On-Call National Pollutant Discharge Elimination System (NPDES) Services Contract

NV5 has provided Riverside County Flood Control and Water Conservation District (RCFC&WCD) receiving water monitoring, special studies, and reporting services. NV5 has been conducting the Santa Margarita River Wet Weather Monitoring and Data Processing Services as outlined in the Santa Margarita River Water Quality Improvement Plan (WQIP). Annually, three wet weather monitoring events are conducted at receiving water mass loading stations and Municipal Separate Storm Sewer System (MS4) outfall locations are monitored once annually. Responsibilities include field reconnaissance, equipment installations, flow monitoring, automated sample collection and wet weather event data collection.  NV5  has also formatted field, chemistry and toxicity monitoring data into California Environmental Data Exchange Network (CEDEN) compatible data files, as well as uploaded the files into the CEDEN database.

NV5 developed a post-fire monitoring plan to assess the potential water quality impacts of the 2018 Holy Fire and the 2019 Tenaja Fire. NV5 implemented wet weather water quality monitoring to assess post-fire contaminant concentrations and flux by sampling stormwater runoff from the terminal end of burned catchments and a reference site. Monitoring included flow monitoring, water quality sampling, visual observations and aerial drone survey to assess pre-storm, during storm and post-storm conditions. NV5 calculated the post-fire contaminant flux and compared  data from the burned catchments to reference sites to assess the effects on the hydrologic response, sediment loads and contribution of pollutant loads (metals, nutrients and organic contaminants). NV5 worked with RCFC&WCD to create a final report and presented the study results to multiple agencies, including the Regional Board. The scientific data gained from this study is now available to build upon and help in future management decisions, including strategies used to comply with the LE/CL nutrient total maximum daily load (TMDL). NV5 conducts nutrient TMDL monitoring to support the RCFC&WCD with responding to a Regional Board Investigative Order for the upper Santa Margarita River.


Riverside, CA


Riverside County Flood Control and Water Conservation District, Riverside, CA


  • Receiving Water Monitoring
  • Wet Weather Monitoring
  • TMDL Monitoring
  • Special Studies
  • Monitoring Records
  • Electronic Data Management
  • Monitoring Program Development
  • Automated Sampling
  • Obtaining Access Permits
  • Supply, Install, Operate, and Maintain Flow Equipment
  • Laboratory QA/QC
  • CEDEN Formatting
  • Stakeholder Meeting Support
  • Annual Reporting

Key Facts

Budget: $1,000,000
Duration: Ongoing, 2015 to 2018, 2018-Present