environment science + tips

Itching for more knowledge on the world that surrounds us? You’ve come to the right place for science and tips on all things straight-up environment, from climate to water to wetlands. Go ahead, get smarter.

climate science + tips

hot snow science

Ode to snow: we love it, we love it, we need more of it.
Ode to snow: we love it, we love it, we need more of it.

cool snow tips

  • Global Warming Myth: It Don’t Mean a Thing to…Freshwater Fish
  • Myth: Lake Michigan Is So Big That Chicago Can’t Run Out of Water
  • Myth: Road and Sidewalk Salt Is Natural and Just Disappears

hot trees and climate change science

Reason #57 climate change sucks: Its lousy impact on trees.

Reason #57 climate change sucks: Its lousy impact on trees.

cool trees and climate change tips

**Hint: for information on how climate change is affecting wildlife, please go to our Animal Science + Tips page.

water science + tips

hot water supply/drought science

Myth: We can get more water elsewhere. Reality: We wish...

Myth: One drought-stricken city can get water from another. Reality: We wish…

cool water supply/drought tips

hot DIY water management science

You don’t need to be a rain surgeon to maximize water!

cool DIY water management tips

  • Buying a Rain Barrel with the MWRD
  • Make Your Own Rain Barrel with tips from the City of Chicago
  • Rain Barrel FAQs from the MMSD
  • Rain Garden info from the MMSD
  • Rain Garden info from the Chicago Botanic Garden

wetlands science + tips

hot wetlands science

What wetlands are: awesome. What they aren't: the reason your flooded...

What wetlands are: awesome. What they aren’t: the reason your basement flooded…
  • An Ecological Solution to the Flood Damage Problem [PDF], Donald Hey, Jill Kostel, and Deanna Montgomery, Saint Louis University, 2009
  • Drainage: The Pros, the Cons, and the Future [PDF], Donald Hey, Hydrological Science and Technology, American Institute of Hydrology, 2002
  • Coastal Flooding and Wetland Loss in the 21st Century, Robert Nicholls, Global Environmental Change, 2004
  • Wetlands, WJ Mitsch and JG Gosselink, John Wiley & Sons, 2007The Essential Environment: The Science Behind the Stories, JH Withgott and S. Brennan., Pearson/Benjamin Cummings Press, 2009
  • Reducing nitrogen loading to the Gulf of Mexico from the Mississippi River Basin: Strategies to counter a persistent ecological problem,” WJ Mitsch, BioScience, 2001

cool wetlands tips

Waterways in Chicagoland science + tips

hot chicago river science

Repeat after us: it's NOT toilet water!

Repeat after us: it’s NOT toilet water!

cool chicago river tips

The mission to clean up the Chicago River must continue!

The mission to clean up the Chicago River must continue!

hot lake michigan science

  • Summer E-Coli Patterns and Patterns Along 23 Chicago Beaches, RL Whitman and MB Nevers, Environmental Science and Technology, 2008
  • Foreshore Sand as a Source of Escherichia coli in Nearshore Water of Lake Michigan Beach, RL Whitman and MB Nevers, Applied and Environmental Microbiology, 2008
  • Effects of the Nuisance Algae, Cladophora, on Escherichia coli at Recreational Beaches in Wisconsin, ET Englebert, C. McDermott, and GT Kleinheinz, Science of The Total Environment, 2008

cool lake michigan tips

Do You Need to Wash Your Recycling?

It’s time we had a little talk. Sometimes in life, we have dirty things we want to, ahem, recycle. This can mean we have to rinse containers before recycling them…except for when we don’t. Well, it’s certainly clearer than it used to be. But, the need to rinse really depends on the local recycling provider in your area. More often than not, though, a light rinsing is called for.

It used to be that some cities, such as Chicago, didn’t need residents to rinse their recyclables. The services took on the job of cleaning recyclable materials themselves. But Chicago and more areas like it now ask residents to remove the bulk of food residue.

This change is likely due to the potential contamination of paper, now that many recyclers have moved to curbside “single stream” recycling – where glass, plastic, paper and cardboard no longer need to be sorted into separate bins at home.

Another benefit of rinsing is that good washing helps deter rats and insects from trying to get at the recyclables before pick-up.

Even within facilities operated by the same waste management company, rules vary by location. That’s because the washing, sorting, and recycling equipment is continually being upgraded, improving its ability to handle more types of containers.

How Clean Do Those Containers Need to Be?

But it’s not that complicated. Waste Management, Inc. the largest recycling company in the world, says this about rinsing recyclable containers:

While all bottles, cans, and containers should be clean, dry, and free of most food waste before you place them in your recycling container, they don’t need to be spotless. The goal is to make sure they are clean enough to avoid contaminating other materials, like paper. Try using a spatula to scrape cans and jars, or using a small amount of water, shake the container to remove most residue.

Republic Services, Inc., another of the largest recyclers in the U.S., provides some simple recycling rinsing guidelines, and very easy to understand reasons for the rinse:

“Recyclables must be empty, clean and dry to prevent the contamination of other recyclables in the collection truck and at the recycling processing center. 

One ketchup bottle or not quite empty milk carton can cause your entire bin of otherwise perfectly recyclable items to be contaminated. Why? Because if the milk or ketchup leaks onto any paper, the paper is no longer recyclable. In some cases, the load won’t be accepted at many commercial processors. So, yes, it may end up in the trash.

“Unfortunately, contaminated materials have to be sent to the landfill, making your recycling efforts null and void.” But it’s easy to prevent this from happening by following these three steps:

Rinsing Recyclable Containers – Three Easy Steps

Step #1 – Empty.  
First, empty all liquid and residue from food and beverage containers. This makes a big difference for the next step.     

Step #2 – Clean.
Once excess liquids or solids are removed, give the containers a quick rinse – if needed – to clear any remaining residue. A rinse is usually needed for packaging that held milk, juice, sauces and condiments. A thorough wash isn’t called for, even here. No dish soap is necessary – a quick rinse and swish will do! 

Step #3 – Dry.
Now that your recyclables are empty and clean – let them dry out. They can sit upside down in the sink for a bit. Just don’t put wet containers in the bin.
And don’t stress if a little water remains. The rule of thumb is to never leave more than a teaspoon of liquid in a container. This will usually evaporate before your recyclables get picked up. 

Fortunately the answer in other areas is just a click away, thanks to Earth911’s recycling database, also available by app, which has compiled nationwide guidelines by zip code. Just enter the container type you want to recycle, and your ZIP code, and the search will identify the recycling facilities available for you. Then, check out the recycler’s guidelines.

As you’ll note, these recycling guidelines almost always say, “Please empty and rinse all containers and do not flatten containers.”

Why Aren’t Rinsing Requirements Consistent?

Why do the service requirements differ at all? And what happens if you don’t follow your local guidelines? We posed those and other questions to Eric Masanet, PhD, a Northwestern University Energy and Resource Systems Analysis Laboratory professor and researcher, and editor-in-chief of science journal Resources, Conservation and Recycling. His short take: It’s smart to follow the rinsing guidelines in your area, but not necessary to stress if you sometimes forget.

What happens if you don’t rinse recycling?

One big FAQ from people whose recycling service recommends rinsing is what happens when you forget to do it. Will your jar/bottle/can/what-have-you end up in a landfill anyway?It’s a valid question given that Waste Management, which manages half the country’s curbside recycling programs, used to state on its website that one dirty item can contaminate thousands of pounds of collected plastics. These days, WM just advises, “While all bottles, cans and containers should be clean, dry and free of most food waste before you place them in your recycling container, they don’t need to be spotless. “

But, yes, as Republic Services’ website says, “One ketchup bottle or not quite empty milk carton can cause your entire bin of otherwise perfectly recyclable items to be contaminated.”

So, please go ahead and rinse out any remaining liquids, in particular.

But the fact that an item is contaminated doesn’t relegate it to landfill status, explains Masanet. The recycling facility will use a mix of people and machines to sort then purify or clean everything according to type. Metal is the least sensitive to contaminants, he says, while plastic is so easily contaminated that even residue from a label can alter its chemistry and affect the quality of the recycled material in the end—exactly why recycling facilities have robust cleaning processes in place.

The real issue here is contamination of paper products in the same recycling bin. So, it’s more important to remove liquids than solids, like peanut butter.

More Reasons to Rinse Recyclable materials

Another downside of dirty recyclables is that contaminated recycled material has less market value—which means the recycling service provider has less to spend on things like improving service and green technology. So even though the recycling police won’t arrest you for not rinsing, Masanet advises complying with local guidelines so that the system is most efficient.

Curious about how recycling works once it leaves your bin? Take this video tour of a single stream recycling facility in Philly, courtesy of Waste Management, the country’s largest recycling provider.

Is Rinsing Recyclables a Waste of Water?

Another concern people have is whether rinsing recyclables wastes too much water. Generally though, Masanet recommends recycling as an “environmental slam dunk,” for saving energy, resources, and pollution. Even when considering water use on your end and at the recycling center, recycling almost always leads to energy savings when we consider the water needed to produce virgin glass, steel, plastic, or aluminum.

To rinse at home, just scrape out the majority of any remaining food with a spatula, and rinse it. Better yet, after washing any dishes by hand, just quickly swoosh around your recycling in the dishwater you’ve already used. That’s good enough for bottles, cans, and jars heading for your recycling bin. That’ll also be enough to keep your recycling bin from getting too smelly. The recycling facility will provide any further rinsing.

And, you’re not wasting water in the process.

How Much Water Does Recycling Save?

Working with data from various sources, Masanet is able to draw some interesting conclusions.

  • For steel and aluminum, it takes 3-10 times as much water to produce virgin metals as it does to recycle them. In other words, even extensive rinsing won’t reverse the water benefits of recycling. (Supporting intel comes from EERE and the Aluminum Association.)
  • For glass, the water use of recycled glass is closer to that of producing standard glass, but still, we’re likely to save 1-2 pints of water for every glass pint bottle recycled. 
    Conclusion: Prudent rinsing should preserve the water benefits of recycling. (Info from a WRAP report.)
  • For PET and HDPE plastics, they are thoroughly washed as part of the recycling process given that they are sensitive to contaminants. Different life cycle analyses and different recycling processes lead to different conclusions about how much water recycled plastics save, with a range of negligible water savings to more than 30 liters for recycling a one-liter bottle. Masanet’s verdict: prudent rinsing is not likely to negate the water savings of recycling plastics, but reckless rinsing might. (Via WRAP.)
  • So rinsing is nearly always the better, green approach.

A huge point to keep in mind, reminds Masanet, is that saving water is only one of the many benefits of recycling. We also save energy, greenhouse gas emissions, and pollution to air and water. “So, even if we occasionally use more water than we should, the other environmental benefits really make recycling a slam dunk.”

Uncovering the Basic Rinsing Tips

To rinse or not to rinse may not always have a black and white answer (it usually is!), but here are a few general pointers, in those cases where rinsing is not strictly required:

  • Empty is preferable:
    • It’s greener to consume or at least trash the food/drink/cleaning product in containers before recycling them. In addition to attracting vermin and upping the ick factor in your bin for the brave personnel who have to handle it, excess debris in your recycling bin requires extra energy to clean and dispose.
  • Rinsing for single-stream recycling:
    • Combined bin peeps, (those with “single stream recycling” – which is becoming more and more the norm) it’s a good call to err on the side of rinsing, since paper and cardboard are especially sensitive to residue. If nothing else, though, it is important to dump all liquids out of containers to help keep the paper goods recyclable.
  • Conserve water when you rinse:
    • Scrape food out first with a wooden spoon or rubber spatula, then swish a little bit of water around in the container versus letting it sit under a running faucet. If you have several containers to rinse at once, just fill up a bowl and use the same water for the whole job.

EcoMyth Outcome: Myth Mostly True – You generally SHOULD rinse all recyclable containers

You really should rinse all containers prior to recycling, unless your local recycling provider says you don’t have to. Emptying containers and rinsing when it seems appropriate will help make the whole process more economical. The main thing is to find out best practices in your area and follow them as well as you can.

And, as always, if there’s a question, contact your local recycling facility by phone or visit their website. You’ll almost certainly learn something else interesting along the way.

Do One Green Thing

OneGreenThing-rinsing-recyclables

Type your zip code into Earth911’s curbside recycling guide for the simple do’s and don’ts in your area.

More ways to help:

  • Empty all containers prior to recycling them, to help keep paper and cardboard nice and dry.
  • Rinse conservatively–no need to go all Mr. Clean on that milk carton when a simple swish of water will do the trick.
  • Reduce use in the first place, as suggested by Masanet. How? Opt for items in bulk where possible.

The Multiplier Effect

If more people recycle their beverage containers, we’ll redirect salvageable stuff from the landfill and save resources needed for new material production. Here are three cool cases in point from the EPA:

  1. Five 2-liter recycled PET bottles produce enough fiberfill to make a ski jacket.
  2. Recycling one soda can save enough energy to run a computer for three hours.
  3. The energy saved from recycling one glass bottle will operate a 100-watt light bulb for four hours.

One More Thing…

A couple of more very important tips on recycling:

  • Great that you’re recycling! Next step – are you composting? Check out our guide to figuring out what’s compostable vs recycling.
  • Interested in composting those paper plates? Find out which paper plates are actually compostable (or not!)
  • Don’t put plastic bags in your recycling bin – ever. Bags are very likely to jam up the sorting equipment.
  • For any other potentially recyclable materials than the usual plastic bottles, cans, jars, paper and cardboard, be sure to check out your recycler’s website (or app!) to make something is recyclable.