The Sacramento District Army Corps of Engineers began construction of the Napa River flood protection project with Contract 1 A in August 2000. Work was completed in October and concrete rubble was left at the edge of the lower terrace. The material appeared to be old highway concrete bridge railing and concrete paving, with more than 250 pieces ranged in length from three to eight feet in diameter and 3.5 feet high. The rubble protruded above the surface of the marsh plain terrace. At higher tides this rubble was covered by water, making it a navigational hazard for small craft.
As prime contractor, Cerrudo Services removed all concrete rubble that protruded one foot or more above the edge of the marsh plain terrace, approximate elevation 0.0 NGVD on the West bank of the Napa River from C-Line Station 32+00 to 52+00 (River Station 640+00 to 659+00) without disturbing the marsh plain sediment and worked around endangered species and wildlife habitat without impact. Approximately 176 tons of concrete were removed and recycled.