Special Bd. of Aldermen — 10/26/15 Page 5
Mr. Millan-Ramos So in a nutshell what is our recommended alternative, again on the site, the Mohawk
Tannery site? As | said, consolidating all the waste, sludge and soils from those satellite areas at lagoon areas
1 and 2 using one of three vertical containment technologies, | already mentioned we are leaning towards the
so-called secant wall, backfilling those excavations with clean fill, protecting the integrity of the encapsulated
area and preventing the use of ground water, the land-use restrictions and ensuring the remedy effectiveness
stays with groundwater monitoring and regular maintenance.
| know that you probably have a lot of questions about the cost estimate that we put in the EC/CA and | think
the best source of information that we have to show the basis of those estimates, is what we call the Technical
Memorandum. That is a document, it is called Removal Alternatives Update Technical Memorandum. It is on
our website and | have put here a link to the document. | have shared this with the City already | am sure and
it is a public document, it shows how the cost estimates were developed. The cost estimates that we included
in that amended EC/CA.
I’ve also left in this presentation the repositories of materials that we have including our own websites, offices
and the Nashua Public Library. And, of course, if you have any questions, please just call or send me an e-
mail and we will do our best to clarify anything. | think that is basically the gist of what | wanted to make sure
you guys understood tonight. Thank you.
President McCarthy
So | had actually asked a question regarding removal of materials and moving them around and | am
paraphrasing what | heard from some of the neighbors. There seem to be some of the neighbors who were
reasonably content with the idea of the secant wall to retain what is in the lagoons but less so with the
containment on top with the retaining wall and moving the sludge.
| guess my question would be do we have any understanding of the cost difference of if we are going to dig
material up, and move it from one place on the site to another, what would it cost for the amount of material
that we are talking about, to dispose of it instead. To contain the two big lagoons and to remove the waste that
is on the Fimbel site for example instead of moving it?
Mr. Millan-Ramos | believe we do have preliminary estimates for that.
Ms. Taylor We do. EPA didn’t really have a contractor that we had available to do an additional cost estimate
for this type of work so we actually asked the developer themselves and his consultant who is actually in the
audience tonight, Darren Santos, from Geolnsight, to work on an estimate for this. So they did contact the
disposal facility up in Rochester, NH and got some estimates for transportation and disposal and with all the
other line items and | have to tell you it is a back of the envelope calculation, it is not detailed, but they believe
that it would cost about $6.5 million dollars to dispose of Fimbel Door off-site, at an off-site disposal facility.
President McCarthy
That’s incremental cost or is that just the cost of removing it because presumably there is some cost savings if
we are not capping that on-site because we don’t have to build the ...
Ms. Taylor Yes | mean | don’t think that has been clearly determined in my discussions with the developer. He
feels like possibly if he didn’t need a retaining wall there possibly could be about a $2 million dollars saving.
So | guess there would be then $4 to $4.5 million dollars. But again, that is back of the envelope, we didn’t do
anything in detail.
