Why IX for interim and not solely GAC?

A GAC filtration system will require significantly more equipment and footprint for interim treatment. In this case, the equivalent amount of GAC vessels would require four semi-trailers instead of two.

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1. What is “PFAS6”?
2. What are the current federal PFAS regulations?
3. What are the current PFAS regulations in Massachusetts?
4. What other PFAS requirements are coming? Is there a test currently available?
5. More than 4700 PFAS compounds exist. Are others likely in our water too?
6. What are the possible sources of the PFAS contamination?
7. Does the fire (or other) departments have any remaining fire retardant foam that contains PFAS?
8. What level of effort would be needed to investigate potential sources?
9. What technologies are effective for PFAS removal?
10. If we implement GAC, why can't we skip the interim filter and install.
11. Why is Wellesley considering GAC over IX? Should we use both?
12. I have heard reverse osmosis is more effective. Why not use that?
13. Of the more than 4700 PFAS compounds how many can GAC remove?
14. Is expended GAC media for PFAS removal considered hazardous waste?
15. Are there broader pollutant tests that we can execute to determine presence of contaminants beyond USEPA requirements? Would GAC filter improve the results?
16. What is the GAC disposal process?
17. Natick is implementing the granulated activated carbon filter system and is expected to go online at the end of December 2021. Could Wellesley piggy-back off of that solution in the interim?
18. What will interim PFAS treatment at the Morses Pond WTP include?
19. Why IX for interim and not solely GAC?
20. Is the interim treatment lifespan driven by time or gallons? If gallons, why not maximize the MWRA capacity to extend the lifespan of the interim system treatment media?
21. If we are able to minimize the use of the container filter, can we re-deploy the interim container filter to our other wells after Morses has been resolved?
22. Any idea on the expected life of the GAC media before replacement/regeneration is needed?
23. Could we simply use MWRA water during that time period?
24. What is the cost difference between using the MWRA water during this 15-18 month time period versus the ion exchange interim solution?
25. Would we own the $1.5 million interim ion exchange solution, or is this a rental or lease?
26. If we own this solution, could it be repurposed to treat water from the other wells if they test over the acceptable limit?
27. Could we share or resell this solution to another municipality once our granulated carbon solution is online?
28. What is the level of confidence in the MWRA connection improvement requiring 3-5 years?
29. What is the minimum Wellesley water sourcing at which our total life cycle is cost competitive with MWRA?
30. Is there a risk that other communities tap into MWRA that Wellesley will lose that option?
31. Can you explain the physical limitations of the current MWRA connection?
32. Please describe the risks of relying solely on our MWRA connection.
33. Should the physical limitations of the current MWRA connection be remedied?