Tritium: breakfast of salamanders
Former San Antonio Water System attorney Russell Johnson cautioned City Council last week about the potential legal pitfalls associated with attempts to reverse developers’ grandfathered rights over the Edwards Aquifer Recharge Zone.
Although Johnson said he has “no dog in this fight,” he debated Austin attorney Doug Young during a “B” session of the City Council, which appears to be on the road to establishing more stringent aquifer-protection rules. “The recharge zone is vast,” Johnson said. “We could pave the entire area in Bexar County and not affect much.”
Johnson added that he believes contamination from real-estate development, oil, pesticides, and other chemical runoff is minimal.
Then he dropped the bomb.
Tritium, a radioactive isotope of hydrogen, has contaminated the Edwards Aquifer since the 1950s when the government tested nuclear warheads above ground in the Western United States.
According to the U.S. Environmental Protection Agency, “Tritium has several important uses. Its most significant use is as a component in the triggering mechanism in thermonuclear fusion weapons.”
Tritium occurs naturally in the environment, in the form of tritiated water that easily disperses in the atmosphere, water bodies, soil, and rock. Everyone is exposed to small amounts of tritium, but those who work or live near nuclear research or nuclear weapons development facilities face an elevated risk of exposure. Higher levels of tritium were dispersed in the atmosphere during weapons testing in the 1950s-60s, and it peaked in 1963.
It is a byproduct of nuclear reactors, and also is used in luminous devices, such as exit signs, aircraft dials, gauges, and wristwatches.
Tritium emits a weak beta particle that can be swept up with a broom, provided the sweeper wears a canary yellow jumpsuit and breathes through a filtered air device.
| Tritium emits a weak beta particle that |
can be swept up with a broom, provided
the sweeper wears a canary yellow jumpsuit
and breathes through a filtered air device.
According to the EPA, “Tritium primarily enters the body when people swallow tritiated water. People may also inhale tritium as a gas in the air, and absorb it through their skin ... exposure to tritium increases the risk of developing cancer.”
So, the question is, did the blind salamander that lives in the aquifer lose its sight from excessive exposure to radioactive tritium deposits in the Edwards Aquifer? Does tritium bleach the skin of the albino catfish? Does it cause cravings for guzzling excessive amounts of beer and Jell-O shots among college students who float the Comal River in the summertime? There’s no reason to hit the panic button, says George Rice, a local groundwater hydrologist who also serves on the Edwards Aquifer Authority, representing Bexar County’s District 3.
Johnson’s remark about tritium made little sense during the council session on the aquifer last week, says Rice.
“If he had a point, I missed it. The only thing it means is that rainwater is reaching the water table in the Edwards, and we knew that.”
Rice, who attended last week’s “B Session” along with numerous members of Aquifer Guardians in Urban Areas and the Greater Edwards Aquifer Alliance. He confirms that Tritium exists in the atmosphere from above-ground nuclear weapons testing, and that it “comes down as rain, can be measured in groundwater.”
Furthermore, its presence is useful because one can measure the relative age of groundwater based on tritium concentrations.
Johnson’s point might have been that if the aquifer contains tritium, then why should San Antonians worry about runoff from pesticides, dry-cleaning solvents, antifreeze, or paint thinner in the city’s sole source of drinking water?
AGUA and GEAA have proposed that City Council adopt stronger aquifer protection rules, such as limiting pavement to 15 percent over the Edwards Recharge Zone, inside and outside of the city limits. Developers could pave 30 percent of the land around their shopping centers or subdivisions provided they purchase twice the original acreage and give half the land to the city for parks, watershed protection, and open space.
Another recommendation is to limit storage of hazardous materials, including fertilizers, pesticides, and petroleum products to no more than 600 gallons inside a container that can hold twice as much in case of a spill.
Despite Johnson’s tritium scare, Young assured Council it could enforce a 15-percent impervious cover limit over the aquifer without worrying about being sued. “Controlling impervious cover is the best way to protect water quality,” he said. •
By Michael Cary
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