In a recent toxicity test, the U.S. Environmental Protection Agency mixed 10 percent unfiltered wastewater with water from the neighboring Shirtee Creek, into which it ultimately aims to safely discharge treated wastewater. Booth said minnows and other living organisms in the mixture were monitored and all died within a short time – but not because of the toxins one may think.
“The toxicity test fails, not because of lead, not because of mercury, not because of arsenic. There’s too much salt in the water,” Booth said. “This water is too salty for that creek. It’s got high levels of sodium, chlorine, calcium, stuff that isn’t that bad on its own, but adding saltwater to a freshwater stream is going to kill (the ecosystem).”
The same test is being re-run at 1, 2 and 5 percent wastewater dilution to determine a potential discharge rate when factored in with the flow of the creek, he said. Final results are pending, but EPA hopes to use the information to formulate a “worst-case scenario” plan. Roughly 16 million gallons of industrial wastewater remain at the Twin Street site since the now-bankrupt company, which served mostly auto and oil industries, ceased operations in mid-2010.
“Based on the flow of the creek, we can put in a certain percentage of water every day using these numbers and know that nothing will die,” Booth said. “This is in its current state without sending it through filters or anything, but I just wanted to see how bad it is to start, and then we can always improve on that.”
On Tuesday, 5,000 gallons of industrial-strength hydrogen peroxide was again added to one of the 3.5 million gallon equalization basins to oxidize the water and eliminate hydrogen sulfide emissions that cause the familiar rotten egg odor. Other aeration and filtration systems will eventually be used to remove or reduce suspended solids in the waste; however, salt presents a challenge as physical filters are not effective once it has dissolved. Booth said reverse osmosis and distillation are two options to reduce salt concentration, but each costs anywhere from $10-20 million – far more than the project’s $2 million budget.
“What we will most likely do is run PVC pipe into a grassy field on the northern side of the site and basically just water the yard,” he said. “It isn’t going to hurt the grass.”
EPA has already constructed a dirt barrier around the fence line to block water from seeping through, and Booth said they can possibly discharge 200,000 gallons a day onto the clay-like soil.
“We went ahead and took soil samples, and it’s not contaminated, and then we’ll take some afterward,” he said. “By the time we discharge, the water will be so diluted that it shouldn’t be a concern. If needed, we can always scrape the top couple inches of soil to be conservative and dispose of it at a designated landfill.”
In addition to water treatment, EPA has installed Viper 24/7 air monitoring equipment at four locations along the fence line that constantly monitor volatile organic compounds and other pollutants. Recent readings show VOCs at 0.101 parts per million in an eight-hour environment.
“It’s not even a concern until it hits maybe 5 million parts per million,” Booth said, adding that neither he nor other contractors on site have experienced any physical side effects since working at REEF. “(The air monitoring system) is not necessary, but it calms people’s nerves and provides data if they do have a legitimate concern about potential effects, so it’s a good thing to have.”
EPA hopes to begin discharging wastewater in about two weeks, once toxicity results are in and the filtration system is fully assembled. If EPA is able to discharge 200,000 gallons a day, the process will last about 80 days, though those numbers are still rough estimates at this point.
Booth admitted previous time estimates, which initially put the cleanup completion date in January, were optimistic, but said the current treatment plan using much of the existing equipment at REEF is a practical and effective approach.
“We’re sitting on a multi-million dollar waste treatment facility, so I figured they should have the equipment to do the job, and they do,” he said.
With a dwindling budget and a government agency feeling the effects of sequestration, Booth said his goal is to “make the water as clean as possible given the monetary constraints.” They have already cut on-site contractors from eight to three people, he said, and done away with most of the rental equipment that was running around $30,000 a month.
“(EPA) incrementally fund(s) us, so at first they gave $700,000, then the next was around $400,000,” Booth said. “Now we’re getting about $200,000 at a time, so it’s tough. We have a little over $500,000 remaining in the budget out here.”
Will that amount take the cleanup to fruition?
“I hope,” he said.
Contact Emily Adams at firstname.lastname@example.org.