Category Archives: Featured Projects


Besant Hill School – Geotechnical Services

By Donna Hebert,


Besant Hill School was impacted by the Thomas Fire (December 2017) which destroyed faculty housing, a maintenance facility, and other structures on the campus. As part of the reconstruction effort, Padre was retained to provide the following services:


  • Perform geotechnical studies to evaluate subsurface conditions for one bridge abutment and development of the proposed building reconstruction sites;
  • Prepare reports presenting findings from field and laboratory results and recommendations for the design and construction of mitigation measures for the bridge abutment and for site grading, retaining walls, and building foundations;
  • Perform and evaluate percolation rates at the site; and
  • Provide engineering design of onsite wastewater disposal systems for the faculty residences, ceramics studio, and maintenance building.

The subsurface condition evaluation conducted by Padre included the advancement of drill holes using a hollow-stem auger, collection of relatively undisturbed soil samples, geologic logging of soil samples and drill cuttings encountered, and laboratory testing of selected soil samples for classification, strength, compressibility, expansion, and corrosion. Padre evaluated the data obtained from the efforts outlined above and prepared a geotechnical report for the design and construction of projects which included findings and recommendations.  

Padre also conducted percolation testing in both drill holes and backhoe test pits, and preliminary seepage pit tests in an effort to identify suitable disposal areas for the proposed onsite wastewater systems. Padre is currently working with the client to develop the onsite wastewater disposal systems for the proposed structures.


Agromin Composting and Soil Amendment Facility EIR

By Donna Hebert,

Padre prepared an Environmental Impact Report (EIR), on behalf of the County of Ventura for the proposed Major Modification to the Conditional Use Permit for the Agromin Composting and Soil Amendment Facility (Project) located off Arnold Road, in the unincorporated area of Ventura County. The Project would allow for continued use of the facility until March 2019, an increase in the volume of feedstock and compost that can be present on the Project site from 10,000 cubic yards to 17,500 cubic yards, and the installation of various facility improvements. The proposed facility improvements include: SmartFerm dry anaerobic digestion system; 30-foot high mesh screen on the eastern boundary; fire access and hydrants; and three retention basins.

The County of Ventura Planning Division prepared an lnitial Study which revealed that the project has the potential to create a significant impact to endangered, threatened, or rare species; therefore, an ElR was determined to be the appropriate California Environmental Quality Act (CEQA) compliance document. The EIR focuses on biological resource issues, primarily the attraction of predatory birds by food material and resulting impacts on the nearby nesting population of western snowy plover, California least tern, light-footed clapper rail and Belding’s savannah sparrow.

Padre developed a multi-faceted, Integrated Predatory Bird Management Plan to minimize the attraction of predatory birds to the Agromin Facility and resulting impacts to listed bird species. The Plan included bird deterrence features (mylar flagging, flight diverters, air dancers, spike stripping, effigies), a hazing dog program, a full-time falconry program, lethal control, and monitoring and adaptive management plan.

In mid-2018, the applicant proposed substantial project modifications prompted by expiration of the permit authorization for a research food material composting operation. These modifications focused on replacing the proposed dry anaerobic digestion system with a Bio-Drum aerobic composting system and extending the permit termination date to December 31, 2020. In response to these modifications, the Draft EIR was revised and recirculated for public comment. A Final EIR was prepared in April 2019 and is anticipated to be approved by the Board of Supervisors in May 2019.


Mallard Farms Pipeline Replacement Project

By Donna Hebert,

Padre is providing construction monitoring for regulatory permit compliance and environmental oversight for the Mallard Farms Pipeline Replacement Project. The project involves the replacement of an approximately 1.7-mile segment of refined products pipeline from Honker Bay to the Grizzly Island Wildlife Area in the Suisun Marsh area of the Delta using horizontal directional drilling (HDD) techniques. The project requires the construction of a temporary work platform for the HDD drill rig in Honker Bay and the temporary construction of an HDD drill pad in wetland habitat in the Grizzly Island Wildlife Area. Padre provided biological services support for the project including the completion of protocol-level surveys for Ridgway’s rail, rare plant surveys, and pre-construction breeding bird surveys. Padre is currently providing construction monitoring support for regulatory permit compliance. Construction monitoring includes underwater noise monitoring using a Reson TC-4033 hydrophone during pile driving operations associated with construction of the temporary work platform. Underwater noise monitoring is being conducted to ensure project compliance with peak sound pressure level thresholds set forth in the California Department of Fish and Wildlife Incidental Take Permit for protection of listed fish species (delta smelt, longfin smelt, and winter-run and spring-run Chinook salmon). Padre is providing on-going support through the construction phase of this project which is expected to be completed in summer 2018.


Encina Marine Oil Terminal Decommissioning Project

By Donna Hebert,

Padre and its subconsultant Longitude 123 prepared a Project Execution Plan (PEP) on behalf of Cabrillo Power I LLC addressing the decommissioning of its Encina Marine Oil Terminal (MOT). The MOT historically supported electrical energy production at the Encina Power Station in Carlsbad, California and is partially located offshore within a State Lease area. The PEP is designed to provide for the decommissioning of the MOT in a manner that is satisfactory to the California State Lands Commission (CSLC) and will allow for a lease termination agreement.

The PEP includes a detailed description of project setting, potential decommissioning project activities including alternative scenarios. The PEP also includes an environmental impact assessment as well as supporting documentation and plans provided to maximize safety and minimize potential environmental impacts. These plans were prepared by Padre and include:

• Marine Safety and Anchoring Plan;
• Marine Wildlife Contingency Plan; and
• Oil Spill Response Plan.

Additionally, the PEP provides information used to support the preparation of the required California Environmental Quality Act (CEQA) documentation and regulatory permit applications.

After submittal of the PEP and approval of the project design by the CSLC, Padre assisted the CSLC with the preparation of a CEQA compliance document for the Project. The Mitigated Negative Declaration may be downloaded at:

The MOT facilities are located within the jurisdictions of multiple federal, state and local agencies. After the completion and approval of the CEQA documentation, Padre assisted Cabrillo Power I LLC with the preparation of permit applications that were submitted to the California Coastal Commission (CCC), United States Army Corps of Engineers (USACOE) and San Diego Regional Water Quality Control Board (RWQCB). These included a CCC Coastal Development Permit application, Preconstruction Notification Package for coverage under the USACOE Nationwide Permit Program, and RWQCB application for Clean Water Act Section 401 Water Quality Certification. Padre also assisted with coordination of a Right of Entry Permit from the California Department of Parks and Recreation.

Once permits were received, Padre assisted Cabrillo Power I LLC with development of a CEQA mitigation and permit condition tracking document. Padre also assisted (under a separate contract) the selected contractor, Curtin Maritime Corporation, complete their Contractor Work Plan for the project which was approved by the CSLC in 2017.

Presently (2018), Padre is assisting Cabrillo Power I LLC with certain tasks associated with mitigation and project permit condition compliance monitoring and reporting. This includes offshore monitoring for the protection of marine wildlife, and other environmental compliance measures, as well as preparation of periodic compliance monitoring reports. Upon completion of the project Padre will prepare a final mitigation and permit conditions compliance summary report on behalf of Cabrillo Power I LLC for submittal to the CSLC.


New School Site Preliminary Environmental Assessment

By Donna Hebert,

Padre prepared a Preliminary Environmental Assessment (PEA) for a proposed new 30-classroom elementary school proposed to be located in Gilroy, California (Project Site). The PEA was conducted in accordance with a Preliminary Environmental Assessment Work Plan, also prepared by Padre and approved by the California Environmental Protection Agency Department of Toxic Substances Control (CalEPA/DTSC). The activities performed were to fulfill the requirements of an Environmental Oversight Agreement issued to the school district by CalEPA/DTSC. Pursuant to Option A of the California Education Code Section 17213.1.a (6) (A), the PEA was made available to the public for review and comment.

The purpose of the PEA was to establish whether a release or potential release of hazardous substances or naturally occurring material, which would pose a threat to human health via ingestion, dermal contact, and inhalation exposure pathways, exists at the Project Site. Chemicals of potential concern (COPCs) identified at the Project Site included:

• Organochlorine pesticides (OCPs) in soil from historic agricultural use;
• Arsenic and copper in soil from historic agricultural use;
• Cobalt in soil related to concentrations identified in a soil stockpile located on the Project Site; and
• Naturally occurring asbestos (NOA) from weathering of ultramafic rock outcrops located in outlying areas.

Analytical results from soil sampling indicate that the amounts of the COPCs identified above are not present in on-site soils at levels that require further assessment or remediation, based upon State of California health risk thresholds with the exception of NOA.

Padre prepared a Removal Action Work Plan (RAW) and Operations and Maintenance (O&M) Plan for the Project Site. The recommended response action to eliminate, reduce, and/or mitigate the identified chemicals of concern is the implementation of engineering controls in the form of a “cap” placed over the NOA-containing soil, creating a barrier to prevent or greatly reduce human exposure and health impacts. After school construction is completed, the O&M Plan will address long-term monitoring and maintenance of engineering controls, and management of soils containing elevated concentrations of NOA at the Project Site.


Remediation Services For Former Service Station, Ventura, California

By Donna Hebert,

Padre provided environmental and demolition support for the removal of the remaining fuel piping associated with the former fuel underground storage tanks (USTs), dispenser islands, underground hoists, waste clarifier, and waste oil UST for a former service station property (Project) located on Main Street in Ventura, California (Project Site).  As part of the scope of work, Padre: 

  • Procured necessary permits from various agencies including the City of Ventura Fire Department (tank removal permit), City of Ventura (grading permit), and Ventura County Air Pollution Control District (exemption from permit);
  • Prepared a Site Restoration Plan for the Project Site;
  • Conducted a geophysical survey of the Project Site to identify underground utilities and hazards;
    Was responsible for removal, recycling/disposal of Project components; Prepared a Technical Work Plan for Preliminary Soil and Groundwater Assessment Activities for the Project;
  • Prepared a Health and Safety Plan for the Project;
  • Conducted preliminary site assessment activities including sampling and analysis of soil and groundwater for assistance with waste characterization and classification for disposal;
  • Provided field oversight, monitoring and documentation of activities associated with the Project;
    Prepared a report summarizing and documenting the demolition and soil sampling activities conducted at the Project Site; and
  • Prepared a Summary Report and Request for Site Closure for the excavation and removal of TPH-containing soil and confirmation sampling/chemical analyses.

The Project Site is planned for future development of mixed uses (residential and commercial) and was part of the Ventura County Cleanup Program with local oversight provided by the Ventura County Environmental Health Division. With Padre’s assistance, the Project Site successfully received site closure status, from Ventura County Environmental Health Division


Oso Flaco Lake Planning and Assessment Project

By Donna Hebert,

Padre assisted the Coastal San Luis Resource Conservation District, working in partnership with the California Regional Water Quality Control Board – Central Coast Region and California State Parks, in completion of sediment assessment activities at Oso Flaco and Little Oso Flaco lakes in southwestern San Luis Obispo County. The two coastal lakes are located at the outlet of a watershed where the predominant land use is irrigated agriculture.  The two lakes have been identified as Section 303d impaired water bodies due to elevated concentrations of organochlorine pesticides, primarily DDT and dieldrin.  Padre subcontracted with TEG Oceanographic Services to complete 17 sediment sample collection locations using a barge mounted vibracore sampling system.  Sediments were collected in continuous cores ranging in depth from 3 to 6 feet at pre-determined locations within both lakes.  Padre geologists logged the sediments, identifying changes in soil type, macroinvertebrates, and layers of organic debris.  Stratigraphic core samples were chemically analyzed for the presence of potential chemicals of concern.  The information gained from the sediment assessment activities will be used by the interested agencies to determine potential remedial options, including dredging, that could be implemented to improve the ecological health of the two lakes.

The photo shows a vibracore sample location near the boardwalk at Oso Flaco Lake.


San Luis Obispo Tank Farm Remediation and Restoration Project

By Donna Hebert,

Since 2007, Padre has been providing permitting, environmental, and remediation services to Chevron Environmental Management Company for the remediation, restoration, and re-development of the former San Luis Obispo Tank Farm Property in San Luis Obispo.  This 332-acre property was historically used for the storage of crude oil as part of the former oil storage and transport system on the Central Coast.  The property was impacted by the release of petroleum hydrocarbons during a 1926 lightning strike and resulting fire that released over a million barrels of oil to the surrounding area. 

Padre has assisted Chevron with the preparation and submittal of permit applications, and consulted on the content and review of the environmental impact report resulting in the certification of the EIR by the City of San Luis Obispo.  Permits have been obtained from the U.S. Army Corps of Engineers, the California Department of Fish and Wildlife, the Central Coast Regional Water Quality Control Board, the County of San Luis Obispo Department of Planning and Building, and the San Luis Obispo County Air Pollution Control District.  Additional reviewing agencies included the City of San Luis Obispo, Caltrans, San Luis Obispo County Regional Airport, the California State Historic Preservation Office, Federal Emergency Management Agency, and the Federal Aviation Administration. 

Padre completed site wide wetland surveys, rare plant surveys, vernal pool fairy shrimp surveys, and cultural resource surveys.  Padre prepared a landscape restoration plan, containing a mitigation plan for fairy shrimp impacts, which will be implemented following site remediation activities at each remediation area.  Padre has conducted cultural resource surveys and testing at several historic features located within the site.  Padre works closely with the remedial construction company to plan and execution remediation in each of the remediation areas of the site.  Padre has conducted various assessment activities to characterize the site prior to remediation and obtain regulatory approvals.  Remedial construction activities began at the site in 2016 for what is anticipated to be an eight-year long remediation and restoration project.

The photos show the ruins of a former oil reservoir at the site destroyed by the 1926 fire, and recent remedial excavations, which are currently in progress.



San Joaquin River Pipeline Crossing Decommissioning Project

By Donna Hebert,

Under contract to Pacific Gas and Electric Company (PG&E) and Longitude 123, Padre provided regulatory permitting and environmental oversight for the PG&E Line 114, Line 114-1, and Line SP4Z San Joaquin River Pipeline Crossing Decommissioning Project (Project).  This included the preparation of an environmental assessment and regulatory permit applications for the Project.  The California State Lands Commission (CSLC) was the lead agency under the California Environmental Quality Act and with the support of Padre, prepared a Mitigated Negative Declaration (MND) for the Project. The final MND was adopted by the CSLC in October 2015.

Padre prepared permit applications for the Project including an application for a CSCL Lease Amendment; United States Army Corps of Engineers pre-construction notification for approval under nationwide permit 12; California Department of Fish and Wildlife Streambed Alteration Agreement notification; and an application for Regional Water Quality Control Board Water Quality Certification.  Padre also prepared a Biological Assessment for Section 7 Consultation with the United States Fish and Wildlife Service and National Marine Fisheries Service and facilitated informal consultation with the federal agencies.  Regulatory permits were issued in early 2016 and removal of approximately 3,600 linear feet of pipeline from the San Joaquin River was completed between August and October of 2016, during the aquatic work window for protection of sensitive fish species occurring in the Bay-Delta.  Padre provided pre-construction surveys and permit compliance monitoring, including water quality monitoring, for the construction phase of the Project.  Removal of the pipeline from the levee on Sherman Island is expected to occur during the 2017 construction season and Padre will provide permit support and construction monitoring services for that portion of the project as well.

The photo shows the derrick barge with a suspended segment of cut pipeline after removal from the San Joaquin River.


Bay Area School Site Remediation

By Donna Hebert,

Padre is currently assisting a San Francisco Bay Area school district with the bioremediation using land-farming techniques of approximately 4-acres of PCBs-containing soil as part of the development of a new elementary school.  Padre’s Sacramento school site consulting / development team led by Alan Klein, C.E.M. and Alan Churchill, P.G. is managing the project.  The photo below shows the mechanical tilling of the PCBs-containing soil following the application of the bioremediation active agent and moisture conditioning.  The bioremediation process is estimated to require approximately 90 days to complete.