Dog waste in public spaces: health and environmental impacts

While many dog owners/walkers consistently pick up dog waste and dispose of it properly, some do not, and even a relatively small number of missed clean‑ups leads to an accumulation over time. In August 2025, the City collected dog waste data from Bert Flinn Park. Based on observations from 223 sample sites, we estimate 490 kilograms (1,080 pounds) of dog waste was left within 20 metres of trails where dogs are required to be on leash. Higher volumes of waste were noted near the main park entrances, particularly the David Avenue entrance. This level of accumulation indicates there is a recurring pattern of uncollected waste with measurable impacts on park conditions, maintenance needs, and visitor experience.

Dog waste is not the same as waste left by wildlife

Some park users may assume that unbagged dog waste can be left in nature because that's what wild animals do. However, there are key differences that mean dog waste should be picked up and disposed of properly.

Volume and concentration

Wild animals disperse waste across large territories, whereas dogs being walked on designated trails tend to leave their waste repeatedly in concentrated, high‑use locations. Over time, this leads to high waste levels that cannot be broken down effectively by natural systems, as demonstrated by the Bert Flinn Park data.

Public and pet health

Uncollected dog waste can carry a range of harmful microorganisms that pose preventable health risks to people and pets in Port Moody’s parks, trails, and other public spaces. A single gram of dog feces can contain millions of bacteria, including E. coli, Salmonella, and Campylobacter, all of which can cause illness in humans and animals.

Additional pathogens identified by the Canadian Public Health Association - such as Giardia, Cryptosporidium, and roundworms - can persist in soil and remain infectious long after waste was first left behind. Children face elevated risk due to their frequent ground contact and hand‑to‑mouth behaviours, especially in grassy or natural areas where contaminated soil may be present. These risks highlight the importance of consistent waste pickup and proper disposal to maintain safe, healthy, and enjoyable shared public spaces.

Impacts on ecosystems

High volumes of dog waste introduce excess nutrients, particularly nitrogen, which can disrupt natural soil processes. Most ecosystems are naturally low-nutrient environments. When there are excess nutrients, this reduces biodiversity by allowing a few thriving plants to drive out others and the wildlife that depends on them.

Biodegradable bags are not the answer

Approximately 15 per cent of the dog waste observed during data collection in Bert Flinn Park was left behind in bags. This suggests a common misunderstanding about “biodegradable” dog‑waste products. Many bags marketed as "biodegradable" are made from bio‑plastics, which break down into microplastics that contribute to long‑term environmental pollution rather than decomposing cleanly.

Bio‑plastics typically require high temperatures - far above those naturally occurring in Port Moody’s parks, soils, or forest understory - to break down efficiently. As a result, discarded bags can remain for years, contributing to litter, interfering with natural decomposition processes, posing additional hazards to wildlife, and having a negative impact on users' enjoyment of our parks and other public spaces.

What to do with dog waste?

Whether it's bagged or unbagged, leaving dog waste in parks and other public spaces has negative impacts on the health of people and dogs, and on Port Moody's ecosystems. If you are out walking your dog, please dispose of waste properly. Here are two recommended methods:

Put it in a red dog waste bin. The City of Port Moody has set up red bins for dog waste in or near a number of parks and green spaces. (These bins are to be used for dog waste generated during a walk or a visit in one of these spaces. Dog waste generated at the pet’s home or other location should be disposed of properly in the home.) Waste collected in the red bins is taken to the Iona Island wastewater treatment plant. Our goal is to reduce the amount of dog waste that goes to a landfill. When in the landfill, dog waste produces methane as it breaks down, which is a greenhouse gas. Dog waste is better dealt with at a wastewater treatment plant.
Take it home with you and flush it down the toilet (without the bag - do not flush the bag even if it's labelled "flushable" or "biodegradable"). Metro Vancouver recommends flushing (without the bag) to ensure the dog waste will go to a wastewater treatment plant with other sewage instead of a landfill. (Note: do not flush cat waste down the toilet.)