- Installed and sampled six groundwater monitoring wells in the access roads along the eastern and western sides of the channel
- Drilled 12 shallow soil borings within the channel bed and collected sediment and soil samples
- Installed absorbent materials along channel levee sub-drain manholes near the area where petroleum sheen had been observed, on-going weekly inspection of replacement of absorbent material as necessary, and daily removal of petroleum product from the well that petroleum product was found (Well R-MW-6).
- Chemically analyzed soil, groundwater, petroleum compounds , and saturated absorbent material samples
- Conducted an outdoor air assessment
Summary of Results: Petroleum seeping into the channel appears to be a refined oil product (an intermediate naphtha) from one or more pipeline sources. Specific pipeline source(s) are unknown. Results from the outdoor air assessment did not reveal a health risk from the odor of a sheen that was observed partially covering the channel.