Boating is a big industry. According to this study there were 11.97 million registered boats in the U.S. alone in 2020. To house and service these pleasure crafts, there were an estimated 9,952 marinas in business that same year.
The result is plenty of fun-filled days on the water for American families. However, an unintended consequence is the release of uncalculated gallons of nonpoint source (NPS) pollutants into our waterways. If we are going to continue to enjoy our aquatic resources, boaters and marinas must find a way to manage nonpoint source pollution.

What is nonpoint source pollution?
NSP is diffuse contamination (pollution) of water that can’t be traced to a single, determined point. In many cases, this results from water, rain, or snowmelt runoff washing pollutants from adjacent areas or objects into a nearby waterway.
How do boaters and marinas contribute to NSP?
At first glance, an observer may think marinas and boats would be designed to protect our waterways. After all, both rely on the waters for their livelihood and recreation. But this is not the case. Boats and marinas are hosts to numerous potential sources of nonpoint source pollution.
These include:
- Poorly flushed waterways
- Boat maintenance
- Cleaning of equipment
- Parking lot runoff
- Discharge of sewage
- Fueling operations
- Erosion of shoreline
- Sedimentation
- Litter
Individually, each of these potential situations is cause for concern. Combined, even a few conditions can be catastrophic to any waterway. The result can include one or more of many adverse outcomes:
- Increased water toxicology
- Pollutant concentrations in sediment
- Pollutant concentrations in aquatic organisms
- Increase nutrient levels
- Decreased oxygen levels
- Algae blooms
- Erosion and sedimentation
- High levels of pathogens
The negative impact of these conditions can result in the loss of aquatic species, contamination of nearby drinking water sources, and even danger to those who use the water for recreation. Rather than tell hobbyists with surfboards and dive weights to stay home, we should do what we can to make waters safe for people as well as aquatic life. The question is not “can we do anything?” but “what can we do?”

What Can Marinas Do?
Because of their size and fixed location, marinas pose a more significant threat than boats. This is especially true when located in a site that allows for year-round operation. While it is unlikely a marina can successfully eliminate nonpoint source pollution, an adequately managed marina can significantly reduce the impact.
Nonpoint source pollution reduction starts at the design and construction phases, long before customers arrive. The potential impact of pollutants can be reduced by selecting a location away from sensitive aquatic populations, vegetation, or water sources.
It’s also essential to design the marina to allow for regular flushing of the waters contained within the facility. This lessens the possibility of a toxic build-up of contaminants. Placing riparian buffers between parking areas and the water will reduce the number of pollutants that reach the water and reduce erosion of shoreline areas.
Once a marina is operational, managing nonpoint source pollutants is an ongoing effort.
All sewage collection and fuel supply systems need to be appropriately maintained. This includes ensuring all components function correctly, and regular cleaning to prevent residue from being washed into the water.
Fueling operations constitute a significant source of both point and nonpoint source pollution. Spills or overflows into the water are the most common point of pollution. However, suppose spills or overflows are not cleaned up correctly. In that case, further pollution occurs every time it rains or waves wash across the area.
To help in controlling this hazard, marinas should ensure that:
- Fueling areas are regularly inspected.
- Spills are recovered immediately with residue adequately disposed of.
- All employees are trained correctly in pollution reduction practices.
Another primary concern is the result of routine maintenance operations. Many marinas also operate boat service centers. Regular activities such as oil changes, winterization, bilge flushing, and painting pose serious hazards.
Performing such operations in designated areas away from water and with runoff contaminants systems will prevent oil, fuel, and antifreeze residue from becoming a nonpoint source pollutant.
If performing painting, chipping, or sanding operations, drop cloths, tarps, and painting booths will limit the number of contaminants that escape the environment. Wiping down or vacuuming areas will further prevent impurities from later being washed onto the ground where they could later enter area waterways.

How Can Boaters Help?
Although boaters are not as big of a source of nonpoint source pollution, small amounts of cleaners, leaking fluids, and even fish parts can result in adverse environmental changes. While large numbers of boats in a concentrated area—such as marina or waterfront communities—are of the most significant concern, individual boats are not exempt.
Even a single boat can produce harmful nonpoint source pollutants. When these pollutants are discharged into the same water area, many toxins, hydrocarbons, and other dangerous contaminants can collect in the sediment or local aquatic organisms. Over time this can result in localized damage and a negative change to the ecosystem.
One of the primary sources of contaminants is improper cleaning of the boat itself. While many boat owners believe that a clean boat is less likely to be a source of pollutants, they fail to understand the damage caused by the cleaning agents themselves.
The first step in reducing this danger is using “green” cleaning products. These products are less harmful to the environment, so if the residue is left behind, there is a reduced concern. In some instances, an organic method of cleaning can be used. An example would be using a vinegar and water solution to clean chrome rails or boat ladders instead of a harsh soap or acid.

However, cleaning should not be done while the boat is on the water. Although washing the boat at the dock is easier, this increases the likelihood of pollutants entering the water. Instead, move the boat to an area away from the water, preferably with a riparian buffer between it and the water.
Finally, there is maintenance. A well-maintained boat offers less opportunity for pollutants to be exposed to the environment. The fewer pollutants available, the less chance nonpoint source pollutants will enter the water. Like the marina operator, individual boaters should:
- Perform maintenance away from the water.
- Use proper means of collection, including drop cloths or vacuums.
- Dispose of all plastic and debris properly.
There is no doubt that boating is a fun-filled pastime that everyone can enjoy. It is much more enjoyable if the water you are boating on is clean and hosts wildlife, vegetation, and aquatic resources you can’t see anywhere else.