A recently released Navy document reveals that an implausible last-minute health-risk theory killed the Navy’s plan for upgrading and expanding wetlands at Alameda Point where a regional park is planned (“Navy To Create New Wetlands,” Jan. 3, 2019).
A 60-acre cleanup site, known as Site 32, was on track to include 15 acres of seasonal wetlands, along with a doubling of watershed drainage into the wetlands. The regulatory agencies overseeing cleanup — namely, the U.S. Environmental Protection Agency, Regional Water Board, and Department of Toxic Substances Control — had signed off on the plan in 2018. But nothing has been done since the tons of clean soil for the project were delivered there in 2019.
A support agency, the CA Department of Public Health (CDPH), interjected claims that trees, other vegetation, and burrowing animals could compromise the proposed soil cover underneath the 15 acres of proposed new wetlands, exposing people and animals to radiological contaminants from paint residue on scattered objects that have been buried there for 65 years.
CDPH is considered a support agency for the CA Department of Toxic Substances Control and only becomes involved in cleanup at Alameda Point when radium-226 is detected. The Navy is responsible for the success of any remedy in perpetuity.
Site 32, located along the Oakland Estuary where the regional park is slated, became contaminated when the Navy added a new runway in the early 1950s. Waste materials with radium-226 used in luminescent paint had been disposed of in the Navy’s underground dump where the runway was to go over. Bulldozing the land for the runway ended up scraping some incidental radium-tainted artifacts from the surface of the dump, such as a glass vial, deck marker, and instrument dial, onto the adjacent land now dubbed Site 32.
Based on common sense and a review of scientific literature, case studies, and two decades of on-site investigations approved by regulatory agencies, the health risk scenario imagined by CDPH is farfetched.
We asked CDPH to explain how this toxin could rise from a depth of four feet and become a health risk on the surface of a seasonal wetland. The original plan called for excavating the existing wetlands to a depth of three feet, scanning and removing any radiological items at the bottom to a depth of one foot, installing a rodent barrier, and placing three feet of new, clean imported soil up to the original elevation. CDPH responded by saying that the soil and vegetation characteristics of the seasonal wetland “will deteriorate the soil” underneath the wetland.
“As the site matures, hydrophytic vegetation including certain trees that thrive in the wetland environment could cause deep rooted growth into and through the soil cover. Some burrowing animal species could also damage and breach the cover,” said CDPH. “The hydraulic relationship above and below the cover could eventually open and water movement between the areas could occur which could bring radioactive contaminants up into the wetland and surrounding vegetation.”
If radium-226 particles on the waste materials could migrate upward onto the surface of a wetland, it would have done so by now. The two wetland areas in question have been maturing there for 65 years since the new runway was built. The surface water and the wide variety of plant species, including a few trees, are there for sampling to see if this phenomenon has occurred. No laboratory testing for radium in existing vegetation has been performed to try to validate this theory, nor have tissue samples from Mallard ducks, Canada geese or other wildlife that forage in the area been analyzed.
As for burrowing animals, ground squirrels do not typically burrow into wetlands. They are smarter than humans when it comes to living quarters — they do not build on a flood plain. If they were going to burrow anywhere, it would be on the other 45 acres of soil cover. In either case, they would run into a plastic mesh rodent barrier under the three-foot soil cover.
As for trees, they would not be planted or allowed to grow on a soil cover, whether wetland or grassland, because they could be blown over and damage the soil cover, and also because they are less effective than grasses at preventing erosion.
According to a study by the International Atomic Energy Agency (IAEA), which looked at the chemistry of radium-226 in soil and groundwater and case studies spanning up to 40 years, the phenomenon of radium-226 migration does not exist. “The Environmental Behavior of Radium” study states, “The overall conclusion drawn from this wealth of data is that radium does not really migrate through the soil.” It adds that studies of various types of groundwater conditions “suggest that radium does not migrate to any significant extent in groundwater. Radium is mobile only in sulfate-free neutral or acid solutions.”
The Navy’s 2018 wetland delineation study to determine the official size of the wetlands at Site 32 described the soil as moderately alkaline. In other words, the soil conditions are the opposite of acid and therefore not conducive to facilitating movement of radium.
Reference material at the U.S. National Library of Medicine at the National Institutes of Health supports the IAEA study’s findings when it states, “Radium can interact with sediments and dissolved solids in water. When released to groundwater, dissolved radium sorbs quickly to solids and does not migrate far from its place of release.”
The results of the Navy’s routine annual groundwater monitoring at Site 32 show that radium-226 was detected, but not at excessive levels and represented naturally occurring conditions.
The scenarios in which radium can migrate through the soil and groundwater to become a public health risk are found next to mining and processing operations. At these locations a continuous supply of contamination can be introduced into the surrounding environment, to the point where the soil can no longer absorb any more radium. This is not the case at Alameda Point.
The Navy compiled decades of individual studies into the 2017 Remedial Investigation and Feasibility Study before making a decision on what to do in 2018. The study concluded that doing nothing and leaving the site as is would not pose an immediate risk to any visitor. The reason that a three-foot soil cover was the proposed remedy is because radiation scanning only provides certainty to a depth of one foot and therefore was insufficient as a long-term solution, taking into account the potential for erosion.
The recently released document, called a Record of Decision, reveals that on January 19, 2021, the Navy acquiesced to CDPH’s ruling by saying it would mitigate for the loss of wetlands at a different location, possibly by paying into a wetland mitigation bank somewhere else on the Bay.
By killing the on-site wetland plan, the Site 32 remediation cost went from $25 million in 2018 to the current projected cost of $35 million. And seasonal wetlands, which are different from tidal wetlands and offer unique food and shelter habitat values for nesting and migrating birds and other species, will be lost and covered with soil. They are unlikely to be replaced at Alameda Point.
Originally published in the Alameda Sun.