study area. The active Hayward fault is 37 km (23 miles) to the northeast. The potentially active Seal Cove Fault is 2.4 km (1.5 miles) off-shore to the west. The project features will be exposed to earthquake shaking during their useful life.

The site lies adjacent to the boundary zone between the North American and Pacific tectonic plates. The faults associated with this zone are predominantly northwest-trending, strike-slip faults that exhibit right-lateral displacement. The San Andreas Fault, which extends 740 miles form the Gulf of California to Cape Mendocino, is the major fault within the plate boundary zone. The nearest major fault is the San Gregorio Fault, which is about two miles offshore, southwest of the site.

The proposed tunnel project features will be exposed to earthquake shaking during their useful life. Please refer to the 1986 FEIS for a discussion of impacts and mitigation measures associated with the Martini Creek alignment alternative.

Mitigation Measures

In general, tunnels survive earthquakes significantly better than surface structures at a given site. The effects of earthquakes on underground structures may be broadly grouped into two general classes; faulting and shaking. Sympathetic fault displacement in the rock mass along the tunnel alignment would result in relatively minor architectural damage. A previous study concluded that damage to tunnels was not likely where horizontal accelerations at the ground surface above the tunnel did not exceed 0.5g.

The effect of an earthquake is to impose deformations on the underground structure which cannot be overcome by strengthening the structure. The object of earthquake resistant design is, therefore, to produce a structure of sufficient ductility to absorb the imposed deformation without losing the capacity to carry static loads, rather than one which can resist seismic loads at a certain stress level. It should also be recognized that although the absolute amplitude of earthquake displacement may be large, this displacement is usually spread over a long length. The gradient of earthquake distortion is generally small , and often within the elastic deformation capacity of the structure.

The magnitudes and durations of straining in the perimeter of a tunnel in rock are not considered to create an overall tunnel stability problem. Local displacement of the rock around the tunnel can occur and can damage the tunnel lining. Aside from steps taken to strengthen portals and insure good contact between concrete lining and the surrounding rock, it is normal procedure to repair such damage to localized areas of the tunnel after it occurs rather than design the tunnel to prevent such infrequent damage from occurring.

 

5.9 HAZARDOUS WASTE

Setting

A hazardous waste Initial Site Assessment (ISA) for the proposed tunnel alternative site was completed on February 19, 1997. A records search of the following list showed no known contamination in or near the project site: (1) the Cal EPA Hazardous Waste and Substances Sites List, (2) the Cal EPA DTSC Calsites, (3) the Regional Water Quality Control Board (RWCQB) LUST Sites, and (4) the RWQCB Fuel Leaks Public List.

Impacts

There is a potential for aerially deposited lead contamination (from motor vehicle exhaust) at the approaches to the tunnel where they intersect existing Route 1.

No hazardous waste impacts of the Martini Creek alignment alternative were identified in the 1986 FEIS. However, there is some potential for aerially deposited lead contamination at the alignment intersection with Highway 1.

Mitigation Measures

Testing will be conducted for the selected alternative during the final design stage. If test results reveal the soils are contaminated, the materials will be handled according to regulatory requirements. The special handling may include implementing a health and safety plan, and reusing the material according to the Department of Toxic Substance Control (DTSC) Lead Contaminated Soils Variance dated June 7, 1995, or it may require off-site disposal of the materials.

 

5.10 HYDROLOGY

Setting

The North Portal area of the proposed tunnel project is located in a watershed area above the Shamrock Ranch. It has steeply vegetated drainages consisting of coastal scrub habitat. The drainages flow toward the ranch area and converge in a valley area that has been altered as a result of previous land clearing and the disposal of mulch and organic material. Within this valley area are two ponds which were developed in the mid-1950s when the existing drainages were dammed to form year-round stock or irrigation ponds.

A steep drainage channel supporting riparian vegetation is located east of the South Portal area.

Within the proposed south disposal site, there is a depressed area immediately adjacent to the existing highway that includes a standpipe and a roadway embankment. This embankment impounds a natural drainage which results in intermittent ponding. This area has been determined to be a low valued wetland.

Impacts

No floodplains will be affected by the current proposed tunnel design.

At the North Portal area, one of the original design options for the tunnel project would have resulted in fill into portions of the north pond and its associated drainages. However, the current design option now includes bridge structures which will clear-span the north pond and its associated drainages. Therefore, the proposed project will not result in any fill impacts to the north pond. The proposed tunnel project will also not result in any adverse impacts to the southerly-most pond.

The proposed fill at the south disposal area is being designed to avoid a wetland area located further up-slope. This wetland area is probably spring fed and is of moderate habitat value and supports a population of tree frogs.

The impacts and mitigation measures for the Martini Creek alignment alternative are described in the 1986 final EIS/EIR.

Mitigation Measures

Mitigation measures proposed for nominal impacts to the area described above will include enhancement of the upslope moderately valued wetland.

 

5.11 NATURAL ENVIRONMENT

Setting

See section 4.1 for a discussion of the environmental setting.

Species of Concern

"Species of concern" include those plant and animal species that are either listed, proposed for listing, or are candidates for listing by the U.S. Fish and Wildlife Service (USFWS) and the California Department of Fish and Game (CDFG), as well as those species which appear to meet the definitions of rare or endangered under the California Environmental Quality Act (CEQA). The prospect for survival of these species of concern is jeopardized by loss or change of habitat, overexploitation, predation, competition or disease.

Caltrans received an updated list of species of concern from the USFWS in November, 1996. A copy of the updated species list is provided in Appendix D. Caltrans has since conducted new and updated biological field surveys within the project area of the proposed tunnel and revised Martini Creek alignment alternatives.

A survey for the San Francisco garter snake (Thamnophis sirtalis tetrataenia) and the California red-legged frog (Rana aurora draytonii) was conducted in 1995 by Dr. Samuel McGinnis, Herpetologist with California State University at Hayward. A subsequent field survey was conducted by Dr. McGinnis between 1997 and 1998. Dr. Richard Arnold, Entomological Consulting Services, Ltd., conducted field surveys for the butterfly species of concern during the spring of 1995 and 1996. Caltrans biologists supplemented the surveys by Dr. McGinnis and Dr. Arnold.

Field surveys to determine the presence of plant species of concern were conducted during the blooming periods from 1995 to 1997. The above normal precipitation in the winter and spring of 1995 and the winter of 1997 had a major influence on the early blooming periods for most plant species during these years. There has been informal Section 7 consultation throughout the natural environment study process for the listed species, including the red-legged frog.

Focused surveys were not conducted for all species for which potential habitat may be present in the vicinity of the Martini Creek alignment. This alternative would include a new bridge over San Pedro Creek, which is open to anadromous fish such as coho salmon and steelhead. Surveys were not conducted for those species, or for habitat for the tidewater goby. Marginal habitat for the San Francisco garter snake and the California red-legged frog is present along San Pedro Creek, the tributaries to Willow Brook, and Martini Creek. These areas have not been trapped or surveyed using visual encounter techniques. The proposed corridor for the Martini Creek alignment was not surveyed for the following plant species from the 1996 list: Presidio manzanita, San Bruno manzanita, western dwarf flax, San Francisco lessingia and white-rayed pentachaeta. These plants are not expected to be present due to the lack of suitable habitat. Surveys were conducted for Hinkman’s cinquefoil and the mission blue butterfly.

Wildlife Species

1. San Bruno Elfin Butterfly (Callophyrs mossii bayensis)

The San Bruno elfin butterfly is a Federal endangered species found only in northern San Mateo County on San Bruno Mountain, Montara Mountain, and Milagra Ridge. This species usually occurs in areas of rocky outcrops located on steep, north-facing slopes in the fog belt. It is always associated with stonecrop (Sedum spathulifolium) which is the sole larval foodplant. Adult nectar plants must also be present or in close proximity to the stonecrop in order to support an elfin butterfly population. The primary nectar plant on San Bruno Mountain is lomatium (Lomatium utriculatum). Secondary sources consist of yarrow (Achillea millefolium), ranunculus (Ranunculus californicus), coast rock cress (Arabis blepharophylla), and wallflower (Erysimum franciscanum).

In 1986, Dr. Richard Arnold conducted a field survey for the San Bruno elfin butterfly in the vicinity of the Maritni Creek alignment alternative. This survey included the butterfly's foodplants and stonecrop was present adjacent to the alignment. The results of that survey determined that a population of the San Bruno elfin butterfly was located on Montara Mountain adjacent to the Martini Creek alignment alternative right-of-way approximately 75 meters (245 feet) above the proposed construction zone. The only observed nectaring by adults occurred on Montara arctostaphylos (Arctostaphylos montarenois).

Dr. Arnold conducted field surveys again in 1995 and 1996 to update the findings of the 1986 survey. Results of the 1995 and 1996 San Bruno elfin butterfly surveys corroborate the findings of the 1986 survey. There have been no major changes in the distributions of the larval or adult foodplants over the past decade. The life forms of the butterfly and stonecrop, the larval foodplant, were not found within the right-of-way for the Martini Creek alignment alternative.

During the field surveys in 1997 for the proposed tunnel alternative, neither the San Bruno elfin butterfly, nor its foodplants, were found within the proposed right-of-way or immediate vicinity.

2. Peregrine Falcon (Falco peregrinus anatum)

The peregrine falcon is a Federal and State endangered species. It is a resident, breeding bird in California and is found from the Pacific coast to the middle elevations of the Sierra Nevada. Breeding birds from the Pacific Northwest also migrate through California, and some birds overwinter here, usually along the coast. The sea cliffs of San Mateo County, including the Devil's Slide area, are historic territory for the peregrine falcon.

Field reconnaissance and observations for the peregrine falcon (Falco peregrinus anatum) were conducted at rock outcrops in the project vicinity. It was determined that an active peregrine falcon nest was located on a rock outcropping just west of Route 1 in the project vicinity. A field review occurred on September 25, 1996 with Ms. Ina Pisani, Biologist for the U.S. Fish and Wildlife Service, and Mr. Brian Walton, Coordinator for the Santa Cruz Predatory Bird Research Group.

The 1996 field reconnaissance detected no other evidence or sign of nesting or perching by raptors. A field survey of the rock outcrops back in 1983 also found no evidence or sign of peregrine falcon use on the east side of Route 1.

3. Mission Blue Butterfly (Plebejus icarioides missionensis)

The mission blue butterfly is listed as a Federal endangered species. This butterfly is known to exist only at Twin Peaks in San Francisco, Fort Baker in Marin County, San Bruno Mountain, Milagra Ridge, and scattered locations around Skyline College in San Mateo County.

There are four locations where one of the larval foodplants, variegated lupine, grows within the project area of the proposed Martini Creek alignment alternative. During the 1995 and 1996 field surveys conducted by Dr. Arnold, no life stages of the mission blue butterfly or signs of larval feeding damage were observed at these four locations. Thus, the absence or limited abundance of nectar plants at these four locations suggests that all habitat requirements for the mission blue butterfly are not satisfied at these locations.

Finally, these four lupine locations are small, quite isolated, and several miles from the nearest known populations of the mission blue butterfly. Much of the intervening habitat is dense coastal sage scrub which is not the type of habitat in which this butterfly species is commonly found.

The larval foodplants for the mission blue butterfly were not found on the proposed tunnel alternative site during the 1997 plant surveys.

4. California Red-Legged Frog (Rana aurora draytonii)

The California red-legged frog is listed as a Federal threatened species and is also designated as a State of California "Species of Special Concern". The red-legged frog is a pond frog that frequents marshes, slow portions of streams, lakes, reservoirs, ponds, and other usually permanent water bodies. They are attracted to ponding areas which contain extensive plant cover including rushes and reeds. Permanency of the water source is a requirement for extended occupancy of a site by this species. Breeding periods are short, lasting only between one and two weeks from January to April.

Populations of the California red-legged frog were found at the two Shamrock Ranch ponds in the northern part of the project site during the 1995 field survey conducted by Dr. Samuel McGinnis. Individuals of this species were also found in two small pool sites along the course of the Green Valley drainage.

The Shamrock Ranch ponds originated in the mid 1950's when the existing drainages were dammed to form stock or irrigation ponds. The south pond site represents a relatively ideal habitat for the red-legged frog. There is adequate shoreline cover for protection of foraging frogs from most predators, and the permanent water supply permits year round residency within the sanctuary of the immediate pond habitat.

During field surveys in 1997 and 1998, Dr. McGinnis found that a small population of adult California red-legged frogs occupies the seasonal north pond from the time it is filled during the rainy season until it dries in late summer or early fall. During the 1997-98 survey period, no evidence of their presence was observed within the west and southwest valleys adjacent to the north pond even though drift fences and track plates were placed to detect frog movement into these areas.

No evidence of successful frog reproduction was observed at either pond site in 1997. Egg and larval predation by water birds and raccoons (north pond) and egg predation by introduced koi carp (south pond) appear to be the most likely causes for these reproductive failures. In the opinion of Dr. McGinnis, the apparent total reproductive failure at both ponds, coupled with the on-going effects of shoreline stock grazing and siltation at the north pond site, combine to create a most uncertain future for the California red-legged frog populations at Shamrock Ranch.

At the Green Valley Creek location, individual adult red-legged frogs were observed in two small pool areas. These frogs appeared to be members of small populations which occasionally inhabit the creek pools. During a field survey by Caltrans biologists in the spring of 1997, an adult red-legged frog was observed on the shore of a very small pond adjacent to Green Valley Creek just east of the foot of the Route 1 roadway embankment. A field review of this same small pond in the spring of 1998 showed that the pond had been severely disturbed by the massive movement of sediment through the drainage during the El Nino storms of the past winter. In 1998, no California red-legged frogs were observed at this site.

5. San Francisco Garter Snake (Thamnophis sirtalis tetrataenia)

The San Francisco garter snake is listed as a Federal and State endangered species. This snake is endemic to the San Francisco Peninsula and historically has been found from approximately the San Francisco County line south along the eastern and western bases of the Santa Cruz Mountains and to Ano Nuevo Point. The San Francisco garter snake is now known only from San Mateo County. In 1995, Dr. McGinnis conducted a field trapping survey of the Martini Creek alignment alternative project site for the San Francisco garter snake at areas which provide suitable habitat. The two pond sites and other suitable habitat areas, including the Green Valley Creek drainage and the Montara wetland were also surveyed using observation techniques.

The San Francisco garter snake was not trapped or observed during the 1995 field survey. Only 3 individual Santa Cruz garter snakes and 9 individual coast garter snakes were captured at the Shamrock Ranch ponds during the three-month study. It appears that the reason that San Francisco garter snake is not present, even though suitable habitat exists, is the inaccessibility of the habitats to San Francisco garter snake populations in nearby drainages.

The oldest remaining possible source for San Francisco garter snake colonization is the San Pedro Creek drainage. In 1992, Dr. McGinnis surveyed this creek, but no San Francisco garter snakes were captured or observed even though numerous coast garter snakes and several Santa Cruz garter snakes were captured.

These results lend final support for the conclusion that, although habitat conditions are very favorable to the San Francisco garter snake at the south pond on the Shamrock Ranch, no specimens exist there due to the lack of a nearby population that could supply colonizing specimens. The San Francisco garter snake was not found during any of the field surveys conducted for the California red-legged frog between 1997 and 1998. In addition, this species was not found during any of the other biological field studies, including wildlife surveys, in 1997.

Plant Species

1. Montara Manzanita (Arctostaphylos montaraensis)

The Montara manzanita was not found within the tunnel alternative right-of-way or immediate project vicinity during the 1997 plant surveys. Historic locations for this species have previously been documented on Montara Mountain.

The species is found adjacent to the right-of-way corridor for the Martini Creek alignment alternative at the summit ridge of San Pedro Mountain.

2. Hickman's Cinquefoil (Potentilla hickmanii)

In San Mateo County, this state listed endangered plant species was known only from a single historic map location near the outfall of San Vicente Creek at Moss Beach and was last documented in 1933.

Prior to 1995, the only known population which still existed was located at the Indian Village site in Monterey County. During the 1995 spring plant surveys for the Martini Creek alignment alternative, a new population of Hickman's cinquefoil was identified by Caltrans biologists. This species was found growing in the grassland hills above Martini Creek. The California Department of Fish and Game was notified of the discovery, and Dr. Barbara Errter, of the University of California Jepson Herbarium, confirmed the identification of this species at this location during a field meeting on June 21, 1995.

Spring field surveys were conducted in 1995 and 1996 to determine the population size and boundaries for the Hickman's cinquefoil. A total cinquefoil population of 2,600 plants was surveyed on June 21, 1995, and a total population of 1,990 plants was surveyed on May 21, 1996. Sticky cinquefoil (Potentilla glandulosa), a common cinquefoil, was also found in the vicinity during the surveys.

Hickman's cinquefoil was afforded Federal endangered status on August 12, 1998.

Impacts

San Bruno Elfin Butterfly

Tunnel Alternative

The San Bruno elfin butterfly and its foodplants were not found within the proposed tunnel alternative right-of-way or immediate vicinity during the 1997 field surveys. The project will have no direct adverse effect on this species. In addition, the tunnel alternative would result in less potential secondary effects, such as dust and automobile exhaust, to this species since the tunnel alternative is approximately 1,097 meters (3,600 feet) further away from the known population than the Martini Creek alignment alternative, and also because a portion of the roadway will be enclosed in the tunnel. The tunnel alternative could be expected to reduce potential impacts to all insect species compared to the existing Route 1 roadway which is a surface road.

Martini Creek Alignment Alternative

There is potential for adverse indirect impacts to the San Bruno elfin butterfly from the Martini Creek alignment alternative, primarily during construction and as a consequence of the operational phase. The location and design of the Martini Creek alignment in the vicinity of the population remains unchanged, and the measures stipulated in the 1986 Biological Opinion are still part of the alternative proposal.

The design profile grade of the alignment where it passes through the summit ridge of San Pedro Mountain has been raised approximately 4.6 meters (15 feet) above the original 1983 proposal. This change has the effect of reducing the excavation at the summit, and will result in a greater buffer zone width between the eastern limits of the project and the elfin butterfly Habitat. These design changes will decrease the potential for impacts to the species and its host plants, and is not likely to adversely affect the San Bruno elfin butterfly.

Peregrine Falcon

Tunnel Alternative

The tunnel alternative corridor is within the foraging territory of a nesting pair at the Devil's Slide promontory. However, since this alternative will relocate a portion of existing Route 1 inside a tunnel, and the peregrine falcon is an aerial predator, the tunnel alternative is expected to have almost no effect on foraging activities.

Construction activities associated with the proposed project could affect the nesting activity of the peregrine falcon. The south portal area of the tunnel alternative is located approximately 1,219 meters (4,000 feet) from the peregrine falcon nest. This distance between the nest and the tunnel will likely be sufficient to avoid any effect on the hatchlings during the January through July nesting period. Nest monitoring is typically required for projects that could affect the nesting activity of the peregrine falcon. If it is determined during monitoring that projects activities are interrupting egg incubation or the feeding of the chicks, it would be necessary to suspend certain construction activities or remove the eggs or chicks.

Eggs that were removed from nests would be artificially incubated at a facility such as that operated by the Santa Cruz Predatory Bird Research Group (SCPBRG ). Any chicks that hatched out would then be hacked-out to occupied nests. In the event that construction activities were interrupting the raising of hatched chicks, those chicks could be removed and hacked-out to other nests. With such a monitoring program in place, the tunnel alternative is not likely to adversely affect the peregrine falcon.

As an alternative to the active monitoring program, the SCPBRG has suggested an up-front contribution of funds for the implementation of a multi-project hacking program coordinated with and approved by the USFWS. This contribution would preclude the necessity of nest monitoring and would provide a positive mitigation measure to benefit the long-term restoration of the peregrine falcon habitat.

Please see section 5.21 of this document for a discussion of potential cumulative effects to the peregrine falcon from this, and other projects within the region.

Martini Creek Alignment Alternative

Construction of the Martini Creek alternative is not expected to affect falcon nesting at Devil’s Slide. The Martini Creek alignment is located approximately 1.5 kilometers (0.93 miles) inland from the existing eyrie, and construction activities are not likely to affect nesting success. This alternative is not likely to adversely affect the falcon.

Mission Blue Butterfly

Tunnel Alternative

The results of the field surveys showed no evidence of mission blue butterfly occurrence in the proposed tunnel project vicinity. The proposed tunnel alternative will have no effect on this species. This butterfly was also not found in the vicinity of the Martini Creek alignment alternative.

Martini Creek Alignment Alternative

Crucial habitat elements for the mission blue butterfly are extremely limited in the vicinity of the Martini Creek alignment. No life forms of the mission blue were observed during any field surveys, therefore, the alternative is not likely to adversely affect the butterfly.

California Red-Legged Frog

Tunnel Alternative

The proposed tunnel alternative will not result in any adverse impacts to the south pond at Shamrock Ranch. At the north pond, one of the original design options for the proposed tunnel alternative would have resulted in fill effects to portions of this pond and its associated drainages. However, the proposed alternative now includes bridge structures which will clear-span the north pond and its associated drainages. Therefore, the proposed tunnel alternative will result in no fill impacts to the north pond.

While the south pond at Shamrock Ranch is not within the project limits of the proposed tunnel alternative, to ensure that the habitat will be protected from any construction activities, the south pond will be designated as an Environmentally Sensitive Area (ESA). This designation restricts any construction activities from occurring within its boundaries. Instead, the transport of construction vehicles, equipment and personnel will only be allowed to occur on temporary access roads from existing Route 1.

Martini Creek Alignment Alternative

The Martini Creek alignment alternative also includes a structure to span the north pond and its associated drainages. However, the alignment would pass directly over the western portion of the pond and the shading effect of the bridge could adversely impact emergent vegetation critical to the frog reproductive process and tadpole rearing phase. The alignment would also cross the drainages feeding the south pond. A structure that would span those drainages well upstream of the south pond is proposed. However, the alignment would affect potential upland retreat habitat for the frog between the two ponds. Temporary construction impacts could be considerable, although details were never sufficiently developed for that alternative to allow a more specific determination of such potential impacts.

Issues such as access routes for construction, location of bridge piers, approach fills, and potential for sedimentation have not been fully explored.

The large fill in the Green Valley Creek drainage and the extensive drainage facilities proposed in that watershed could also have potential implications for the frog. Design modifications to eliminate much of that fill and the associated drainage facilities were under consideration, but a detailed assessment of the original or revised design in terms of impacts to the red-legged frog since its recent listing as a Federal endangered species has not been conducted.

The original plans for the Martini Creek alignment called for permanent fill and extensive drainage improvements in the Green Valley drainage upstream where red-legged frogs were observed. A longer bridge is now proposed across the upper slopes of the drainage that would greatly reduce fill into the Green Valley tributaries. This longer bridge would eliminate the need for drainage facilities that would have been required in the upper end of the main valley. In depth surveys for the frog were not conducted in upper Green Valley after the species was listed because the preferred tunnel alternative would not affect Green Valley. Additional field surveys would be required to verify the frog’s presence and to evaluate the level of possible project impacts if the Martini Creek alignment were selected. Based on current information, it is likely that the Martini Creek alignment could adversely affect the California red-legged frog in the Green Valley drainage.

Suitable to marginal habitat for the California red-legged frog is present along other drainages near the Martini Creek alignment. However, these areas have not been surveyed for the frog. Habitat along the upper tributaries of Willow Brook is typical of San Francisco bay area coastal streams in which the frog is found. There are expected temporary construction impacts to adjacent retreat habitat and movement corridors, even though Caltrans would employ all feasible best management practices to minimize such effects. Based on current information, and the possible presence of the frog at this location the Martini Creek alignment is likely to adversely affect California red-legged frogs that may be present at Martini Creek.

San Francisco Garter Snake

Tunnel Alternative

The1996 field survey results show that San Francisco garter snake is not present at the Shamrock Ranch pond areas. The proposed tunnel alternative would not adversely affect this species.

Martini Creek Alignment Alternative

In 1995 Dr. McGinnis conducted a field survey of portions of the Martini Creek alignment, in the locations that might provide the most suitable habitat for the San Francisco garter snake. Two additional suitable habitat areas, the Green Valley Creek drainage and the Montara wetland were also surveyed using visual encounter techniques. The San Francisco garter snake was not trapped or observed during the 1995 surveys.

In 1992 Dr. McGinnis surveyed the San Pedro Creek drainage for the San Francisco garter snake using a three month trapping procedure identical to the 1995 survey. No garter snakes were captured or observed, although numerous coast garter snakes and several Santa Cruz garter snakes were captured. This creek, like many other coastal drainages, has no sizable quiet pool areas that could be expected to support a population of red-legged frogs. This finding supports the conclusion that although favorable habitat conditions exist, no frogs are present due to the lack of a nearby population that might supply colonizing individuals.

Although the species was not observed during field surveys, additional design details, further trapping efforts, and visual encounter surveys at all three locations including the Willow Brook drainage would be required before a conclusive determination of no effect could be made for the Martini Creek alignment alternative.

Montara Manzanita

Tunnel Alternative

The Montara manzanita is not located within the tunnel alternative right-of-way or immediate project vicinity, and therefore will not be affected.

Martini Creek Alignment Alternative

Montara manzanita is found on a steep drainage on the summit side of San Pedro Mountain just east of, and above, the Martini Creek alignment. The plants are all outside the right-of-way corridor and would not be affected by the project. That area is also where the San Bruno elfin butterfly is found and would be protected as an ESA during construction.

Hickman's Cinquefoil

Tunnel Alternative

The Hickman’s cinquefoil is not located within the proposed tunnel alternative right-of-way or immediate vicinity, and will not be affected. Hillside excavation required for the Martini Creek alignment alternative as originally designed would have affected portions of the Potentilla population discovered in 1995. The segment of the alignment south of Martini Creek was subsequently realigned and retaining walls were incorporated to reduce the hillside cuts and thereby avoid the population.

Martini Creek Alignment Alternative

The alignment of the Martini Creek alternative as originally designed would have affected portions of the cinquefoil population discovered in 1995. The original alignment would have required substantial excavation into the hillside on which the plant is found. Following Caltrans delineation of the population limits in 1995 and 1996, the segment of the alignment south of Martini Creek was realigned, and retaining walls were added to reduce hillside cuts and thereby avoid the population. The Martini Creek alternative as redesigned is not likely to adversely affect this species.

Mitigation Measures

Of the wildlife species of concern, one threatened species is present on the proposed project site and one endangered species is located in the immediate project vicinity. The threatened species, the California red-legged frog (Rana aurora draytonii), is found in association with two ponds on the western end of Shamrock Ranch, at the north end of the tunnel alternative and in close prooximity to the Martini Creek alignment alternative. The peregrine falcon (Falco peregrinus anatum), an endangered species, nests on a coastal bluff near the south portal for the proposed tunnel project.

The original Martini Creek alignment alternative was addressed in a Biological Assessment prepared in 1983. At that time only a single listed species, the San Bruno elfin butterfly, was recorded in the vicinity of the proposed project. The U.S. Fish and Wildlife Service issued a Non-jeopardy opinion in 1986 relative to the elfin butterfly. The recent Biological Assessment focuses on the evaluation of the potential impacts of the tunnel alternative, on species listed by the U.S. Fish and Wildlife Service in 1996.

The current design of the Martini Creek alignment includes features and measures to avoid and protect the San Bruno elfin buttefly, Montara manzanita and Hinkman’s cinquefoil. The alternative is not likely to adversely affect those species. The Martini Creek alignment would displace suitable foraging habitat for the peregrine falcon, although nesting sites would not be affected and the alternative is not likely to adversely affect the falcon. This alternative would incorporate measures to protect the California red-legged frog. The proposed tunnel alternative and the Martini Creek alignment alternative will avoid any effect to the endangered San Bruno elfin butterfly (Callophyrs mossii bayensis) and the endangered Hickman's cinquefoil (Potentilla hickmanii).

An environmentally sensitive area (ESA) was developed in consultation with the USFWS biologists to protect red-legged frog habitat. The ESA will be off-limits to construction personnel, vehicles, construction materials, falsework or other ground disturbances.

As previously noted in Section 2.0, Project Description, in order to avoid direct impacts to the ESA, the segmented balanced cantilever method will be used to construct the bridges. The bridge piers and abutments, located outside the ESA, would be constructed first and the superstructure between the north and south piers would be advanced by cantilevering out from the piers. Falsework could be utilized to support the counterbalancing superstructure outside the ESA between the piers and their adjacent north and south abutments. Because field surveys determine that the hillside areas northwest and southwest of the north pond are not included within the home range of the Shamrock Ranch California red-legged frog population, no significant adverse impacts are anticipated.

With the following measures planned and successfully implemented as part of the proposed tunnel project, potential direct impacts to the red-legged frog will be avoided, and indirect impacts minimized:

  1. Construction vehicles must use temporary access roads from existing Route 1 (rather than the existing Shamrock Ranch road system) to access the pier construction to minimize the probability of harming any frogs or disrupting any migration areas.

b) Construction of temporary access roads and pier foundations will be limited to the dry season (April 15 to October 15) to reduce the likelihood of a large scale silt deposition on the valley floor. Requirements of Section 7-1.01G, Water Pollution of the Caltrans Standard Specifications and project specific Storm Water Pollution Prevention Plan measures will be implemented in early fall so that erosion in all disturbed areas will be kept to a minimum.

  1. A solid ESA fence will be installed along the edge of the pier construction areas and adjoining temporary access roads prior to the beginning of any pier or access road construction. The pond habitat areas will be designated as ESA’sduring construction.
  2. The north pond and surrounding habitat areas will be designated as an ESA during construction. A solid frog/silt barrier fence will be installed along the ESA boundary adjacent to the construction area, and temporary access roads prior to any construction.
  3. The ESA fence will be designed so that surface runoff from all areas above and within the construction zones will drain into small temporary desilting basins prior to discharging into the drainage below. Silt deposits will be removed once they fill more than one third of any desilting basin area or threaten the integrity of the frog/silt barrier.
  4. After construction is completed, the construction access roads will be regraded to match the original ground contours as close as possible. Restoration of the plant communities within all disturbed areas will begin, including the installation of erosion control fabric and a fabric silt fence to prevent any loose soil from entering the pond basin. All disturbed areas will then be hydroseeded with a non-invasive seed mix.
  5. The revegetation effort will include full maintenance of the installed plants during a three year plant establishment period (PEP). Success criteria will be established and a five-year monitoring program will be implemented after the initial planting to document the success of the revegetation effort. Replanting will be performed during the three-year PEP if necessary to meet the success criteria. Once the soil in the disturbed areas has stabilized, the fabric silt fences will be removed and hand-carried from the site by monitoring personnel.
  6. During the operational phase, roadway runoff on the bridges will be contained and directed northward to a drainage on the existing Route 1 roadway which will not be affected by the project and which does not drain to the ponds and their surrounding habitats.

The proposed tunnel alternative will also include measures at the north and south ponds to alleviate or eliminate the existing adverse conditions in the natural environment which now threaten to reduce the California red-legged frog population. These measures will also compensate for potential direct impacts resulting from construction activities such as ground vibration, dust and noise:

  1. Conservation easements will be obtained for both the north and south ponds in order to protect the habitat for the California red-legged frog in perpetuity. Permanent fencing and signs will be installed to protect the ponds from any future livestock intrusion and human trespass.
  2. A one-time, pond silt removal project will be implemented in late summer prior to the installation of the ESA fence in order to lessen the current heavy silt load in the north pond basin.
  3. To insure that the north pond does not continue to dry up in mid-summer and negate successful metamorphosis of the annual California red-legged frog larval crop, the pond will be supplied with a pressurized water line and a heavy duty float valve system. In addition, the shoreline and inshore areas will be planted with a complex of indigenous emergent reed, sedge, and forb species. These actions will create a permanent pond habitat in which perennial inshore vegetation will continue to grow and provide frog protection, where the frog’s larval metamorphosis can always be completed, even during drought years.
  4. An agreement will be sought with the Shamrock Ranch management, as part of the right-of- way agreement, to discontinue the practice of feeding raccoons food waste at the small refuse pit near the north pond to decrease the potential for frog predation.
  5. The koi carp population will be removed from the south pond to eliminate koi carp predation on frog eggs and tadpoles.
  6. A three-year monitoring plan will be implemented following the roadway construction to assess and evaluate the California red-legged frog population and the effects of the proposed mitigation measures.

With the mitigation measures described, permanent impacts will be avoided and short-term temporary construction impacts to the red-legged frog will be minimized and compensated.

The Martini Creek alignment alternative includes the above measures and those outlined in the 1986 final EIS (Section VII.L.3. Mitigation [pages 136 thru 138]).

With regard to the peregrine falcon, a sum of $50,000 will be deposited into the on-going multi-project hacking program already endorsed by the USFWS and CDFG and implemented by the Santa Cruz Predatory Bird Research Group. This action will remove the necessity of monitoring the nest at the Devil’s Slide promontory during construction of the proposed tunnel alternative.

5.12 WATERS OF THE UNITED STATES

Setting

At the north terminus of the project site, the Martini Creek alignment first crosses San Pedro Creek. This permanent creek is dominated by willow and is a documented steelhead trout habitat. The alignment then crosses a small drainage located on the east side of Route 1 just before the San Pedro Terrace Road Junction. At Shamrock Ranch, the Martini Creek alignment crosses the north stock pond, its associated seep drainage, the drainage leading into the south stock pond, and other steep drainages in the hills to the southwest.

The Martini Creek alignment alternative then crosses a perennial tributary to Willow Brook Creek and parallels the tributary for several hundred feet. The alignment is located above the creek in very steep terrain. The tributary is characterized by a dense riparian corridor and dominated by willow and dogwood. This drainage is fed by springs and seeps which enter the stream. This alternative also traverses several tributaries as well as the main stem of Green Valley Creek. This area is densely vegetated by coastal scrub species with the deeply incised tributary stream courses containing dense willow, Myrica, and coffeeberry associations with Corylus and Polystichum.

South of Green Valley, the alignment crosses Martini Creek and several smaller tributaries. Martini Creek is dominated by a dense cover of willow and bulrush. The tributaries are dominated by horsetail, bulrush, oenanthe, and water cress. At the South terminus, the Martini Creek alignment crosses Reservoir Creek and a seasonal depression that is associated with several small drainages.

The original Martini Creek alignment alternative was addressed in a Natural Environment Study prepared in 1983. A description of the wetlands affected by the Martini Creek alignment alternative is included in the 1986 Devil’s Slide FEIS.

Impacts

Wetlands and Riparian Habitat

Tunnel Alternative

The proposed tunnel alternative will have minor impacts to wetlands. With the bridge structure spanning the ponds and drainages at Shamrock Ranch, this alternative will have no permanent affect on wetlands associated with the habitat for the California red-legged frog.

A small wetland area upslope of the south disposal area will be avoided. This spring fed and moderately valued wetland supports a population of tree frogs. It is expected that the tunnel alternative will qualify for an Army Corps of Engineers (COE) nationwide permit. A preliminary wetland delineation has been submitted to the COE.

The tunnel alternative will eliminate an estimated total of 511 square meters (5,500 square feet) of wetlands. This total wetland area comprises a little over (0.05 ha) (1/10 acre) and would include wetlands associated with the south portal drainage area and the fill disposal site.

South Portal Drainage Area

An estimated 269 square meters (2,900 square feet) of wetlands in the south portal drainage area will be filled. The affected wetlands of the drainage area consist of a season wetland depression and a wetland drainage. The drainage, which flows from nearby hills into this depressional area contains strips of wetlands. This site has isolated value due to the lack of freshwater ponds and depressions in the local area, and the topography of the steep hills and surrounding mountains.

Fill Disposal Site

At the drainage area of the fill disposal site an estimated 242 square meters (2,600 square feet) will be filled by the tunnel alternative. The affected wetlands contain a seasonal wetland depression and a seasonal wetland pond. The seasonal depression has formed due to an above ground culvert inlet structure located on the east side of Route 1.

Riparian Habitat

Riparian habitat will also be affected by the tunnel alternative. An estimated 901 square meters (9,700 square feet) of riparian habitat will be eliminated as a result of the proposed alternative. This loss of riparian habitat is approximately 0.09 ha (1/5 acre) which is dominated by willow. The habitat is found in association with the seasonal depressions located at the south portal drainage area and the fill disposal drainage area.

Martini Creek Alignment Alternative

An estimated area of 114,110 square meters (1,227,970 square feet) of preliminary wetlands could be potentially affected as a result of this alternative. The preliminary wetland area is approximately 11 ha (28 acres). In addition, an estimated 56,710 square meters ( 610,180 square feet) of riparian vegetation could also be affected by the Martini Creek alternative. The Martini Creek alternative contains wetlands and riparian habitat in San Pedro Creek, Shamrock Ranch north and south ponds, Willowbrook watershed drainage areas, Green Valley drainage area, Martini Creek, Reservoir Creek, Montara drainage, and several other small drainages. The Martini Creek alignment alternative would likely require an individual permit from the COE.

Erosion associated with cut and fill slopes of the Martini Creek alignment alternative would cause short-term impacts to Martini Creek, Green Valley Creek, San Pedro Creek fork and San Pedro Creek unless mitigated. Turbidity and sedimentation in streams is expected to increase during construction. In addition to the wetland impacts at the Shamrock Ranch north pond, the Martini Creek alignment alternative also cuts across the drainages feeding the south pond.

Although a bridge is included at this location, there would be potential construction impacts to these drainages and the south pond. This alternative terminates at the south end immediately adjacent to a fresh water wetland. Although the California red-legged frog is not present, the wetland does have high habitat value for other amphibians and small birds. The current alignment minimizes effects on the wetland but it cannot be completely avoided.

Focused surveys were not conducted for all species for which potential habitat may be present in the vicinity of the Martini Creek alignment alternative. The proposed bridge over San Pedro Creek could impact anadromous fish such as coho salmon and steelhead. Additional surveys were not conducted for those species, and the creek has not been surveyed for the tidewater goby. The 1986 Devil’s Slide FEIS provides a complete description of impacts associated with the Martini Creek alignment alternative.

Mitigation

Tunnel Alternative

A riparian and wetland mitigation site is proposed as part of the tunnel alternative to replace riparian and wetland habitat eliminated as a result of the project. A ponding depression is proposed at the fill disposal site. A preliminary assessment has indicated that it may be feasible to place a ponding depression near the top of the site on a flat area. Technical studies, including hydrology, geotechnical and geomorphology, will be necessary to verify its feasibility.

It is also anticipated that willows will be planted in association with the ponding depression to replace riparian habitat. If further water balance and other biological studies determine that there may insufficient water retention in the soil for willows to grow, or that a ponding depression is not feasible at the fill disposal site, then another site(s) will be chosen in coordination with responsible agencies.

A conceptual mitigation plan would be prepared for the mitigation site(s) in coordination with the USFWS, CDFG and the COE. A plant establishment and maintenance program would be conducted for three years. A biologist would monitor the mitigation site(s) at the end of each growing season for five years. Caltrans would be responsible for the establishment and care of the mitigation site until the resource agencies determine that the replacement is successful. After the mitigation site becomes established, it is proposed to be transferred to McNee Ranch State Park with the understanding that the site will be protected in perpetuity in order to preserve the replaced natural habitat.

With a wetland and riparian mitigation site(s) proposed as part of the proposed tunnel alternative, the impacts to riparian and wetland habitat will not be significant.

Martini Creek Alignment Alternative

No mitigation is currently proposed for this alternative other than that included in the 1986 FEIS (pp. 136-138). Prior to the development of a conceptual mitigation plan, several studies including a wetland delineation, focused surveys for species habitat, and other biological research would be required if the alternative was selected. These plans and mitigation measures would be prepared for the site(s) in coordination with the USFWS, CDFG and the COE. The COE would require verification of preliminary wetland delineations prior to the approval of any proposed mitigation.

5.13 NOISE

Setting

Existing land uses within the Devil’s Slide area include the McNee Ranch State Park and the Shamrock Ranch Riding Stables. A system of trails also exists throughout the mountains and valleys between Pacifica and Montara.

Environmental noise is typically a conglomeration of distant noise sources which results in a relatively steady background noise having no identifiable source (e.g. traffic, wind, and industrial activities). Superimposed on this slowly varying background is a succession of identifiable noisy events typically brief in duration (e.g. single vehicle pass-bys, aircraft flyovers, etc.).

The existing noise environment for the proposed tunnel and Martini Creek alignment project areas includes vehicular traffic on existing Route 1, commercial and general aviation, and natural sounds such as surf, wind, and birds.

Impacts

There are no noise receptors that will be affected by the proposed tunnel project.

Hauling of material during construction of the proposed tunnel alternative will be within the project limits and will not present any noise-related impacts. Any construction-related noise (e.g. blasting, heavy equipment operation) would be temporary and limited to the duration of construction.

For a discussion of the noise impacts and proposed mitigation measures for the Martini Creek alignment alternative, please refer to the 1995 Final Supplemental EIS/R.

Mitigation Measures

No mitigation measures are proposed for the tunnel alternative.

 

5.14 PARKLAND

Setting

The current proposed alignment of the tunnel alternative is located north of McNee Ranch State Park. The proximity of the tunnel’s south portal to the existing State Park boundary is a distance of 609 meters (2,000 feet). McNee Ranch State Park is located southeast of the tunnel alignment, and the alignment would not encroach on the park. Nor, given the distance and topography, does the tunnel alternative result in any proximity impacts to the park.

The Caltrans right-of-way for the Martini Creek alignment lies between the two separate park parcels. The 79 hectare (196 acre) westerly portion is bounded on the north by San Pedro Mountain, on the south by Martini Creek, on the west by State Route 1, and on the east by the Martini Creek alignment right of way. The easterly portion comprises 174 hectares (429 acres) and is bounded on the north by San Pedro Mountain, on the west by the Martini Creek alignment right of way, and on the south by private property.

The park was acquired by the California Department of Parks and Recreation in 1983 with the stipulation that planning and development of the park would not conflict with the realignment of State Route 1 inland around Devil’s Slide.

Impacts

There are no impacts to parklands or Section 4(f) issues with the proposed tunnel alternative.

Potential impacts and proposed mitigation measures for the Martini Creek alignment alternative are discussed in detail in the 1986 FEIS and the 1995 SEIS/EIR. For a discussion of Section 4(f) of the DOT Act (49 USC Section 303), which requires impacts to parks and similar lands to be avoided if at all possible, see pages 146-152 of the 1986 FEIS.

 

Mitigation Measures

No mitigation measures are proposed for the tunnel alternative.

 

 

5.15 REQUIRED PERMITS

California Department of Fish and Game: Section 1601 of the California Fish and Game Code requires a Stream Alteration Agreement from the California Department of Fish and Game (CDFG) for activities that would divert, obstruct or change the natural flow or adversely affect the bed, channel or bank of a stream and its associated fish and wildlife values, including contiguous riparian habitat. The Martini Creek and tunnel alternatives will require a stream bed alteration agreement.

U.S. Army Corps of Engineers: The discharge of dredged or fill material into the waters of the U.S. is regulated by the Army Corps of Engineers (COE) under Section 404 of the Clean Water Act. The tunnel alternative bridge structure will span ponds and drainages at the Shamrock Ranch and have minor impacts. The tunnel alternative received jurisdictional determination for an Army Corps of Engineers nationwide permit on October 15, 1998. The Martini Creek alternative would require a continuance of the NEPA/404 integration process due to potential impacts to wetlands and waters of the U.S. These impacts are further described in Section 5.12 Waters of the U.S. If an individual permit is required, it will be necessary to demonstrate that there are no practicable alternatives to this alignment as outlined in the U.S. Environmental Protection Agency’s Section 404(b)(1) Guidelines.

California Coastal Commission: All development in the Coastal Zone requires either a Coastal Development Permit or an exemption from Coastal Permit requirements. In order to obtain a permit, the development proposal must comply with the policies of the certified Local Coastal Program (LCP) and the State Coastal Zone Management Program (CZMP). The California Coastal Commission (CCC) reviews federal assistance activities within or affecting the coastal zone to make a determination regarding its consistency with the CZMP. Although required permits are issued by the County, the Coastal Commission determines consistency. If the finding of consistency is denied, the action is not eligible for Federal funding unless it is modified to remove the inconsistency finding.

Regional Water Quality Control Board: The proposed project would involve activities in and near wetlands and other waters of the U.S. The RWQCB has the authority to regulate projects that affect water quality through Section 401 of the Clean Water Act. A water quality certification or a waiver of certification would be required from the RWQCB in order to implement the proposed alternatives.

5.16 SOCIOECONOMIC

5.16.1 Social Setting

The 1986 FEIS evaluated socially-related data from the 1980 Census for the Coastside study area which includes Montara, Moss Beach and Princeton (Census Tract 6136); El Granada, Miramar, and the unincorporated area east of Half Moon Bay (Census Tract 6135); and the City of Half Moon Bay (Census Tract 6137). Geographically, the study area is bounded on the north by Pacifica, on the south by Lobitos Creek, on the west by the Pacific Ocean, and on the east by Skyline Blvd. This study region is designated by the Association of Bay Area Governments (ABAG) as the City of Half Moon Bay and Half Moon Bay Unincorporated.

While there were absolute changes in Coastside population and housing characteristics between 1980 and 1990, the study area's various social attributes, as a proportion of the County's as a whole, remained fairly constant during the decade. For example, in 1980, the study area consisted of 2.81% of the County's overall population, which increased slightly to 3.08% in 1990 (see Table 5-1).

While the overall proportion of population and housing numbers between the Coastside area and the County remained fairly constant between 1980 and 1990, the rate of change of these same attributes was generally much greater in the study area than throughout the County as a whole. For example, the population on the Coastside grew by 21.3% over the ten year period, while the population in San Mateo County rose by only 10.6% (see Table 5-2).

A trend which began throughout the study area in the late 1970's and continued throughout the 1980's, saw the influx of a more affluent, working-professional population. The ideal setting of the Coastside region, including its relative seclusion from metropolitan pressures, but still within reasonable distance to urban job centers, has contributed to its shift from an agricultural area to more of a bedroom community for middle and upper middle class working professionals.

According to ABAG, the total number of jobs within the Coastside region in agriculture and mining fell between 1980 and 1990, while jobs in all other sectors increased (ABAG, 1995). At the same time, there was a 51.1% increase in Coastside residents holding professional/managerial positions, compared to only a 30.7% jump County-wide; and there was 28.5% decrease in the number of families below the poverty level, compared to a 2.2% increase throughout the entire County (see Table 5-2). This demographic shift within the study area between 1980 and 1990 was also evidenced by the relatively large increase in other attributes such as median household income, median housing unit value, and median contract rent (see Table 5-3).

TABLE 5-1: County and Coastside Population and Housing Characteristics in 1980 & 1990


 

1980

1990

Characteristic

County

Coastside

Percent

County

Coastside

Percent

Population

587,329

16,499

2.81%

649,623

20,015

3.08%

Black

35,487

71

0.20%

35,288

124

0.35%

Hispanic Origin

73,339

1,484

2.02%

114,627

3,073

2.68%

Under 19 years

157,785

4,892

3.10%

157,584

5,459

3.46%

Over 65 years

62,048

1,131

1.82%

79,998

1,859

2.32%

Labor Force

313,558

8,779

2.80%

352,964

11,707

3.32%

Professional/Managerial

85,149

2,662

3.13%

111,293

4,022

3.61%

Workers Driving Alone

210,558

5,807

2.76%

251,218

8,393

3.34%

Families

154,205

4,391

2.85%

164,177

3,656

2.23%

Families below Poverty

6,886

158

2.29%

7,035

113

1.61%

Year-Round Housing Units

232,964

6,217

2.67%

251,782

7,649

3.04%

Autoless Housing Units

14,338

178

1.24%

14,683

222

1.51%

Occupied Housing Units

225,201

5,942

2.64%

241,914

7,113

2.94%

Owner-Occupied

134,341

4,397

3.27%

145,750

5,298

3.63%

Renter-Occupied

90,860

1,545

1.70%

96,164

1,815

1.89%

Units Built prior to 1960

132,584

1,657

1.25%

127,489

1,534

1.20%

Source: 1980, 1990 U.S. Census

 

TABLE 5-2: Changes in Coastside and County Population, Housing between 1980 & 1990


 

Coastside

San Mateo County

Characteristic

1980

1990

% Change

1980

1990

% Change

Population

16,499

20,015

21.3%

587,329

649,623

10.6%

Black

71

124

74.7%

35,487

35,288

-0.6%

Hispanic Origin

1,484

3,073

107.1%

73,339

114,627

56.3%

Under 19 years

4,892

5,459

11.6%

157,785

157,584

-0.1%

Over 65 years

1,131

1,859

64.4%

62,048

79,998

28.9%

Labor Force

8,779

11,707

33.4%

313,558

352,964

12.6%

Professional, Managerial

2,662

4,022

51.1%

85,149

111,293

30.7%

Families

4,391

3,656

-16.7%

154,205

164,177

6.5%

Families Below Poverty

158

113

-28.5%

6,886

7,035

2.2%

Work Force (16 yrs.+)

8,549

11,459

34.0%

305,833

346,559

13.3%

Workers That Drive Alone

5,807

8,393

44.5%

210,558

251,218

19.3%

Year-Round Housing Units

6,217

7,649

23.0%

232,964

251,782

8.1%

Autoless Housing Units

178

222

24.7%

14,338

14,683

2.4%

Occupied Housing Units

5,942

7,113

19.7%

225,201

241,914

7.4%

Owner-Occupied Units

4,397

5,298

20.5%

134,341

145,750

8.5%

Renter-Occupied Units

1,545

1,815

17.5%

90,860

96,164

5.8%

Units Built Before 1960

1,657

1,534

-7.4%

132,584

127,489

-3.8%

Source: 1980, 1990 U.S. Census

 

TABLE 5-3: Income/Housing Values for San Mateo County and Coastside in 1980 & 1990


 

Characteristic

1980

1990

 

County

Coastside*

Difference

County

Coastside*

Difference

Median Household Income

$23,172

$25,214

8.8%

$46,437

$57,247

23.3%

Median Housing Unit Value

$124,400

$123,000

-1.1%

$343,900

$355,600

3.4%

Median Contract Rent

$313

$340

8.6%

$711

$844

18.7%

Source: 1980, 1990 U.S. Census

*Median values for Coastside equal the average median value of the three census tracts in the study area.

 

Impacts

No impacts identified.

Mitigation Measures

None proposed.

 

5.16.2 Economic Setting

The 1986 FEIS suggested that the field agriculture industry may begin to lose its dominance as a major employer throughout the mid-coast area. According to ABAG, there was a 15% decline in agricultural jobs between 1980 and 1990 in the coastside region, while all other employment sectors saw positive growth (see Table 5-4). The biggest change was a 281% increase in manufacturing and wholesale trade jobs. The number of jobs in the services sector (1,290) actually surpassed those in the agricultural sector (1,220) by 1990.

The 1986 FEIS also reported that, between 1980 and 2000, employment growth within the coastside region was expected to be small compared to the predicted growth in employed residents. This trend appears to be underway, as total employment within the study area rose by 14% between 1980 and 1990, while the number of employed residents grew by 18% during that time. The trend for the County as a whole was just the reverse: a 20% increase in employment, and only a 13% increase in employed residents. Both the decline in agricultural jobs, and the rapid increase in employed residents, throughout the coastside region, are expected to continue through the year 2015 (ABAG, 1995).

 


TABLE 5-4: Employment in San Mateo County and the Coastside in 1980 and 1990


 

Employment

Coastside Region

San Mateo County

 

1980

1990

% Change

1980

1990

% Change

Agriculture/Mining

1,436

1,220

-15.0%

4,558

3,880

-14.9%

Manufacturing/Whlsl.

105

400

281.0%

59,510

58,550

-1.6%

Retail Trade

734

890

21.3%

42,875

55,190

28.7%

Services

1,002

1,290

28.7%

67,822

98,330

45.0%

Other

696

710

2.0%

85,030

95,650

12.5%

Total Employment

3,973

4,510

13.5%

259,795

311,600

19.9%

Employed Residents

8,522

10,034

17.7%

314,242

353,626

12.5%

Source: ABAG Projections '96

 

 

5.16.3 Environmental Justice

In 1994, President Clinton signed Executive Order 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-income Populations. The Order requires that "each Federal agency shall make achieving environmental justice part of its mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of its programs, policies, and activities on minority populations and low-income populations in the United States...".

The 1990 U.S. Census data indicates that the Coastside region has a comparatively low concentration of minority and low-income residents. For example, African Americans represent only 0.6% of the Coastside population, while they account for 5.4% of the population in San Mateo County, and 8.6% of the population within the San Francisco, Oakland, and San Jose Consolidated Metropolitan Statistical Area (CMSA). On the other hand, 93% of the Coastside is represented by a white population, compared with 72% and 69% of the County and the CMSA, respectively (see Table 5-5). The percentage of low-income Coastside residents is also much lower than similar percentages for the County and the CMSA. Since there are no readily identifiable minority or low-income populations in the Coastside region, neither the tunnel alternative nor the Martini Creek alignment alternative would cause disproportionately high and adverse impacts on minority or low-income populations.

 


TABLE 5-5: 1990 Minority, Low-Income Populations as a Percentage of a Specific Region


 

Coastside

County

S.F., Oak., San Jose CMSA*

Characteristic

Total

Percent

Total

Percent

Total

Percent

Population

20,015

------

649,623

------

6,253,311

------

White

18,582

92.8%

466,885

71.9%

4,334,064

69.3%

Black

124

0.6%

35,283

5.4%

537,753

8.6%

Indian, Eskimo, or Aleut

94

0.5%

2,987

0.5%

40,847

0.7%

Asian or Pacific Islander

619

3.1%

109,281

16.8%

926,961

14.8%

Other

596

3.0%

35,187

5.4%

413,686

6.6%

Hispanic Origin

3,073

15.4%

114,627

17.7%

970,403

15.5%

Persons Below Poverty

801

4.0%

40,405

6.2%

526,124

8.4%

Families

3,656

------

164,177

------

1,528,920

------

Families Below Poverty

113

3.1%

7,035

4.3%

93,069

6.1%

Median Household Income

$57,247**

------

$46,437

------

$41,459

------

Source: 1990 U.S. Census

*Consolidated Metropolitan Statistical Area

**Median value for Coastside equals the average median value of the three census tracts in the study area.

 

 

5.16.4 Right of Way Acquisitions/Relocations

Setting

The proposed tunnel project would affect portions of six private properties.

No persons will be displaced from their residence as a result of the proposed project. No businesses will be relocated.

Impacts

Permanent acquisition of approximately 74 acres would be required, including underground easement, for the proposed tunnel alternative.

Mitigation Measures

Property acquisitions would be negotiated between Caltrans and the private property owners affected by the tunnel alignment. Costs for acquisition of land depends on the value of the property, which would be determined by the use and zoning of the property and numerous other relevant factors at the time of purchase.

The impacts and mitigation measures for the Martini Creek alignment alternative are described in the 1986 FEIS (pp. 51,52,54).

Any previously acquired right-of-way not needed for the project will be declared as excess property and will be disposed of in accordance with appropriate right-of-way procedures.

 

 

5.17 TRAFFIC

Setting

The major freeways in San Mateo County, Highway 101 and Interstate 280, are generally oriented in a north-south direction. Other highways and local streets and roads act as arterials to complete the regional transportation system. As a result of increased residential development in the foothills, east-west traffic volumes have grown in the past decade and many of the east-west arterial roads carry more traffic than the roads were designed to carry. Many east-west roads are narrow, winding, and lack shoulders. These roads create concern for safety and access of emergency vehicles because of poor sight distances and inadequate pavement widths. These local highway and road conditions impede access and result in a generally poor traffic circulation system. The future projected traffic volumes discussed in the 1986 FEIS (pp. 162-169) are still applicable.

Public Transit

The County public transportation system is based on rail service supplied by Caltrain, and diesel coaches operated by SamTrans (San Mateo Transit). The majority of public transit service operates on the Bay side of San Mateo County along the El Camino and Highway 101 corridors. SamTrans provides local and express bus service throughout San Mateo County. The district operates approximately 300 buses over 57 routes. Generally, local routes are operated weekdays with 30 or 60 minute headways with limited Saturday and Sunday service in the coastside area.

During 1993, both Federal and State gasoline taxes were increased for the first time in nearly a decade. A portion of the tax increase was applied to public transit, including the extension of the Bay Area Rapid Transit (BART) System into San Mateo County. These public transit options do not offer an efficient alternative for coastal residents.

The marginal level of regional service is continually overtaxed during the periodic closures of Devil's Slide while coastal traffic to and from Pacifica and northern points is forced to divert to Highway 92 or other east-west arterials.

Impacts

Neither project is capacity increasing, therefore no traffic operational changes, relative to existing conditions, are anticipated.

Mitigation Measures

None proposed

 

5.18 WATER QUALITY

Setting

The following discussion applies to both the proposed tunnel alternative and the Martini Creek alignment alternative.

Since the release of 1986 FEIS, there have been some changes in the regulatory setting with regard to water quality. Caltrans is currently subject to the National Pollutant Discharge Elimination System (NPDES) Permit No. CAS029998 issued by the San Francisco Bay Regional Water Quality Control Board in August of 1994. This permit contains a comprehensive set of requirements that Caltrans shall adhere to in compliance with the Clean Water Act. Among the requirements that apply on a project-by-project basis, is the consideration of Permanent Control Measures (PCM) to eliminate or minimize the discharge of pollutants associated with the new facility. Caltrans has a process to be considered in the project design phase to determine whether PCMs are needed. The process provides a framework for documenting the selection and/or rejection of PCMs. This process would be implemented prior to completion of the final design of the chosen alternative.

Impacts

Long-term and construction related water quality impacts will be better identified during the pre-construction process. There are probable erosion impacts in the project vicinity of either alternative due to excavation and potential non-storm water discharges that could occur during construction activities.

Construction-related Impacts

Non-storm water discharges include all liquids used by the contractor that have the potential to be discharged, either accidentally (spills) or as part of the construction process. Although these types of discharges are most likely to be small quantities, they have the potential to adversely impact receiving water quality in a localized area. Therefore, they would be managed accordingly with an appropriate Storm Water Pollution Prevention Plan (SWPPP).

Long-term Impacts

The pollutants contained in roadway storm water run-off from the additional paved area outside the tunnel will contribute only a small percentage to the project. This anticipated run-off will not substantially increase loading. A possible long-term impact may be associated with tunnel maintenance. Pollutant build up from vehicle exhaust must be periodically removed. Wash water from this maintenance activity could impact receiving water and should be properly controlled.

Mitigation Measures

Caltrans mitigation measures include those that will be required during construction of the project, as well as measures that consider long term benefits. Mitigation during construction is implemented through the SWPPP, which is a two-step process. The conceptual SWPPP, which is prepared during design of the project will identify control measures and Best Management Practices (BMP) that may be implemented.

These BMPs can include:

  1. Erosion and sediment control plans that incorporate vegetative stabilization such as seeding, planting and mulching.
  2. Physical stabilization using geotextiles and mats, dust control implementation measures and temporary stream crossings, and the stabilization of access roads and construction staging areas.
  3. Diversion of run-off using earth dikes, temporary drains and swales, and slope drains and also measures to reduce run-off such as slope terracing/roughing and check dams.
  4. Trapping and filtering of runoff may be accomplished by the construction of silt fencing, straw bale barriers, brush and rock filters, sediment traps and basins, infiltration basins and trenches, and detention ponds.

Prior to the beginning of any construction activities, the SWPPP must be complete and in compliance with any applicable permits. A Storm Water Pollution Prevention Plan (SWPPP) Checklist is used by the Resident Engineer to verify that all required sections of the plan have been completed, and whether each item has been adequately addressed.

The final selection of appropriate control measures for erosion and sediment control and construction waste management can depend on several factors such as the type and location of the project, construction methods, and the location of equipment and materials. There are specific minimum controls required by the permit that must be considered, as well as a list of extended controls that must be evaluated for possible selection.

The final SWPPP will be prepared by the contractor after the contract has been awarded and the field conditions have been identified. The final SWPPP is based on the conceptual SWPPP prepared during the design process and addresses those BMPs and control measures related to special site conditions and construction staging. The final SWPPP is required to be amended any time there is a change in the field conditions or construction activities which has not yet been addressed.

Long-term Mitigation

Caltrans long-term mitigation measures involves the evaluation of potential adverse impacts that the operation of the new facility may have on receiving water quality. The evaluation process considers all aspects of the project, and determines the need for the inclusion of permanent control measures (PCM) into the design of the project as previously described. The process also provides for the evaluation of available PCMs and the feasibility of their use in the projects. The evaluation includes consideration of the following criteria:

 

5.19 THE RELATIONSHIP BETWEEN LOCAL SHORT-TERM USES OF MAN'S ENVIRONMENT AND MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY

The information provided in the 1986 environmental document is still relevant and also applies to both the revised Martini Creek alignment alternative and the proposed tunnel alternative. The primary difference between the two alternatives is that the loss in natural productivity of the land would be less severe with the proposed tunnel project than with the proposed Martini Creek alignment alternative.

 

5.20 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES

Implementation of the proposed project would involve a commitment of natural, physical, human and fiscal resources. Approximately 29.9 ha (74 acres) of additional land would be committed. Direct an indirect energy consumption would occur during construction. Large amounts of highway construction materials and labor would also be expended. All of these resources, and state and federal funds expended would generally be non-retrievable. However, the commitment of these resources would have direct benefits to residents of the area through improved safety, savings in time and fuel and the provision of a dependable transportation system.

 

5.21 UNAVOIDABLE ADVERSE ENVIRONMENTAL EFFECTS

No significant adverse impacts have been identified nor are expected as a result of the construction and operation of the proposed tunnel alternative nor the revised Martini Creek alignment alternative.

 

5.22 GROWTH INDUCING IMPACTS

The 1986 FEIS concluded that the proposed Martini Creek alignment project was not growth inducing essentially because it would not accommodate growth beyond that which is planned in the City and County general plans as well as that projected by ABAG. The tunnel proposal would likewise not add capacity to Route 1 nor accommodate any greater traffic demand beyond what currently exists.

Population growth estimates for the region have not changed significantly since the release of the 1986 FEIS. The 1992 San Mateo County Local Coastal Program (LCP) estimates the build-out population for the Coastside area to be 30,500-32,000 (compared to 30,000-31,500 as projected 10 years ago). According to ABAG's Projections 96, the Coastside population will reach 31,200 by the year 2005, which is five years later than ABAG's Projections 86 estimated that the build-out population would be reached. According to Projections 96, however; it is not assumed that complete build-out will be reached by 2005, and instead, ABAG estimates that the region will continue to grow and will attain a population of 38,400 by the year 2015.

There have been no design changes with regard to the capacity of the proposed Martini Creek alignment project since the 1986 FEIS was finalized, nor does the proposed tunnel project add any additional capacity. The long-range population growth estimates for the coastside region used in the 1986 document still apply. Thus, the conclusion in the 1986 environmental document that the preferred alternative is not growth inducing is still valid. The tunnel alternative is similarly not growth inducing.

In addition, a 1991 study conducted by ABAG concluded that transportation networks in general affect land use patterns differently, and that highway improvements in and of themselves do not create a cause and effect relationship with land use (ABAG, 1991).

 

5.23 CUMULATIVE IMPACTS

The Council for Environmental Quality's (CEQ) regulations for implementing NEPA (40 CFR Section 1508.7) defines a "cumulative impact" as "the impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (Federal or non-Federal) or person undertakes such other actions. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time."

The proposed tunnel project is essentially a replacement of a section of highway to avoid the geologically unstable Devil's Slide area. There are no cumulative impacts expected as a result of the tunnel project.

No significant cumulative impacts were identified in the 1986 FEIS for the proposed Martini Creek alignment project, and none are expected for the current tunnel project or the revised Martini Creek alignment project.

There is a potential for temporary traffic impacts for both of these alternatives, however, these are expected to be short term pending the construction schedule. Route 92 between Half Moon Bay and Interstate 280 is the primary east-west transportation corridor between the Coastside and the Bayside areas of San Mateo County. If construction of the proposed uphill climbing lane project on Route 92, between Route 35 South and I-280 coincides with construction of the Devil's Slide project, motorists who normally travel this corridor may choose to avoid construction-related traffic delays on Route 92 and utilize Route 1, past Devil's Slide.

Neither the tunnel nor the Martini Creek alignment projects are expected to create serious traffic delays along existing Route 1 during construction, since the majority of the construction activities would occur inland of Route 1. However, some delays would be expected as a result of heavy construction truck traffic and the movement of equipment, especially during construction at the north and south conforms to existing Route 1. Such delays could be intensified should traffic on Route 1 increase from motorists choosing to avoid Route 92. These delays, however, would be temporary.

There are projects underway to retrofit the San Francisco/Oakland Bay Bridge, the Richmond/San Rafael Bay Bridge, and the Hayward/San Mateo Bridge, as well as a plan to construct a new east span of the Bay Bridge. It is expected that all of these projects could effect nesting sites of the peregrine falcon.

The potential impacts from these projects on the peregrine falcon are being addressed by having the Santa Cruz Predatory Bird Research Group monitor nests and rescue/hack-out eggs and chicks which could be affected by the bridge projects. Similar mitigation is being proposed for the tunnel alternative project. With the implementation of similar mitigation measures for each of these projects, no cumulative effects on the peregrine falcon are expected.

With the implementation of mitigation measures for the proposed tunnel alternative, no permanent adverse effects to the California red-legged are expected. Two other highway projects in San Mateo County, the State Route 92 Safety and Improvement Project (currently under construction) and the Crystal Springs Dam Bridge Replacement Project are expected to affect the frog. Both projects are currently in the process of fulfilling Section 7 consultation requirements pursuant to the Endangered Species Act. With mitigation measures planned for these projects, no long-term effects will result.

Cumulative impacts to listed species are not anticipated because other projects in the area include measures to protect those species, if present, and to mitigate for unavoidable impacts. Neither alternative will increase the capacity of State Route 1 through the Devil’s Slide area, and no growth inducement impacts are expected.

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