Leave it a Lawn

rain and cars

I was discussing the other day how buying an electric vehicle (EV) is “low-hanging fruit” with regard to making changes. Well, another piece of low-hanging fruit might be as close as our front doors—our lawns. Which are related to water-quality, which is also related to… EV’s, in a great big circle.

To back up a bit, the center of this particular story has to do with where storm water goes when it rains. Fifty years ago cities regularly built their wastewater treatment systems so that storm water from their streets would flow into their wastewater treatment plants (WWTPs). These were called “Combined Sewer” systems. The reasons were obvious—all the oil and chemicals, and trash, for that matter, that ended up on the streets would get filtered and treated before it was dumped back into rivers and streams (or the ocean, in coastal areas). But, when all things were taken into account, these systems had more drawbacks than positives, because the volume of water that flows into them during heavy rains results in what water engineers refer to as CSO, or Combined System Overflow—the system can’t treat the water fast enough, and it all just flushes straight through into the environment—the storm water and the sewage.

So cities have avoided this combined design, and very few or none have been built in the last 40 years (Only about a quarter of US cities have combined systems today, and most of those are trying to move away from this process). Which is good, because they can do a much better job treating sewage without dealing with storm water. BUT—the downside is that in the vast majority of places all across the U.S. (I’m not sure how Europe does it), anything on the street, or that washes into the street, goes directly into the environment when it rains.

Now, let’s go somewhere else for a second—the Gulf of Mexico. Where the Mississippi River flows into the Gulf, and up and down the coast in Texas and Louisiana, are huge areas where oxygen levels are so low that fish and other marine life have a very hard time surviving, if they can survive at all. It’s called the “Gulf of Mexico Dead Zone,” and can affect as many as 7,000 sq. miles of water (it’s worse in the summer). And the dead one is caused by, mainly, fertilizer runoff. So, this is all a topic for another day, but the short version—almost 2 million pounds of potassium and nitrogen fertilizers wash into the Gulf of Mexico each year. (And the same problem exists in coastal areas worldwide, but the Gulf of Mexico dead zone is one of the worst).

NASA image of polluted runoff at Mississippi River delta

NASA image of polluted runoff at Mississippi River delta

Which brings us back to lawns. When you look at it per unit of area, Americans put 40 times more chemicals on their lawns than U.S. farmers put on their fields. And when it rains, those chemicals and fertilizers, the second they hit pavement at the edge of a lawn (or drainage of any sort), are sluiced into the environment in a flash. And that 2 million pounds of fertilizer in the Mississippi River? A full ten percent of it comes from lawns and gardens (and my guess would be that the “garden” part of that figure is probably relatively small).

In the end, all those pretty lawns across America—they’re pretty disastrous in the big scheme of things. If you have a lawn—please quit spending your money buying bags and bags of “Weed and Feed” and such, and then dumping those chemicals straight into the outdoors. For that matter, quit bagging your clippings—if you quit taking the nutrients off of the lawn, you wouldn’t have to be trying to put them back with chemical fertilizers. If you just can’t stand not to bag your clippings, then start a good compost pile and spread the completed compost back on the yard. Upon reflection here, lawns are definitely some “low-hanging fruit”. We could save time, and we could save money, and we could use that saved money to redirect demand in some positive way, and we could help the bees, and we could have a huge effect on water quality, and we could help the shrimp, and the crabs, and the fish, all by “leaving it a lawn”.

And those EV’s? Well, they don’t drip oil onto streets, because they don’t have engines, or transmissions. Just like our environment, the solutions tie together in a great big web.

 Opening image credit: inganielsen / 123RF Stock Photo