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What is the “Leachate Loophole”?
Modern landfills must take extensive measures to contain leachate – the toxic liquid that is created as water percolates through landfills. These controls are required in order to protect surrounding groundwater and streams from the highly concentrated contaminants that leachate contains – including chemicals such as per- and polyfluorinated alkyl substances (PFAS) and 1,4-dioxane. Yet once this leachate is collected, the standard practice is to send it to municipal sewage plants, which are not equipped to remove such chemicals. As a result, the contaminants in leachate pass through sewage plants and into rivers. We call this set of regulatory gaps the “Leachate Loophole.”
How is this project organized and who is involved?
This project is the work of an independent group of advocates organized as The Hudson and Mohawk Rivers Leachate Collaborative. The group includes Jen Epstein (GIS Analyst and Lead Writer), Rebecca Martin (Project Manager), Captain John Lipscomb (Technical Advisor), Pace Environmental Litigation Clinic, Inc. (Legal Research), and Good Work Institute (Fiscal Sponsor).
What exactly is leachate?
Leachate is the liquid that forms as rainfall or snowmelt percolates through a landfill. As the water travels through the decomposing waste, it accumulates pollutants such as heavy metals, pesticides, and synthetic chemicals. Modern landfills are constructed with impermeable barriers that prevent leachate from flowing offsite and polluting nearby ground and surface waters. Some landfills treat leachate onsite, but advanced treatment to remove broad classes of harmful contaminants is not required and is not the norm.
How does leachate reach our rivers?
Most landfills send leachate to municipal sewage plants for disposal. Sewage plants are designed and equipped to treat sewage, not the broad array of harmful substances present in leachate. Consequently, their operating permits focus on a short list of water quality indicators related to human waste. As a result, potentially hazardous or toxic compounds pass through sewage plants into our rivers.
How is leachate transferred from landfills to wastewater treatment plants?
Some landfills have pipes that connect directly to sewer systems. Other landfills use tanker trucks to transport leachate.
How bad is this problem?
Our analysis showed that an average of 89 million gallons of leachate passed through municipal sewage plants in the study area annually for the years 2017-2023. The practice of disposing of landfill leachate at sewage plants that are not specially equipped to handle it is common throughout New York State and beyond the state’s borders. Sewage plants in the study area accepted leachate from landfills as far as 250 miles away, both in New York and out of state.
Why does this issue matter?
The Hudson and Mohawk Rivers are primary drinking water sources for 368,000 people, including groups that disproportionately experience environmental harms. Because the leachate is not treated as it passes through municipal sewage plants into these rivers, potentially hazardous or toxic compounds from landfills threaten these drinking water sources and communities. The communities that utilize the river water for drinking must assume the cost of treating the water to make it safe for consumption. In some cases, operators of drinking water plants are unaware that sewage plants are accepting and discharging leachate nearby.
How does leachate threaten public health?
In the project area, actively operating landfills that discharge to sewer plants handle municipal solid waste (i.e., household trash), ash, construction and demolition debris, and industrial waste. Inactive landfills that predate modern record-keeping are also involved, and may contain domestic and industrial waste.
Leachate picks up chemicals from all the materials in the landfill, producing a liquid that contains a diverse mixture of potentially harmful substances, including heavy metals, and manmade chemicals such as pesticides, flame retardants, plastic additives, solvents, non-stick and stain-blocking chemicals, and industrial chemicals. Many of these chemicals are derived from fossil fuels.
Because the types of pollutants found in leachate are broad, so are the potential effects, which include cancer, immune system problems, effects on organs such as the liver and kidneys, and developmental effects. The burden of exposure is not distributed evenly. Black and Hispanic women have higher levels of toxic chemicals in their bodies compared to other groups. The effects of emerging contaminants on pregnant and breastfeeding women are passed along to fetuses and infants, who are especially susceptible to harm from chemical pollution because they are still developing.
Aren’t drinking water treatment plants testing for dangerous chemicals?
Under the Safe Drinking Water Act (SDWA), drinking water treatment plants are required to test for approximately 90 drinking water contaminants. Regulations such as drinking water limits are only placed on chemicals after evidence of harm is clear and irrefutable, and the process of developing new regulations is slow. The U.S. Environmental Protection Agency (EPA) lists over 86,000 chemicals that may be used in U.S. commerce. Most are poorly studied because our regulations do not require companies to conduct risk assessments before marketing these substances, or even to disclose all of the information they have about chemical risks. When chemicals do receive scrutiny or regulation, manufacturers often respond by replacing them with slightly different formulations, which often carry similar risks, a situation known to toxicologists as “regrettable substitution.”
What are the economic aspects of the Leachate Loophole?
If landfills were to discharge leachate directly into nearby waterbodies, the Clean Water Act requires some onsite treatment and an operating permit under the State Pollution Discharge Elimination System (SPDES) program. By passing leachate onto wastewater treatment plants, landfills avoid the costs and regulatory obligations involved with onsite treatment. In turn, municipal sewage plants earn revenue for accepting leachate. According to the data we obtained from sewage plants in the study area, the average price for leachate disposal was $0.04 per gallon. This added up to approximately $3.6 million in sewage plants revenue annually.
In some cases, landfills and sewage plants have reciprocal agreements whereby landfills accept sludge (the solid material that remains after the sewage treatment process), and sewage plants accept leachate.
Shouldn’t our environmental laws prevent this?
Our report, The Threat of Landfill Leachate to Drinking Water in the Hudson and Mohawk Rivers, details the environmental regulations that are designed to protect water quality at each step of the way from landfill to drinking water. These regulations divide our built infrastructure and natural ecosystems into silos (solid waste, surface water, drinking water) to facilitate their management, which leads to gaps such as the Leachate Loophole.
In addition, chemical innovation has outpaced and outstripped our regulatory frameworks and agencies. Agencies such as the NYS Department of Environmental Conservation (DEC) and U.S. Environmental Protection Agency (EPA) have huge backlogs of permit and chemical safety reviews.
What are “emerging contaminants”?
“Emerging contaminants” (also called “contaminants of emerging concern”) are substances that may be harmful to people or ecosystems, but are not regulated. The “emerging contaminants” label encompasses a diverse group of chemicals, microplastics, and microorganisms. Emerging contaminants come from many sources, including prescription drugs, personal care products, pesticides, and industrial processes. This includes thousands of synthetic chemicals derived from fossil fuels. They are present in a multitude of everyday goods like clothing, furniture, and packaging. U.S. environmental regulations are based on the assumptions that pollutants are safe in very low levels; that they break down rapidly in the environment; and that they can be regulated one at a time. Emerging contaminants are showing that these assumptions can no longer be relied upon.
Emerging contaminants are not necessarily new contaminants. For example, per- and polyfluoroalkyl substances (PFAS) were invented in the 1930s. The companies that make them have been aware of their potential harms for decades, but drinking drinking water limits for PFAS were approved by the U.S. Environmental Protection Agency (EPA) only very recently, in 2023. (New York instituted drinking water limits for two PFAS chemicals in 2020, but these limits will be superseded by the federal rules, which come into full effect in 2029.) The new federal drinking water limits cover six PFAS, but there are 15,000 chemicals in the PFAS group.
What is the “Precautionary Principle,” and how is it related to landfill leachate?
The term “emerging contaminants” itself reveals the core problem: Our environmental laws are reactive, not proactive, so these chemicals become known as pollutants only if adverse effects are shown. Under our current environmental regulations, chemical manufacturers are able to gain approval to use new chemicals in manufacturing – and market their benefits – without demonstrating their safety.
A better way of regulating manmade chemicals is to employ the Precautionary Principle, which states that action should be taken to avoid harms to human health and the environment, even amidst scientific uncertainty, when the threats are large. This is a proactive approach, similar to the Food and Drug Administration’s (FDA) system for approving pharmaceuticals. It removes the burden of proof from the public, and prevents chemical manufacturers from avoiding regulation by requiring indisputable proof of causation.
How can people outside of the project area find out if their river or drinking water is affected?
It is difficult to know whether municipal sewage plants are discharging leachate because they are not required to publicly report this information. The best way to find out if a sewage plant near you is discharging leachate is to ask them directly by submitting a Freedom of Information Law (FOIL) request. Most municipalities provide instructions on submitting such requests on their websites. It’s important to address your request to the correct municipality. The NYS Department of Conservation (DEC) has an interactive map that you can use to identify sewage plants that discharge into your waterbody of interest. The sewage plants are in the “Permits and Regulations” group of the map legend.
Isn’t the state considering new regulations on leachate?
In 2023, the NYS Department of Environmental Conservation (DEC) announced that it was considering new regulations to require leachate treatment and disposal onsite at landfills, and that it intended to move forward by formally proposing new regulations that year. DEC did not meet that target.
The formal process that NYS agencies take when developing new rules is called “rulemaking.” The NYS Department of State says that the process “is designed to ensure that the public has opportunity to comment on, and participate in, the development of agency rules.” As part of the rulemaking process, DEC must publish a public notice once it has proposed a draft rule. This public notice formally opens a public comment period of at least 60 days. DEC may alter the proposed rules according to feedback received in these comments.
We are urging DEC to develop these new regulations as soon as possible, with a 90-day comment period to provide ample opportunity for public input, and we urge others to let DEC know that this issue is important to them.
Are there any politicians in the state senate or assembly who are working on this issue?
Yes, lawmakers are working on addressing the Leachate Loophole and pushing for immediate action in the 2025 budget discussions. During the Joint Legislative Public Hearing on the 2025 Executive Budget Proposal, held on January 28, Assemblymember Deborah J. Glick (Manhattan) raised concerns about municipal wastewater treatment plants not being equipped to handle contaminants in landfill leachate, especially emerging pollutants. Senator Michelle Hinchey (Dutchess, Ulster, Columbia and Greene Counties) also raised concerns, particularly for her district, asking the NYS Department of Environmental Conservation (DEC) about support for onsite leachate treatment solutions like storage tanks and reverse osmosis. She emphasized that the problem will only grow and urged funding for mitigation efforts.
What are the best methods for treating leachate?
Treating a concentrated stream of leachate at the landfill is far better than dispersing it back into the environment and treating it later at the point of consumption, where even very small concentrations of some contaminants can have negative health impacts. Allowing leachate to enter streams and rivers means that it has a chance to affect wildlife and to migrate (potentially via unanticipated routes) to air, water, and soils. It is also more efficient to engineer a treatment system at a landfill, where the waste stream is relatively controlled and stable, compared to municipal sewage plants, where many types of industrial and domestic wastewater are mixed together in fluctuating ratios. Many different types of contaminants may be present in leachate, depending on the nature of the waste in the landfill, the age of the landfill, and other factors. Therefore, the precise treatment strategies will vary by site.
Won’t opponents use this concern as a reason to continue incinerating waste on the false promise that it is a clean energy source?
That question is a distraction from the real issue at the heart of this problem: we produce too much waste. In our “disposable culture,” we throw away huge amounts of single-use plastic, food (which can and should be composted), and recyclable materials. Closed landfills – those that are not actively receiving garbage – generate much less leachate because they are capped with impermeable covers that prevent water infiltration. If we can reduce our reliance on landfills by creating less trash, we can significantly reduce the problems posed by landfill leachate.
Are landfills required to test their leachate? Where can I find the results?
Actively operating landfills are required to test leachate for several dozen chemicals on a quarterly basis. The information is publicly available as part of compliance reports submitted to the NYS Department of Environmental Conservation (DEC). You will need to know the DEC Region that your landfill of interest is located in. Laboratory reports with leachate sample results are usually located in an appendix at the end of the compliance report. You may need to search through the report to determine the sample ID numbers for the leachate samples.
What kind of containment is used for the leachate collected by a landfill? How is security of this containment assured?
Actively operating landfills in New York State are required to have two layers of impermeable liners, with some exceptions for alternate systems at some types of landfills. The liners sit underneath gravel layers that hold the leachate collection pipes. Actively operating landfills are also required to routinely test nearby groundwater and surface water for indicators of leachate leakage.
Some per- and polyfluoroalkyl substances (PFAS) were recently designated as hazardous waste. Does this affect how leachate will be handled?
The hazardous waste designation will not apply to PFAS that are put into consumer goods and disposed of in landfills, nor to municipal leachate, so this designation will not directly affect how leachate is handled.
Won’t onsite leachate treatment have its own impacts to the environment?
The residue produced by leachate treatment will contain concentrated amounts of the pollutants that have been removed, and will need to be safely contained, disposed of, or destroyed. There is no “silver bullet” solution that will make the problem of leachate disappear, but the impacts can be reduced and controlled. The fact that some impacts will remain is not a valid reason to continue the current practice.
How much will onsite treatment cost compared to the cost of sending leachate to a wastewater treatment plant?
There are multiple potential technologies for onsite leachate treatment, and each system will have unique properties that require different engineering specifications. As an example, construction of a reverse osmosis (RO) system may cost $1-3 million, with operating costs around 5-10 cents per gallon.
Trucking leachate to a municipal sewage plant may appear to be the cheaper option, but because sewage plants do not remove the contaminants in leachate, this is an irresponsible practice whose long-term costs are externalized.
Would onsite treatment of landfill leachate solve the problem of contaminated sewage sludge?
Sewage sludge – the solid material that remains after the wastewater treatment process – also contains the types of toxic contaminants that are a concern in landfill leachate, such as per- and polyfluoroalkyl substances (PFAS). Onsite treatment of landfill leachate will reduce the load of contaminants flowing into municipal sewage plants, but not eliminate it because landfills are not the only source of these chemicals. Household wastewater also contains PFAS and other pollutants. However, landfills represent a concentrated and controlled source of toxic contaminants, so addressing the contribution of leachate to sewage plant contaminant loads is an important piece of the puzzle.
Where does my drinking water come from?
If you’re a resident of New York State and want to know where your drinking water comes from, you can locate your annual drinking water quality reports by visiting the NYS Department of Health’s KNOW YOUR WATER website.
Where are active and inactive landfills in New York State?
Visit the DECinfo LOCATOR to find active and inactive landfills in New York State.
- “Search” by location in the upper left hand key
- Enable layers for “Active Landfills” and “Inactive Solid Waste Landfills” in your area
- Contact the municipality or county who has jurisdiction over the landfill of interest to learn about their operation.
What is Zero Waste Hierarchy?
“Zero Waste: The Conservation of all resources by means of responsible production, consumption, reuse, and recovery of all products, packaging, and materials without burning them and with no discharges to land, water, or air that threaten the environment or human health.” – Zero Waste Hierarchy
The Zero Waste Hierarchy describes a progression of policies and strategies to support the Zero Waste system, from highest and best to lowest use of materials. It is designed to be applicable to all audiences, from policy-makers to industry and the individual. It aims to provide more depth to the internationally recognized 3Rs (Reduce, Reuse, Recycle); to encourage policy, activity and investment at the top of the hierarchy; and to provide a guide for those who wish to develop systems or products that move us closer to Zero Waste. It enhances the Zero Waste definition by providing guidance for planning and a way to evaluate proposed solutions. Users are encouraged to develop policies and actions starting at the top of the hierarchy.