Our expertise includes all aspects of waste management planning, siting, design, impact assessment, and permitting. Our engineers and planners have a thorough knowledge of applicable local, state, and federal regulations. We design solid waste facilities, conduct waste stream analysis and surveys and recycling, and evaluate waste management systems and practices (including environmental best management practices).

Herrera engineers provide landfill gas leachate and engineering services that include operation planning, permit assistance, and construction oversight. Our landfill gas expertise includes all aspects of collection, conveyance, monitoring for operational compliance, monitoring for design basis, gas control, and conformance with Title V air operation. Herrera engineers design active and passive gas collection, conveyance and control systems for landfill sites, remediation sites, and adjacent and ancillary facilities associated or impacted by landfill gas. We have extensive knowledge and expertise working with landfill operations staff to troubleshoot and design retrofits for operation efficiency and gas control. Our construction engineers are knowledgeable in solid waste design and operations to ensure that our designs are efficiently implemented during the construction phase.

Key Projects

• Cedar Hills Regional Landfill Area 6 Closure Design - King County
• South Cushman Solid Waste Landfill Expansion - Fairbanks North Star Borough
• Vashon Landfill Development and Final Closure - King County
• Carnation Landfill Corrective Action Plan - City of Carnation
• Engineering Services for Thurston County Leachate Landfill - Thurston County
• Closure of Municipal Solid Waste Landfill Cell #6 - Fort Lewis Public Works