Swimming in Chemicals We Created
Every year, sunscreen, lawn chemicals, and runoff from city streets make their way into the beaches and lakes people love to swim in, and most of it traces back to everyday items. However, a few small shifts can keep your favorite waters swimmable for years to come.
Sunscreen Chemicals Wash Into Recreational Waters
If you’re headed to the beach, you’ll probably be wearing sunscreen. The moment you jump into the water, it starts washing off your skin and into the surrounding ecosystem. Every year, an estimated 4,000 to 6,000 tons of sunscreen rinse off swimmers and into the oceans worldwide.
The culprits are usually chemical UV filters like oxybenzone, octinoxate, and avobenzone. These ingredients accumulate in the water, where they can bleach coral, disrupt fish reproduction and work their way up the food chain to larger marine life.
Look for mineral-based sunscreens with zinc oxide or titanium dioxide as active ingredients. These elements sit on top of your skin instead of soaking into it, and they’re less likely to harm marine life once they wash off.
Covering up with a rash guard, UV shirt, or wide-brimmed hat also reduces your need for sunscreen, which means less product ends up in the water in the first place.
It’s a small habit shift, but when multiplied across the millions of people who swim in beaches and lakes each summer, it makes a real difference for aquatic ecosystems.
Storm Drains Carry Street Pollution Into Lakes and Beaches
Every time it rains, everything on your street, from motor oil and pesticide overspray to plain old trash, funnels into storm drains. This runoff then goes straight into nearby waterways. Nonpoint source pollution like this is considered the top cause of water quality issues nationwide.
Unlike contamination from a factory pipe dumping waste into a river, this kind of contamination has no single source, making it much harder to regulate or clean up. It’s the accumulation of everyday choices like washing your car in the driveway, over-applying weed killer, or letting leaves and debris build up near a drain.
Small changes add up. Choose a car wash that filters and recycles its water, rather than hosing your car down at home. Sweep up yard debris and grass clippings instead of letting them wash into the street, and check your car for oil leaks before they turn into a slick on the pavement.
If you’re doing any home projects, keep paint, solvents and other chemicals far away from storm drains, since anything that goes down them usually ends up in a lake or river untreated. Even something as simple as picking up after your dog helps, since pet waste is an overlooked source of bacteria in recreational water.
Old Docks and Sewer Systems Add Pollution to the Water
Sometimes the contamination isn’t coming from what you’re putting into the water, but from what’s already sitting in it. Older docks, piers, and waterfront structures are frequently built with pressure-treated wood that requires chemical sealants to resist rot and pests. Over time, those treatments leach into the surrounding water and put aquatic life at risk.
Aging sewer systems also play a role. Heavy rainfall can overwhelm combined sewer systems, sending untreated wastewater directly into recreational waters. The EPA found that beaches nationwide were swimmable only 91% of the time in 2023, with stormwater runoff and sewer overflows among the most common culprits.
The fix for dock owners is more straightforward than you might think. Materials like high-density polyethylene are designed to withstand the elements, making them low-maintenance.
Not needing chemical treatments to increase longevity means fewer chemicals leak into the surrounding water, unlike with treated wood docks. These modular systems also skip the foam filling found in many older floating docks, since that foam breaks down over time and adds yet another pollutant to the water.
On the municipal side, supporting local investment in updated stormwater and sewer infrastructure is one of the most effective ways to reduce overflow events during heavy rain. By voting for or backing local water infrastructure projects, an individual can influence the problem at its source.
Farm and Lawn Chemicals Fuel Unsafe Algal Blooms
Fertilizers and pesticides applied to crops don’t always stay where they’re applied. Rain and irrigation carry excess nitrogen and phosphorus off fields and into nearby waterways.
Once that runoff hits the water, it can trigger harmful algal blooms that harm fish and can make the water unsafe to swim in. The same principle applies to overfertilized lawns closer to home.
You can help from your backyard. Reducing how much fertilizer and pesticide you use on your own lawn keeps these elements from washing downstream every time it rains. Testing your soil before you fertilize means you only add what your plants actually need.
If you want to go a step further, choosing native plants that need less fertilizer can reduce your chemical use while giving you a lower-maintenance yard in return. Supporting local farms that use cover crops or buffer strips also helps, as these practices capture runoff before it reaches the water.
Even a modest planted buffer along a ditch or creek bank can filter out a surprising amount of nutrient runoff before it travels any farther.
Start a Ripple Effect
Every choice, from the sunscreen in your bag to the dock under your feet, adds up. Small swaps like mineral sunscreen, smarter lawn care, and low-maintenance materials can go a long way toward keeping beaches and lakes clean enough to actually enjoy.
The water’s waiting, so make sure it stays worth jumping in.
