EPA's Vessel General Permit and Small Vessel General

Both pre- and post- permit receiving water concentrations are orders of magnitude below
individual toxicant effects thresholds identified by EPA and those thresholds identified through
our review of recent literature as was the net PAH-MAH toxicity for freshwater taxa. The
aggregate PAH-MAH toxicity for saltwater organisms was somewhat higher, with an RQ of
0.08, approaching the threshold between “remote” and “no effect”. NMFS concludes that PAH-
MAH contributions from vessels are not expected to tip the balance between neutral and harmful
levels in waters where our species occur.
2,4,6-Trichlorophenol
EPA post permit 2,4,6-trichlorophenol in the estuarine harbor model to average 0.0927 ng/L and
ranged from 0.00607 to 0. 514 ng/L, suggesting a 48 to 50 percent reduction in 2,4,6trichlorophenol
discharged. For the river harbor model, EPA's average post permit 2,4,6trichlorophenol
was 0.00376 ng/L and ranged from 0.0000313 to 0. 00986 ng/L, suggesting a 30
to 67 percent reduction in 2,4,6-trichlorophenol discharged. Post permit 2,4,6-trichlorophenol
estimates fell below the response thresholds selected by EPA for evaluating risks of exposure to
2,4,6-trichlorophenol. These thresholds ranged from 0.46 to 5,923 ug/L for freshwater
organisms. The threshold values EPA selected for freshwater vertebrates were derived from a
NOEC and LOEC, with the NOECs being 530 ug/L. EPA stated that threshold values were not
available for estuarine/marine organisms. After review of the available literature, concurs with
EPA’s conclusion. Further, NMFS literature searches did not identify information of effects
important to our species such as olfaction, immune function or behavior.
Both pre- and post- permit receiving water concentrations are greater than 3 orders of magnitude
below toxicant effects thresholds identified by EPA and thresholds below those identified by
EPA or for effects not considered by EPA were not found through NMFS literature reviews.
NMFS concludes that 2,4,6-trichlorophenol contributions from vessels are not expected to tip the
balance between neutral and harmful levels in waters where our species occur.
Bis(2-Ethylhexyl) Phthalate (DEHP)
EPA estimated post permit DEHP in the estuarine harbor model to average 0.754 ng/L and range
from 0.048 to 4.24 ng/L, suggesting a 25 to 61 percent reduction in DEHP discharged. For the
river harbor model, EPA's average post permit DEHP was 0.0839 ng/L and ranged from
0.000979 to 0.175 ng/L, suggesting a 14 to 58 percent reduction in DEHP discharged. EPA
stated that it was unable to find threshold response data for DEHP useful in evaluating risk to
aquatic organisms.
NMFS identified several studies evaluating DEHP as an endocrine disruptor. California EPA
reviewed these and other studies evaluating more traditional effects (Carlisle et al. 2009).
Response threshold data were reviewed for effects on development and maturation, growth, and
reproductive tissue metrics. The concentrations at which responses were reported ranged from
0.01 to 10,000 ug/L. The only responses that occurred at concentrations at or below those
modeled by EPA for its hypothetical harbors used the standard laboratory species medaka.
Mortality rates were higher and male body weights were lower for adult individuals hatched
from eggs exposed to as little as 0.01 ug/L DEHP. Exposure did not affect female body weights
or the gonadosomatic index (GSI) of either sex (Chikae et al., 2004a – after Carlisle et al 2009).
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