Caltrans Headquarters - Storm Water Quality Monitoring Program Ornamental Roadside Vegetated Treatment Study (ORVTS)

Interstate 380 monitoring station in San Mateo for collection of stormwater runoff from ornamental ice plant vegetation
Prime Contractor: 
Period of Performance: 
February, 2010 to July, 2012
Project Description: 

The Ornamental Roadside Vegetated Treatment Sites (ORVTS) Pilot Study is comprised of two types of study sites: the Expanded Roadside Vegetated Treatment Sites (ERVTS) and the Groundcover Roadside Vegetated Treatment Sites (GRVTS). The purpose of the ORVTS study at the ERVTS sites is to evaluate the ability of groundcover vegetation species to provide treatment of highway runoff and to compare treatment potential to existing grass and for vegetation within the Caltrans rights-of-way (ROW).

The ERVTS sites were constructed to expand the treatment strips at existing site locations of the original Roadside Vegetated Treatment Sites (RVTS) Pilot Study with new groundcover. Existing RVTS data will be utilized as a baseline condition, providing supplemental data on alternate vegetation types. Two ERVTS sites were chosen, one in each geographic region (Northern and Southern California), for construction and monitoring. At each selected site, up to four additional test plots were installed adjacent to the existing test plots for the RVTS Pilot Study. The purpose of the ORVTS study at the GRVTS sites is to evaluate the benefit of existing groundcover and low-growing shrub-vegetated systems in providing treatment for highway runoff within the Caltrans ROW. The data generated from the RVTS and ORVTS Pilot Studies will be used to evaluate and compare the performance of existing and newly established groundcover vegetation in treating stormwater runoff and the comparability to existing grasses and forbs within the Caltrans ROW.

These test plots were grubbed and vegetated with groundcover or low-growing shrub species (e.g., ice plant, ivy, Myoporum, Baccharis, or alternative species) and monitored in sequence with the existing RVTS test plots. The data generated will be used to make comparisons between the different vegetation type effects on treatment performance. In addition to the two ERVTS sites, seven GRVTS sites were chosen for this study. For this two to three year study, automated samplers and flow meters are used to collect flow-weighted composite samples throughout entire storm events from each of the monitoring locations for laboratory analyses. Up to twelve storm events will be sampled at each monitoring location. 

ADH Responsibilities: 
  • Maintenance and operation of six automated, flow-weighted stormwater monitoring and sampling stations • Remote instrument communication for data acquisition and programming control
  • Storm event forecasting
  • Storm event monitoring, including composite and grab sampling, field documentation, and preparation and transfer of environmental samples to analytical laboratories
  • Drainage areas measurements and calculations
  • Preparation of the post storm technical memoranda components
  • Equipment demobilization
  • Site decommissioning
  • Migratory bird nest survey
  • Maintenance of site vegetation
  • Review and editorial comment for end of season monitoring reports