Waste Discharge Requirements Order and Stormwater Compliance at Power Generation Facility

Terraphase has been delivering environmental services to this biomass power generation facility, which is located in the California Central Valley and utilizes rice hulls as fuel to produce electricity via a steam turbine.

Wastewater generated on the site is temporarily stored in two Title 27-compliant Class II surface impoundments, where it undergoes solar evaporation.

Scope of Services

Terraphase supports the facility in maintaining compliance with the Regional Water Quality Control Board (RWQCB) Waste Discharge Requirements (WDR) Order, which governs the surface impoundments.

Specifically, Terraphase manages a Title 27-compliant groundwater monitoring network and evaluates the effectiveness of the leachate collection and recovery system. Free-board measurements are assessed to ensure adherence to the WDR Order, and semiannual reports are prepared for submission to the RWQCB.

Terraphase also delivers comprehensive stormwater compliance solutions, maintaining facility compliance with the California’s Industrial General Permit (IGP) requirements for stormwater discharges. Our expert team develops and implements a tailored Stormwater Pollution Prevention Plan (SWPPP), safeguarding operations from regulatory risks.

We streamline compliance by preparing and submitting annual reports through California’s Storm Water Multiple Application and Report Tracking System (SMARTS), keeping the facility in good standing with regulatory authorities.

Additionally, Terraphase provides essential support for regulatory documentation, including the Spill Prevention Control and Countermeasure (SPCC) Plan and the Hazardous Materials Business Plan (HMBP), helping the facility maintain a proactive and compliant environmental strategy that is protective to its employees and to the surrounding community.

Notable Accomplishments

• Over 20 years of ongoing compliance support, 15 of which have been with Terraphase
• Developed the site’s SWPPP and prepared and submitted reports in California State Water Resources Control Board Stormwater Multiple Application and Report Tracking System (SMARTS)
• Prepared the site for Certified Unified Program Agency (CUPA) inspections, resulting in zero notices of violation (NOVs)

Utility Construction Stormwater Compliance Support

Terraphase has provided ongoing construction stormwater compliance support for a California utility client. Our long-term engagement reflects our ability to navigate complex regulatory frameworks and deliver responsive, practical solutions for a wide range of construction projects.

Scope of Services

Terraphase has supported this utility client with Risk Level 1, 2, and 3 linear and traditional construction projects, delivering full-scope services including Stormwater Pollution Prevention Plan (SWPPP) and permit registration preparation, site inspections, water quality sampling, best management practice (BMP) installation, and emergency response. We assist with regulatory documentation such as Changes of Information and Amendments, Annual Reports, and Notices of Termination (NOT), while also providing crew training and developing internal and external guidance materials. Our team works closely with client staff to meet local agency requirements, support legal teams, engage with landowners, and provide regulatory interpretation and negotiation. We also support design-build and high-volume programs, treatment system design, and special permitting related to California Environmental Quality Act(CEQA)/National Environmental Policy Act (NEPA), endangered species, U.S. Fish and Wildlife Service (FWS), California Department of Fish and Wildlife (CDFW), U.S. National Park Service (NPS), and Clean Water Act (CWA) Sections 401/404 requirements.

Notable Accomplishments

• Over 10 years of ongoing stormwater compliance support
• Successfully managed Risk Level 1–3 construction projects
• Delivered SWPPP documentation, inspections, and emergency response
• Supported permitting, legal teams, and agency coordination
• Streamlined compliance for CEQA/NEPA and CWA projects

Port of Oakland On-Call Stormwater Services

Terraphase provides on-call environmental compliance services to the Port of Oakland (Port) in California, supporting a wide range of infrastructure, airport, and property-related environmental programs. Our team works closely with Port staff and regulatory agencies to manage risk, ensure regulatory compliance, and implement effective environmental strategies across Port-owned properties and facilities.

Scope of Services

Terraphase services encompass stormwater management, National Pollutant Discharge Elimination System (NPDES) permit compliance, and water quality treatment design, along with drainage infrastructure evaluation and environmental site characterization. Our team developed and implemented the Oakland International Airport stormwater compliance program including preparing the airport-wide Stormwater Pollution Prevention Plan (SWPPP), performing Qualified Industrial Stormwater Practitioner (QISP) inspections and sampling,  preparing the site stabilization plan, designing best management practices (BMP) under the Industrial General Permit (IGP), and training airport tenants.

Terraphase also assists the Port with property transaction due diligence, site investigations, and remedial planning, and provides ongoing support for regulatory engagement and compliance documentation. Our team implemented erosion and sediment control practices, performed vapor monitoring for methane, and collected soil, groundwater, and stormwater samples.

Notable Accomplishments

• Prepared recommendations for investigation of, upgrades to, and maintenance of stormwater treatment bioswales and retention areas at Oakland International Airport South Field
• Prepared Geographic Information System (GIS) maps of Port post-construction BMPs implemented to meet Municipal Separate Storm Sewer System (MS4) Permit requirements
• Installed vapor monitoring wells and performed methane monitoring at two Port-owned properties
• Developed closure strategies and completed comprehensive review of historical documents and evaluation of site conditions relevant to low-threat closure, including free product gauging at groundwater monitoring wells