On Tuesday, the Elementary School Building Committee approved a contract with ADS Environmental Engineering, LLC (through Vertex) not to exceed $41,030 for soil testing and removal on the future Charleswood School site.

Vertex project manager Chris Eberly noted that a goal during construction is to “balance the site … meaning as much soil as you pull out of the ground, you put on the surface,” thereby eliminating the need to export dirt off-site.

The Charleswood School site, however, has slopes with many level changes as well as almost 8,000 cubic yards of loam and subsoil that must be exported, Eberly said.

Eberly talked about a “chain of custody” that links the exportation of soil back to the district. He said in order to export to and be accepted by a permitted facility, a professional must sign off that the soil is “clean.”

The project manager said, “If you give the soil away and someone finds something in it that creates an issue for them, they can trace the soil back to us. Quite often, university and municipal clients do not want to expose themselves to that risk.”

Eberly said ADS was hired for the much-smaller Hopkins School project’s soil testing as well.

He said the work involves “characterizing” the soil, going in with an excavator, taking samples of topsoil and subsoil and evaluating whether it falls within Massachusetts Contingency Plan (MCP) standards.

MCP publishes what it considers normal.

Several years ago, during soil testing at Marathon School, “some things were found in the soil” that resulted in it having to be treated differently, Eberly said.

He added that the findings were not “an extensive problem” in response to a question from ESBC vice chair Tiffany Ostrander.

The scope of the work for licensed professional ADS includes the test pitting program (dig, sample field screening, review of tabulated data, etc.), subcontracted services (backhoe and operator, analytical lab testing) and offsite shipping documentation.

Eberly said the Hopkins School project showed that hiring a licensed professional for this purpose is a “valuable service that would be useful.”

It is better to know upfront and not have to pay someone to move different piles of soil around and test repeatedly as discoveries are made, he added.

If the work is able to start immediately, which is uncertain, the district will know if the soil exceeds MCP levels and the unit costs the contractor would use to deal with it, Eberly said.

If the results are not available ahead of time for bidders, Eberly said, Vertex would describe in the bid documents the approach that would be used. Vertex would ask bidders for unit costs to dispose of soil with a contaminant versus one below the Massachusetts standard. Then the contractor would pay the costs falling below the standard, he added.

ESBC member Mike Shepard asked if $50,000 is the industry standard amount for ADS to have as a risk allocation.

“Essentially it says if they screw something up [negligence, errors, omissions], they are limited to $50,000,” Shepard said.

He added if the town is later sued for the mistake, it will be for a lot more than $50,000.

Eberly said the activities ADP would be doing are very low risk.

“Ultimately, you own the soil, the disposal of it and what is in it,” said Dan Colli, project manager at Perkins Eastman.

Both Eberly and Colli said it is difficult to imagine errors happening when “putting dirt in a jar.”

List of prequalified contractors accepted

The ESBC also voted to accept the list of prequalified contractors as determined by a subcommittee using a state point system and agreed upon scoring system.

In total, eight general contractors and more than 90 subcontractors submitted requests for qualifications. The subcommittee reviewed all firms and determined recommended six general contractors to consider.

The number of qualifiers in each subcontractor category broke down as follows: electrical, four; masonry, acoustical ceiling tile and resilient floors, six; miscellaneous metals, HVAC, waterproofing/damp proofing/caulking, roofing and flashing and tile, seven; plumbing, glass and glazing, eight; metal windows and fire protection, nine; and painting, 11.

Eberly said no firm was interested in being prequalified for elevators following two attempts, so that will move forward under the rules for sub-bidding.