Warning raised about ’emerging contaminants’
by Cynthia McCormick
A new study by the Silent Spring Institute in Newton (MA) shows that sewage treatment plants aren’t any better at removing a new class of contaminants from treated water than septic systems.
Researchers found that antibiotics and chlorinated flame retardants, for instance, pass through both systems relatively unscathed.
The results weren’t surprising because wastewater treatment systems are made to remove pathogens and solid waste, not the chemicals contained in medicine, herbicides, plasticizers and other products, Silent Spring Institute research scientist Laurel Schaider said.
But the study shows that systemsbeing developed to protect the Cape’s coastal waters from nutrient overloading and algae blooms should also take steps to protect drinking water from what scientists call “emerging contaminants,” she said.
Many of the chemicals are considered hormone disrupters that act like estrogen, which has caused breast cancer cells to grow in a laboratory setting.
For the report — available at www.silentspring.org — the Newton-based research institution analyzed 16 already existing studies of wastewater and septic system treatments, including two originating on Cape Cod.
In recent years, Silent Spring has released studies showing the presence of dozens of emerging contaminants in public and private wells on the Cape. The Cape now has “a critical moment” in deciding the future direction of wastewater treatment and how it affects drinking water, Schaider said.
“It is a concern, and the county will be looking at how best to deal with the issue,” Tom Cambareri, water resources program manager for the Cape Cod Commission, said. “We’re evaluating all possible alternatives.”
Bacteria break down some chemicals and use them as a food source, removing them from the water supply, Schaider said. Both sewage treatment systems and septic systems do a good job removing chemicals such as caffeine and acetaminophen, for instance, she said.
Other chemicals such as the antibiotic sulfamethoxazole and TCEP, a chlorinated flame retardant, pass through both systems largely unchanged, Schaider said.
Next, Silent Spring will look at whether ecological toilets of the type being evaluated for use in Falmouth remove the contaminants from treated water, Schaider said.
Source: South Coast Today.
