Making LA River Revitalization a Reality

City of Los Angeles, Bureau of Engineering

Site Assessments

Safe Testing Procedures

All testing was completed in accordance with a site-specific Work Plan and Health and Safety Plan approved by the California Department of Toxic Substances Control (DTSC), the overseeing regulatory agency. The primary goal of these plans is to assure the safety of nearby residents, schools and parks, our workers, and our environment. Health and safety procedures included:

  • Visual dust monitoring
  • Work zone air monitoring (using air quality meters)
  • Chemical-specific gas measuring and filtering devices
  • Water spray for dust control during excavations
  • Proper disposal of soil samples


What We Investigated

Groundwater Sampling

  • 22 samples from 16 monitoring wells

Soil Gas Sampling

  • 228 sample locations
  • 452 total samples

Soil Sampling

  • 78 locations
  • 645 total samples

Excavation Test Pits

  • 14 pit and trench excavations

What We Looked For

  • Petroleum hydrocarbons
  • Metals (e.g lead and cadmium)
  • VOC's (solvents historically used in maintenance/cleaning)
  • Semi VOC's (compounds found in petroleum products)
  • Pesticides/herbicides
  • PCBs (coolants historically used in electrical equipment)

What Is The Remedy?

Solution may include a combination of alternatives to achieve appropriate residential/ecological standards:

  • Risk assessment for soil, soil gas, and groundwater
  • Soil: excavation; engineered cap/paving (temporary or permanent)
  • Soil gas: extraction/venting; vapor mitigation system
  • Phytoremediation
  • Groundwater: extraction/in-situ treatment in targeted areas