Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the Landfill Monitoring topic
No spam. Unsubscribe anytime.
Health department: landfill groundwater results stable; CDC consultant classifies site as GW‑3, contaminant levels well below regulatory triggers
Summary
Annual groundwater resampling at the capped landfill showed results consistent with April sampling; CDC consultant risk characterization classifies most samples as GW‑3 with no hot spots and contaminant concentrations far below GW‑3 standards and far below drinking-water limits for the site’s use.
Department staff reported to the Board of Health on July 21 that recent groundwater resampling at the capped landfill produced results consistent with prior sampling and that a consultant’s risk characterization classifies the site largely as GW‑3.
Michael (health department staff) summarized that historical averages and the late‑June sampling showed no material change from the April results. A consultant working with the department — described in the report as a CDC consultant — prepared a risk characterization that places groundwater in three categories: GW‑1 (within a drinking-water supply area), GW‑2 (groundwater within 30 feet of a building) and GW‑3 (all other areas). The landfill samples were classified mainly as GW‑3, which carries higher numeric standards for some contaminants than GW‑1 and GW‑2.
Michael said the site’s concentrations are “not even remotely close” to the GW‑3 numeric standards used in the risk characterization. He gave 4‑dioxane as an example: well results in the range of 4–8 were far below the GW‑3 standard cited in the consultant’s report (the consultant’s chart used a GW‑3 level that the consultant reported as 50,000 [units as reported in the report]). The consultant’s analysis found no hot spots — no sampling locations with levels markedly higher than the surrounding area.
Staff noted some parameters show visual trends (for example, a rising pH at some wells) but that overall the results do not indicate an unusual pattern tied to the landfill cap or surface-water sampling; one surface-water location to the northwest could not be sampled earlier in the season because it was dry.
The department said it intends to continue resampling whenever there is an exceedance and had previously requested relief from a certain state program (rescinded per the report). No immediate public‑health action was recommended in the meeting discussion.
Why it matters: Ongoing monitoring informs whether the capped landfill is producing off‑site impacts and whether the town needs to take remediation or notification steps. The consultant’s GW‑3 classification and the absence of hot spots suggest consistent conditions across sampled locations.
Background: Staff said the consultant used historical data to produce risk categories and the department will maintain annual monitoring and resample after any exceedance.
