The long-awaited review of a soil study examining the safety of planned Jefferson Parkway construction was presented to the Arvada City Council on Aug. 24. With the review came a verdict from the …
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The long-awaited review of a soil study examining the safety of planned Jefferson Parkway construction was presented to the Arvada City Council on Aug. 24. With the review came a verdict from the Colorado Department of Public Health and Environment (CDPHE) that the proposed project is safe.
Bill Ray, executive director of the Jefferson Parkway Public Highway Authority (JPPHA) — the entity planning the Jefferson Parkway, a proposed toll road through northwest Arvada — presented the findings with Jennifer Opila, director of the Hazardous Materials and Waste Management Division of the CDPHE.
“We are confident that construction of the parkway is not going to produce a risk to a parkway construction worker or a resident that would need to be under regulatory control,” Opila said. “There is a very small possibility that there could be something out there that would be discovered during parkway construction and if that were the case, then there are already agreements in place between the Department of Energy, Environmental Protection Agency and the state health department to basically stop all activities when anything like that occurs and to evaluate what the situation is.”
JPPHA launched the study in May 2019 to ensure the proposed route, specifically the portion of the route that runs adjacent to the site of the former Rocky Flats Nuclear Weapon Plant, was safe. Active from 1952 to 1989, the plant was shut down by the federal government after leaks, fires and other incidents caused plutonium to contaminate the site's soil.
The site was cleaned up by the early 2000s. But numerous community members have spoken against the Jefferson Parkway's proximity to Rocky Flats, believing the construction could stir up particles of plutonium that were left behind after the cleanup and put members of the public at a greater risk for developing cancer.
The JPPHAhas sought to ease these concerns with its study. The study tested about 250 samples from about 2.5 miles of land, Ray said.
Three months after the study got underway, the JPPHA reported to CDPHE that a soil sample had tested for 264 pCi/g (picocuries per gram) of plutonium. Based on a government-established safety measure, soil should contain no more than 50 pCi/g of the substance.
In the original testing of the soil sample, only a portion of the sample was tested, CDPHE's Lindsay Masters told Colorado Community Media in a previous interview. Masters is the agency's environmental protection specialist.
A second test on a different portion of the sample found less than 2 pCi/g of plutonium.
Even so, potential environmental concerns, in addition to other concerns, were enough to spark Broomfield city councilmembers to unanimously vote to withdraw from JPPHA in February. Broomfield has been one of three entities involved in JPPHA, alongside Arvada and Jefferson County.
Meanwhile, throughout the remainder of the study, no other samples were found to have plutonium levels above or close to the established safety levels of 50 pCi/g. In October, the CDPHE announced that a batch of 25 samples in the area all tested for less than 4 pCi/g.
Even so, when the CDPHE created its review of the report, it ran a “worst-case scenario,” Opila said. In other words, the CDPHE ran the numbers for a hypothetical scenario in which particles with that higher rate of 264 pCi/g were imagined to be scattered throughout the entire testing site.
Even in that scenario, construction workers would be exposed to a radiation dose measured at 11.52 milligrams per year. Opila said regulatory intervention begins only for areas where nearby individuals would face a minimum exposure level of 25 milligrams per year, more than two times the level construction workers would face in the so-called worst-case scenario.
Opila added that nearby residents, in that same scenario, would only face a dose of 2.6 milligrams per year.
Councilmembers had several questions, particularly about the depth of the soil sampling process. Ray said that while the vast majority of samples were taken within the top two inches of the soil, a handful, or about six to 10, were taken at “various depths.”
Opila said the CDPHE approved of this methodology because “the historic literature on the windblown contamination that exists within the refuge and the parkway transportation corridor shows that it is primarily in the first couple of inches in the soil.” Further, “even if there was higher concentrations at a lower depth, we believe our modeling actually takes that into consideration.”
The majority of councilmembers did not weigh in one way or the other about the study's findings.
But councilmember David Jones, who is also the chairman of the JPPHA board, said he found that the findings reinforced other studies that have been conducted in the Rocky Flats area.
“For me, having grown up and here and seen Rocky Flats while it was in its active state and then through the shutdown, it's good to know that the studies have been reinforced,” he said, “and we continue to see that there's no great danger or harm as long as you stay out of that operable unit area,” or the central, off-limits portion of the Rocky Flats site.
JPPHA has been waiting to go forward with several items of business until the soil study findings could be reviewed by the CDPHE. Now, the next step for the parkway is to negotiate the terms of Broomfield's withdrawal from the authority, Ray said in an email.
“Once that matter is resolved, the county and Arvada will have to make a determination about how to proceed,” he said.
The city of Arvada's communications manager, Ben Irwin, said negotiations between the three parties had not yet begun as of Aug. 27 but are expected to begin soon.
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