Water and land

Water, Ash, and the Contamination Record

Plainfield’s public drinking water is drawn from the ground, not from a reservoir. The residues that waste-gasification and incineration plants produce — fly ash, bottom ash and process leachate — are documented in the peer-reviewed literature to carry leachable heavy metals and PFAS, and, in the regulatory record, to have reached groundwater at comparable sites. This page sets those facts side by side, using primary sources.¹²⁵

Three questions, answered from the record. Where does Plainfield’s water actually come from? How dangerous are the specific contaminants already documented in this kind of ash, on a well-water pathway? And at facilities and processes like the one proposed, what have the ash and leachate done to groundwater elsewhere? Each precedent below is labeled as a comparable precedent, not a prediction, and each is anchored to its primary EPA, CT DEEP, USGS, CDC, IARC or peer-reviewed source.

Part one

Where Plainfield’s Water Comes From

Plainfield does not draw its public supply from a surface reservoir. The relevant water here is groundwater — the same water body under and around the proposed site.

• The public water system serving Plainfield — Connecticut Water’s Plainfield System, state identifier CT1090081 — draws its supply from groundwater wells, not from a surface-water source.¹
• CT DEEP identifies Connecticut’s stratified-drift deposits, including those of the Quinebaug River basin, as the “most productive aquifers in State… especially where thick, coarse grained, and hydraulically connected to large streams or lakes.” By contrast, the state’s bedrock yields only “adequate supplies for domestic use.” The large-yield water under this region is the stratified-drift aquifer.²
• The scale of that aquifer is measurable. The State of Connecticut’s own Quinebaug Valley State Trout Hatchery, in Plainfield, draws 1,290,816,000 gallons of groundwater a year from 12 high-volume wells operating around the clock. A 2023 state project to conserve between 632 million and 946 million gallons a year is described by CT DAS and DEEP as “significantly reducing the stress on the aquifer.”³
• In the rural corridor around the site, homes outside the Connecticut Water service area draw their household supply from private groundwater wells tapping that same subsurface water.¹²

The aquifer-protection finding, stated plainly. This page does not claim the parcel sits within a state-designated Aquifer Protection Area. CT DEEP’s official Aquifer Protection Areas map for Plainfield and a live point-in-polygon query against DEEP’s own GIS service both return zero regulated Aquifer Protection Area at the site; a 500-meter buffer also returns none, and the nearest APA (Gallup, No. 78) lies roughly 500 to 1,000 meters away. That negative finding is stated here as a fact. The verified water risk is narrower and firmer: Plainfield relies on groundwater — public wells and private wells drawn from the Quinebaug stratified-drift aquifer — and the state trout hatchery draws about 1.29 billion gallons a year from that same aquifer system.²³¹⁴

Listed species: what the state map shows, and does not

The proposed site does fall inside a current CT DEEP Natural Diversity Data Base area — a live query against DEEP’s mapped polygons returns a hit at the site (map date June 2026), meaning a state-listed species or a significant natural community is known within the mapped area. But DEEP masks the identity: on all public NDDB products, “exact locations and species names have been masked.” So the accurate statement is this: the site is within a state-mapped listed-species area; the species is not publicly disclosed, and no official record confirms bald eagle specifically. Only a formal DEEP Environmental Review Request could resolve which species is present.¹⁵¹⁶

Part two

Who Lives Around the Site

Connecticut’s environmental-justice law is not abstract here. Under CGS § 22a-20a, a proposed “affecting facility” in an environmental-justice community must file a meaningful public-participation plan — and CT DEEP already has such a plan on file for the SMART Technology Systems project at Norwich Road and Black Hill Road.⁴⁵

• Plainfield is on the state’s 2025 distressed-municipalities list with no grace period, which by statute makes the whole town an environmental-justice community.¹⁷
• The census block groups encompassing the project area are low-income by the state’s own measure: 43.1%, 37.0% and 44.5% of residents live below 200% of the federal poverty level — each above the 30% threshold that defines an EJ community under CGS § 22a-20a(a).¹⁷
• CDC/ATSDR’s Environmental Justice Index places the surrounding census tracts’ environmental burden in the 57th to 75th percentile nationally — a live federal substitute for the EPA EJScreen tool that was removed from public access in February 2025.¹⁸

These figures cover the census tracts and block groups encompassing the project area, geocoded from the road-name centroid; no public parcel-boundary service exists to tie them to the exact parcel line. The whole-town distressed / EJ status is firm regardless.

Part three

What the Residues Contain — and Why It Matters

Waste-to-energy plants of this kind do not make their input disappear. They convert it into flue gas, energy, and solid and liquid residues — fly ash, bottom ash or slag, and process leachate. What those residues contain is established in the peer-reviewed literature and the federal regulatory record.

• A 2025 peer-reviewed review in the journal Toxics states that municipal-solid-waste incineration fly ash “is recognized as a hazardous solid waste due to its enrichment in toxic heavy metals and high leaching potential,” naming lead, cadmium, chromium, arsenic, mercury, nickel, copper, zinc and others, alongside chlorides and dioxins. The same review notes that in landfills these pollutants “could migrate through various pathways such as leachate transport, groundwater diffusion, and plant uptake.”²⁵
• The U.S. EPA has made coal-combustion residuals a formal National Enforcement and Compliance Initiative — “Protecting Communities from Coal Ash Contamination” — citing the “long-term release of contamination into groundwater, drinking water, or surface water.” The heavy metals of concern in coal ash (arsenic, cadmium, chromium, mercury, lead) are the same class found in municipal-waste combustion ash.¹¹²⁵
• Waste gasification and pyrolysis are regulated as waste incinerators in the United States and the European Union, because the synthetic gas they produce is ultimately combusted; the process is distinct from mass-burn, but the residue and emission concerns are not eliminated by the name.¹²²⁷

Why those metals matter — and the well-water pathway

The point is not the list of chemical names; it is what authoritative agencies say those specific contaminants do, and that Plainfield’s exposure route is drinking water drawn from the ground.

• Arsenic and cadmium are classified by IARC as Group 1, carcinogenic to humans. ATSDR ties drinking-water arsenic specifically to bladder, kidney, liver, lung, gastrointestinal, pancreatic and skin cancers, including from in-utero exposure — the exposure route that matters where households draw water from private wells.¹⁹²⁴
• Lead has no known safe blood level. In 2021 the CDC lowered its childhood blood-lead reference value from 5.0 to 3.5 µg/dL and states plainly that no safe level has been identified; low-level exposure lowers children’s IQ, learning and development. Lead is an IARC Group 2A probable carcinogen.²⁰²¹
• Mercury and cadmium are governed by federal minimal-risk levels set very low: mercury’s chronic inhalation MRL is 0.3 µg/m³ and its oral inorganic MRL as low as 0.00001 mg/kg/day, while cadmium’s critical effect is kidney (renal tubular) damage. These are the same metals the peer-reviewed review names in the ash, and the reason their leaching potential is treated as a hazard, not a nuisance.²²²³²⁵

PFAS: measured in real facility streams, not destroyed

The concern that thermal treatment does not eliminate PFAS is not an assumption; it has been measured at full-scale plants.

• At three full-scale waste-incineration plants, PFAS was measured in leachate (mean 215 ng/mL), fly ash (16.4 ng/g) and bottom ash (14.6 ng/g); one plant discharged roughly 384 kg of PFAS a year through leachate alone. PFAS survives combustion and concentrates in the residues.²⁸
• A 2023 study made the first confirmed measurement of PFAS in waste-to-energy flue gas — 4.0 to 5.6 ng/m³, rising to 27 with sludge co-firing — as well as in bottom ash, air-pollution-control residue and treated process water. PFAS leaves through the stack, not only in ash and water.²⁹
• A critical review found that PFOA and PFOS only fully mineralize at about 1,000 °C or higher; below that, products of incomplete combustion of unknown toxicity form. Typical municipal-waste plants run below that threshold.³⁰
• A synthesis of the three disposal routes — landfill, wastewater and incineration — concluded that none eliminates PFAS; each returns it or its breakdown products to another medium, a cyclical problem rather than a destruction solution.³¹

The residues are not the argument. What the residues have done, in the documented record, is.²⁵

Part four

The Contamination Record

Precedent, not prediction

Each entry below is a documented, comparable precedent — a real facility or process whose groundwater outcome is on the primary regulatory or scientific record. None is offered as a forecast of what the Plainfield proposal would do. Each is offered as evidence of what this class of facility has done, so the risk can be weighed on facts rather than assurances.

In Plainfield: Gallup’s Quarry

Plainfield already has one federally documented groundwater-contamination site — and a gasification plant already operates on part of it.

• Gallup’s Quarry is a 29-acre former gravel pit in Plainfield placed on the EPA Superfund program after illegal chemical dumping. Groundwater, soil and sediment there carry volatile organic compounds, PCBs and heavy metals; arsenic and 1,4-dioxane were added to monitoring in 2012, and PFAS compounds were detected during the November 2020 groundwater sampling event. The remedy relies on long-term monitoring and institutional controls that restrict use of the contaminated groundwater.⁶
• Part of that same Superfund site is now home to the Plainfield Renewable Energy biomass gasification facility, which “became fully operational in January 2014.” Plainfield’s only documented groundwater-contamination site already hosts one gasification plant; the SMART proposal would add a second, larger one taking in mixed municipal waste.⁷

On Plainfield’s river: the Putnam ash landfill

• A 2021 CT DEEP adjudication decision documents the Wheelabrator / Waste Innovations ash landfill in Putnam, on the Quinebaug River — the same river system as Plainfield — which receives ash from Connecticut’s trash-to-energy incinerators. Its leachate is sent to the Putnam water pollution control facility, and the decision addresses first-time PFAS testing of that leachate and site groundwater. Ash from a new Plainfield plant would enter the same disposal stream on the same river.⁸

Coal gasification, decades on: Mason City and Waterloo, Iowa

Two former coal-gasification plants show how long groundwater damage can persist — and that in one case the federal government has declared it beyond cleanup.

• Mason City, Iowa (operated 1900–1951): coal-tar contamination reached both the shallow and the deeper aquifer. EPA’s April 2023 five-year review found that in the deeper aquifer, “levels of benzene and benzo(a)anthracene were increasing at some locations” — more than seventy years after the plant closed.⁹
• Waterloo, Iowa (operated 1901–1956): contamination was severe enough that EPA “determined that it was not feasible to clean up all of the groundwater contamination” and designated a “technical impracticability zone.” The groundwater there “is expected to remain contaminated for the foreseeable future.”¹⁰

PFAS from combustion: Norlite, New York

• At the Norlite incinerator in Cohoes, New York, which burned PFAS-laden firefighting foam under federal contract, Bennington College sampling reported by The Intercept found PFAS in soil and water around the plant, with PFOS measured “twice as high downwind from the facility than upwind of it.” The plant sits less than 200 meters from a public-housing complex home to more than 70 families; New York regulators directed a halt to the foam incineration, and the State subsequently enacted a law banning PFAS-foam incineration in cities including Cohoes. This is an academic sampling result reported in the press, presented here as such; the regulatory action is on the official record.¹³³²

The national pattern: coal ash and groundwater

• The most comprehensive national analysis of federal coal-ash monitoring data, by the Environmental Integrity Project with Earthjustice, found that 242 of 265 monitored U.S. coal plants — about 91 percent — had unsafe levels of at least one coal-ash pollutant in nearby groundwater, including arsenic, lithium, cobalt and cadmium. The same heavy metals appear in municipal-waste combustion ash.²⁶¹¹

Questions and answers

Frequently Asked Questions

Where does Plainfield get its drinking water?

Plainfield’s public water system (CT1090081) draws from groundwater wells, and homes in the rural corridor outside the service area use private groundwater wells. The relevant water body is the aquifer, not a surface reservoir.¹²

Is the proposed site on a designated Aquifer Protection Area?

No. CT DEEP’s official Aquifer Protection Areas map and a live GIS query both return zero regulated Aquifer Protection Area at the site; the nearest one is roughly 500 to 1,000 meters away. What is documented is that the region’s water is groundwater from the productive stratified-drift aquifer that supplies wells and the state trout hatchery.¹⁴²

Is the proposed site in a mapped wildlife-protection area?

It is within a state-mapped listed-species area; the species is not publicly disclosed, and no official record confirms bald eagle specifically. CT DEEP’s Natural Diversity Data Base masks species identity on all public products, and only a formal Environmental Review Request could identify what is present.¹⁵¹⁶

Are the metals in the ash actually dangerous in drinking water?

Yes, by authoritative classification. Arsenic and cadmium are IARC Group 1 human carcinogens, arsenic in drinking water is tied to several cancers, and lead has no known safe blood level per the CDC. Plainfield’s exposure route is groundwater drawn from wells, which is why the leaching potential of these metals matters here.¹⁹²⁰²⁴

Does gasification or incineration ash contain contaminants that can reach groundwater?

The peer-reviewed literature classifies municipal-waste incineration fly ash as a hazardous waste “due to its enrichment in toxic heavy metals and high leaching potential,” and notes those pollutants can migrate through leachate and groundwater. EPA treats coal-ash groundwater contamination as a national enforcement priority.²⁵¹¹

Is PFAS destroyed when waste is burned?

Not reliably. PFAS has been measured surviving into leachate, fly ash, bottom ash and even the flue gas of full-scale plants; full mineralization needs about 1,000 °C, above what typical municipal-waste plants reach. No disposal route studied — landfill, wastewater or incineration — eliminates it.²⁸³⁰

Has a gasification plant ever contaminated groundwater beyond repair?

At the former Waterloo, Iowa coal-gasification site, EPA determined full groundwater cleanup was not feasible and designated a “technical impracticability zone” expected to remain contaminated for the foreseeable future.¹⁰

Does Plainfield already have a documented contamination site?

Yes. Gallup’s Quarry is an EPA Superfund site in Plainfield where PFAS was detected in November 2020 groundwater sampling; a biomass gasification plant now operates on part of it.⁶⁷