28 Jones Flashcards
what did william ruckelshaus say?
“we should remember that risk assessment data can be like the captured spy: if you torture it long enough, it will tell you anything you want to know”
what a brief history of the rocky mountain arsenal (RMA)?
-it is located in commerce city, colorado, approximately 10 miles northeast of downtown denver
-in 1942, during world war II, the US army purchased 17,000 acres (26 square miles) for chemical weapons manufacture: mustard gas, white phosphorus, napalm
-to foster economic growth, offset operational costs and maintain facilities for national security, RMA facilities were leased to industry for pesticide production after the war
-as of 1982, chemicals or weapons were no longer produced or stored at RMA. the site’s only mission was the safe, timely and cost-effective cleanup and transition to one of the largest, urban national wildlife refuges
what are the environmental issues of RMA?
-wastes generated at RMA were disposed of using best practices of the time (unfortunately that practice was dig a hole and bury it)
-efforts contain liquid wastes began after the discovery that contaminated groundwater caused crop damage north of RMA in the mid-1950s
-the army and shell began a systemic investigation into the contamination problems resulting in the army’s installation restoration program
-beginning in 1974, Interim response actions (IRA) were implemented to protect public health, the surrounding community and the environment
-included in the 14 IRAs was the construction and operation of groundwater treatment systems both on and off the site. Currently, the five groundwater treatment systems still treat >750 million gallons of groundwater a year, this will continue in perpetuity
what is the regulatory framework of RMA?
-in july 1987, the rocky mountain arsenal was placed on the national priorities list (superfund) mandates publicly funded clean-up with responsible parties liable for costs
-1995: intensive public involvement helped the Army, Shell, U.S Fish and Wildlife service, colorado department of public health and environment and the US EPA reach two monumental decisions
-the off-post record of decision (ROD), signed december 19, 1995 and the on-post ROD, signed june 11, 1996, provide the framework, purpose and rationale for clean-up actions
-by 1997, the majority of 31 clean-up projects identified in the on- and off-post RODs were well in progress or complete. Project completion was estimated to be 2011
-a whole lot of stuff happened between 1974 (IRA) and the 1995 (ROD)
how did the RMA become a national wildlife refuge?
-US-FWS involvement at RMA began in 1986 when a winter communal roost of bald eagles, then an endangered species, was found on site
-US-FWS soon realized that more than 330 wildlife species inhabit RMA including deer, coyotes, white pelicans and owls
-1992: congress passed the Rocky mountain arsenal national wildlife refuge act, making RMA part of the national wildlife refuge system after cleanup
what is the overall RMA remediation?
-well underway by 1997
-2 billion price tag
-alot of dirt already moved
-and then something happened
what are the parties involved?
-the Army (PRP?, site owner, federal gov.)
-PRPs (potentially responsible parties): shell (inherent liability?)
-trustees: US-EPA, US-FWS, CDHE (state agency)
-local community (standing, see trustees)
what was the thing that happened during remediation?
state of colorado (CDHE) received results indicating the presence of dioxins on site
-4 soil samples and 7 tissue samples
-still a little “unclear” how samples were obtained and analysis funded
-this “study” was conducted unilaterally by the state
what is the dioxin issue?
-all previous work was based on remediation for organochloride pesticide residues (dieldrin, aldrin and endrin)
-during the RA phase the analysis of some samples indicated the presence of dioxins-not previously discovered or investigated on site
-should dioxins be a CoC (contaminant of concern)? should RD/RA be stopped until extent is known? go back to the beginning (1974)
-common sense prevailed and RA (remediation actions) continued while dioxin issues were addressed with a risk assessment process by the BAS (biological advisory sub-committee)
-the dioxin assessment provides a mini example of how the larger process was undertaken
what are the structures of dioxin-like chemicals?
what is the H4IIE-luc bioassay?
when exposed to dioxins, they produce light
what are the two methodologies of TCDD-equivalent measurements?
TEQ (toxic equivalent)
-based on instrumental measurements
-concentration of chemical times toxicity factor
-only specified congeners are accounted for
TCDD-EQ
-bioassay derived mammalian cells in culture
-detects presence/toxicity of unknowns
-no information on individual chemicals
what are the disadvantages of TCDD-EQ and TEQ?
TCDD-EQ
-indirect measure of toxicity
-response to TCDD-EQ varies among species
-no knowledge of specific congeners in sample
TEQ
-non-additive interactions are not accounted for
-only specified congeners are accounted for
-potential for future ‘surprises’
what is the project summary?
what is the study design?
what was the study design for american kestrel?
what is the study design for great horned owls?
what were the toxicity reference values in the data analysis?
what are the hazard quotients?
what is the decision procedure?
-integrating multiple lines of evidence
-excruciating (months) negotiations
-trying to cover absolutely all eventualities
-data ‘available’ but not considered
-approach used to ensure that an objective decision was made
-carp (aquatic environment) essentially a non-issue-very low concentrations (at least a little common sense)
what was the decisions matrix?
-comparing results for on-site vs. reference
-one matrix for each species
what were the results of the carp eggs?
-small reference sample size
-concentrations very low
-not considered further
what were the results of american kestrel eggs?
-concentrations of TCDD-EQ and TEQ were comparably low
-no statistical differences in concentrations of TCDD-EQ or TEQ were found between reference and RMA locations
-HQs<1
what were the results of great horned owl livers?
clear exceedance of HQ
-but reference also in exceedance
-TEQ and TCDD-EQ results were comparable
-statistically significant differences in TCDD-EQ between adult owls from reference and RMA (small sample size may not be representative)
-some owl liver specimens had HQ>1
-highly variable results
-some high hits
-dieldrin poisoning (confounding factor)
