President, Principal Engineer
Carlos E. Herrera, PE, founded Herrera Environmental Consultants, Inc. in 1980 in a small office in Seattle’s Wallingford neighborhood. Under his leadership, the company has grown from that small office to over 140 employees and offices in Washington, Oregon and Montana, while earning a reputation for excellence and building a cooperative, team-oriented work environment. His engineering expertise spans the full range of civil and environmental engineering design. Carlos mentors project managers and personally reviews many engineering and environmental work products to ensure they meet the high standards of quality the company is known for.

In 2005, Herrera became an employee-owned company and Carlos sold his ownership to the staff. Today, Herrera continues to grow as a profitable, employee-owned company and Carlos remains passionate about the success of the firm and its employees.

Senior Vice President, Principal Scientist
Dr. Trial directs surface water quality studies at the firm. His background includes more than 33 years of professional experience in environmental problem solving, surface water and sediment quality monitoring, stormwater management, environmental data interpretation and analysis, and NEPA/SEPA environmental impact assessment. He has designed and directed numerous investigations of local streams, lakes, and estuaries focusing on nonpoint source pollution, including toxicants and bacterial contamination, urban runoff impacts to surface waters, and evaluating and implementing stormwater treatment and source control best management practices. Dr. Trial serves as Herrera’s quality assurance officer on numerous ongoing surface water quality and stormwater monitoring projects.

Vice President, Principal Engineer
Michael Spillane has over 19 years of experience specializing in civil/environmental design and development. Mr. Spillane has extensive experience assisting public works, tribal, regulatory, and private sector clients throughout the western United States with site development, infrastructure protection, river design and restoration, mitigation and banking, solid waste planning and design, environmental monitoring, and construction management. Mr. Spillane has conducted numerous assessments, feasibility analyses, value engineering and constructability reviews supporting the design and development of wastewater, transportation, and water resources projects ranging in size from $5K to $15 million. His excellent communication skills and interdisciplinary understanding of engineering and environmental analyses and regulations enables him to efficiently balance engineering goals, environmental needs, and permitting requirements to direct varied and multifaceted design and construction efforts.

Vice President, Principal Engineer
Carol Slaughterbeck has 18 years of civil and environmental engineering experience specializing in water resources. Her project management experience and interdisciplinary understanding of engineering and environmental analyses and regulations enables her to lead a range of engineering studies, including facility plans, compliance studies, and upgrade assessments. Ms. Slaughterbeck has conducted numerous water resources evaluations including hydrologic, hydraulic, and water quality modeling; stormwater treatment and system design; BMP analysis and drinking water regulatory compliance studies; water quality assessment; inflow and infiltration assessment; stormwater manual updates; and comprehensive planning for wastewater systems.

Planning Principal
Art Campbell has worked as a local government planner and as a consultant for 27 years. His background includes leading environmental projects for private and public agency proponents. Mr. Campbell has prepared environmental documentation and analyses for a wide range of public agency projects including solid waste, water supply, wastewater, communications, recreational, and transportation facilities; courthouse, detention, office and other institutional buildings; fish hatcheries; and comprehensive plans. Mr. Campbell is thoroughly familiar with NEPA and parallel state environmental requirements and has prepared land use plans, economic analyses, and related planning studies. He also has provided permitting and regulatory compliance support for wastewater, transportation, and water resources management projects.

Vice President, Natural Resources Principal
Kittie Ford has over 21 years of experience in environmental consulting, managing interdisciplinary analysis teams for SEPA/NEPA compliance, conducting natural resource inventories and ecological studies, providing specialized wetland services, and managing project permitting efforts. Ms. Ford has prepared numerous large-scale environmental analyses for public development projects and programmatic actions. Her EIS management and writing experience includes urban/suburban and industrial developments; long-range regional land use and transportation policy plans; and site-specific roadway, light-rail, airport and water-borne transportation projects. She has coordinated and assisted others with project scoping, public involvement programs, and client and agency coordination. She has assisted numerous clients in Washington and Oregon to obtain project approvals for complex proposals involving wetland and other natural resource impacts.

Hazardous Materials Principal
Peter Jowise has 23 years of experience in hazardous/mixed waste site investigation, regulatory compliance evaluation, water quality management, ground and surface water hydrology, chemical transport modeling, and unsaturated zone leachate assessment. He has proven program management experience, managing on-call contracts and large-scale tasks for the Department of Energy, EPA, GSA, Seattle City Light, and the Washington State Department of Ecology. He has extensive field experience investigating hazardous waste sites; conducting geophysical and soil gas surveys, multimedia sampling, and facility audits; conducting remedial design; and managing remedial activities.

Surface Water Engineering Principal
Mark Ewbank has 18 years of experience in water quality, water pollution control, stormwater management, stream restoration, and related hydrologic and hydraulic analyses. Mr. Ewbank has conducted numerous assessments of hydrologic conditions in natural and developed environments and is thoroughly familiar with the development of stormwater treatment and detention system designs, as well as applications of source control best management practices for the protection of surface and ground water. He has conducted analyses of the effects of various pollutants on streams, lakes, wetlands, and estuaries, and analyzed alternative strategies for effectiveness in controlling surface water pollution. He has also prepared erosion and sediment control plans and contributed to the design of several stream restoration projects.

Water Quality Principal
Joy Michaud has 25 years of water resources experience that includes positions with state regulatory agencies, federal research facilities, and private industry. She operated her own very successful environmental consulting business (EnviroVision) for nearly 20 years before joining with Herrera in 2008. She has extensive watershed experience where she works closely with community groups and technical advisory committees to protect water resources. Joy enjoys technical writing and has produced a number of guidance manuals for both citizen and technical audiences. Water has always been a big part of Joy’s life. She grew up in Green Bay, Wisconsin and was known to spend Packer game Sundays exploring the lakeshore; possibly the only human life form not watching the game. She is an active member of the Olympia Area Rowing club and can often be found rowing in the morning mist of Budd Inlet.

Aquatic Science Principal
Rob Zisette has 24 years of professional experience specializing in surface water management, including lake restoration projects, aquatic plant management studies, stormwater management plans, and environmental impact statements. He has developed and implemented monitoring and quality assurance project plans for marine, freshwater, and sediment quality investigations. Mr. Zisette has mapped aquatic plants, evaluated aquatic plant management techniques, assessed plankton communities, identified nutrient sources, and characterized taste and odor sources in lakes and reservoirs. He has assessed benthic invertebrate populations, fish habitat, and riparian conditions in streams, and has evaluated nonpoint source pollution and the effects of best management practices (BMPs) in stream and urban drainage basins.

Senior Ecologist
Leonard Ballek has 35 years of experience restoring habitat and function to disturbed land.  Len specializes in native plants and planting plans for wetland mitigation and restoration and using bioengineering techniques for stream bank stabilization and erosion control.  He has additional expertise in habitat enhancement, exotic vegetation control, out-planting techniques, native plant seed collection and plant propagation planning, and investigation of innovative restoration techniques and success monitoring.  Len recently worked with Pioneer Technical Services on the Opportunity Ponds Wetland Development in Anaconda MT. He also assisted in the development of the Pacific Northwest Native Plant Farm in Skagit County, WA. When not at work, Len cares for his organic mini-farm in the Bitterroot Valley.  He grows giant pumpkins and holds the record for the second largest pumpkin grown in Montana.  Len is also an avid fisherman and elk hunter.

Senior Water Quality Scientist
John Lenth has 14 years of experience in aquatic ecology, water quality, hydrology, and watershed management. He is known for his excellent people and communication skills which he uses to effectively manage multiple projects. He has successfully implemented countless long-term water quality monitoring projects. He has also assisted in navigating the ever-changing environment of water quality related regulations including NPDES permitting assistance and compliance monitoring; TMDL studies; AKART engineering analyses and related mixing zone studies. He is active in educating community groups on issues related to water quality, watershed management, and benthic ecology. His passion for water related pursuits permeates both his professional and personal life. For example, when not at work, John spends most of his time fly fishing in local streams or standing on a rain drenched sideline coaching his daughters’ soccer teams.

Herrera’s Portland office is located in the historic Captain Couch building, a 2-story brick building at the corner of NW 2nd Ave and NW Couch Street.

The office is located only 2 blocks away from the MAX light rail stations at Old Town/Chinatown (to the northeast) or Skidmore (to the southeast).

There is 90-minute metered parking along 2nd Avenue and along Couch Street. There are two surface parking lots and a SmartPark ramp along Davis Street one block north of the office.

Driving directions

From I-5 South:

1. At I-5 Exit 302A, turn off onto Rose Quarter/City Center Ramp
2. Bear right (South-West) onto N Broadway St
3. Continue (South-West) on Broadway about 1/3 mile
4. Bear left (South) onto NW Broadway St
5. Turn left (East) onto NW Everett St. (one-way)
6. Turn RIGHT (South) on 3rd Ave. (one-way) for two blocks.
7. Turn LEFT (East) on Couch Street. The building is on the SE corner of Couch and 2nd. Parking lots are one block north.

From I-5 North

1. Take the I-405 Exit 299B on the left toward City Center
2. Take Exit 1A on the left toward Naito Pkwy.
3. Turn RIGHT (North) onto SW Naito Pkwy. Proceed north about 3/4 mile.
4. Turn LEFT (West) onto NW Couch. The building is two blocks west on the SE corner of Couch and 2nd. Parking lots are one block north.

Herrera’s Missoula office is located in the Montana Building on the southeast corner of East Broadway and North Higgins Avenue.

Driving directions

From I-90:

1. Take the Orange Street exit
2. Head south on Orange Street
3. Turn left (east) on Broadway
4. The Montana Building is on the SE corner of Broadway and Higgins
5. Enter the building at the Broadway entrance.

Herrera’s main office is located in Seattle’s downtown / Belltown area, in the Denny Building on Sixth Avenue between Bell and Blanchard streets.

Parking is available both in metered spaces and in several commercial lots surrounding the Denny building.

NEW! Check the weather before you arrive from our new Seattle Weather page.

Driving Directions

From I-5 Northbound:

1. Take the Seneca Street exit
2. Merge onto Seneca Street
3. Turn right at the first intersection, onto 6th Avenue
4. After crossing Blanchard Street, the Denny Building will be on your right

From I-5 Southbound:

1. Take the Stewart Street exit
2. Veer to the right onto Stewart Street
3. Turn right onto 6th Avenue
4. After crossing Blanchard Street, the Denny Building will be on your right

From I-90 Westbound:

1. Take the I-5 North exit
2. Take the Madison Street exit
3. Turn left onto Madison Street
4. Turn right onto 6th Avenue
5. After crossing Blanchard Street, the Denny Building will be on your right

From 520 Westbound:

Take I-5 South and follow I-5 southbound directions

Jeryl Kolb and Darcey Miller

Herrera welcomes Jeryl Kolb and Darcey Miller to our natural resources group.

Mr. Kolb has been an environmental scientist for 18 years, specializing in conducting and managing wetland assessments and hazardous waste sites. His current assignments include wetland delineations and mitigation plans for WSDOT along both SR 18 and SR 518, a wetland mitigation monitoring project for the City of Bellevue, the Burke-Gilman trail extension shoreline permit for the City of Seattle, and a wildlife assessment for a private property owner on Cougar Mountain.

Darcey Miller is a staff ecologist with 7 years of experience specializing in wetland and stream analysis and related regulatory standards. Her work experience includes completion of wetland and stream determinations and delineations, wildlife habitat evaluations, and wetland mitigation site monitoring. She is currently working on the Beartooth Highway Improvement Project, the Dungeness River ELJ Restoration Project, the Norfolk Basin Drainage and Water Quality Improvements, and the Kent/Auburn CSI Project.

Alexander Jones

Herrera welcomes Alexander Jones to our hazardous materials group. Mr. Jones has 9 years experience in Phase I Environmental Site Assessments, site investigations, soil and ground water compliance, and site remediation. He has field experience in the design, implementation, and operation and maintenance of soil vapor extraction systems, dual-phase extraction systems, passive bioventing, and permanganate oxidation technology. He is currently working on storm water manual rewrites for both the City of Tacoma and Pierce County, and will be assisting with on-call field support for the WSDOT Archeological Soil Boring Study at the Mukilteo Multimodal Project site.

Herrera Welcomes Returning Staff
Mark Merkelbach
Herrera welcomes back Mark Merkelbach, this time to our engineering group. Mr. Merkelbach was previously employed as a water quality specialist at Herrera and returns after obtaining his master’s degree in civil/environmental engineering with experience in civil design, wetland and stream habitat improvements, environmental monitoring, and documentation. He is currently leading a fish passage and stream restoration design project for the Skagway Traditional Council in Alaska. He is also working with Herrera’s natural resources group to conduct hydrogeomorphic assessments and map wetlands located within a 1,900-acre tract in the Matanuska-Susitna Borough, Alaska. In his home state of Washington, he is designing a wetland mitigation bank in Mount Vernon and a conducting a hydraulic reach analysis for the Puyallup Tribe of Indians on the White River.

The August 3rd edition of the Bellingham Herald included a front-page article about the construction of the South Fork Nooksack River/Lower Hutchinson Creek Salmon Restoration Project under construction near the town of Acme, Washington. As Herrera Environmental Consultants’ principal river and coastal geomorphologist, Tim Abbe, explains, “The South Fork Nooksack project is one of Herrera’s largest river restoration projects to date. The project goal is to reconnect the river to a portion of its floodplain and initiate the formation of side channels. The project involves removing about 400 ft of levee, setting back a similar length of bank protection revetment, constructing six large engineered logjams and adding habitat structures throughout the affected floodplain.”

The project is being built by the Nooksack Tribe and the Lummi Nation. Herrera designed the engineered logjams (ELJs) and provided the supporting public outreach, geomorphic assessment, and risk analysis for the project. Jennifer Goldsmith manages the project, and Kevin Houck oversees construction for Herrera.