Draft RI/FS Human Health Risk Assessment Coming Soon
- Details
- Published: Monday, 02 December 2019 20:37
The Environmental Protection Agency (EPA) updated the community on the Upper Columbia River Site Remedial Investigation & Feasibility Study (Upper Columbia RI/FS) in Northport, WA on October 15th.
The big news is that the draft Upper Columbia Human Health Risk Assessment (HHRA) is expected to be released by November 11, 2019. The public will have the opportunity to review the draft through the Citizens for a Clean Columbia organization. The Final HHRA is expected by February 2020. “It’s a critical milestone representing years of effort and the collective work of multiple agencies and stakeholders,” said Robert Tan, EPA’s Upper Columbia Remedial Project Manager.
EPA describes the HHRA as “the process to estimate the nature and probability of adverse health effects in humans who may be exposed to chemicals in contaminated environmental media, now or in the future.”
Of particular interest to the upper Columbia River Valley and Northport Community is human exposure to lead. A focal point for the HHRA is children who’s rapidly growing bodies absorb lead more rapidly than adults. Child exposure, for instance, can negatively affect cognitive development and self-control.
At the Northport meeting, EPA previewed how the HHRA will use blood level modeling to characterize human health risks in the Upper Columbia Valley. EPA will share this process at the Lake Roosevelt Forum Conference as well.
Because the science and regulatory environment regarding lead toxicology is still evolving, 3 lead risk evaluation benchmarks will be shown in the HHRA. These protection benchmarks can then be compared to the presence of lead in soils to evaluate human health risk.
Using sites sampled to date, the difference in number of sites exceeding the benchmarks is far higher when using the most protective benchmark. Specifically, 392 sampling units previously tested exceed the most protective benchmark; 88 units exceed the middle benchmark, and 12 units exceed the least protective benchmark. These results will help EPA plan for future potential cleanup actions or assessments and may be considered during the planned Feasibility Study.
As noted in the RI/FS updates, to date 17 residential properties have received soil cleanup via voluntary agreements between EPA and Teck American Incorporated.
The HHRA is expected to be a lengthy document covering findings for river-based exposures such as fish consumption, beaches and surface water; and upland exposures such as plants and contact with soils. Once the draft is released, then finalized after public comment, EPA and project partners will begin the process of assessing interim clean-up or other remedial measures that may need to be taken prior to completion of the Remedial Investigation and conducting a site-wide Feasibility Study.
The HHRA is being completed as part of a 2006 settlement agreement between EPA and Teck American Incorporated.