3.3 Water Resources
study area. Borrow site SO-6 is the closest to an outfall point and is approximately 350 feet north of the
San Elijo Wastewater outfall pipeline and greater than 4,000 feet from the outfall discharge area. The
entrance to San Elijo Lagoon is approximately 4,500 feet from the dredge area. Proposed borrow sites
SO-9 and MB-1 are located over three miles upcoast and inshore of wastewater outfalls and a mile or
more from rivers or bays. Proposed borrow sites SO-7 and SO-5 are located more than two miles
downcoast and inshore of wastewater outfalls, and 3,000 and 4,500 feet offshore lagoons, respectively.
Borrow site SS-1 is located approximately 2,250 feet north of the City of San Diego outfall.
As stated in Section 3.1, sampling has been performed to determine grain-size compatibility between the
borrow sites and receiver sites. All material proposed to be placed would be compatible in terms of grain-
size. A detailed comparison of the chemical characteristics of the borrow sites and receiver sites is
provided in Table 3.3-1.
Borrow Sites
Proposed borrow site sediments range from very fine- to coarse-grained sand. Contaminant concentrations
pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and phenols were
non-detectable to low at all borrow sites. Percent solids ranged from 79.2 to 86.6 percent, total sulfides
were 0.2 to 1.1 mg/kg, and total organic carbon concentrations ranged from 0.02 to 0.22 percent.
While no regulatory criteria exist for the protection of aquatic life from exposure to potentially contaminated
sediments, the NationalOceanographic and Atmospheric Administration (NOAA) publishes effects-based
sediment quality values for evaluating the potential for constituents in sediment to cause adverse biological
effects. These values are referred to as Effects Range-Low (ER-L) and Effects Range-Median (ER-M).
The ER-L concentrations indicate the low end of the range of concentrations at which adverse biological
effects are observed or predicted. The ER-M values are concentrations at which effects were observed
or predicted in 50 percent of the test organisms evaluated. The ER-L and ER-M concentrations are not
accepted standards or criteria, but provide effects based guidelines. Contaminant concentrations in the
sediment at each borrow site were compared to ER-L and ER-M values for metals and organics. None
of the sediment materials exceeded the NOAA values.
Regional Beach Sand Project EIR/EA
Page 3.3-5
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