MS4 Outfall Monitoring and Reporting

NV5 provided the City of Oceanside with MS4 Outfall Monitoring in accordance with the San Diego Regional Municipal Separate Storm Sewer System (MS4) Permit during the 2017-2018 and 2018-2019 monitoring years.

NV5 conducted dry weather field screening and reporting activities. NV5 conducted two separate dry weather outfall field screenings at 75 major MS4 outfalls throughout the city. During the field screenings, NV5 looked for evidence of obvious illicit discharges and noted suspected/known discharge sources based on discharge characteristics and conditions near the outfall. Field screening visual observation and applicable source identification investigation data were formatted into a regional data-sharing spreadsheet. California Environmental Data Exchange Network (CEDEN) formatted the spreadsheet for those constituents required to be uploaded to CEDEN under the Regional MS4 Permit.

During the second round of the 2019 dry weather MS4 outfall field screenings, NV5 conducted inspections during the early morning hours at targeted outfalls. In general, the early morning field screenings and upstream investigations resulted in increased effectiveness in tracing illicit connections/illicit discharges (ICIDs) as compared to the afternoon inspections.

NV5 also conducted one wet weather MS4 outfall monitoring event at an MS4 outfall site within the Carlsbad Watershed Management Area (WMA) once during the 2018-2019 monitoring year to comply with Permit. After the data was finalized, NV5 compiled, formatted and submitted the data to the City in a CEDEN-compatible format for watershed assessment purposes.  The data included all site characteristics, visual observations, field measurements and laboratory data.  NV5 used the available data sharing templates to facilitate compilation of other Carlsbad WMA datasets for assessments and reporting. NV5 also reviewed and finalized all flow data, as well as prepared flow volume calculations, flow hydrographs and other appropriate information. NV5 submitted all data and deliverables in a brief technical memorandum describing the methodology and presenting the results.


Oceanside, CA


City of Oceanside


  • Outfall Field Screening
  • Wet Weather Outfall Monitoring
  • Upstream Investigations
  • Illicit Discharge Detection and Elimination (IDDE) Investigations
  • Data Formatting, Assessment and Reporting

Key Facts

Budegt: $30,000 annually
Duration: 2018 – 2019