Popis

Potential risk to ecological receptors in Heeia Stream and Wetland was characterized through the use of a foodweb model to predict effects to the Hawaiian stilt, chosen as a representative species for all waterbirds. It was assumed that risk estimates for Hawaiian stilt would support management decisions that would be protective enough for other avian receptors as well as native aquatic biota. Risk estimation involved a hazard quotient methodology to calculate critical exposure levels for individual stilt. If an exposure point concentration exceeded the critical exposure level for a particular CPEC, then the potential for adverse ecological effects was indicated. The model predicted that seven of the CPECs total DDT, dieldrin, PCB Aroclors 1254 and 1260, barium, manganese, and vanadium posed some level of ecological risk. The majority of exposure to organic CPECs in this model was obtained through fish consumption. Exposure to riskposing metals was variably partitioned among fish, invertebrate, and sediment consumption. Based on the results of the field study, exposure assessment, ecological effects assessment, foodweb model, and lines of evidence examined, all but five CPECs were eliminated from further consideration in the risk assessment. The five contaminants identified to constitute a risk to ecological receptors in Heeia Stream and Heeia Wetland were total DDT, dieldrin, PCB Aroclor 1254, barium, and manganese. Since indications of potential adverse effects to offsite ecological receptors were not necessarily the result of past practices at the Omega Station, the distribution patterns of these five CPECs in sediments and tissues were closely evaluated for evidence of their relationship to the Omega Station site. Results of this evaluation were as follows: Total DDT and Dieldrin appeared to be attributable to a local source of DDT in the vicinity of lower Heteia Stream. PCB Aroclor 1254 insufficient data to attribute or disqualify the Omega Station as the source. Barium may be attributable to Omega Station activities. Manganese data indicate a depleted source that is equally affecting the lower stream and wetland system at Heeia. It is possible that this source may be the Omega Station. Due to the overall level of uncertainty in the risk assessment and the fact that contaminant hot spots in Heteia Stream and Heeia Wetland have not been delineated, contaminants found offsite of the Omega Station do not warrant cleanup at this time. However, additional studies targeting PCB Aroclor 1254, barium, and manganese are justified since these were shown to pose ecological risk and could potentially have come from the Omega Station. Heeia Wetland is a dynamic environment, affected by intermittent flooding and drying. Therefore, organic contaminants may be widely dispersed. Several followup studies were recommended to help clarify the need for delineation and cleanup of contaminant hot spots caused by past activities at the Omega Station. The following general conclusions were drawn from the ecological risk assessment: The main receiving medium of concern is sediments, which may contain residual levels of contaminants transported from the Omega Station site. The primary exposure pathways are ingestion of contaminated sediment and bioaccumulation along the food web. Dieldrin was the most ubiquitous contaminant found in this study. With the highest hazard quotient and strong lines of evidence, it appeared to pose the greatest relative risk to Heeia Stream and Wetland receptors. However, the Omega Station was not shown to be a source of dieldrin contamination. The lines of evidence presented herein suggested that there is little to no risk of acute or shortterm chronic impacts to ecological receptors in Heeia Stream and Wetland. However, no predictions can be made regarding the longterm survival, growth, and reproduction of native aquatic biota, endangered waterbirds, and migratory birds.

Obecné informace

• Dokumentace

  http://catalog.data.gov/dataset/heeia-stream-contaminants-study Do you think this data is incorrect? Let us know

• Poskytovatel

  US Fish and Wildlife Service, Department of the Interior Do you think this data is incorrect? Let us know

Právní informace

• Právní prohlášení

  http://catalog.data.gov/dataset/heeia-stream-contaminants-study Do you think this data is incorrect? Let us know

• Under which licence can people outside the US reuse this data?

  Creative Commons CCZero Do you think this data is incorrect? Let us know

• Obsah chráněný autorským právem

  yes, and the rights are all held by the same person or organisation Do you think this data is incorrect? Let us know

• Licence obsahu

  Creative Commons CCZero Do you think this data is incorrect? Let us know

• Strojově čitelná data právního prohlášení

  licence k datům Do you think this data is incorrect? Let us know

• Ochrana soukromí

  nehraje roli, data se netýkají fyzických osob Do you think this data is incorrect? Let us know

Praktické informace

• Relevantní datové katalogy

  http://catalog.data.gov/organization/fws-gov Do you think this data is incorrect? Let us know

• Zastarávání

  data časem zastarají, ale mají časové razítko Do you think this data is incorrect? Let us know

• Zálohování dat

  data jsou zálohována offsite Do you think this data is incorrect? Let us know

Technické informace

• URL datové sady

  http://ecos.fws.gov/ServCatFiles/reference/holding/21724?accessType=DOWNLOAD Do you think this data is incorrect? Let us know

• Formát dat

  standardizovaný, otevřený Do you think this data is incorrect? Let us know

Sociální informace

• Strojově čitelná metadata

  název Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  popis Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  hlavní URL Do you think this data is incorrect? Let us know

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  URL dokumentace Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  poskytovatel Do you think this data is incorrect? Let us know

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  klíčová slova Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  hlavní témata Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  distribuce Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  datum vydání Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  datum poslední změny Do you think this data is incorrect? Let us know

• Strojově čitelná metadata

  související časové období Do you think this data is incorrect? Let us know

• Strojově čitelná metadata k distribucím

  datum vydání Do you think this data is incorrect? Let us know

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• Strojově čitelná metadata k distribucím

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• Strojově čitelná metadata k distribucím

  typ média Do you think this data is incorrect? Let us know

• Kontakty

  http://catalog.data.gov/dataset/heeia-stream-contaminants-study Do you think this data is incorrect? Let us know

• Zpětná vazba k publikovaným datovým sadám

  http://www.data.gov/issue/?media_url=http://catalog.data.gov/dataset/heeia-stream-contaminants-study Do you think this data is incorrect? Let us know