Mercury Reduction in Waterstream

Environmentally-Friendly Madison, WI Dentists Keep Amalgam — and Mercury — from Going Down the Drain

Throughout the country, it’s been estimated that dentists handle about one to two pounds of amalgam each year, mainly in the form of old silver-colored fillings removed from teeth. In Wisconsin, amalgam waste cannot be flushed down the drain due to regulations from local municipal wastewater authorities.  How do you dispose of amalgam compliantly yet cost-effectively? 

Before we get into inexpensive ways to properly dispose amalgam, here is a recap of why it can’t go down the drain.

What’s Wrong With Amalgam? 

The problem with amalgam is that it is about 50 percent mercury by weight. Even those with limited chemistry knowledge generally know one thing about mercury: It’s bad for the environment.

Once mercury enters the water stream, microorganisms convert it into methyl mercury – a highly toxic compound that then accumulates in fish, shellfish and any animals that eat them. This exposure rises straight to the top of the food chain, leading to methyl mercury exposure in humans.

EPA studies showed that, unless there was a large industrial source in a community, dental offices using silver amalgam were the single largest source of mercury discharged to Publicly Owned Treatment Works (POTW), accounting for nearly half of the mercury it received.

Madison Metropolitan Sewerage District (MMSD) in Wisconsin was one of the first municipal wastewater authorities in the state to regulate dental amalgam. By working with the local dental community, MMSD was able to significantly reduce mercury in its discharge. The dotted line represents the deadline for dental clinics in MMSD’s service area to install amalgam separators to capture amalgam from dental wastewater, preventing it from entering the sewer.However, changes like at MMSD can only be effective if dentists everywhere understand the importance of being good environmental stewards. 

It will likely not be as much of a problem in the future as dentists are switching from using amalgam fillings to safer alternatives, such as resin composites. But, since so many existing fillings may contain mercury, it could take a generation for amalgam fillings to fully disappear as a mercury source at dental clinics. 

Even if your local municipality does not currently have amalgam regulations, it’s possible that the Environmental Protection Agency will mandate all dentists to have special mercury collection devices in the next few years.

Disposing Your Amalgam Compliantly and Inexpensively

Many environmentally friendly dentists now have a chair-side vacuum line that collects large chunks of the alloy drilled out of teeth. The installation of filters or gravity separators remove 95% or more of the remaining amalgam in the sludge of water, saliva and other fluids suctioned out of a mouth.  This material is collected in a special trap or canister.

At MERI, we pick up amalgam from chair-side traps and mercury capsules, at the same time we pick up other hazardous waste from dental offices. Besides amalgam, MERI also collects hazardous materials like lead aprons, fixer, developer and pharmaceuticals such as Lidocaine.

Because MERI picks up hazardous materials at the time we are picking up sharps and other biohazard materials, there is no additional stop fee. 

Just give us a call ahead of time to make sure that the proper hazardous paperwork is prepared ahead of time before arriving to collect your amalgam or other hazardous materials.

If you’ve yet to find a compliant, inexpensive way to dispose of amalgam, give us a call!

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