How to Wash your Car Sustainably This Fall

Fall is coming — and with it falling leaves which might deposit debris on your car. This is all in addition to the regular kinds of dirt which accumulate over time. We all want to keep our vehicles clean, and the temperate fall weather might make it the right time to seize the moment and clean the car.  But when cleaning your car this fall, make sure to keep in mind the various impacts that even a simple car wash can have on the environment.

The first thing is that washing your car at home uses a lot of water. According to the EPA, the typical home car wash uses 116 gallons of water. Not only is this a lot of water — it means a larger water bill too! And if you happen to wash your car on your driveway or any other impermeable surface, it’ll most likely make its way to a storm drain and eventually into our water supply.

This might not seem like an issue, but soaps with phosphates can pose a huge problem if they’re caught in runoff. If enough of these nutrients runoff into our lakes and streams, the algae in the water can begin to grow out of control in an algal bloom. These blooms sap the water of its dissolved oxygen and reduce the ability of other aquatic life to survive. Moreover, they diminish the beauty of our waterways and make them unsuitable for recreation and enjoyment.

Fortunately, there are plenty of sustainable options to choose from when we have to wash our cars. The most sustainable choice is going to a carwash. Car washes have infrastructure which allows them to both recycle used water and keep pollutants out of our water supply. They tend to have new technology that can ensure a more sustainable operation, and overall this is recommended as the best choice for washing your car in an environmentally-safe way.


However, if you would rather wash your car at home, there are plenty of options to make sure you keep the water clean. Consider a biodegradable, phosphate free soap to reduce the risk of water pollution and algal blooms down the line. And try using less soap too – you might find that a little bit of soap can go a long way. Hose nozzles that turn the water off when not being used are great ways to keep your water usage down – they could reduce your water usage by up to 70 gallons. And washing your car on a permeable surface like your yard allows the water to be filtered by the soil. Impermeable surfaces like concrete allow water to runoff and move pollutants into waterways, and avoiding washing your car on them can make a big difference.

Stay safe this fall and enjoy your clean ride in sustainable style! And if you want to read more about sustainable car washing, check out the links below.

Snow is stormwater

Here in North Carolina, our snowstorms (or often sleetstorms) are few and far between. As such, we may not think about snow as stormwater – and snowmelt as stormwater runoff. Though the risk for flooding is lower, transportation of pollutants is still an important consideration when preparing your home for inclement weather. Importantly, we tend to introduce a new pollutant into the mix when it might snow: salt.

Salt can come in many forms (think table salt, rock salt, brine) and with different chemical constituents, but the common denominator among salts we use to address ice concerns is that they contain chloride: sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2) most commonly. Chloride is of concern because it does not biodegrade, nor do organisms uptake and repurpose it naturally. This means all of the salt we apply – to our roads, sidewalks and driveways – is going to end up in the surrounding environment.

There are a few different ways that these chloride salts make their way into our ecosystems and waterways. Driving on salted roads can spray the salt onto vegetation and soils adjacent to the roadways, which can impact the growth of vegetation – altering the habitat and impacting native species. The chloride can then migrate into groundwater, which can degrade municipal and personal water supplies over time. When the snow melts, those salts can get carried into the stormwater system. In places like North Carolina, with Municipal Separate Storm Sewer Systems (MS4), these salts are delivered directly to our streams.

High concentrations of salt can be extremely detrimental to aquatic life, both flora and fauna. Thankfully in North Carolina, we do not have to apply salt frequently, but even occasional shocks to the system can hurt sensitive wildlife. In particular, macroinvertebrates are sensitive to increased salinity – and reduced macroinvertebrate population and diversity impacts the whole aquatic food web.

The brine applied to roads has a much lower rate of runoff than plain rock salt, which means that brine impacts ecosystems a bit less. Brine is typically 20-30% salt. Hydrating the salt in advance helps it stick to the road. Though the salt will still enter the environment, the overall chlorine measured in adjacent soils and waterways is significantly lower when compared to levels seen with rock salt. It is also worth noting that salt, particularly rock salt, is corrosive to both infrastructure and cars.

Some states are starting to use beet juice in their road brine to reduce the total salt load, while maintaining the benefits of treating the roadways. The beet juice is water-soluble, non-corrosive, and created as a byproduct of agricultural processing. As a relatively new technology, scientists are still researching possible ecosystem impacts of the use of beet juice on aquatic organisms.

There are many reasons to consider alternative solutions to putting rock salt down on your property. You may want to apply an inert substance like sand (which will not dissolve), to increase traction without impacting water quality. Some websites may recommend coffee grounds for a similar application, however the nutrients in coffee grounds may cause adverse impacts to water quality. Salt only helps melt snow at temperatures around freezing, so it may not be particularly helpful for your residence. Consider investing in a good snow shovel, enlisting the help of friends, kids, or neighbors, and only clearing when you need to. Snowstorms are rare here – if you are able, take the time to enjoy it!

Did you know that good old fashioned dirt is actually a MAJOR stormwater pollutant?!

What happens to dirt in stormwater?

When soil, dirt, sand, clay, or other tiny bits of earth end up in stormwater, we then call it “sediment” because those pieces can eventually settle out to the bottom of a body of water. However, moving water such as stormwater runoff through our neighborhoods and cities keeps the sediment from settling and can cause serious problems for water quality.

What does sediment do in the environment?

Sediment pollution creates many issues in the environment; here are just a few!

  • Clogs fish gills and suffocates small insects and other animals;
  • Creates murky, cloudy water that blocks sunlight from reaching plants;
  • Transports hundreds of other chemicals and pollutants to our drinking water that are hitching a ride on the sediment;
  • Encourages growth of toxic algae that can make people and animals sick;
  • Completely changes the course of a river or stream by depositing new banks!

What can we do to reduce stormwater pollution from sediment?

Sediment can come from many sources, such as construction sites or digging, erosion when vegetation has been removed, and even just dust and grime from your driveway, car, and sidewalk. You can help keep this dirt from getting in our streams and rivers by sweeping up instead of hosing down!

If you see muddy brown water being deliberately sent into the storm drain like in the photo below, or if you see lots of sediment coming from a construction site, call your local water department (contact info here) and let them know right away.

Run off

What is a Watershed?

A watershed is an area of land where all water drains to a particular waterbody, usually a stream, river, or the ocean. Watersheds cover the entire land surface of the earth. Watersheds contain homes, neighborhoods, cities, forests, farmland, and more. Watersheds come in all shapes and sizes and can even cross state lines.

The graphic above shows how water travels over a landscape and eventually forms streams and rivers. In a natural environment, this water would be pretty clean; however, when rain hits an impervious surface it creates stormwater runoff, which picks up pollutants and enters the nearest creek or stream. This creek or stream will join others to form larger streams, which join others to flow into larger rivers. Just like streams, smaller watersheds join together to form larger watersheds. That means any pollution that enters our stormwater can transported throughout an entire watershed.

All of us live in a watershed – let’s keep them clean! Use this EPA tool to Surf Your Watershed and find out more about how stormwater, runoff, and streams connect to form watersheds in your area.