MONTPELIER — New soil and groundwater tests at the site of a proposed public parking garage confirm that two lots on which it will be built are contaminated with a variety of industrial pollutants that will require remediation.
The reports confirm two earlier studies of the Capitol Plaza Hotel parking lot off State Street. A range of commercial and industrial uses of the site dating back to the 1820s had polluted the site with oil, gasoline, lead, arsenic, mercury, dry-cleaning fluids and carbon from the burning of coal, wood and building fires on the site, according to the studies.
The new tests included soil and groundwater samples taken from the adjacent Heney Lot — on which the garage will be partially built — and also show similar contamination of the site.
The tests were required as part of an 81-room Hampton Inn & Suites hotel and garage project proposed by the Bashara family that owns the Capitol Plaza Hotel and Conference center. The Basharas received permits for the hotel and garage in May but then asked the city to partner with them on the garage. The city agreed but increased the size of the garage from 230 to 348 spaces, which extended the footprint of the building onto part of the adjacent Heney Lot. The Bashara family will be required to conduct its own soil and groundwater tests of the hotel site.
The city of Montpelier commissioned Waterbury-based engineering consultants Weston and Sampson to test the garage site on the two lots.
The report on the half-acre site for the garage on the Capitol Plaza parking lot confirmed the site was used for a variety of commercial and industrial purposes over the last 200 years.
“The location of the site in an historically commercial and industrial area of Montpelier indicates that the subsurface soils at the site likely have elevated concentrations of ubiquitous urban contaminants such as polycyclic aromatic hydrocarbons (PAHs), arsenic and lead,” the report said.
Groundwater samples at the northwest corner of the site found the presence of trimethylbenzene, a gas additive, and naphthalene, used to make moth balls, that will require remediation. Several other compounds — benzene, toluene, ethylbenzene and xylenes — were detected but were below Vermont Groundwater Enforcement Standards. The report recommended that monitoring wells at the site can be decommissioned.
However, the report recommended that a corrective action plan be prepared for the site that will include the removal and disposal of contaminated soil off-site. The project calls for the removal of 5 feet of soil across the footprint of the building, amounting to 4,300 tons.
The report found similar contamination of the Heney Lot site that will also require similar remediation.
City officials have said it is too early to provide an estimate of the costs of remediating contaminated soil on the project site.
Remediation of the Capitol Plaza parking lot portion of the project — which has been donated and deeded to the city — will be paid for by the Department of Environmental Conservation because the project site falls within the newly created Tax Increment Financing District that funds infrastructure improvements to promote development in downtowns. Remediation of the Heney Lot will not be covered by DEC because it is a private lot being leased by the city.
City Manager Bill Fraser acknowledged Thursday that the report on soil tests confirmed there would need to be remediation of contamination of the garage site.
“As we expected, given the history of the property, there are various levels of contaminated soils on the site that will have to be remediated,” Fraser said. “There are various levels of remediation — everything from leaving it alone, to reusing on site to disposal in Coventry (at a landfill site) — and we’ll have to sort through what soils go where. It’s a good opportunity to clean up a problematic site and leave the property in much better environmental shape.
“The hotel did their investigation independently. From what we understand, they are in a similar circumstance, but because of the nature of their construction, they have a lot less soil to be removed,” Fraser added.