RESOLUTION NO____________

BOARD OF SUPERVISORS, COUNTY OF SAN MATEO, STATE OF CALIFORNIA

* * * * * *

RESOLUTION ADOPTING FINDINGS AND STATEMENT OF FACTS SUPPORTING FINDINGS WITH RESPECT TO THE ENVIRONMENTAL REVIEW FOR THE DEVIL’S SLIDE IMPROVEMENT PROJECT AND APPROVING A MITIGATION MONITORING AND REPORTING PROGRAM

______________________________________________________________

RECITALS

WHEREAS, it is the policy of the State of California and the County of San Mateo, as provided in the California Environmental Quality Act of 1970, as amended, and Title 14, California Code of Regulations, Guidelines for Implementation of the California Environmental Quality Act of 1970 (hereinafter “CEQA” and “Guidelines,” respectively), that the County should not approve projects as proposed if there are feasible alternatives or feasible mitigation measures available which would mitigate the environmental effects of such projects to a level of insignificance; and

WHEREAS, in May, 2002, the California Department of Transportation (“CalTrans”) published the Second Supplemental Environmental Impact Statement/ Environmental Impact Report (“SSEIR”) to the 1986 Environmental Impact Statement/ Environmental Impact Report (“1986 EIR”), originally prepared for the Devil’s Slide Improvement Project; and

WHEREAS, the SSEIR has been prepared pursuant to Sections 15162 and 15163 of the CEQA Guidelines to address environmental effects of the preferred alternative (Tunnel Alternative Design Variation A), and alternatives to the preferred alternative for the Devil’s Slide Improvement Project; and

WHEREAS, the SSEIR, in conjunction with the 1986 EIR and the first Supplemental Environmental Impact Statement/Environmental Impact Report adopted in 1995 (“SEIR”), addresses all potential environmental effects of the proposed project; and

WHEREAS, CalTrans has certified the Final SSEIR as being adequate, accurate and complete; and

WHEREAS, the County is serving as a responsible agency pursuant to Section 21069 of CEQA, by virtue of its responsibility to issue a coastal development permit for the Devil’s Slide Improvement Project; and

WHEREAS, Section 15091 of the Guidelines requires that the County make one or more of the following findings prior to approval of a project for which an EIR has been completed, and which identifies one or more significant effects of the project, along with statements of fact supporting each finding:

Finding 1 – Changes or alternations have been required in, or incorporated into, the project which avoid or substantially lessen the significant environmental effects thereof as identified in the Final EIR.

Finding 2 – Such changes or alterations are within the responsibility and jurisdiction of another public agency and not the agency making the finding. Such changes have been adopted by such other agency or can and should be adopted by such other agency.

Finding 3 – Specific economic, social, or other considerations make infeasible the mitigation measures or project alternatives identified in the Final EIR; and

WHEREAS, the Final SSEIR determined that the project would result in no significant environmental effects in the following areas: consistency with local and regional plans, cultural resources, farmlands, hydrology, noise and traffic.

NOW, THEREFORE, BE IT RESOLVED, that the San Mateo County Board of Supervisors hereby adopts the following Findings and Statement of Facts in Support of Findings upon its review and consideration of the Final 1986 EIR, the Final SEIR, and the Final SSEIR and other substantial evidence in the record.

FINDINGS AND STATEMENT OF FACTS IN SUPPORT OF FINDINGS FOR THE DEVIL’S SLIDE IMPROVEMENT PROJECT

I.

PROJECT DESCRIPTION

Tunnel Alternative Design Variation A

Tunnel Alternative Design Variation A is a 4,000-foot long double-bore tunnel facility through San Pedro Mountain. The tunnel location and alignment are inland of the unstable slide plane area and will meet the project’s purpose and need, which is to provide a safe, dependable and stable State highway route to bypass the geologically unstable area along a portion of the highway known as Devil’s Slide.

This alternative will maintain the existing single lane of traffic in each direction on the highway. The roadway alignment, while proceeding south from Pacifica, departs from existing Route 1 at Post Mile (PM) 39.8. The new roadway alignment follows a 7% uphill grade and crosses the valley at Shamrock Ranch via a bridge structure. It then passes through a small ravine as it approaches the North Portal located on Shamrock Ranch property. The north approach road is approximately 1,500 feet long and the south approach road is approximately 1,000 feet long. The alignment exits the tunnel just south of the Devil’s Slide area where it rejoins the existing highway at PM 37.9.

The major elements of this alternative are the tunnel bores, the north and south portals, and the bridge approach structures. A disposal area, which is located southeast and slightly inland of the South Portal, has been designated as the site for placement of the excavated material generated by the construction of the project. Other elements of the project include temporary construction access roads, a haul road for transporting excess material from the South Portal area to the disposal area, the north and south roadway approaches, the operations and maintenance building. Since existing Route 1 is a conventional highway and bicyclists will not be prohibited from the tunnel, it is proposed that the existing highway be the designated bicycle/pedestrian path. The project design will include placement of informational/directional signs directing bicyclists to use existing Route 1 rather than the tunnel roadway. Tunnel Alternative Design Variation A, which has a smaller cross-sectional width of 30 feet, is consistent with San Mateo County Board of Supervisors Resolution #61060 which identified the County’s preference that the bicycle/pedestrian facility associated with the tunnel project be located on the existing highway.

II.

DESCRIPTION OF ALTERNATIVES TO PROPOSED PROJECT

Tunnel Alternative Design Variation B

Tunnel Alternative Design Variation B is the same proposal as Tunnel Alternative Design Variation A except with a wider cross section of 36 feet to provide a physical separation between traffic inside the tunnel and the pedestrian and bicycle access. The issues of the cross-sectional width of the tunnel and whether or not bicycle access would be provided were subject to much debate and discussion early in the environmental process. Since Design Variation B results in increased costs due to higher volumes of excavation and since there was considerable public concern regarding the tunnel cross-sectional width, Design Variation A was identified in the Final SSEIR as the preferred alternative.

Martini Creek Alignment Alternative

The Martini Creek Alignment Alternative is a new two-lane highway facility located inland of the existing highway. It is approximately 4.5 miles in length and includes an uphill climbing lane in each direction where grades are 6% or greater. Northbound on Route 1, this alternative begins at approximately 0.25 mile north of the town of Montara, near the Chart House Restaurant, where it proceeds inland in a northeasterly direction ascending the south side of Martini Creek and crossing it in a northerly direction. The alignment swings northwesterly past a proposed vista point, then northerly to skirt Green Valley, and continues to the summit of the San Pedro Mountain saddle. North of the summit, the alignment proceeds northwesterly along the flat portion of Shamrock Ranch, swings back in a northeasterly direction on the north side of the ranch, then proceeds northerly to join the existing Route 1 at Linda Mar Boulevard in Pacifica. Since grades exceed 6% on either side of the summit, the design includes climbing lanes for approximately 2 miles in each direction. A slow vehicle lane is required to extend a short distance over the summit in both directions to allow slower vehicles to regain speed before merging into the single downhill lane. A non-paved vehicle recovery area is included in the downhill directions for safety reasons.

As detailed in the Final EIR, Final SEIR, and Final SSEIR, the Martini Creek Alignment Alternative would result in several significant environmental impacts that, given the alignment and design requirements, cannot be substantially mitigated. These include significant and severe visual scars from cuts and fills along the alignment, the loss of 10 acres of farmland, substantial increases in predicted noise levels at several locations within McNee State Park, and the loss of 28 acres of wetlands. Further, the Martini Creek Alignment is not consistent with the San Mateo County Local Coastal Program, which prescribes a tunnel around Devil’s Slide. For all of these reasons, the Martini Creek Alignment Alternative would not substantially lessen the environmental impact of the proposed project, and is hereby rejected.

No Project Alternative

The no project alternative consists of continuing with the general maintenance and repair of the existing alignment. There would be no new construction or any new roadway work. Periodic slides and slip-outs, resulting in road closures of various lengths of time, are expected to continue with this alternative. There is a high probability that a seismic event of sufficient magnitude will eventually occur and result in permanent closure of the existing roadway. This alternative does not meet the purpose and need for the project, and is hereby rejected.

Alternatives Considered But Withdrawn

The Final SSEIR includes a discussion of the following alternatives, which were considered but withdrawn from consideration as a viable alternative for the project.

The “Existing Alignment Alternative” in the 1986 Final EIR referred to what had been commonly known as the Marine Disposal Alternative (MDA), and involved realigning a 4,300-foot section of the highway at Devil’s Slide approximately 250 feet inland and uphill of the existing highway. The landslide would be stabilized by excavation of 14.5 million cubic yards of material to reduce and lessen the driving force on the slide plane. The material would be deposited into the ocean to serve as a buttress for the coastal slope supporting the roadway above. With this alternative, the highway would still be subject to the severe marine and geologic conditions unique to the Devil’s Slide area. In 1986, the Marine Disposal Alternative was rejected primarily due to the additional cost and construction time (approximately $11 million and 1.8 years) involved when compared to the Martini Creek Alignment Alternative. Now, with the establishment and formal designation of the Monterey Bay National Marine Sanctuary in late 1992, the MDA would be inconsistent with Federal laws that govern marine sanctuaries and is therefore not considered a reasonable alternative.

The De-watering Alternative discussed in the Final SSEIR involved an extensive effort to drain the active slide and the adjacent landmass in order to preserve the existing highway. CalTrans engineering and geologic staff had always believed that de-watering was not comparable to the certainty of the tunnel alternative in meeting the purpose and need of the project; however, there was insufficient data at that time to fully resolve the adequacy of de-watering as a permanent solution. In response to a request from the San Mateo County Board of Supervisors that de-watering be considered as a project alternative, it was determined that in the absence of conclusive cause for rejection, de-watering would be evaluated as part of the environmental process. A de-watering feasibility study was initiated in November of 1997 to determine if the de-watering of Devil’s Slide with deep wells was feasible as a long-term solution to the recurring slide movement within the most active portions of Devil’s Slide. The major component of this effort was the installation of two test wells to provide a means to potentially improve roadway stability in anticipation of the projected wet “El Niño” winter. These wells were to also provide the data and information needed regarding the feasibility of using deep wells to de-water and stabilize this area in order to support and maintain a stable and permanent highway. It was determined that de-watering the landslide would not slow down nor stop slide creep within the coastal bluff and that de-watering would not be effective as a long-term stabilization solution for the existing alignment. De-watering would be also extremely difficult in this area because the groundwater regime is very complex and there has been limited ability to remove groundwater. For these reasons, the De-watering Alternative is rejected.

III.

FINDINGS WITH RESPECT TO THE POTENTIAL SIGNIFICANT ENVIRONMENTAL IMPACTS ASSOCIATED WITH THE DEVIL’S SLIDE IMPROVEMENT PROJECT

The San Mateo County Board of Supervisors hereby finds that changes and alterations have been required in, or incorporated into, the project which avoid or substantially lessen the potential significant environmental impacts associated with the Devil’s Slide Improvement Project, as follows:

1.

AESTHETICS

a.

Impacts

Design Variation A and Design Variation B were analyzed in the Visual Assessment. Both design variations included two tunnel bores, each with a single lane of traffic in one direction and an outside shoulder and raised sidewalks for emergency and maintenance personnel access. The design variations differ in that Design Variation B has a wider cross section to include a concrete barrier separating a bike lane from traffic and the outside shoulder. As proposed in the SSEIR, Design Variation A would have resulted in 947,000 cubic yards of excess material while Design Variation B would have resulted in 998,000 cubic yards of excess material. Refinements in design for the proposed project have now reduced the amount of excess materials to 610,000 cubic yards. The visual impacts at the North and South Portal Areas are similar in nature but somewhat more extensive under Design Variation B, due to the wider cross-sectional area and thus, the greater amount of fill material at the disposal site.

(1)

North Portal Area

The bridge structure, estimated to be 1,050 feet in length, will span the small valley at Shamrock Ranch and connect the highway with the North Portal. The visual presence of the bridge will have a negative visual impact on this small valley, which currently enjoys minimal intrusions from development.

Trees and hillside vegetation will be cleared and grubbed for construction of the tunnel portal and the approach to the portal. The contrast between the cleared area and the chaparral-blanketed hillsides will result in a negative visual impact.

The North Portal facade will be visible for a short duration to motorists and bicyclists.

The elements that comprise the North Portal, including the rock cut, tunnel portal, guardrails, and small structures, will have a negative impact on the existing visual environment as viewed by motorists and bicyclists.

(2)

South Portal Area

A single location has been identified within the project limits, just south of the South Portal, for disposal of excavated material from the tunnel construction. The site, identified as the Disposal Site, will undergo negative visual changes as a result of the placement of fill material in a coastal scrub-covered valley located close to the coastal bluffs. As proposed in the SSEIR, with Design Variation A, the disposal site was to receive an estimated 881,691 cubic yards of excess material. The fill area was to create a hill with 2:1 slopes, 590 feet in diameter and reaching 295 feet in height. Approximately 65,400 cubic yards would have been disposed off site. Design refinements have reduced the total amount of excavated materials to 610,000 cubic yards, all of which will be placed at the disposal site, eliminating the need for off-hauling of materials.

The Operations and Maintenance Center (OMC) will be located approximately 1,000 feet south of the South Portal, on a portion of the disposal site for excavated material. Its location will be determined in conjunction with the design of final grading plans for the disposal site. As a result of design refinements, the OMC will be placed farther back on the subject parcel than originally planned and tucked behind berms to hide it from Route 1. Although it is intended that the site be graded so the building is shielded from view from Route 1, the building will still be visible from nearby hiking trails. The building will be a visually intrusive feature in a relatively undisturbed environment and thus result in a negative visual impact.

The South Portal facade will be visible from a short distance to motorists on the highway, and from much longer distances to those on boats on the ocean. There are no residents within the vicinity of the South Portal that will experience long exposure views of the South Portal.

A large rock cut at the South Portal Area is necessary to align the highway and to provide adequate sight distance and radius curve. A smaller rock cut is necessary at the top of the South Portal. The rock cuts will be visually prominent and will contrast with the vegetated hillsides.

Other elements of the South Portal Area include drainage features, a turnaround area, and a guardrail. To reduce both the primary visual and secondary biotic impacts associated with this original design, the project has been modified to incorporate a soil-nail wall at the South Rock Cut. This wall will be approximately 650 feet in length and 72 feet in height at its tallest point. The exterior of the wall will be textured and stained to appear as natural rock formation, similar to the soil-nail walls constructed on Highway 92.

b.

Mitigation Measures

(1)

North Portal Area

The overall appearance of the bridge will have a negative visual impact on the Shamrock Ranch valley and the surrounding area. Mitigation for this visual impact will 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, will mitigate the visual impact of the bridge. Standard monolithic concrete structures lacking form, pattern, or articulation will not provide adequate mitigation for this impact.

The proposed mitigation also includes a major revegetation effort. The revegetation strategy includes site-specific measures for erosion control and the collection, propagation, and planting of native plant species, as well as installation of automatic irrigation systems. Mitigation and monitoring measures include a plant establishment period of 10 years.

Construction clearing and grubbing activities will have clearly defined limits. The negative visual impact from vegetation removal will be mitigated with revegetation. Over time, the successful establishment of trees, shrubs and other materials, is expected to provide a new land cover that will mitigate the visual impact of clearing and grubbing.

Mitigation for the potential negative visual impact of the North Portal facade includes the use of an architectural treatment for the tunnel portal in order to provide a cohesive, substantive design for the tunnel entrance that complements the environment. The architectural aesthetic treatment will provide the design theme for other built elements of the North Portal Area, and visual continuity of proposed facilities within the entire portal area will be included in project planning. Aesthetic treatment includes landscaping for a softening effect and transition of the built elements into the hillside.

(2)

South Portal Area

The proposed mitigation for the visual impact of the placement of fill material at the Disposal Site will include contour grading of the fill to match the adjacent hillsides and the floor of the valley and revegetation with plants that blend with the surroundings.

The South Portal will present an aesthetically pleasing exterior that matches the North Portal’s aesthetic treatment. Architectural surface treatment will be included in the project cost estimate. The final location of the South Portal and adjoining retaining walls will be determined during the design phase of the project, after geotechnical testing.

The rock cuts required in this area will not be left with a machined or unnatural appearance. The faces of existing rock cuts in this area have a natural, uneven, coarse appearance consistent with natural rock faces. The faces of the new rock cuts will be made to match the appearance of existing rock cuts.

The Operations and Maintenance Center will be shielded from view of the highway through the use of earthen berms and small-scale screen plantings.

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

2.

AIR QUALITY

a.

Impacts

Current methodologies for calculating ambient air quality have changed since air quality studies were conducted for the approved 1986 FEIR. Air quality calculations now include a “roll back” factor which is the ratio of expected future year emissions to the estimated base year emissions. Computer programs, which estimate vehicle emissions in order to predict pollution concentrations adjacent to the roadway, have also been revised since project air quality calculations were performed for the 1986 FEIR. Based on the current emission factors, projections of pollution for the year 2010 are lower than those derived from previous calculations using the former emission factors.

In the 1986 FEIR, 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 1986, the Martini Creek Alignment Alternative has not essentially changed. The tunnel alternative does not add any additional capacity beyond that of the Martini Creek Alignment Alternative and since neither build alternative increases roadway capacity nor moves the roadway closer to any receptors, there will be no violation of State or Federal CO standards.

According to the tunnel feasibility study (Woodward-Clyde Consultants, 1997), the ventilation requirements for the tunnel were based on acceptable levels of pollution in the tunnels during normal or congested traffic operation. The minimum air quality requirements are based on an approved computer-generated estimate of carbon monoxide (CO) emissions as well as maximum CO concentrations within tunnels as established by EPA and FHWA. The allowable CO concentrations and exposure times are:

•

Maximum 120 ppm for 15 minute exposure time

•

Maximum 65 ppm for 30 minute exposure time

•

Maximum 45 ppm for 45 minute exposure time

•

Maximum 35 ppm for 60 minute exposure time

The feasibility study recommended the use of jet fans for ventilation in double bore tunnels. A jet fan unit is an axial fan with a direct drive motor to deliver a wide range of thrust capabilities in both the forward and reverse direction. The jet fan system will force air to the downstream (direction of traffic) portal and out of the tunnel, while introducing fresh air into the tunnel at the upstream end. A design option without pedestrian/bicycle access would allow the higher 120 ppm CO limit. However, since the design option does not preclude pedestrian/bicycle access, a more restrictive 65 ppm CO limit will be used for the tunnel ventilation design.

There are no established EPA or FHWA requirements with regard to tunnel ventilation and potential tunnel air quality impacts to bicyclists. It is anticipated that adverse conditions will be infrequent if at all.

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

b.

Mitigation Measures

CalTrans will incorporate the lower 65 ppm CO limit and the recommended ventilation systems to provide acceptable air quality conditions for bicyclists. The proposed tunnel design will also include a “real time” air quality monitoring system that includes variable message signs to advise bicyclists if unacceptable air quality conditions exist in the tunnel.

To reduce dust generated by construction, hauling, and grading, as well as other activities that might generate dust, CalTrans construction specifications for dust control will 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 and will effectively mitigate most particulate air quality impacts for the build alternatives.

3.

CONSTRUCTION

a.

Impacts

Activities such as phased clearing, grubbing, construction of the access roads, and construction in general, will typically result in increased levels of truck traffic, noise, dust, and visual impacts.

Temporary traffic impacts can be expected, particularly at the Route 1 and San Pedro Terrace Road intersection where construction related traffic will be headed to and from the Shamrock Ranch entrance area, located off San Pedro Terrace Road.

Temporary noise impacts will occur from pile driving, blasting, and general construction activities. Construction activities also typically result in the generation of substantial quantities of dust.

As noted in the preceding Aesthetics Section, construction clearing and grubbing activities will result in visual impacts from the loss of existing vegetation. Construction operations within view of the public and the presence of construction equipment and vehicles in an undisturbed natural area are visual impacts.

b.

Mitigation Measures

Most construction workers typically arrive at and depart from the work site during non-peak traffic period. Truck trips will generally be restricted to off-peak hours at critical locations such as the Route 1 and San Pedro Terrace Road intersection. Public notices and the posting of roadway signs will be implemented to alert the public of any temporary road closures, lane reductions, or other construction scenarios which may affect traffic. No long-term traffic impacts are expected.

Noise suppression devices will be employed on equipment and vehicles and the use of enclosures will be considered if feasible or necessary in certain situations. Construction activities will be limited at locations where there may be sensitive receptors and where night work can be avoided. Standard construction methodologies and dust control measures will be implemented.

Revegetation and the provision of a new land cover will mitigate the visual impacts of clearing and grubbing activities. Where possible, construction staging areas will be located in less visible areas. Most construction impacts are unavoidable; however, they will be temporary during the course of the 3-year construction period and wherever possible, every effort will be made to minimize the impacts.

4.

FOG

a.

Impacts

Information in the 1986 FEIR shows that the higher elevations along the coast in the Devil’s Slide area are more affected by fog than the lower elevations. The areas where reductions in sight distances occur due to fog are usually at elevations above 650 feet. The north and south entrances of the proposed tunnel are at approximate elevation of 350 feet and 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 FEIR (pages 95-97) for the Martini Creek Alignment Alternative still apply to the revised project alternative. The maximum elevation for the Martini Creek Alignment Alternative is approximately 730 feet. Based on the assumption that there is a linear increase of 5.5% fog occurrence per 100 feet rise in elevation, the Martini Creek Alignment Alternative will likely be affected by fog more frequently and for longer duration than the tunnel alternative.

b.

Mitigation Measures

Exterior night lighting at the tunnel approaches will be provided to improve visibility. The entire lighting system will be computer controlled and have an uninterruptible power supply.

5.

GEOLOGY

a.

Impacts

The Devil’s Slide area at San Pedro Mountain is located within a seismically active area and therefore the project will be subject to earthquakes and ground shaking. The San Andreas Fault is less than 4 miles east of the study area, the active Hayward Fault is 37 km (23 miles) to the northeast, and the potentially active Seal Cove Fault is 2.4 km (1.5 miles) offshore to the west.

The project site is 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 from 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 2 miles offshore and southwest of the site.

The tunnel alternative will be exposed to vibrations and ground movement during earthquakes.

b.

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 will result in relatively minor architectural damage.

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 produce a structure 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 degree of earthquake distortion is generally low and often within the elastic deformation capacity of the structure.

The magnitudes and duration of straining in the perimeter of a tunnel in rock are not the critical concerns regarding overall tunnel stability. Local displacement of the rock around the tunnel can occur and can damage the tunnel lining. Aside from measures to strengthen portals and ensure 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 to design the tunnel to prevent such infrequent damage from occurring.

6.

HAZARDOUS WASTE

a.

Impacts

Typically, the top layer of unpaved areas adjacent to older and/or heavily traveled highways may be contaminated with aerial deposited lead (ADL) from motor vehicle exhaust resulting from historic usage of leaded gasoline. There is a potential for aerial deposited lead contamination at the approaches to the tunnel where they intersect existing Route 1.

b.

Mitigation Measures

Testing will be conducted for the selected alternative during the final design stage. If test results reveal lead levels which exceed California hazardous waste criteria, the contaminated soils will be handled according to regulatory requirements. The Department of Toxic Substances Control has issued CalTrans a variance (dated September 22, 2000) for the management of ADL material. Material with lead levels exceeding California hazardous waste criteria may be reused within CalTrans projects under the conditions of the variance. Any material with lead that cannot be reused under the variance will have to be hauled off to a Class I landfill.

7.

NATURAL ENVIRONMENT

a.

Impacts

(1)

Peregrine Falcon

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 being an aerial predator, the tunnel alternative is expected to have almost no effect on foraging activities.

Construction activities associated with the tunnel alternative could affect the nesting activity of the peregrine falcon. The South Portal Area of the tunnel alternative is located approximately 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.

(2)

California Red-Legged Frog

The tunnel alternative will not result in any adverse impacts to the south pond at Shamrock Ranch. While the south pond at Shamrock Ranch is not within the project limits for the tunnel alternative, the pond will be designated as an Environmentally Sensitive Area (ESA) to ensure that the habitat will be protected from any construction activities. This designation prohibits any construction activities including the movement and location of heavy equipment within its boundaries.

At the north pond, one of the original design options for the tunnel alternative would have resulted in fill effects to portions of this pond and its associated drainages. However, this alternative now includes bridge structures that will clear span the north pond and its associated drainages, and result in no fill impacts to the north pond.

Direct effects to the red-legged frog include the potential for harassment, injury, and mortality. Frogs that are captured and moved from the north pond will be subject to all the above adverse effects. Frog exclusion fences may fail or may actually trap frogs on the construction side of the fencing, leading to increased chances of the frogs being crushed by construction activities.

This alternative will result in a temporary loss of red-legged frog foraging and potential breeding habitat at the north pond. Frogs displaced by construction activities or actual relocation may experience increased competition for food and space. Petrochemicals, solvents, soaps or concrete over wash that spill or leak from vehicles or construction sites could kill frogs in all life stages. Sediment discharges to the north pond could suffocate frog embryos and tadpoles. Noise and vibration from construction activities may harass frogs.

Indirect effects may result from disturbance of the natural soil horizons during grading because reestablishment of existing type vegetation may be difficult and problematic in some locations, leading to invasion by exotic, noxious weeds. Construction activities can also lead to the accumulation of trash and garbage that might attract predators such as raccoons and skunks.

New Pond at Shamrock Ranch

During informal consultation with the USFWS, a strategy was developed to maximize protection for the California red-legged frog during construction of the project. The plan called for creation of a third pond on Shamrock Ranch. Prior to construction of any access roads, frogs will be trapped and relocated from the existing north pond to the new pond. The frogs will be held in the new pond for the duration of the construction activities. This new pond will become a permanent feature and will continue to provide additional habitat for the red-legged frog following completion of the project.

The USFWS biological opinion (Appendix J to the SSEIR) recognizes that a new pond provides mitigation for indirect impacts to the frog resulting from construction of the tunnel alternative. The USFWS fully endorsed this plan by including the new pond in the Conservation Measures stipulated in the biological opinion. This strategy will be applicable and required for either the tunnel alternative or the Martini Creek Alignment Alternative. Furthermore, benefits to the frog will accrue regardless of the alternative selected, including the No-Build.

Due to the overall benefits to the frog and in an effort to minimize potential project delays, CalTrans, with the approval of the USFWS, went ahead with creation of the new pond in the fall 2000, using State-only funds. Creation of this new pond was determined to have met the criteria for a categorical exemption under CEQA. The new pond was constructed just below the existing south pond in a horse pasture dominated by introduced annual grasses and weedy forbs. The area was swept for red-legged frogs and a perimeter frog exclusion fence was erected around the site prior to construction. Construction of the pond did not have any adverse impacts on the California red-legged frog or other sensitive resources, such as wetlands.

Upon further approval of the USFWS, frogs were trapped at the north pond and relocated to the new pond between April and July 2001. Egg masses were also collected and moved to both the new pond and the south pond. The relocation process directly affected frogs and eggs. The frogs may have been subjected to physiological stress and may have experienced difficulty adapting to the habitat at the new pond. Frogs that attempt to leave the new habitat, which is enclosed in a frog-proof fence, may be exposed to avian predators and may become further stressed and suffer a decrease in physical fitness. Eggs could become desiccated or otherwise adversely affected by the relocation, which could result in a lack of development of the embryo. Adult and juvenile frogs will be competing for food and space in a smaller, more confined area than exists at the north pond.

In spite of these potential adverse impacts, the USFWS allowed the relocation on the premise that the long-term benefits to the red-legged frog population outweigh the immediate short-term impacts. Habitat for the California red-legged frog at Shamrock Ranch has been enhanced by creation of the third pond. The new pond is shown on the wetland jurisdictional maps (see SSEIR, Figures 5-3, 5-6 and 5-9).

Additional Surveys

CalTrans conducted additional frog and garter snake surveys of wetland areas within the project site during the spring and summer of 2002. On May 16, 2002, four CRLF were found within the Seasonal Ponding Depression and Permanent Drainage. Based on the survey results, it appears that this drainage provides foraging habitat for randomly wandering CRLF, but since the ponding area around the standpipe does not last until the end of August, the drainage does not provide suitable breeding habitat for this species. In addition to sediment detention and foraging habitat for CRLF, this depression functions as a small area of open space. As a result of these findings, FHWA requested re-initiation of formal endangered species consultation with the USFWS on April 8, 2003, for the CRLF. In March of 2004, the USFWS completed the re-initiation of formal endangered species consultation and issued the USFWS letter dated March 25, 2004.

b.

Mitigation Measures

Of the wildlife species of concern, one threatened species is present on the proposed project site and one former endangered species is located in the immediate project vicinity. The threatened California red-legged frog (Rana aurora draytonii) is found in association with the three ponds on the western end of Shamrock Ranch, at the north end of the tunnel alternative and in close proximity to the Martini Creek Alignment Alternative. The peregrine falcon (Falco peregrinus anatum), a de-listed Federal endangered species, nests on a coastal bluff near the South Portal for the tunnel alternative.

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

The segmented balanced cantilever method will be used to construct the bridges in order to avoid direct impacts to the ESA. The bridge piers and abutments, located outside the ESA, will be erected first. The superstructure between the north and south piers will then be constructed by cantilevering out from the piers. Field surveys determined 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. Therefore, false work could be utilized to support the counterbalancing superstructure outside the ESA between the piers and their adjacent north and south abutments.

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

(1)

A frog exclusion fence will be installed around the immediate perimeter of the north pond prior to initiation of any exploration or construction activities associated with the North Portal and approaches (see SSEIR, Figure 5-0.2). The frog exclusion fence is unique in that it includes one-way funnels that allow frogs that might be in the adjacent construction areas or ESA to “escape” to the pond, while frogs already in the pond are “excluded” from the construction zone. Frog exclusion fencing is also required in the vicinity of the proposed embankment repair at the south pond.

(2)

Following installation of the frog exclusion fence, ESA fencing will be installed (see SSEIR, Figure 5-02). This fence will consist of solid sediment/frog barrier panels along segments of the temporary construction access roads. High visibility orange polypropylene fabric can be used along portions of the ESA. These fences must be completely in place prior to access road construction at the North Portal and approaches.

(3)

The sediment/frog barrier fence will be designed so that surface runoff from all areas above and within the construction zones will drain into small temporary de-silting basins spaced along the construction side of the fence. The spacing of these basins will be determined in the field based on the size and characteristics of the individual drainage sheds involved. Silt deposits will be removed once they fill more than one third of any basin or if the integrity of the sediment/frog barrier fence is threatened.

(4)

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 Stormwater Pollution Prevention Plan measures will be implemented in early fall to ensure that erosion in all disturbed areas will be kept to a minimum.

(5)

After construction is completed, the construction access roads will be re-graded 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 hydro-seeded with a non-invasive seed mix.

(6)

The revegetation effort will include full maintenance of the installed plants during a 10-year plant establishment period (PEP). Success criteria will be established and a 10-year monitoring program will be implemented after the initial planting to document the success of the revegetation effort. Replanting will be performed during the 10-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.

(7)

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 tunnel alternative will also include enhancement measures at the north and south ponds to alleviate or eliminate the existing adverse conditions that now threaten to reduce the California red-legged frog population. These measures include conditions of the USFWS biological opinion and will also compensate for potential direct impacts resulting from construction activities such as ground vibration, dust and noise:

(1)

Conservation easements will be sought for both the north and south ponds as well as the new pond in order to protect the habitat for the California red-legged frog in perpetuity. If a USFWS approved conservation easement cannot be secured, an off-site mitigation area or other agreement satisfactory to USFWS will be secured.

(2)

Following completion of the highway project, a one-time, pond silt removal project will be implemented at the north pond in order to lessen the current heavy silt load in the north pond basin. This operation will be undertaken in late summer following removal of the sediment/frog barrier fences but prior to removal of the frog exclusion fence at the pond.

(3)

To ensure that the north pond does not continue to dry up in mid-summer, thereby negating successful metamorphosis of any 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, and where the frog can complete larval metamorphosis, even during drought years.

(4)

The koi carp population will be removed from the south pond to eliminate koi carp predation on frog eggs and tadpoles.

(5)

A 3-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.

In addition to the measures described above, the USFWS (Service) biological opinion (SSEIR, Appendix J) imposes several non-discretionary terms and conditions to further minimize the impacts of incidental take of the California red-legged frog due to direct impacts to the species and its critical habitat if the tunnel alternative is implemented. These terms and conditions are listed below, and are subject to modification in the event that consultation is reinitiated with USFWS:

(1)

CalTrans shall implement the project, along with the proposed protection measures for red-legged frogs, as described in the proposed project description [refer to Biological Assessment – Species of Concern, issued by CalTrans on December 15, 1999].

(2)

Individuals that handle and remove red-legged frogs, tadpoles or egg masses must be pre-approved by the Service prior to trapping, capturing or collecting on-site.

(3)

Red-legged frogs shall be marked only with Service approval. The method of marking red-legged frogs must be approved by the Service.

(4)

Annual management at the mitigation [new] pond shall be determined each year based on the anticipated carrying capacity of the pond. The determination as whether or not to move egg masses, where those egg masses shall be moved to, or allow the red-legged frogs to disperse from the new pond shall be at the Service’s discretion. Experimental releases of adult or newly metamorphosed red-legged frogs fitted with radio-transmitters or PIT tags shall be at the Service’s discretion in cooperation with CalTrans.

(5)

All translocated or moved egg masses shall be monitored daily to determine the level of coddling.

(6)

Regular inspection of the fence around the construction access road and the north pond shall ensure that red-legged frogs do not cross the road and enter the north pond. CalTrans shall install an electric fence around the new pond fence to prevent mammalian predation.

(7)

The trapping dates of April 15 through June 30, set forth in the Minimization Measures 2000 [Appendix J: Biological Opinion, page 4] may be changed at the Service’s discretion. [Trapping actually occurred between April 15 and June 30, 2001, with the approval of the Service.]

(8)

CalTrans shall install sediment control structures around the perimeter of the dirt access road where runoff is likely to drain to any of the three ponds or the creek. Any silt control structures that breach or become damaged during a storm event shall be repaired or replaced within 24 hours. Any straw/hay bales that may be used for sediment control shall be free of star thistle seed.

(9)

CalTrans personnel shall inspect the environmentally sensitive area fence every day when construction activities are being conducted for openings and/or breaks in the fence that would allow red-legged frogs to enter the construction area. The exception to this is when construction activities are occurring solely on the bridges and no traffic is within the environmentally sensitive area. Any openings in the fence where red-legged frogs could enter the environmentally sensitive area shall be repaired within 12 hours.

(10)

Before any construction activities begin on the project, a Service-approved biologist shall conduct a training session for all construction personnel. At a minimum, the training shall include a description of the natural history [of the] red-legged frog and its habitat, the importance of the red-legged frog and its habitat, the general measures that are being implemented to conserve the red-legged frog as they relate to the project, the penalties for non-compliance, and the boundaries (work area) within which the project may be accomplished. Training sessions shall be repeated for all new employees before they access the project site. Sign up sheets identifying attendees and the contractor/company they represent shall be provided to the Service within one week of such training.

(11)

A Service-approved biologist shall be present at the work site until all red-legged frog removal and worker instruction have been completed.

(12)

Stockpiling of construction materials, including portable equipment, vehicles and supplies, including chemicals, will be restricted to the designated construction staging areas.

(13)

Refueling of construction equipment and vehicles may not occur within 300 feet of any water body or anywhere that spilled fuel could drain to a water body. CalTrans shall check and maintain equipment and vehicles operated in the project area daily to prevent leaks of fuels, lubricants or other fluids.

(14)

Equipment may not be washed in a place where wash water could drain to the creek or the ponds.

(15)

CalTrans shall clean hazardous material spills immediately. Such spills shall be reported to the Service immediately. Spill cleanup and remediation shall be detailed in post-construction compliance reports.

(16)

CalTrans shall comply with all reporting requirements in this opinion, including those proposed in the project description [refer to Biological Assessment – Species of Concern, issued by CalTrans on December 15, 1999].

The USFWS biological opinion also specifies the following terms and conditions to minimize the impacts of incidental take resulting from indirect effects of construction, subject to modification in the event that consultation is reinitiated with USFWS:

(1)

CalTrans shall remove litter and construction debris from the construction site daily and contain the waste at an appropriate site. All trash that may attract predators shall be securely covered at all times in locking metal containers, removed from the work site and disposed regularly. Following construction, all trash and construction debris shall be removed from the work areas.

(2)

No captured bullfrogs shall be released back into the wild.

The biological opinion includes terms and conditions to minimize the take of red-legged frogs from future bridge maintenance activities:

(1)

Prior to implementation, future bridge maintenance activities and remedial actions that may impact red-legged frog habitat must be reviewed and approved by the Service.

(2)

If CalTrans is unable to secure a Service-approved conservation easement as proposed in the Conservation Measures [Appendix J: Biological Opinion, page 5], CalTrans must secure a Service-approved off-site mitigation area or other agreement satisfactory to the Service.

(3)

CalTrans shall provide an endowment to provide for management of the conservation easement area and a copy of the endowment agreement to the Service for review and approval prior to construction. The agreement shall contain specific information on the endowment to manage the site for the red-legged frog in perpetuity.

(4)

CalTrans shall prepare and implement a detailed habitat monitoring plan within the proposed conservation easement. The plan shall include, but not limited to, specific performance standards, monitoring methods and requirements, exotic species control (plant and animal), and contingency measures for habitat to be restored and managed for red-legged frogs. The site shall provide hydrologic stability, habitat complexity and food production potential. CalTrans shall submit the final plan to the Service for review and approval prior to initiation of any project work.

Finally, to protect the California red-legged frog and its habitat from direct impacts due to construction, the applicant shall fully comply with the biological opinion issued by the United States Fish and Wildlife Service, dated December 2000 and revised by letter from the USFWS dated March 25, 2004. The biological opinion authorizes take of the California red-legged frog. The applicant shall submit to San Mateo County copies of any monitoring reports required pursuant to the biological opinion. Any proposed revisions to the conditions of the biological opinion shall be based on continuing field research and studies and shall be made only in consultation with the USFWS.

With the mitigation measures and terms and conditions listed above, permanent impacts will be avoided and short-term temporary construction impacts to, and incidental take of, the California red-legged frog will be minimized and compensated.

Under provisions of the Federal Migratory Bird Treaty Act, nest monitoring is typically required for projects that could affect the nesting activity of the peregrine falcon. If it were determined during monitoring that project activities are interrupting egg incubation or the feeding of the chicks, it will be necessary to suspend certain construction activities or remove the eggs or chicks.

Eggs removed from a nest are to be artificially incubated at a facility such as that operated by the Santa Cruz Predatory Bird Research Group (SCPBRG). Any chicks that hatched out are to 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 recovery of the peregrine falcon.

8.

AQUATIC RESOURCES AND ASSOCIATED HABITATS

a.

Impacts

The wetland impacts evaluated in the SSEIR are discussed in detail at pages 89 to 115 of Volume 1 of the SSEIR. In summary, the project as originally proposed would have resulted in wetland impacts of .25 acres under Corps of Engineers criteria, .06 acres under County of San Mateo Local Coastal Program criteria, and 1.45 acres under California Coastal Commission criteria.

CalTrans has undertaken numerous design refinements in order to reduce the wetland impacts. Because the Coastal Commission criteria represent the most protective criteria in terms of identifying the extent of potential impact, that criteria were employed to evaluate the reduction in impact resulting from design refinements. In summary, the impact to wetlands was reduced from 1.45 acres to approximately .97 acres. In more detail, impacts are as follows:

Unavoidable wetland impacts will occur within the drainage areas for the Fill Disposal site, South Portal site, and North Portal/Shamrock Ranch site as a result of the project. The total area of wetlands that will be affected by the project is approximately 0.97 acres (42,253 sq. ft). In addition, the project will permanently affect wetland buffer zones totaling approximately 12.68 acres (552,340 sq. ft.). These impacts are further discussed in detail below:

North Portal Drainage Area/Shamrock Ranch

A total of approximately 0.67 acres (29,185 sq. ft.) of wetlands and 4.02 acres (175,111 sq. ft.) of buffer zones will be impacted at the Shamrock Ranch Drainage Area. This includes the following:

(1)

Approximately 3,049 sq. ft. of wetlands and 44,431 sq. ft. of buffer zones found on the earthen dam of the north pond and 20,473 sq. ft. of buffer zones at the Shamrock Ranch corral will be filled by the temporary construction access road. These wetlands function as habitat for wildlife and contain a high diversity of vegetation. All wetlands associated with the ponds have a high wildlife habitat value because the ponds also provide habitat for the CRLF. The buffer zone is generally of moderate to high habitat value. However, along the south side, the buffer zone consists primarily of a horse pasture characterized by closely cropped annual grasses. Wildlife habitat values in this area are low.

(2)

Approximately 23,086 sq. ft. of wetlands and 82,764 sq. ft. of buffer zones found in association with the North Portal intermittent drainage will be filled as a result of the project. The North Portal intermittent drainage habitat value is moderate to high due to the diversity of the cover. The coastal scrub provides habitat value for birds and other wildlife. The North Portal intermittent drainage buffer zone is characterized by dense coastal scrub vegetation with moderate to high habitat value.

(3)

A small portion of a wetland area, approximately 3,049 sq. ft. and 27,442 sq. ft. of buffer zones, located down slope from the south pond and immediately adjacent to an existing horse trail, will be permanently filled due to the construction of an access road to the North Portal. These wetlands function as habitat for wildlife and contain a high diversity of vegetation. All wetlands associated with the ponds have a high wildlife habitat value because the ponds also provide habitat for the CRLF. The buffer zone is characterized by generally high quality habitat with only minimal disturbance.

South Portal Drainage Area

The Seasonal Ponding Depression and Permanent Drainage wetland and buffer zone area will be impacted at the South Portal Drainage Area. This includes the following:

A total of approximately 5,227 sq. ft. of the lower portion of a permanent wetland drainage, which terminates in a seasonal ponding depression, will be filled as a result of the planned approach that connects the tunnel’s South Portal with the existing Highway 1 roadway. This work will also impact approximately 66,646 sq. ft. of buffer zones in this area. This wetland functions as marginal, limited value wildlife habitat for amphibians such as Pacific tree frog and Coast garter snake. The South Portal Drainage Seasonal Ponding Depression buffer zone area is characterized by coastal scrub with relatively high habitat value.

Fill Disposal Site Drainage Area

A total of approximately 7,840 sq. ft. of wetlands and 310,582 sq. ft. of buffer zones will be impacted at the Fill Disposal Site Drainage Area. This includes the following:

(1)

Approximately 4,791 sq. ft. of wetlands will be impacted at the Half Moon Bay-Colma Road Trail by the disposal of excavated materials from the tunnel and the South Rock Cut. Approximately 134,600 sq. ft. of the Half Moon Bay-Colma Road Trail buffer zone will be impacted. It is important to note that the compacted soil area within the Half Moon Bay-Colma Road Trail alignment is dominated by either pampas grass or bare ground; therefore, the wetland does not provide good habitat for wildlife. The buffer zone for the Half Moon Bay-Colma Road Trail is characterized by coastal scrub habitat of moderate to high value habitat.

(2)

Four other small areas within the Fill Disposal area, totaling 3,049 sq. ft. of wetlands and 175,982 sq. ft. of buffer zones, will be filled as part of the OMC building and access road construction. These wetlands may provide some habitat for birds, but due to the small size of the areas, no other important wetland functions are associated with them. The buffer zone for these small wetland areas is characterized by coastal scrub habitat of moderate to high value habitat.

b.

Mitigation Measures

(1)

Avoidance Measures

To avoid impacts to the north ranch pond and associated wetlands, a bridge will be constructed across the valley, at the westerly end of Shamrock Ranch. These wetlands support a known population of the California red-legged frog. Filling this canyon to support the approach road (as originally proposed) would have resulted in permanent impacts to wetlands, the north pond, adjacent uplands and upstream drainages. The avoidance of these wetland impacts is substantial, because the original fill design variation would have resulted in permanent impacts to frog habitat, wetlands and adjacent buffer zones.

An environmentally sensitive area (ESA) has been developed in consultation with the U.S. Fish and Wildlife Service to protect wetlands and upland refuges utilized by the frog. The ESA will function to restrict all construction activities and the movement and location of heavy equipment. These areas will be delineated and marked with high visibility fencing. Where appropriate, temporary silt barriers will be provided in addition to the ESA fencing. The ESA and silt barriers will also be monitored during construction by a staff biologist.

A segmented balanced cantilever method will be used to construct the bridge. The bridge piers and abutments, located outside the ESA, will be constructed first and then the superstructure between the north and south piers will be advanced, by cantilevering out from the piers. False work will be used to support the counterbalancing superstructure outside the ESA between the piers and their adjacent north and south abutments.

(2)

Ranch Pond Restoration

The existing earthen impoundment (dam) at the south ranch pond will be repaired. This dam sustained serious damage during heavy winter storms a few years ago. Vegetation will be removed from the dam and spillway area, the face of the dam will be re-graded, and slope protection fabric and a system of drainage pipes will be installed. The repairs are necessary to ensure that the pond, which also supports the frog, continues to function as a viable habitat.

(3)

Compensatory Mitigation Plan

The Army Corps of Engineer’s “Habitat Mitigation and Mandatory Proposal Guidelines” requires a detailed mitigation plan to compensate for unavoidable impacts to jurisdictional wetlands. The California Coastal Commission’s “Procedural Guidance for Evaluating Wetland Mitigation Projects in California’s Coastal Zone,” also requires mitigation. For the purposes of this document, mitigation required for impacts to resources regulated by the California Coastal Commission includes wetland creation, wetland restoration and wetland enhancement. On October 10, 2000, the Coastal Commission approved the conceptual mitigation measures that were outlined in the Federal Consistency Certification. The County of San Mateo will also review the mitigation plan during the coastal development permit process.

The type of compensatory mitigation, its location relative to the impact site, and the mitigation ratio are elements that affect the design and implementation of any mitigation proposal. The goal of the mitigation is to replace the functions and values of the resources impacted by the project. Conceptual mitigation to compensate for the unavoidable impacts to ACOE and CCC wetlands, buffer zones, riparian corridors and sensitive habitat areas has been developed. A final more detailed mitigation plan will be coordinated with the various permitting agencies once replacement ratios for the various habitat elements have been determined.

The mitigation ratio determines the overall size of the mitigation project and is defined as the ratio of values gained per unit area to values lost per unit area. The actual mitigation ratio is based on several factors such as the relative values of the affected resources, regional wetland resources, expected temporal losses of functional habitat, and the chances of success. Ratios required by resources or regulatory agencies such as the Army Corps of Engineers, the California Coastal Commission, and the County of San Mateo can range from 1:1 to 4:1, depending on the criteria stated above. In the case of the later two agencies, mitigation ratios may include temporary and permanent impacts to wetlands, sensitive habitats, riparian corridors, and their adjacent buffer zones.

(4)

Off-Site Mitigation

The off-site mitigation, proposed to compensate for temporary and permanent impacts to wetlands, sensitive habitat areas, and buffer zones, involves the restoration and enhancement of a partially filled-wetland area located south of the tunnel alternative on Route 1. This site is across the highway from the Charthouse Restaurant (see Figure 5.10, Proposed Mitigation Site). The parcel is approximately 363,648 sq. ft., and is under private ownership. The tunnel alternative will result in 63,752 sq. ft. of permanent impacts to wetlands, and 327,672 sq. ft. of permanent impacts to buffer zones. The proposed mitigation site could provide for a ratio of just under 6:1 for wetland impacts, but a portion of the site will also be used to mitigate permanent impacts to coastal buffer zones.

The existing land use on this site is agricultural. There are row crops grown north of the site and residential land uses on the south side of the site. To the west, the land use is open space and recreational. The existing Route 1 roadway separates the mitigation site from the open space and recreational area. This parcel of land has been disturbed by past agricultural activities and by the placement of fill material. Prior plowing and grading have disrupted the northern drainage and since the site has not been used for agricultural purposes, wetlands have evolved over time and have increased in size. A culvert under Route 1 allows the parcel to drain and ultimately flow to the Pacific Ocean.

The fill material previously placed on this site is now an upland area that does not contain hydrophytic vegetation. The proposed mitigation is to remove this fill material in order to create a seasonal pond and to enhance the total wetland area. This will be accomplished by excavation of the previously filled areas, restoration of the disturbed areas, and re-grading of the existing upland area back to wetland elevations. Other measures include planting the re-graded areas with targeted wetland plant species and eliminating non-native species.

The mitigation site also includes a relatively undisturbed drainage in the southern portion of the property. Hydrophytic vegetation is present in association with both drainages. Willow dominates this undisturbed drainage channel which parallels Route 1 before it crosses under the roadway.

9.

PARKLAND AND RECREATIONAL AREAS

a.

Impacts

The tunnel alternative will not impact any established publicly owned parklands but it will affect sections of existing trails on private property within the project area. The placement of fill material at the South Disposal Area will impact that section of the abandoned Half Moon Bay-Colma Road through the disposal area (see SSEIR, Figure 5-11). Consultation with the San Mateo County Planning Division and an analysis of Assessor’s records indicates that these trails are on private property. While there may be the possibility of claims of implied dedication of public access over these trails, there are no easements on record and there is no established jurisdiction by any public agency over any of the trails within the project area.

Access to the San Pedro Point Headlands property, located north of the project area, is provided by a gated dirt road, connecting to existing Route 1, approximately 200 feet from the northern approach to the project area. This access location will not be impacted by construction of the tunnel alternative. The physical and operational conditions should also not be impacted by this alternative.

b.

Mitigation Measures

During construction of the tunnel alternative, trail access will be maintained by means of trail detours. After construction, any trail affected by the project, including the impacted section of the old Half Moon Bay-Colma Road Trail, will be reestablished or realigned and reconnected to maintain trail continuity.

10.

SOCIOECONOMIC – RIGHT-OF-WAY ACQUISITION/RELOCATION

a.

Impacts

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

b.

Mitigation Measures

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

In accordance with the Federal Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970, as amended, and the California Relocation Act (Chapter 16, Section 7260 et seq. of the Government Code), CalTrans will provide relocation assistance to any person, business, farm or non-profit organization displaced as a result of the acquisition of real property for public use.

11.

WATER QUALITY

a.

Impacts

Long-term and construction-related water quality impacts will be better identified during the pre-construction process. Potential erosion impacts in the project vicinity of either alternative due to excavation and potential non-stormwater discharges that could occur during construction activities will be addressed by the standard implementation of erosion and sediment control practices both during and after construction.

(1)

Construction-Related Impacts

Non-stormwater 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 will be managed accordingly with an appropriate Stormwater Pollution Prevention Plan (SWPPP).

(2)

Long-Term Impacts

Potential long-term water quality impacts are associated with the operation and maintenance of this new facility, which will include additional paved areas and thereby increase the volume of stormwater runoff. Although the concentration of pollutants discharged in stormwater runoff is not expected to change, the loading (transport) of these pollutants may increase relative to the increase in runoff volume. These issues will be addressed during the final design phase for the project, which will include the PCM consideration process as well as inclusion of treatment control BMPs in accordance with the CalTrans Stormwater Management Plan.

Maintenance activities, primarily associated with tunnel washing operations to remove the buildup of pollutant from vehicle exhaust, may result in water quality impacts if the wash waters are not properly managed before being discharged to receiving waters. The CalTrans Maintenance Operations Plan includes implementation of BMPs for all maintenance activities and specific BMPs for washing operations.

b.

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 is implemented through the SWPPP, which is a two-step process. The conceptual SWPPP (Step 1), which is prepared during design of the project, will identify control measures and Best Management Practices (BMPs) that may be implemented.

These BMPs can include:

Erosion and sediment control plans that incorporate vegetative stabilization such as seeding, planting and mulching.

Physical stabilization using geotextiles and mats, dust control implementation measures and temporary stream crossings, and the stabilization of access roads and construction staging areas.

Diversion of runoff using earth dikes, temporary drains and swales, and slope drains and also measures to reduce runoff such as slope terracing/roughing and check dams.

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 final SWPPP (Step 2) must be complete and in compliance with any applicable permits. A Stormwater 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 involve 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 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 their feasibility in the projects. The evaluation includes consideration of the following criteria:

Water quality benefits to be obtained from the PCM;

Cost of the PCM relative to the project cost;

Feasibility of the PCM;

Maintenance of the PCM including safety, access, cost of maintenance, special personnel training, related maintenance impacts, disposal of accumulated pollutants; and any special monitoring needs of the PCM.

In addition to any permanent control measures or treatment control best management practices to be considered and included in the project, the landscape plan will include erosion and sediment control as well as landscape plantings.

IV.

FINDING WITH RESPECT TO IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS OF RESOURCES

Implementation of the tunnel alternative will involve a commitment of natural, physical, human and fiscal resources. Approximately 74 acres of land will be committed to the preferred alternative. Direct and indirect energy consumption will occur during construction. Large amounts of highway construction materials and labor will also be expended. All of these resources, as well as the State and Federal funds expended, will generally be non-retrievable. However, the commitment of these resources will have direct benefits to residents of the area through improved safety, savings in time and fuel, and the provision of a dependable transportation system.

V.

FINDING WITH RESPECT TO UNAVOIDABLE ADVERSE ENVIRONMENTAL EFFECTS

No significant adverse impacts have been identified nor are expected as a result of the construction and operation of the project as mitigated.

VI.

FINDING WITH RESPECT TO GROWTH-INDUCING IMPACTS

The 1986 FEIR concluded that the proposed Martini Creek Alignment project was not growth inducing essentially because it would not accommodate growth beyond that which was planned in the City and County general plans as well as that projected by ABAG. The tunnel proposal will 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 FEIR. The 1992 San Mateo County Local Coastal Program (LCP) estimated the build-out population for the Coastside area to be 30,500-32,000 as compared to 30,000-31,500 projected 10 years ago. According to ABAG’s Projections 96, the Coastside population would reach 31,200 by the year 2005, which is five years later than when ABAG’s Projections 86 estimated the build-out population would be reached. According to Projections 96, it was assumed that complete build-out would not occur by 2005 but nevertheless, ABAG estimated that the region will continue to grow and will attain a population of 38,400 by the year 2015.

The proposed tunnel project does not 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 Martini Creek Alignment 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).

VII.

FINDING WITH RESPECT TO CUMULATIVE IMPACTS

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 FEIR for the proposed Martini Creek Alignment project, and none are expected for the current tunnel project.

There is a potential for temporary traffic impacts; 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.

The tunnel alignment is not expected to create serious traffic delays along existing Route 1 during construction, since the majority of the construction activities will occur inland of Route 1. However, some delays will 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, will be temporary.

There are projects underway, or recently completed, to retrofit the San Francisco/Oakland Bay Bridge, the Richmond/San Rafael Bay Bridge, and the Hayward/San Mateo Bridge, and to construct a new east span of the Bay Bridge. It is expected that all of these projects could affect nesting sites of the peregrine falcon. With monitoring of nesting activity, the tunnel alternative is not likely to adversely affect the peregrine falcon. With the implementation of mitigation measures for the proposed tunnel alternative, no permanent adverse effects to the California red-legged frog are expected. Two other highway projects in San Mateo County, the State Route 92 Safety and Improvement Project (recently completed) and the Crystal Springs Dam Bridge Replacement Project are expected to affect the frog. 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.

NOW, BE IT FURTHER RESOLVED, that the San Mateo County Board of Supervisors hereby approves the Mitigation Monitoring and Reporting Program for the Devil’s Slide Improvement Project.

* * * * * *