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Watershed Assessment

Watershed Assessment
In today’s complex regulatory environment, a broad set of skills is required to effectively assess watershed conditions and develop a successful watershed management plan.

Because of its diverse technical specialties, Herrera’s experienced team of environmental planners, scientists, and engineers is uniquely suited to provide a comprehensive approach for watershed assessment. We routinely collaborate with clients who must manage a complex set of external regulatory requirements and budget limitations, while developing and prioritizing internal policies and programs related to watershed protection and management.

We have developed watershed assessment expertise through a wide range of successful planning, implementation, and design strategies that have been applied to many projects for federal, state, and local clients. Our investigations of lake and stream hydrology, geomorphology, habitat, biology, and water quality have resulted in the development of successful management strategies for lake and stream rehabilitation, fisheries protection, sediment management, and water quality improvement. In particular, our experience working in urban and developing watersheds has required a comprehensive understanding of various influences from land cover changes to watershed hydrology and their associated impacts on aquatic habitat and ecosystem functions. The comprehensive and interdisciplinary skills of our technical staff are used to assist our clients in developing watershed-wide strategies for assessing and managing water and sediment resources.

Key Projects

  • Murray/Sequalitchew Watershed: Watershed Management Plan – Fort Lewis, Washington
  • Seattle Comprehensive Drainage Plan, Water Quality Program – City of Seattle, Washington
  • Regional Water Quality Program, Thea Foss Watershed, Tacoma, Washington – City of Tacoma
  • Gilliam Creek Basin Stormwater Management Plan – City of Tukwila, Washington
  • Tributary 0056 Sedimentation Study – City of Kenmore, Washington

Technical Guidance and Policy Development

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Herrera provides comprehensive, state-of-the-art services for stormwater management planning, technical guidance, and policy development.

Our staff consists of more than 100 highly qualified engineers, planners, environmental scientists, and biologists with stormwater management experience throughout the western United States. We have been closely involved with the history and evolution of stormwater management guidelines and regulations in the Pacific Northwest, providing services such as the following: preparation of technical analysis procedures and design guidelines; writing of portions of stormwater management manuals currently used by many of the major city, county and state jurisdictions in the Northwest; and technical review of proposed policies.

Herrera staff expertise includes development of stormwater management policy, comprehensive drainage planning, development of technical stormwater design guidance, technical evaluation of stormwater facility effectiveness, stormwater permitting and regulatory compliance, and training and education for stormwater management. Staff members are also experts in the complementary areas of engineering design, hydrologic and hydraulic modeling, assessment of pollution sources and control measures, stormwater facility cost estimating, and construction management, all of which enable us to provide practical, well-rounded guidance. Clients include local, state, and federal agencies; Native American tribes; and private sector firms. The ability of Herrera staff members to work together across all disciplines involved in stormwater management contributes significantly to our continued success in developing innovative and cost-effective stormwater management solutions for our clients.

Key Projects

  • Highway Runoff Manual technical writing, technical review, and training – Washington State Department of Transportation
  • Comprehensive Drainage Plan – City of Seattle
  • Water Resources Manual – Oregon Department of Transportation
  • Surface Water Management Manual – City of Tacoma
  • Stormwater Management Manual and Drainage Code – City of Seattle
  • Stormwater Management and Site Development Manual – Pierce County
  • Stormwater Management Manual for Airports in Washington – Washington State Department of Transportation

Low-Impact Development

Low-Impact Development

Herrera is a Pacific Northwest leader in all aspects of stormwater management.

From small site developments to large transportation projects and regional planning efforts, we provide interdisciplinary, technically sound services that achieve cost-effective results for our clients. We are at the forefront of technical and regulatory developments in stormwater management, including the development of innovative and low-impact development techniques for stormwater management.

Our staff has extensive experience in many of the technical fields that are key to successful low-impact development innovation and implementation. Working with clients ranging from small land developers to large public agencies, Herrera has established a strong record of successfully integrating the following areas of expertise to low-impact development objectives:

  • Evaluation of stormwater management options and costs
  • Watershed assessment
  • Civil engineering design
  • Environmental permitting
    • Public policy and code development
  • Performance monitoring

Key Projects

  • Low Impact Development Technical Guidance Manual published by the Puget Sound Action Team – Contributing author
  • Homestead Creek Residential Low Impact Development – Hydrologic performance analysis documentation and design of single-family residential cluster development in rural Snohomish County, Washington, French Creek Properties, LLC
  • Lakewood RainCatchers – Pilot project to test cost-effectiveness of rain gardens, vegetated swales, and drainage cisterns in a single-family residential neighborhood in Seattle to reduce combined sewer overflows to Lake Washington, Seattle Public Utilities
  • Twin Creeks – Transit-oriented development in southern Oregon incorporating low-impact development techniques to create an environmentally friendly community and protect two bordering creeks, Twin Creeks Development Company
  • Compost-Amended Vegetated Filter Strips – Pilot project for design, installation, and long-term monitoring to provide scientifically defensible justification for use of this relatively low-cost option for treating runoff and reducing runoff volume, Washington State Department of Transportation
  • High Point Revitalization – Low-impact design support and hydraulic performance modeling for urban subdivision/mixed-use development in Seattle, Washington; Seattle Public Utilities
  • Carkeek Park Environmental Learning Center – Design of rainwater capture and reuse system, Seattle Parks
  • Thornton Creek Water Quality Channel – Hydraulic modeling to support design of natural drainage system channel to provide water quality treatment for 680 acres in the headwaters of the south branch of Thornton Creek in Seattle, Washington; Seattle Public Utilities
  • Rainwise Stormwater Incentives Package – Incentives package developed for Seattle Public Utilities to encourage the use of onsite low-impact design measures that help protect infrastructure and the environment, as well as allowing customers flexibility to manage stormwater onsite and reduce their utility costs, Seattle Public Utilities

Erosion and Sediment Control

Erosion and Sediment Control

Herrera has been a Pacific Northwest regional leader in the planning and design of construction site erosion and sediment control for over 15 years.

Our staff members’ diverse expertise in water quality, construction management, civil engineering, and stormwater monitoring enables us to tackle any issue related to erosion and sediment control on construction sites. We have assisted clients in developing technical guidance for the preparation of erosion and sediment control plans, developing guidance for the selection of erosion and sediment control measures tailored to particular site conditions, and compiling information on the full array of erosion and sediment control products and services that are available to them. Herrera’s experience in monitoring the effectiveness of erosion and sediment control measures at construction sites and monitoring water quality at construction sites provides invaluable insight into the techniques that are most successful under various site conditions. This insight strengthens our ability to anticipate erosion and sediment control problems and to develop effective design solutions for clients. Several of our staff members are certified erosion and sediment control specialists in the state of Washington.

Key Projects

  • Erosion and Sediment Control Design for State Route 518 Widening – Washington State Department of Transportation
  • Erosion and Sediment Control Products and Services Catalog – Washington State Department of Transportation
  • Stormwater Pollution Prevention Plan Template – Washington State Department of Ecology
  • Link Light Rail Construction Monitoring – Sound Transit
  • Third Runway Construction Monitoring – Seattle-Tacoma International Airport
  • Construction Temporary Erosion and Sediment Control manual and code update – City of Seattle

Sediment Management

Sediment Management
Herrera scientists evaluated the effectiveness of a nearshore confined disposal facility by monitoring mercury in intertidal groundwater at the West Eagle Harbor Superfund Site for WSDOT.
“I doubt you’ll ever know how much I appreciate your work at the Eagle Harbor Superfund Site. I have worked with many consultants and nobody has equaled you in terms of the level of trust I’ve been able to place in you — you’ve been wonderfully reliable in the level and quality of service you’ve given us. THANK YOU so very much.”
~Washington State Department of Transportation
Herrera performs physical, chemical, and biological monitoring and assessment of marine and freshwater sediments for various public agencies and private clients throughout the Pacific Northwest.

Herrera scientists and engineers apply a multidisciplinary approach to a variety of sediment management projects. Our senior geomorphologists are renowned experts in the analysis of erosion and sediment transport in coastal waters, lakes, rivers, and streams. The Herrera sediment management group also includes water quality scientists, hazardous materials specialists, biologists, and engineers who monitor, characterize, and design controls for contaminated sediments that are affecting the surrounding environment.

Our technical experts interpret the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Resource Conservation and Recovery Act (RCRA), the Clean Water Act, and various state and local programs to address site-specific regulatory requirements. We also typically use the Washington state sediment management standards (SMS) and the Puget Sound dredged disposal analysis (PSDDA) criteria for marine sediment evaluation and rely on additional guidelines for freshwater sediment evaluation. Our senior scientists have over 25 years of applied sediment monitoring experience in the Pacific Northwest that includes the following:

  • Preparation of detailed sampling and analysis plans using the Puget Sound Estuary Protocols
  • Collection of sediment samples using various grab sampling and coring techniques for evaluating conditions before cleanup and after construction
  • Validation and interpretation of sediment chemistry and bioassay data
  • Monitoring water quality impacts during dredging operations
  • Sampling and evaluation of toxic contaminants in fish and other aquatic organisms at sediment remediation sites
  • Sampling and interpretation of benthic community data for site characterizations and impact analyses
  • Evaluating the recolonizaton of cap materials by benthic invertebrates at various remediation sites in Puget Sound

Key Projects

  • Operations, Maintenance, and Monitoring Plan Implementation for Contaminated Sediment Management at West Eagle Harbor Superfund Site, Bainbridge Island – Washington State Department of Transportation
  • Beach Sediment Survey of the Puget Sound Shoreline – Thurston County Regional Planning Council
  • Structural Inspection, Sediment Monitoring, and Site Remediation for Georgetown Flume – Seattle Public Utilities
  • Boeing Plant No. 2 Sediment Site Characterization – U.S. Army Corps of Engineers, Seattle District
  • Lake Ozette Sediment Study – U.S. Department of the Interior, National Park Service
  • Geomorphic Analysis of the Grays River – Bonneville Power Administration, Oregon
  • Big Spring Creek Sediment Remedial Investigation and Feasibility Study – Private Client
  • Monitoring and Assessment for Dredged Material Management Disposal Site – Washington Department of Natural Resources
  • King County Sediment Management Plan – King County, Washington

Compliance Monitoring

Compliance Monitoring

“We are so impressed with you guys. I think you have sampled in the two worst/best rain events I have seen in a long time. Your team must be tough!”
~Senior water resources planner, Whatcom County
Rigorous attention to detail in environmental monitoring is a hallmark of Herrera’s service record. Our dedicated group of field scientists has extensive monitoring experience across the Pacific Northwest and beyond.

Successful monitoring programs frequently require data collection under inclement conditions and during non-business hours. At Herrera, data integrity comes first and staff members are committed to producing high-quality field results. Our stormwater monitoring team is highly responsive and mobile; staff members in Portland, Seattle, and Bellingham successfully monitor stormwater conditions throughout western Oregon and Washington. Our hazardous materials monitoring team mobilizes throughout the Pacific Northwest, assessing long-term changes in ground water contaminants at sites that are undergoing cleanup.

Herrera uses the latest monitoring technologies, including low-flow sampling, automated samplers, data sondes, multiparameter meters, underwater diver surveys and videography, and telemetered hydrologic and water quality monitoring equipment. Our monitoring programs also include inventories of plankton, benthic macroinvertebrates, aquatic macrophytes, riparian vegetation, large woody debris, and sediment contamination and transport.

Our interdisciplinary approach to large projects applies a broad range of scientific applications to environmental monitoring that sets the company apart as regional monitoring experts.

Key Projects

  • Stormwater Monitoring for National Pollution Discharge Elimination System: Permit Compliance and Best Management Practices Performance Evaluation of Compost-Amended Filter Strips – Washington State Department of Transportation
  • Stormwater and Hazmat Quality Monitoring of Link Light Rail Construction Site – Sound Transit, Seattle, Washington
  • Water Quality Studies for Issaquah Highlands Master Plan Development – Port Blakely Communities, Inc., Washington
  • Drinking Water Testing Program – Seattle Public Schools
  • Engineering and Monitoring Services for Green Lake Water Quality Improvements and Alum Treatment – Seattle Parks and Recreation
  • Walsh Lake Aquatic Plant Survey and Milfoil Control Project – Seattle Public Utilities
  • Twin Lakes Water Quality and Aquatic Plant Assessment – Twin Lakes Home Owners Association, Federal Way, Washington
  • Multiple ground water monitoring projects for petroleum and dry-cleaning chemicals at shopping malls in Washington – Various private clients
  • Assessment and Long-Term Monitoring Study for Federal Building Motor Pool Ground Water Treatment System in Fairbanks, Alaska – U.S. General Services Administration, Region 10
  • Long-Term Monitoring for Maintenance Shop Petroleum Cleanup – City of Sumner, Washington

Contaminant Source Tracking

Contaminant Source Tracking
 
 
Herrera engineers and scientists conduct contaminant source tracking studies to evaluate both point and nonpoint sources of chemical and biological contaminants.

Projects range in scale from Superfund sites to drainage basins and watersheds. Our services related to contaminant source tracking include study planning, investigation, design, and remediation for upland soils, surface water sediment, surface water, stormwater runoff, and ground water. Source tracking studies for chemical contaminants involve an evaluation of sources associated with current and historical operations, as well as an evaluation of redistribution and recontamination of sediments. We have designed microbial source tracking studies using genetic fingerprinting technologies for local governments, focusing on public health issues, the development of best management practices, and the development of total maximum daily loads for fecal coliform bacteria, as required by the Clean Water Act.

Key Projects

  • Diagonal Avenue South Drainage Basin Stormwater Pollutant Source Investigation - Seattle Public Utilities
  • Norfolk Basin Water Quality Investigation - Seattle Public Utilities
  • Commercial Business Discharge Source Control Inspections – Seattle Public Utilities
  • City of Seattle Facilities Source Control Inspections - Seattle Public Utilities
  • Eagle Harbor Operations, Maintenance, and Monitoring, Bainbridge Island, Washington - Washington State Department of Transportation
  • Microbial Source Tracking Study for Thornton Creek and Matthews Beach - Seattle Public Utilities
  • Willapa River Microbial Source Tracking Study, Pacific County, Washington - Pacific County Department of Community Development
  • Drayton Harbor Watershed Fecal Coliform Bacteria Contamination Source Investigation - City of Blaine, Washington

Site Development

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Herrera provides the full spectrum of hazardous materials (hazmat) services to support site development.

Services include initial Phase I environmental site assessments at the planning stage to identify issues associated with potential contamination and their impact on the property valuation process; Phase II environmental site assessments to confirm the presence, or lack, of contamination; cleanup design and cost estimating; and construction oversight. Our staff includes state-licensed geologists and underground storage tank assessors, as well as AHERA-certified asbestos building inspectors.

We have developed plans and specifications for the cleanup of contaminated sites for private clients and numerous public agencies. Cleanup projects have focused on tank removals, building materials, and soil and ground water contaminated with petroleum products, polychlorinated biphenyls (PCBs), solvents, and heavy metals. We work within the framework of state cleanup regulations across the Pacific Northwest and routinely assist clients in navigating through the cleanup documentation process, whether it entails working with the regulators or working independently.

Our remediation oversight staff includes engineers and scientists who have received 40-hour hazmat training. All of the staff who oversee remediation are experienced with the entire hazmat cleanup processes, having participated in the planning, investigation, design, and cleanup phases of the work.

Key Projects

  • Southwest Harbor Redevelopment Project - Port of Seattle
  • Federal Way Park and Ride - King County
  • Lakewood Towne Center Mall Redevelopment, Lakewood, Washington – Confidential client
  • Rainier Beach Low-Income Housing Redevelopment, Seattle, Washington – Confidential client
  • Milwaukee Electrical Railroad Station PCB Cleanup - Confidential client
  • Clear Valley Farm Wetland Bank Redevelopment - Sustainable Environments, LLC
  • Seattle Federal Courthouse Development Project - U.S. General Services Administration

Site Characterization

Site Characterization
 
 
Herrera conducts site characterizations for private clients and public agencies to meet regulatory and legal obligations.

Having worked for both the U.S. Environmental Protection Agency and Pacific Northwest state regulators, we understand the particular regulatory concerns and requirements of these agencies and bring this knowledge to work that we perform for the regulated community. We have developed and implemented work plans for complex sites involving soil, sediment, ground water, surface water, sediment, and air sampling. Our licensed geologists are experienced in designing and providing oversight for monitoring well installation oversight under complex geologic conditions using appropriate drilling methods. Data validation performed by experienced chemists provides data quality that stands up to legal scrutiny. Our commitment to quality is exemplified by our technically accurate and highly readable reports.

Key Projects

  • Big Spring Creek Remedial Investigation and Feasibility Study, Lewistown, Montana – Private Client
  • Euclid Road Ground Water Investigation, Spokane County, Washington – U.S. EPA Region 10
  • Duwamish River Sediment Sampling, Seattle, Washington – U.S. Army Corps of Engineers
  • Kingsly Air Field Ground Water Assessment, Klamath Falls, Oregon –U.S. General Services Administration
  • Federal Building Former Motor Pool Site Characterization, Fairbanks, Alaska – U.S. General Services Administration
  • Underground Tank Removal and Remediation, Federal Courthouse, Boise, Idaho – U.S. General Services Administration

Remedial Design

Herrera’s design engineers use a comprehensive approach that includes screening of alternatives, treatability studies, cost estimation, contracting, and construction oversight to facilitate the installation and operation of remedial systems.Our remedial design experience has focused on biological remediation systems, interception trenching, free-product recovery, bioventing, soil vapor recovery and distribution systems, drainage control, and control systems for stormwater runoff and runon. Our technical staff is highly qualified in both the design of remediation systems and the field implementation of these systems, including oversight of construction, operation and maintenance activities, and followup monitoring to evaluate cleanup.

Key Projects

  • Pacific Sound Resources Wood Treatment Facility Demolition Design, Seattle, Washington – Port of Seattle
  • South Precinct Police Station Fuel System Upgrade and Remedial Design, Seattle, Washington – City of Seattle, Fleets and Facilities
  • Interim Action, Feasibility Study, and Cleanup Design for Asphalt Plant – confidential client, Yakima, Washington
  • Contaminated Dry Well Removal Design and Oversight in Moses Lake, Washington – U.S. General Services Administration
  • Transfer Station Tank Closure and Fuel System Design in Seattle, Washington – Seattle Public Utilities, City of Seattle
  • Design and Construction Management Support for PCB Remediation Project at the Juneau Federal Building, Juneau, Alaska – U.S. General Services Administration

Property Transfer – Due Diligence

Property Transfer – Due Diligence
 
 
Herrera has been performing Phase I and Phase II due diligence environmental site assessments for property transactions for 15 years.

Our work product has evolved with each ASTM procedure update to address All Appropriate Inquiry requirements under CERCLA. We use checklists to expedite the compilation of historical information and standardized forms, and we use questionnaires during site reconnaissance and interviews. Reporting is accomplished rapidly by the use of templates that meet individual client’s needs. Recognized Environmental Conditions identified during the Phase I assessment are quickly evaluated to develop concise sampling and analysis plans to direct Phase II efforts. We have developed effective working relationships with experienced drillers and laboratories to efficiently coordinate activities related to field work and data evaluation.

Key Projects

  • Phase I and II support for Sound Transit Link Light Rail – Sound Transit, Seattle, Washington
  • Phase I and II environmental site assessments for Lakewood Towne Center Mall, Lakewood, Washington – Confidential client
  • Phase I and II environmental site assessments for Pavilion Mall, Tukwila, Washington – Confidential Client
  • Phase I and II environmental site assessments for property transfers throughout Washington – Washington State Department of Transportation
  • Phase I and II environmental site assessments in Washington, Oregon, and Alaska – U.S. General Services Administration
  • Phase I and II environmental site assessments – King County Department of Natural Resources

Hazmat Construction Oversight

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Herrera’s civil and environmental engineers are experienced in construction management and field inspection services related to hazardous materials contamination and water quality issues encountered during construction. Onsite specialists provide technical advice related to identification and delineation of contamination, recommendations for preventing or reducing worker exposure, application of regulations pertaining to toxic chemicals and conventional parameters, and issues associated with air, noise, wetlands, and wildlife issues. Our engineering services include the following:

  • QA sampling and testing
  • Performance monitoring documentation
  • Field design
  • Review of submittals and shop drawings
  • Change order preparation
  • Preparation and verification of progress payment
  • Contract modifications
  • Conflict resolution

    • Key Projects

    • Hazmat and Water Quality Monitoring Support for Sound Transit Link Light Rail Construction - Sound Transit, Seattle, Washington
    • Construction Management for Southwest Harbor Remediation Area 3 Landfill Closure - Port of Seattle, Seattle, Washington
    • Hazmat and Water Quality Oversight Support for Southeast Interceptor Sewer Line Construction - King County, Department of Natural Resources, Wastewater Treatment Division, Renton, Washington
    • Construction Monitoring for South 180th Street Grade Separation - City of Tukwila, Washington
    • Lead Paint Construction Monitoring for North Queen Anne Bridge Seismic Upgrade - Seattle Department of Transportation
    • Construction Oversight for Abatement of PCB-Amended Paint, Juneau Federal Building - General Services Administration, Juneau, Alaska

    Environmental Documentation

    Environmental Documentation
     
     
    Herrera provides the full spectrum of environmental documentation services to support site development under the National Environmental Policy Act (NEPA), the Washington State Environmental Policy Act (SEPA), and the Montana Environmental Policy Act (MEPA), including initial Phase I environmental site assessments and corridor studies to identify issues associated with potential contamination.

    Our work products include technical discipline reports, environmental assessments, and environmental impact statements written in both “reader friendly” and standard formats. We also perform site characterization in support of biological assessments under the Endangered Species Act and in support of designs for site development. We routinely work directly for public agencies, managing environmental documentation efforts, and in support of engineering firms that are involved in project planning and design.

    Key Projects

    • NEPA and SEPA Environmental impact statements in Seattle and Tacoma, Washington – Sound Transit Light Rail
    • NEPA Environmental impact statement, Eugene Federal Courthouse, Oregon – U.S. General Services Administration
    • NEPA Environmental assessment, Mukilteo Ferry Terminal, Washington – Washington State Department of Transportation, Washington State Ferries
    • NEPA Environmental impact statement, Seattle Federal Courthouse, Washington – U.S. General Services Administration
    • NEPA Environmental impact statement, Seattle Federal Courthouse, Washington – U.S. General Services Administration
    • Southwest Interceptor Sewer Alternatives Analysis and Design, Renton, Washington – King County Department of Natural Resources, Wastewater Treatment Division

    Mine Site Assessment, Stabilization, and Site Restoration

    Mine Site Assessment, Stabilization, and Site Restoration
     
     
    Herrera develops engineering options to contain and stabilize mine waste, restore habitats critical to endangered species, and limit public exposure to contaminants.

    Throughout the assessment and reclamation process, we facilitate coordination between multiple stakeholders including local communities, Native American tribes, and state and federal agencies such the U.S. Environmental Protection Agency, U.S. Forest Service, U.S. Fish and Wildlife Service, and State Historic Preservation Offices. We provide site stabilization and reclamation designs and support the construction process by delineating contaminated areas, monitoring health and safety conditions, evaluating best management practices, and documenting and reporting cleanup activities. Our staff members have up to 30 years of experience performing restoration work at mine sites in Arizona, Colorado, Idaho, Montana, South Dakota, Washington, and Wyoming.

    Key Projects

    • Continental Mine Site Removal Action and Site Restoration (stabilized mine waste and restored critical habitat for threatened and endangered species in Boundary County, Idaho) – U.S. Environmental Protection Agency
    • Idaho Lakeview Mine and Mill Removal Action (restored critical bull trout habitat above Lake Pend Oreille near Lakeview, Idaho) – U.S. Environmental Protection Agency
    • Harmony Mine Site Emergency Removal Action (stabilized mine waste after devastating forest fire near Salmon, Idaho) – U.S. Environmental Protection Agency
    • LeRoi Smelter Removal Site Evaluation to reduced community exposure to heavy metals in Northport, Washington – U.S. Environmental Protection Agency, Region 10