1.1 MB pdf - Bolsa Chica Lowlands Restoration Project

SECTION 3: ANALYSIS
in more than one-half the samples. Surface water samples had less than 20 percent detection
frequency for pesticides. Small mammal tissues had various pesticide detects up to
60 percent. Aquatic invertebrate samples had few pesticide detects, with the exception of
4’4-DDD. Fish tissue also had relatively few detects, although 4’4-DDD and 4’4-DDE were
found in all 12 samples.
PAH detects were relatively infrequent and occurred in sediment/soil, small mammal
tissue, worm and fish tissue. Small mammal samples and fish tissue had frequencies of
approximately 50 percent.
Semi-volatiles were occasionally detected in sediment/soil samples although sample sizes
were large and detects were low.
TPH-diesel and waste oil were found in sediment/soil and surface water. Frequency of
detection was greater in surface water.
Garden Grove - Wintersburg Flood Control Channel
Detected chemical groups in the flood-control channel include metals, pesticides, PAHs, and
semi-volatiles. Metals were detected in almost all sediment/soil samples. In surface water,
metals were detected frequently although sample size was small.
Overall, pesticides were detected in less than one-half the sediment/soil samples.
Exceptions include 4’4-DDD and 4’4-DDE, which were detected in 4 of 7 samples.
PAHs, on the other hand, were most often detected in more than one-half of the
sediment/soil samples.
Semi-volatiles were detected often in sediment/soil samples, and most were detected more
than 80 percent of the time.
Gas Plant Pond Area
Detected chemicals include metals, pesticides, PAHs, and semi-volatiles. Several metals
were detected in all sediment/soil samples, while others were detected in only some.
Terrestrial plant, aquatic invertebrate, small mammal, and fish tissue all had small sample
sizes with several metal detects.
Pesticides were detected in sediment/soil, fish, small mammal, and aquatic invertebrate
tissue. All sample types had small sample sizes.
PAHs were detected in sediment/soil samples, but generally occurred in fewer than
10 percent of samples.
Semi-volatiles were rarely detected in sediment/soil samples.
TPH-Diesel and waste oil were the most commonly detected analytes in the Gas Plant Pond
area in sediment/soil and surface water samples.
Muted Tidal Plus Rabbit Island
Samples from the Muted Tidal area were found to contain metals, pesticides, PAHs, and
semi-volatiles. Metals were found in sediment/soil at high frequency. Several metals
occurred in more than 80 percent of samples. Chromium, mercury, selenium, zinc, and
SAC/143368(003.DOC) 3-11 ERA REPORT
7/31/02