Langan: Limited soil impacts found at proposed Middletown 9-1-1 center; delineation recommended to estimate costs

Jamie Barr, principal at Langan Engineering and Environmental Services, told the Middletown Public Safety 9-1-1 Center Building Committee on July 31 that a limited phase 2 investigation of the 499 Mile Lane site found only a few localized soil impacts and did not trigger Connecticut Department of Energy and Environmental Protection (DEP) reporting.

Barr said Langan took 13 soil borings across the proposed building footprint and attempted groundwater sampling but did not encounter groundwater (the deepest bore reached about 18 feet). He reported localized petroleum-related compounds near an old underground storage tank and one separate detection of arsenic. "It was relatively benign," Barr said. "We did not identify anything that would trigger Connecticut DEP reporting or a release." He added that such hits are "not uncommon" on urban or light-industrial sites.

Why it matters: Barr warned that moving or disposing of soils with those marginal exceedances could increase development costs. "If we're gonna remove those soils for development, they will come with some kind of premium cost," he said, recommending a delineation study — step-out borings at 5-to-10-foot intervals around the exceedances — to estimate the extent and volume of impacted material before construction. The delineation is not required by DEP based on current results but would give the committee a clearer cost estimate.

Committee members pursued follow-up questions about regulatory oversight and site history. A member asked whether DEP approval would be required before excavation; Barr replied there was no DEP involvement at this stage because reporting thresholds were not exceeded. The committee also discussed historical use of part of the property as a former Nike missile site and noted that, according to one participant, the Department of Defense transferred the parcel and was required to deliver a ‘‘clean site’’ in that transfer.

Practical next steps discussed included having the architect consider minor footprint adjustments to avoid the small impacted areas and incorporating the delineation results, if obtained, into design and cost estimates. The committee received an estimate for the delineation phase from Langan during the meeting and did not take an immediate formal vote to authorize that work at the special meeting. Barr said the team will coordinate with the project architect on grading and soil-management plans to try to minimize off-site soil movement and disposal costs.

The committee also noted the site’s likely construction approach (slab grade with limited excavation) and that a lack of groundwater in borings reduces the chance of encountering deeper groundwater contamination during routine construction. Barr cautioned the committee that, on sites like this, additional isolated hits are possible and that delineation would reduce uncertainty about potential disposal volumes and costs.

The committee will consider the delineation estimate and coordinate next steps with the architect and Langan in upcoming meetings.