Environmental health experts at Environmental Health Coalition filed this comment letter today on the most recent monitoring reports on the Chatham contamination. EHC Chatham Comment Letter Feb 26 2015.
There is important information about 1,4-Dioxane and it speaks eloquently to several issues we are facing locally. We are very grateful to EHC to their enduring commitment to community health.
Here are some excerpts
Regarding whether Natural Attenuation is occurring:
“The latest monitoring
results do not provide evidence that natural attenuation is occurring. Increased levels of TCE occur at sampling
sites up and down Felicita Creek, including both the northern and southern
portions. Not only are the levels not diminishing, this pattern of monitoring results does not support the Hargis
contention that levels in the more northerly part of the creek will diminish
first, followed by levels in the down gradient portions of the creek and plume.
In fact, these results show neither a short term nor a long term pattern of
attenuation in TCE levels. Levels in FC-4, one of the wells in the northern
part of Felicita Park, show an increasing trend over the 20-year period from
1994 through mid-2014, as charted in Figure 7 of the Hargis Technical
Memorandum of January 16, 2015.
results do not provide evidence that natural attenuation is occurring. Increased levels of TCE occur at sampling
sites up and down Felicita Creek, including both the northern and southern
portions. Not only are the levels not diminishing, this pattern of monitoring results does not support the Hargis
contention that levels in the more northerly part of the creek will diminish
first, followed by levels in the down gradient portions of the creek and plume.
In fact, these results show neither a short term nor a long term pattern of
attenuation in TCE levels. Levels in FC-4, one of the wells in the northern
part of Felicita Park, show an increasing trend over the 20-year period from
1994 through mid-2014, as charted in Figure 7 of the Hargis Technical
Memorandum of January 16, 2015.
Another well in the
northern area of the Park, FC11/11A, shows an increase since the previous round
of monitoring in April 2014. Levels of TCE in MW-58 appear to be exactly the
same in the most recent results as they were 15 years ago, in 2000, also shown
in Figure 7.”
northern area of the Park, FC11/11A, shows an increase since the previous round
of monitoring in April 2014. Levels of TCE in MW-58 appear to be exactly the
same in the most recent results as they were 15 years ago, in 2000, also shown
in Figure 7.”
Regarding the length of time of the natural attenuation:
“Not only do these results
fail to support the PRP consultant’s theory, the PRP group fails to provide any
estimates of how long they expect this natural attenuation process to take. How
long are they expecting Felicita Creek and groundwater to remain contaminated?
How many more years are they asking Escondido families to be patient while
upwelling of contaminants continues into their neighborhood park and their
groundwater wells? A generation of children has grown up since the Chatham
plume began its migration, and we’re still being told that attenuation will
eventually occur. It is past time for DTSC to demand that the PRPs take additional
action to remediate the plume, as well as to treat all wells that have
measurable levels of chlorinated hydrocarbons or 1,4-dioxane.”
fail to support the PRP consultant’s theory, the PRP group fails to provide any
estimates of how long they expect this natural attenuation process to take. How
long are they expecting Felicita Creek and groundwater to remain contaminated?
How many more years are they asking Escondido families to be patient while
upwelling of contaminants continues into their neighborhood park and their
groundwater wells? A generation of children has grown up since the Chatham
plume began its migration, and we’re still being told that attenuation will
eventually occur. It is past time for DTSC to demand that the PRPs take additional
action to remediate the plume, as well as to treat all wells that have
measurable levels of chlorinated hydrocarbons or 1,4-dioxane.”
Regarding what the MCL does and doesn’t mean and a preference for the PHGs:
“Finally, we urge DTSC to
bear in mind that MCLs are only as health protective as is technologically and
economically feasible. They are not truly health protective standards, and it is
inaccurate to state or imply that water meeting MCL levels is “safe.” In the
case of TCE, which has both an MCL and a Public Health Goal (PHG), we urge you
to use the PHG as the basis for decisions to post signs along the creek, and as
a cleanup level for creek and well water.”
bear in mind that MCLs are only as health protective as is technologically and
economically feasible. They are not truly health protective standards, and it is
inaccurate to state or imply that water meeting MCL levels is “safe.” In the
case of TCE, which has both an MCL and a Public Health Goal (PHG), we urge you
to use the PHG as the basis for decisions to post signs along the creek, and as
a cleanup level for creek and well water.”
Regarding health information on 1,4-Dioxane
“Levels of other
contaminants are also of continuing concern. 1, 4-Dioxane levels are high in several
wells, including an all-time high of 100 μg/l in FC-04, a level 33 times the
OEHHA public health notification level of 3 μg/l. This is of particular concern
in a location where children may be exposed. 1,4-Dioxane has been listed on
California’s Prop. 65 list as a carcinogen since 1988. Most of the human
toxicology of the substance derives from worker exposure; effects of low dose
exposure to children are not known. Nor has OEHHA developed a child-specific
reference dose for this compound. 1,4-Dioxane exposure can occur through dermal
exposure as well as inhalation and ingestion — all plausible routes of
exposure for children playing in or near the creek. In short, the possible
impacts of exposing children to 1,4-dioxane are not known, and DTSC must act to
protect children who visit the park.”
contaminants are also of continuing concern. 1, 4-Dioxane levels are high in several
wells, including an all-time high of 100 μg/l in FC-04, a level 33 times the
OEHHA public health notification level of 3 μg/l. This is of particular concern
in a location where children may be exposed. 1,4-Dioxane has been listed on
California’s Prop. 65 list as a carcinogen since 1988. Most of the human
toxicology of the substance derives from worker exposure; effects of low dose
exposure to children are not known. Nor has OEHHA developed a child-specific
reference dose for this compound. 1,4-Dioxane exposure can occur through dermal
exposure as well as inhalation and ingestion — all plausible routes of
exposure for children playing in or near the creek. In short, the possible
impacts of exposing children to 1,4-dioxane are not known, and DTSC must act to
protect children who visit the park.”
Please read this letter for yourself. You will learn a lot.
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