How Cars Affect the Lake Whatcom Watershed

Since January 2014, Whatcom Watch, has been rerunning articles from issues printed 20 years ago. The below article appeared in the August 1998 issue of Whatcom Watch.

by Amy Kenna

Recently, a concerned citizen wrote Whatcom Watch requesting an article on the environmental impact of automobiles on the Lake Whatcom watershed.

After a bit of research, I came across a Huxley environmental impact assessment about the effect of stormwater runoff on Lake Whatcom watershed. The report had a section which seemed to best describe the impact automobiles and roads have on our watershed:

“Pollutants from the road are washed into Lake Whatcom by stormwater runoff. Impervious surfaces (mostly paved surfaces) increase the rate of runoff which in turn increases soil and road erosion.”

Impervious Surfaces Increase Runoff
Automobile use brings with it increased roads and pavement, (also known as impervious surfaces). Impervious surfaces, in a nutshell, are any material which prevents the infiltration of water into the soil. The best example of this is roads, but impervious surfaces also include rooftops, sidewalks, patios, and even compacted soil.

Development and impervious surfaces are like Siamese twins, one never seems to exist without the other. When the percentage of land covered by impervious surfaces increases, then the amount of water absorbed by soil decreases. For example, in an area where the ground cover is natural, 40 percent of rainwater evaporates, 10 percent of it becomes runoff, 25 percent infiltrates the soil on a shallow level, and 25 percent of the water becomes deep infiltration.

In contrast, in an urban area with 75 to 100 percent impervious surfaces, 55 percent of the water becomes runoff, 30 percent evaporates, and only a miniscule 15 percent even infiltrates the soil at all (with only 5 percent becoming deep infiltration).

In other words, roads, pavement and other impervious surfaces seriously affect water cycles, allowing only a tiny percentage of water to actually be absorbed by soil at all, and causing most of the water to simply become runoff.

The alteration to the hydrologic cycle is only the beginning of the problem.

The Source of Our Water Woes
The definition of nonpoint source pollution, as indicated by the Journal of American Planning Association, is this: “polluted runoff derived from contaminants washed off the surface of the land by stormwater and carried either directly or indirectly into waterways or groundwater.” Controlling nonpoint sources is difficult since its source is not able to be specified. Also, the responsibility for controlling such pollution often shifts through varying levels of government and is complicated by regulatory and management considerations.

According to the Environmental Protection Agency, nonpoint source pollution is the nation’s leading threat to water quality, especially since point source pollution is increasingly being brought under control.

Runoff in the Lake Whatcom Watershed
If you’ve ever been down to Sudden Valley or Alabama Street, you will notice runoff grills on the sides of street above which is painted a white picture of a fish and the words “Runs to Lake-Do Not Pollute.” As though all the people driving by in cars can read those little white signs.

The point is, automobiles bring roads, roads increase runoff (which is a form of nonpoint source pollution), and runoff is bad news, especially when it is emptying into our watershed. Here are just a few of the bad things which come from our roads, as cited by the Huxley impact assessment:

“Hazardous wastes in the Watershed, as a result of the road, most likely come from the transportation of fuels within the Watershed and the use of pesticides for roadside spraying. Another serious pollutant is sediment, which is generated during road construction.”Also, cars leak oil, antifreeze and other nasty chemicals into stormwater drains.”

The degree of pollutant loading for roadways increases with increased traffic volumes, especially in heavy metals. Depending on the nature of local land uses, stormwater may contain varying levels of pollutant concentrations such as suspended solids, oils and grease, fecal coliform bacteria, heavy metals, phosphorous, nitrogen, bio-available oxygen demand, oxygen-consuming compounds, and toxic organics. Stormwater runoff then carries these pollutants into Lake Whatcom.”

Stormwater Drains Shift Responsibility From Polluters
Stormwater drains on streets can serve as free garbage bins for people using polluting chemicals. The environmental assessment states, “The view of landowners is that the primary task in developing land is to move water to the road where it then becomes part of the managing body’s problem. Effort should be made so that water and runoff be dealt with on-site (instead of on the road) and efforts made to retain the natural drainage.”

According to the EPA, enhanced runoff brings other problems as well: erosion from construction sites, downstream areas and stream banks. Increased volume of water and sediment can alter streams by making them wider and straighter, therefore increasing the chance of floods.

Minimizing Pollution From Roads
What are our choices for protecting the lake from damage due to roads? The option to stop building roads seems is impossible. The Huxley assessment states, “If no action is taken in regards to the transportation network then traffic volumes for 2010 are forecasted to exceed the resulting capacity at some locations. Emergency and public service response time will continue to increase. Amounts of vehicle-generated pollutants entering the Lake would increase with greater traffic volume.”

Responsible Automobile Use
But perhaps the most important goal of all is to reduce automobile use. The Whatcom County Comprehensive Plan provides some alternatives in its safety for transportation section, including adopting a prioritized bicycle facilities improvement plan, and achieving the bicycle plan’s service standards. Minimizing time delays at intersections is another way to reduce car use.

However, as we have proved that automobiles and roads are a serious threat to our watershed (and if we fall within the national average, then they are perhaps the number one threat), the simplest solution to minimizing road-related pollution to the watershed is to minimize car use altogether. This can be done through improvements in city bicycle plans, but also through carpooling and increased use of public transportation, as well as improvement and expansion of public transportation services in the county.

Take the Pledge
Perhaps the Whatcom Watershed Pledge says it best: “Automobiles are one of the biggest sources of water pollution in urban areas. An efficient car saves money, resources, and time while protecting the environment. Cars can leak oil, antifreeze and other fluids that can be washed into storm drains to into the nearest creek, harming plants, fish, wildlife and humans.” So, let us all pledge to:

 Reduce the number of automobile trips I make in and out of the watershed by consolidating errands

 Wash my car at an approved commercial car wash. If I wash it at home, I will wash it on gravel or grass with phosphate-free soap.

 Maintain my car with regular tune-ups and check for fluid leaks.

 Dispose of used motor oil properly. I will put it in a plastic container with a screw-on top marked “used oil” and place it with other recyclables for curbside collection.

 Dispose of anti-freeze properly by taking it to the disposal of toxics facility or the Lake Whatcom Water and Sever District office.

 Close the oil recycling loop by reusing re-refined oil in my car.

 Use public transportation, carpool, bike or walk whenever possible.

• Huxley College of Environmental Studies.  “Stormwater Runoff in Lake Whatcom: An Environmental Impact Assessment” Bellingham, Washington: W.W.U., 1995.

• Whatcom Watersheds Pledge by RE Sources.

Amy Kenna was a student in 1998 at Whatcom Community College.