Dog Waste & Environment

What Does the EPA Say About Dog Waste?

Most people think of dog waste as a nuisance — an inconvenience to be bagged, knotted, and forgotten. Few think of it as an environmental crisis. But the U.S. Environmental Protection Agency does.

The EPA classifies dog waste as a nonpoint source pollutant — placing it in the same regulatory category as pesticides, herbicides, oil, grease, and toxic chemicals. This isn't an overstatement. It's the result of decades of water quality research that links untreated pet waste directly to contaminated waterways, closed beaches, and public health risks across the country.

Here's what the EPA's position actually means — and why it matters for every dog owner.

Why the EPA Classifies Dog Waste as a Pollutant

Dog feces is not inert. It contains a range of pathogens — bacteria, viruses, and parasites — that pose genuine risks to human health and aquatic ecosystems when they enter the water supply.

Specifically, dog waste can carry:

• E. coli — a bacteria that can cause serious gastrointestinal illness in humans
• Salmonella — a bacterial infection transmitted through contaminated water and food
• Giardia — a parasitic infection that affects both humans and animals
• Roundworm (Toxocara) — a parasite whose eggs can survive in soil and water for years
• Campylobacter — a leading cause of foodborne illness in the United States
• Cryptosporidium — a parasite resistant to standard water chlorination

When dog waste is left on the ground, these pathogens don't stay there. Rain carries them into storm drains, streams, rivers, and ultimately bays and coastal waters — the same water bodies where people swim, fish, and harvest shellfish.

The Scale of the Problem

Put the volume in perspective: 12.4 million tons of dog waste per year is the equivalent of over 330,000 fully loaded tractor-trailers. Lined up end to end, they would stretch from Boston to Seattle and back.

This waste doesn't disappear when it's bagged. It moves from the ground to a landfill — where the pathogens are entombed rather than treated, and where the plastic bag surrounding the waste will persist for hundreds of years.

Dog Waste and Water Quality

The EPA's nonpoint source pollution framework emerged from a recognition that water contamination doesn't only come from industrial pipes and factory discharge. It also comes from diffuse, everyday sources — agricultural runoff, urban stormwater, and yes, pet waste — that collectively degrade water quality across entire watersheds.

In dense urban and suburban environments, the impact of dog waste on water quality can be substantial. Studies have found that pet waste is a significant contributor to elevated fecal coliform bacteria levels in urban stormwater — sometimes accounting for as much as a third of the bacterial contamination in tested waterways.

The mechanism is straightforward:

1. Dog waste is left on the ground — in parks, on sidewalks, in yards
2. Rain washes the waste and its pathogens into storm drains
3. Storm drains (in most cities) empty directly into local waterways — without treatment
4. Bacteria and parasites accumulate in rivers, bays, and coastal waters
5. Water quality testing triggers closures for swimming and shellfishing

This is not a theoretical risk. Beaches across the country close every year due to elevated bacterial counts, and pet waste is consistently identified as a contributing source.

The Great Lakes Connection

For dog owners in the Chicago and Naperville area, the stakes are particularly direct. The Great Lakes represent 21% of the world's surface fresh water and are the primary drinking water source for tens of millions of people. The waterways that drain the Chicago metropolitan area — the Des Plaines River, the Chicago River, the Illinois River — all eventually connect to this system.

The Alliance for the Great Lakes has identified urban stormwater runoff, including pet waste, as a meaningful contributor to water quality challenges in the region. Every bag of dog waste that goes to a landfill is a missed opportunity to route biological material through treatment infrastructure rather than into the watershed.

What the EPA Recommends

The EPA's guidance for pet waste disposal is clear and consistent:

• Always pick up after your dog. This is the baseline — leaving waste on the ground is both a public health issue and, in most places, illegal.
• Dispose of waste in the trash when no better option is available — this at least prevents it from washing into waterways, even if the bag contributes to landfill volume.
• Flush waste down the toilet where local wastewater systems permit — the EPA recommends this as one of the most environmentally sound disposal methods, routing biological waste through treatment infrastructure designed to handle it.
• Consider in-ground pet waste digesters as a backyard option — these use enzyme activity to break down waste without the pathogen risks of backyard composting.

Picking Up Is Necessary — But Not Sufficient

One of the most important nuances in the EPA's position is this: picking up after your dog is the essential first step, but what happens to the waste after collection matters too.

Bagging dog waste in a standard plastic bag and placing it in the trash removes the immediate pathogen risk from the ground and waterways — which is meaningful. But it creates a secondary problem: an estimated 82 billion single-use plastic bags per year across North America (Mai et al., 2022), each one destined for a landfill where the waste it contains will never be treated and the bag itself will persist for centuries.

The EPA's recommendation of flushing reflects an understanding that the best outcome is routing biological waste through the infrastructure designed to treat it — not simply moving it from one environmental problem to another.

What Responsible Dog Ownership Looks Like

The EPA's framework for pet waste management aligns closely with what most responsible dog owners already believe: picking up is non-negotiable. What's less widely understood is that the method of disposal matters — and that the plastic bag, for all its convenience, is not actually the end of the environmental story.

Optimal dog waste management looks like this:

1. Collect waste on every walk, every time — no exceptions
2. Transport it in a way that prevents spillage and odor
3. Dispose of it through the most environmentally sound method available — ideally, flushing where permitted
4. Avoid single-use plastic bags wherever possible

A reusable collection and transport system — one that seals waste during the walk and empties directly into the toilet at home — satisfies all four conditions without requiring a single plastic bag.

Frequently Asked Questions