CALTRANS STORMWATER DATA REPORTS
State Route 55 PSR, Storm Water Data Report
Client: PBS&J, Caltrans District 12, OCTA
Orange County Transportation Authority initiated a
project study report along SR-55 from I-405 to I-5 to determine
the feasibility of adding new lanes, either general purpose, auxiliary, or HOV lanes. OCTA
selected the PBS&J team for the PSR prep. PBS&J hired Civil Works Engineers to prepare the
Storm Water Data Report (SWDR) as part of the PSR. Five alternatives were studied. The SWDR
identified both design pollution prevention and treatment Best Management Practices in a section of
freeway which currently has very few BMP measures in place. The proposed BMPs included six
biofiltration swales and five infiltration basins.
Multi-chambered treatment trains (MCTT) are to be
evaluated further. Detention basins and wet basins were determined not feasible.