Need to return call by / at/between and . Signature: Project No.: 0172.08.036.500 Page 1 of 2

Project Name: Dental Amalgam 

### CBI?

Yes

No TELEPHONE CALL RECORD Incoming Outgoing Date: 05/10/11 Time: 2:30 am

pm

Company Name: SolmeteX ERG Staff Name: Kimberly Landick

Contact Name: Al Dube` Contact Phone Number: (508) 397-9725

General Subject: Polishing System for Removing Dissolved Mercury



### TOPICS DISCUSSED AND ACTION TAKEN

On May 10, 2011 at 2:30pm I called SolmeteX (508-393- 5115) and asked for information about the polishing system for removing dissolved mercury. I talked to a support team member, Kelly, an d was told to contact Al Dube` directly on his cell phone (508 -397-9725). I called Mr. Dube` and left a message explaining that I was requesting information on the polishing system for removing dissolved mercury.

On May 10, 2011 at 4:00pm Mr. Dube` retuned my call. I explained that ERG is working with EPA to compile some information about the polishing system for removi ng dissolved mercury and that I had some questions for him. See questions below with answers following in blue.

1. Can you explain the components of the polishing system?

It is a pump and treat system working with an am algam separator. The waste first goes from the each chair to a standard amalgam separator that eliminat es the mercury solids. This separator is large enough to hold the liquid for one day. At the end of the day the amalgam separator is shut off and the liquid is pumped to a secondary step holding tank (with no solid s present). It then goes through an oxidation step (normally it is not recommended to oxidize the dent al waste stream but doing so without any solids present allows for speciation of th e mercury, which allows for removal of dissolved mercury – this technology is patented by SolmeteX), and then is pumped through 3 filters. The first filter is a granulated activated carbon filter, the second is a Keyle:X resin cartridge, and the third is a 0.5 micron filter. This process allows for the removal of dissolved mercury. It is not perfect however; the dental stream is very difficult to treat because there ar e so many constituents. For example there are over 35

different line cleaners with various ingredients and also the possibility for organics to enter the waste stream. But by allowing speciation of the mercury with the oxidation step and using the 3 filters, the dissolved mercury can be removed.

2. Can you give an estimate of the capital cost for the polishing system?

The approximate retail cost is $4,000 each.

3. Can you give an estimate on the operation and maintenance costs for the polishing system?

There are 3 pieces of the polishing system that require maintenance. The first is the filters which need to be replaced about twice a year, depending on the dental office’s waste stream. The filters are $600 for

the series of three. This is an annual cost of $1200. The standard am algam collection container attached to the polishing system also needs to be replaced. Th is costs $300 per container and needs to be replacedNeed to return call by / at/between and . Signature: twice a year, adding $600 to the annual O&M cost. Th e final maintenance cost is chlorine tablets for

disinfection. These are obtained fr om any local pool vendor and it is es timated that 2-3 buckets are used annually. Costs can be gathered from local vendors.

4. Are the components of the polishing system replaced at the same time as the amalgam separator components?

Not really. The collection container has a fill line so a visual inspection can be done to determine when to replace it. The filters are replaced when breakth rough has occurred (determined by a spike in the waste stream). These replacements can occur at a ny time and do not necessarily line up with when an amalgam separator components need to be replaced.

5. How much demand do you currently ha ve for the polishing system?

Not much. There is no law/statue/rule in the United St ates that requires a de ntal office to remove dissolved mercury. Toronto has a 10 ppb discharge limit for mercury but doesn’t enforce it because it is not possible to meet consistently. Therefore, there is not a demand for the system.

6. Do you know what percentage of the total me rcury is considered dissolved vs solids?

2-3% of mercury is dissolved if you’re looking at a dental practice. They did a study for Gentle Dental in Massachusetts looking at concentrations of merc ury and found that 2-3% of total mercury can still be a significant amount.

7. Do you know where I can find information on chair si de traps (costs, how ma ny dentists have them, etc)?

Chair side traps are integral to a de ntal chair so if they have a chai r, they have a trap. The traps are maintained by cleaning out the solid particles by dumping them into a bucket or other storage device. The purpose of the chair side traps is to collect larger fragments immediately. Costs can be obtained from dental dealers. Google De ntal Equipment Supply Companie s and Henry Shine and Patterson Dental should be some of the first to pop up.

Chair side traps and vacuum pumps work in tand em to remove mercury. ADA estimates that 78% of dental mercury is removed with only a chair side trap and vacuum pump. Canadians estimate that the percentage is more like 40-60% removal. There are two types of vacuum pump s – wet and dry. 75% of vacuum pumps in the US are wet, 25% are dry. Dry vacuum pumps provide a much larger water savings than the wet pumps. They are more environmentally fr iendly (because they use a lot less water) and they are more economical. Most dentists use wet pumps b ecause that’s the way they have always done it and they don’t care to change. However, if there was a rule requiring dentists to install dry pumps or knowledge that they provide a large cost savings on water, then many de ntists would change to the dry

vacuum pumps.

8. Can you please send me any pictures of the polishing system you may have?

Mr. Dube` asked for me to send him an email and that he would get back to me with pictures. I sent the email at 4:45pm on 5/10/11. Please s ee attached email correspondence.

I thanked Mr. Dube` for his time and told him I’d call back with a ny further questions.