California Department of Transportation BMP Retrofit Pilot Program

Abstract

The California Department of Transportation (Caltrans) is conducting a multi-year study in Los Angeles and San Diego to examine the technical feasibility, costs, and operation and maintenance requirements of retrofitting structural Best Management Practices (BMPs) into existing highway and related infrastructure. Thirty-three locations are being retrofitted with thirty-nine BMPs using twelve different types of BMP technology. Automated monitoring stations have been installed upstream and downstream of each BMP to determine removal efficiencies from flow weighted composite samples. Constituents monitored in the runoff include: suspended solids (e.g., sediment), metals, nutrients, and organics (e.g., gasoline).To date, most projects have been sited, designed, constructed and monitored for at least one year. The purpose of the program is to identify the problems and solutions that occur with structural BMP retrofit, and to collect operation, maintenance, and performance data for the BMPs. Results to date indicate that there are substantial construction, maintenance, and cost challenges in retrofitting existing infrastructure with conventional structural BMP technology. Water quality monitoring results to date indicate that average pollutant removal efficiencies are 2 consistent with published values. Upon completion of the study, the information collected will enable more accurate prediction of cost and performance of BMPs for treating highway runoff.

Assessment of treatment systems for highway runoff pollution control in Portugal

“…Some of the issues identified coincide with the ones from the study by Taylor & Barret (1999), although the data It is of main importance to discuss detection and quantification limits with the laboratory in charged of analysis, previous to the start of the monitoring programme, giving them possible ranges for the expected concentrations.…”

“…Taylor & Barret (1999) evaluated for the Caltrans (California Department of Transportation) BMP Retrofit Pilot Program, in California, 37 BMP at 33 sites, with 9 types of technology.…”

“…Table 1, based on data by Taylor & Barret (1999), shows relative costs and average annual maintenance hours needed for several BMP. Taylor & Barret (1999) concluded that biofiltration swales and strips are the best choices, for being relatively inexpensive, having a comparable effectiveness for many runoff constituents and requiring no specialized maintenance. These are followed by the extended detention basins, due to their moderate cost, flexible sitting, moderate performance and low maintenance.…”

“…It was observed that the most original and innovative BMP systems are also seldom monitored (Taylor & Barret 1999).…”