This project is the expansion of the Limestone Quarry mining pit by 17 acres and amendment of the revegetation program component of the Reclamation Plan. Major issues include water quality impact of mining on Liddell Spring which is a municipal water source for the City of Santa Cruz. Geology affecting the spring is karst making the source of turbidity difficult to identify. The scope of the EIR includes substantial hydrogeologic investigation including drilling new monitoring wells and dye tracer studies. Noise and air quality impact modeling is also included to address the effect of moving the mining pit closer to adjoining residential properties. Biology is also a significant issue. The proposed amendment would change the revegetation program approach from the goal of re-establishing climax vegetation communities (needlegrass grassland, maritime chaparral, redwood forest) which existed prior to mining to one of establishing early successional vegetation communities only. Lead Agency/Client: Santa Cruz County

There were numerous issues of concern associated with this project. The mining would lower the riverbed by 20 feet, drastically changing the river hydrology. The EIR evaluated the importance of the river to groundwater recharge and the potential threat to adjacent agricultural wells. The City of Hollister operates wastewater percolation ponds next to the Granite Rock property. There is a potential for wastewater to be uncovered by lowering the flood zone in the area. Surrounding properties are agricultural and dependent on wells. Residents viewed the project as a threat to groundwater recharge provided by the river. A tremendous amount of truck traffic would be introduced to the rural roads creating noise, congestion and safety problems at unsignalized intersections and deterioration of road surfaces. Other issues evaluated in the EIR include the impacts on adjacent agriculture, visual quality, riparian habitat, endangered species and spawning gravels downstream in the Pajaro River. Lead Agency/Client: San Benito County

In 1988, an EIR was prepared for the renewal of a 5-year surface mining permit and reclamation plan. The impact analysis included review of the proposed grading plan, revegetation plan, and conceptual development plan for light industrial uses on the quarry floor at the completion of mining. The major issues included complaints about the nuisance of dust drifting outside the quarry boundaries, concern about potential health effects of dust upon sensitive receptors, siltation of storm drains and the Brisbane Lagoon, the use of city streets by quarry traffic and the safety of school aged children and deterioration of the aesthetic value of San Bruno Mountain. TRA set up two PM10 and meteorological instrumentation stations, one upwind and the other downwind of the project site to assess the impact of quarry operations on the ambient air quality. The monitoring period was extended to determine the effectiveness of mitigating measures. TRA also tested water samples from input and output of sedimentation ponds to determine the quality of storm runoff to the Guadalupe Valley Municipal Improvement District.

In 1993, an EIR was prepared to renew the quarry's permit and reclamation plan. The 1988 EIR was updated to reflect a variety of changes that occurred since preparation of the 1988 EIR. Some of these changes included relocating the haul route to avoid central Brisbane, the recycling of broken concrete and asphalt for use in quarry product, the purchase of quarry-owned property by the State for use as managed open space and nearby residential development. The primary environmental impacts identified in the 1993 EIR are dust levels, sedimentation of the local drainage system and the potential for hazardous substances to be leached from the recycled material storage piles. Lead Agency/Client: San Mateo County

The project was highly controversial because it would extend the impacts of the quarry operation from its historical mining boundary to the quiet rural residential area. Issues of concern include slope stability of the overburden embankment, hydrological changes in the canyons, erosion potential, destruction of oak woodland, increased ambient noise levels, violation of air quality standards for fine particulates (PM10) and health risks associated with PM10 and crystalline silica. The EIR concluded that the impacts on noise levels, air quality and the oak woodland were significant and unavoidable with mitigation.

The key issue for the County in considering the project is whether an alternative exists that could eliminate the use of an offsite location for overburden disposal. In the Draft EIR, the project Applicant asserts that onsite disposal is infeasible and would result in the loss of harvestable granite. During the public review period, the community group presented an alternate mining plan calling for the disposal of overburden within the pit (the area previously mined). To provide the County with an independent review of both the Applicant's and the community's onsite (in-pit) alternative, a third party mining consultant was retained. The consultant concluded that the In-Pit alternative was technically feasible and that the costs would be comparable to the proposed project. Lead Agency/Client: San Benito County

The EIR focused on geology, biology, visual quality and cultural resources. The biological impact of the project is a central issue of the study. Areas proposed for reclamation provide habitat for several state and federal species of concern including the endangered Smith's blue butterfly. The EIR also evaluates the stability of the proposed sand dune slopes, and the adequacy of setback zones for coastal erosion and tsunamis. To depict the landform changes, the change in topography from rolling sand dunes to a flattened area was modeled by computer-generated graphics. An archaeological investigation of the site was also conducted. Lead Agency/Client: City of Marina