A green, well-manicured turfgrass lawn shows we are good neighbors and symbolizes our affluence. The environmental impact of keeping our lawns green, weedless, and pest free is significant.
A previous post explored how Americans became obsessed with turf grass lawns. In this post, we’ll look at the impact of turfgrass lawns on the environment, people, and other denizens of Earth.
The news is filled with stories of droughts, low water tables, and record high temperatures. Many water utilities, especially in the southeast and southwest, are concerned about being able to provide enough water to meet customer demand.
There are a few areas in the U.S. where turfgrass lawns grow adequately with only rainfall, but most lawns require supplemental watering, especially during the summer.
All the water supplied to our homes is potable (safe for drinking). It takes a lot of energy, resources, and money to provide potable water. Our lawns do not require drinking quality water but they use a lot of it.
The average American household uses 320 gallons of water a day, of which about 30% is used for watering lawns and gardens (35,040 gallons annually). Of that 30%, as much as 50% is wasted due to evaporation, wind, or runoff (17,520 gallons annually) 1. Picture lawn sprinklers watering the street or running in 100° weather. In a dry climate, water usage increases and outdoor irrigation can reach 50-70% of total household water use 2.
During the summer, water usage can go up over 100% which strains water supplies. This is called peak demand and is similar to the pressure put on power plants when everyone cranks up their air conditioners at the same time.
Like most plants, turfgrass has both growing and dormant periods. We do not like to see dry brown grass on our lawns, even though they might be dormant and still healthy, so we apply extra water in an effort to keep our grass green year round.
Human interaction with turfgrass lawns contributes to air, water, soil, and noise pollution.
The fertilizers, insecticides, and herbicides we apply to our lawns contribute to pollution even before they arrive at our homes. This is not unique to lawn care products but worth mentioning. Manufacturing products and packaging uses resources and energy and generates air pollution and toxic effluents. The fossil fuel-powered trucks and cars we use to transport products from the factory to the store to our homes add to air pollution.
Fertilizers contain nutrients such as nitrogen and phosphorus which are intended to improve the health and greenness of our lawns. There is such a thing as too much of good thing. During watering or rain, fertilizer residue is washed off lawns into street gutters, down storm drains, and ends up in rivers, lakes, and coastal waters. Too much nitrogen or phosphorus in water causes excess algae growth and decreases oxygen which can create a dead zone where fish and other aquatic life can’t breathe 3.
Each year, Americans put over 70 million pounds of pesticides (insecticides and herbicides) on our lawns to kill bugs and weeds 4. As with fertilizer, residue runs off lawns and contaminates water sources. We contribute extra pollution by rinsing out containers in our driveways and pouring excess or unused pesticides down the drain or street.
I am leery of any product designed to kill something. Chances are it will have unintended consequences. Of the 30 commonly used lawn pesticides, many are probable or possible carcinogens and are linked to a myriad of health problems such as birth defects, neurotoxicity, liver and kidney damage, and endocrine system disruption 5.
Lawn Mowers, Edgers, and Blowers
The EPA estimates gas-powered lawn and garden equipment is responsible for a whopping 5% of our air pollution. One hour of mowing the lawn with a gas-powered lawn mower emits 11 times more pollution than driving a car for the same hour. 4
That is to say nothing of the noise pollution caused by tens of millions of Americans revving up their lawn mowers, edgers, and blowers every weekend. Who wants to be woken up on Saturday morning by their neighbor’s roaring lawnmower?
Leaving grass clippings on the lawn is good for lawn health, minimizes the need for fertilizer, and acts as a carbon sink, but clippings look messy and spoil the manicured lawn look Americans seem to value. So, we collect our grass clippings in plastic bags and put them in the trash. In 2011, we sent 14.4 million tons (42.7%) of our yard trimmings to landfills around the country 6. Besides wasting valuable nutrients, transporting grass clippings to landfills generates air pollution, and huge amounts of grass decomposing anaerobically generate methane, a powerful greenhouse gas.
Empty lawn care product boxes, bags, and bottles and obsolete, broken, or unwanted equipment thrown in the trash add to the lawn waste stream.
Now we have learned about some of the consequences of our obsession with turfgrass lawns. It is not pretty.
In the next post, we will expand our horizons beyond turfgrass and look at the possibilities for a new American lawn appropriate for the 21st century.
- The American Lawn – Be the Envy of the Neighborhood
- The American Lawn – Our Obsession with Turf Grass
- EPA WaterSense – Outdoor Water Use in the United States
- EPA WaterSense – Research Report on Turfgrass Allowance
- EPA – Nutrient Pollution – The Problem
- EPA – Beneficial Landscaping
- Beyond Pesticides – Lawn Pesticide Facts and Figures
- EPA – Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for 2011