Soil in the City with Tim Bennett from Bennett Compost
This week on Gritty and Green, Meredith Nutting takes us on a journey through time to explore the origins of our city soil. Then she sits down with founder of Bennett Composting, Tim Bennett to learn about how compost is created and why it will save the world.
For more information about Bennett Composting go to: www.bennettcompost.com
To learn more about the partnership between Bennett and Philadelphia check out:
https://www.phila.gov/programs/farmphilly/community-composting/
If you want more information about local sustainability go to
EPISODE TRANSCRIPTION
NAT SOUND: worm eating. removing another tray
MEREDITH: SORRY IF THIS IS TOO GROSS – IT’S THE SOUND OF MY RED WRIGGLER WORMS MOVING ABOUT MY VERMICOMPOSTER. THEY ARE DARK PINK AND STRETCHED OUT LONG AND GLISTENING WET. THE STUFF THEY’RE SLITHERING OVER IS OLD, ROTTING, MOLDY FOOD SCRAPS.
BUT IF I LOOK IN THE NEXT LAYER – THE WORMS ARE STILL WRIGGLING BUT THE STUFF THEIR IN IS BEAUTIFUL, DARK AND NUTRIENT RICH. IT’S THEIR POOP. GARDENER’S GOLD! WORM CASTINGS.
NAT SOUND: worm bin closing
Meredith: Ok little friends, do good work!
Gritty and Green Theme Music
MEREDITH: THIS IS GRITTY AND GREEN. I’M YOUR HOST, MEREDITH NUTTING. ON THIS EPISODE WE’RE GETTING DIRTY AND TALKING SOIL.
I’VE GOT TIM BENNETT FROM BENNETT COMPOSTING TO TEACH US ABOUT HOW ELIMINATE YOUR FOOD WASTE AND TURN INTO FOOD – FOR YOUR PLANTS.
I’LL ANSWER SOME OF YOUR GARDEN QUESTIONS BUT FIRST SOIL – WHAT IS IT? WHERE DOES IT COME FROM? AND IS THE KEY TO HAPPINESS? OK, LET’S GET GROWING!
Paul Harvey Archival Audio: They were the soft soiled hands of a gardener. Bare of gloves they delved eagerly into the earth.
MEREDITH: THAT’S RADIO HOST PAUL HARVEY IN HIS SERIES “THE REST OF THE STORY”. HE’S THE PERSON THAT SAID
“MAN – DESPITE HIS ARTISTIC PRETENSIONS, HIS SOPHISTICATION AND HIS MANY ACCOMPLISHMENTS – OWES HIS EXISTENCE TO A 6 INCH LAYER OF TOPSOIL AND THE FACT THAT IT RAINS”
AND IT’S TRUE – SOIL IS AMAZING. IT’S ALIVE. TEEMING WITH OVER HALF OF THE EARTH’S SPECIES. THERE ARE MORE MICROORGANISMS IN ONE TEASPOON OF SOIL THAN THERE ARE PEOPLE ON THE EARTH. AND ITS CREATION IS SLOW. IT TAKES UP TO A THOUSAND YEARS TO CREATE A LAYER OF SOIL ONE INCH DEEP.
WELL, NOT QUITE, WE’VE JUST STARTED. HAVE YOU EVER CONSIDERED WHERE SOIL BEGAN AND WHAT IT’S MADE OF?
LET ME TAKE YOU ON A JOURNEY –
IT’S ABOUT 9.3 BILLION YEARS AFTER THE BIG BANG. DUST AND ROCKS HAVE BEEN SWIRLING AROUND SPACE COLLECTING IN BIGGER AND BIGGER PIECES. AS THE CLUMPS GET BIGGER THE GRAVITATIONAL FORCE INCREASES PULLING IN MORE AND MORE DUST. EVENTUALLY WE ENDED UP WITH THE PLANETS.
AND WHEN EARTH WAS JUST A BABY PLANET THE MOLTON ROCK AND METALS IT IS MADE OF STARTED TO CONDENSE AND COOL. THE SURFACE SOLIDIFIED FORMING THE LAYER WE LIVE ON. THE CRUST. ON AVERAGE IT’S ABOUT 20 MILES DEEP MAKING UP ONLY 1% OF THE EARTH’S VOLUME BUT MAN DOES IT HAVE A LOT GOING ON! AT LEAST NOW IT DOES – BUT BACK THEN THE CRUST WAS JUST MADE OF BEDROCK.
BEDROCK IS BASICALLY THE BASE LAYER AND IT’S DIFFERENT DEPENDING ON WHERE YOU ARE. IN PLACES WITH VALCANOES THE BEDROCK IS MADE OF BASALT AND GRANITE. IN OTHER PLACES ITS LIMESTONE AND IN OTHERS SANDSTONE. AS THE TETONIC PLATES THAT CREATE THE CRUST COLLIDED THEY CRATED MOUNTAIN RANGES AND ROCKS LIKE SCHIST AND GNEISS BECAME BEDROCK.
WHATEVER THAT MATERIAL IS, THAT IS THE PARENT MATERIAL OF THE SOIL THAT WILL COME. IT IS THE MATERIAL THAT ERODES FROM THE FORCES OF WIND AND WATER. EVENTAULLY THOSE ROCKS TURN BACK INTO THE DUST AND SAND THEY STARTED AT BILLIONS OF YEARS AGO – EXCEPT THIS TIME THEY’RE NOT SWIRLING IN SPACE, THEY’RE ON EARTH.
SO THAT’S THE FIRST FACTOR OF SOIL COMPOSITION– THE BROKEN-DOWN BEDROCK. THE SECOND COMPONENT IS CLIMATE. THE CLIMATE DICTATES HOW FAST THAT EROSION WILL HAPPEN BUT IT ALSO INFLUENCES WHAT KIND OF ORGANIC MATTER WILL BREAK DOWN.
OF COURSE BETWEEN A BARREN DUSTY PLANET AND THE LUSH GREEN ONE WE HAVE CURRENTLY WAS THE EVOLUTION OF LIFE ON EARTH BUT WE’LL JUST FAST FORWARD THROUGH THAT FOR NOW. THERE’S LIFE ONE EARTH, IT LIVES IT DIES AND WHEN IT DIES ALL THE MOLECULES IN ITS TISSUES BREAK DOWN TO FORM ORGANIC MATTER.
IN WARM MOIST PLACES DECOMPOSITION HAPPENS FASTER THAN IN COLD DRY PLACES. PLACES WITH A LOT OF LIFE MATTER LIKE THE AMAZON RAINFOREST HAVE MORE MATERIAL TO BREAK DOWN THEN PLACES LIKE THE SAHARA.
THESE TWO FACTORS – BEDROCK COMPOSITION AND CLIMATE HAVE CREATED OVER 7,000 DIFFERENT TYPES OF SOIL AROUND THE WORLD ALL VERY PARTICULAR TO THE PLACES THEY EXIST.
THE SOIL IN PENNSYLVANIA IS A VARIED MIX WITH THE MOST FERTILE, WELL-DRAINING SOILS IN THE SOUTH EAST AND THE OLDER, MORE WEATHERED SOILS IN THE MIDDLE AND WESTERN PART OF THE STATE. PERHAPS THE MOST IMPORTANT TYPE OF SOIL IN PENNSYLVANIA IS THE HAZELTON SERIES – YES THESE SOILS ALL HAVE NAMES TOO. THESE HAZELTON SOILS COVER 1.5 MILLION ACRES ACROSS PENNSYLVANIA AND GO SOUTH DOWN INTO KENTUCKY. IN FACT THERE’S EVEN A STATE BILL – HOUSE BILL 771 – TO OFFICIALL MAKE THE HAZELTON SERIES THE STATE SOIL OF PENNSYLVANIA.
IN THE PHILADELPHIA AREA, THE BEDROCK IS COMPOSED OF SCHIST WHICH ERODED TO CREATE SOILS RICH IN MINERALS AND NUTRIENTS.
THE SCHUYLKILLL AND DELAWARE RIVERS CARRIED A LOOSE SILT AND GRAVEL CALLED ALLUVIUM. BUT YOU CAN REALLY ONLY SEE THIS KIND OF SOIL IN PLACES LIKE FAIRMONT PARK OR HISTORIC CEMETARIES. MOST OF THE SOIL IN OUR BACKYARDS HAS BEEN TRASHED BY YEARS OF CONSTRUCTION AND BUILIDNG.
SO IT’S UP TO US TO CREATE THE SOIL OUR PLANTS ARE GOING TO GROW IN. AND TO DO THAT WE NEED BOTH THE SAND AND THE ORGANIC MATTER ALSO KNOWN AS, COMPOST. AND WHO BETTER TO TALK ABOUT COMPOST THAN SOMEONE WHO SPENDS HIS LIFE MAKING IT!
Tim Bennett: I'm Tim Bennett. I am the founder of Bennett Compost. We are a curbside composting collection composting company. So we pick up food scraps from people's homes at apartments throughout Philadelphia, and we make those food scraps into compost and other soil products
MEREDITH: BY MY COUNT THERE ARE NOW THREE FOOD SCRAP PICK UP SERVICES IN PHILADELPHIA – BENNETT, CIRCLE COMPOST AND THE ROUNDS. BUT BACK IN THE AUGHTS, THERE WAS ONE OPTION TO HAVE FOOD SCRAPS PICKED UP AND THAT WAS WITH YOUR TRASH.
Tim Bennett: We got started back in 2009 because I was living in South Philly at the time and the second floor apartment and I wanted to compost and I didn't feel like I had a good way to do it. So I looked around and thought, Is there a place I can take it to? And there wasn't a place I could take it to. I thought, Is there someone who would pick it up? And there wasn't able to pick it up and I didn't have space to do it, outdoor space to do it. And knowing what I know now, 15 years later, I probably should have just tried worm composting and that would have worked or wouldn't have, and I might have moved on to something, something else. But I, I didn't. I didn't realize that was the thing at the time.
MEREDITH: COINCIDENTALLY THAT’S ACTUALLY WHY I STARTED MY WORM BIN. I HAD A SMALL SOUTH PHILLY APARTMENT. I WAS DOING A WEIRD COMMUTE THAT MADE ME MISS TRASH DAY ALMOST EVERY WEEK AND THE WORM BIN WAS MY SOLUTION TO AVOID MY TRASHCAN STTING AROUND WITH STINKY FOOD SCRAPS. THE WORMS ATE THEM UP!
Tim Bennett: And I was just like, well, maybe, um, maybe there's something here, maybe there's an opportunity. Maybe there are other people like me who want to compost, to live in the city and don't have a way, a way to do it. And I was kind of at a place in my life where I was kind of trying to figure out what was the next thing I was going to do. And so I took a hundred bucks and put it in a bank out and said, I'm just going to see whether there's something here. And if it doesn't go anywhere, I've spent 100 bucks and worst things in my life for this. And that was kind of the genesis of it. I figured out figured everything else out from there.
MEREDITH: ONLY A FEW CITIES IN THE UNITED STATES HAVE COMPOSTING PROGRAM – PROBABLY NOT SURPRISNGLY SAN FRANCISCO WAS ONE OF THE FIRST. RESIDENTS ARE MANDATED TO PUT OUT THEIR COMPOSTABLES IN A GREEN BIN SEPARATE FROM THEIR TRASH AND RECYCLING.
PHILLY DID HAVE A KIND OF SYSTEM FOR ABOUT 60 YEARS. FROM THE 1930S TO 1990S FARMERS FROM JERSEY WOULD COME ACROSS THE RIVER TWICE A WEEK AND PICK UP FOOD SCRAPS TO FEED THEIR PIGS. SEVENTEEN FARMERS PICKED UP OVER 30,000 POUNDS OF FOOD SCRAPS A YEAR AND THEY WERE PAID 1.9 MILLION DOLLARS. IT WOULD HAVE COST THE CITY DOUBLE TO HAVE THAT THROWN INTO LANDFILLS. OF COURSE THAT HAD ENDED BY THE TIME TIM INVESTED $100 INTO HIS NEW VENTURE.
Tim Bennett: You know, maybe after the first month of getting started, we pick it up from three or four households. So it was maybe 40 pounds a week. Right. And now we're picking up probably around 4 million poundsa year. So it's been quite the it's quite the trajectory we pick up from over 6000 households down at 125 businesses all here in Philadelphia. And it's been kind of a wild ride. it was just me when we started. And now there are close to 30 people who work here.
MEREDITH: IN JUNE 2023, WITH SUPPORT FROM THE EPA BENNETT AND THE CITY’S PARKS AND RECREATION DEPARTMENT ENTERED A PARTNERSHIP. BENNETT COMPOST GOT A LONG-TERM LEASE AT A VACANT PARKS AND REC FACILITY IN THE CRESCENTVILLE NEIGHBORHOOD. IN RETURN BENNETT COLLECTS FOOD SCRAPS FROM THE REC CENTERS AND RETURNS COMPOST TO THEIR GARDENS FREE OF CHARGE.
Tim Bennett: And this is where all the material that we collect comes here at its first stop. It's where we make all the compost that we make and all of our soil stuff comes out of. It's kind of our central kind of hub for everything that we do,
MEREDITH: OK SO WE’VE BEEN TALKING ABOUT IT FOR AWHILE BUT WHAT EXACTLY IS COMPOST?
Tim Bennett: compost itself is a soil amendment. And so that what that technically means is it's something that you add to soil to replenish nutrients, to add microbes and microbial life to existing soil. For people who aren't as familiar with gardening, it's kind of very similar to think of what a fertilizer like. In some ways it's very similar to what a fertilizer would do.It also has kind of just a web of kind of soil life and microbial life that is part of it. So it's also kind of helping to encourage that growth in the soil and replenishing that stuff.
MEREDITH: TURNING FOOD INTO FERTILIZER ISN’T A QUICK PROCESS. TAKE AN APPLE CORE FOR EXAMPLE --
Nat Sound: Apple being bitten. Apple drops into bucket
Tim Bennett: So the Apple core starts its life as an apple. You take a bite of it, you eat it. You put it in your Bennett compost bucket. We come by and we empty that bucket into one of our collection vehicles, whether it's one of our bicycles or one of our trucks, depending on where you are in Philadelphia. Then that vehicle brings it. That vehicle brings it up here and here we that food, along with all the other food scraps.
And the food scraps are then blended with with the woodchips that we have on site. They're blended with the leaf mulch that we have onsite a little bit that Philly Go project material that we talked about earlier on site and they are all built into these big piles that are probably about eight feet tall, 20 feet long, ten feet wide and have a pipe kind of running down the the middle of the bottom of the pile.
MEREDITH: THAT HUGE MOUND IS THEN COVERED WITH FINISHED COMPOST FROM THE PILE THAT CAME BEFORE.
Tim Bennett: it acts as a bio filter so that it helps to kind of keep smells down and keep animals away.
MEREDITH: AND THAT PIPE RUNNING ALONG THE BOTTOM OF THE PILE – THAT GETS PUMPED FULL OF AIR THAT INFLITRATES THE MIXTURE OF FOOD SCRAPS AND WOOD CHIPS.
Tim Bennett: And that air is helping to feed all the natural decomposers and microbes that are all around us and that help to break down all that kind of material. So essentially what we're doing is we're creating the right habitat by having the right blend of different materials and oxygen that creates a air, a home for all of this microbial activity that actually helps to do all that become decomposing. The panels get very hot, so they usually get between 150 and 160 degrees. And so that is hot enough that it kills all the harmful pathogens that might be in the rotting food but is not so hot. As long as you keep it under 170, you're not going to kill some of the beneficial bacteria and microbes that are helping to break down the that material.
MEREDITH: THAT PILE SITS FOR ABOUT FOUR WEEKS WITH THE MICROBES EATING ALL THOSE FOOD SCRAPS, INCLUDING THAT APPLE CORE WE STARTED WITH. AS IT BREAKS DOWN IT RELEASES ALL THE WATER IT HELD AND THE PILE GETS SMALLER AND SMALLER.
Tim Bennett: And by the time it's gotten through the first four weeks, most of the food waste is is completely unrecognizable.
MEREDITH: DIFFERENT PILES ARE COMBINED TO MAKE A HUGE MOUND 120 FEET LONG WHERE IT SITS FOR ANOTHER MONTH.
Tim Bennett: Then it moves to a final set for two weeks. That's ten weeks. And then we take that material and we run it through a screening process.
MEREDITH: THAT’S WHERE THEY SIFT OUT THE BIGGER PIECES THAT HAVEN’T QUITE BROKEN DOWN. AND THAT IS WHAT GOES ON TOP OF A NEW PILE TO STOP SMELLS FROM GETTING OUT AND CRITTERS FROM GETTING IN.
Tim Bennett: So at that point, the material looks, for the most part how it will look when it's a final product, but it's still not done yet.
MEREDITH: ALL THE SMALL BROKEN DOWN MATERIAL GETS PUT IN – YOU GUESSED IT – ANOTHER PILE. THIS TIME, WITHOUT AIR WHERE SITS FOR ABOUT 6-8 WEEKS.
Tim Bennett: that's our curing pile. And so that the temperatures are going to get down a little bit more. You're going have temperatures that are going to be more than 110 to 115 range and then kind of go down from there. And that just allows for different kind of microorganisms and bacteria to thrive and help kind of finish off the composting process. So it is a stable kind of product that you can use to help your your plants and your vegetables kind of grow.
MEREDITH: WANNA GET A BIT NERDY WITH ME? WHEN THE COMPOST PILE STARTS THE BACTERIA BREAKING DOWN FOOD ARE REFERRED TO AS MESOPHILIC – THEY LIKE TEMPERATURES BETWEEN 68 AND 113. THEY BREAK DOWN THE SIMPLE ORGANIC COMPOUNDS. AND AS THEY DO IT THE TEMPERATURE IN THE PILE RISES. THEN THE THERMOPHILIC BACTERIA TAKE OVER – THOSE ARE THE HEAT LOVERS. THEY BREAK DOWN MORE COMPLEX COMPOUNDS LIKE PROTEINS AND FATS. THEY ALSO KILL WEED SEEDS AND PATHOGENS. THEN AS THE TEMPERATURE DROPS THE MESOPHILES RETURN ALONG WITH FUNGUS AND BREAK DOWN ANYTHING THAT’S LEFT. SO, WORKING A COMPOST PILE ISN’T JUST TURNING DIRT, IT REQUIRES CARING FOR A BILLION MICROSCOPIC CREATURES.
Tim Bennett: is a living we call it living soil right. Like mean it's it's not a lot of soil that you might buy in a you know if you're buying a bag at a store of soil and there's no way for oxygen to get into it like right Like you're going to get a different product than you are.And it's a living kind of I mean, it's living, breathing, uh, material, but there's lots of microscopic inorganic life. It's all kind of very beneficial for for plant growth.
MEREDITH: SOIL MICROBES ARE VITAL TO GROWING PLANTS. THEY CYCLE NUTRIENTS, BREAK DOWN ORAGNIC MATERIAL, CONTROL PESTS AND PATHOGENS, DEGRADE POLLUTANTS, AMONG OTHER BENEFITS. AND FOR PEOPLE THESE MICROBES ARE RESPONSIBLE FOR OUR IMMUNE SYSTEMS FROM THE TIME WE WERE GRUBBY CHILDREN DIGGING IN THE DIRT. THEY CREATE ANTBIOTICS AND PROBIOTICS THAT KEEP US HEALTHY. AND THEY CAN TRIGGER A RELEASE OF SERATONIN WHICH IS THE CHEMICAL THAT MAKES US FEEL HAPPY. SO THESE BACTERIA PRESENT IN COMPOSTING ARE VITAL TO THE HEALTH OF LIVING THINGS BUT COMPOSTING IS ALSO IMPORTANT FOR THE HEALTH OF OUR PLANET.
Tim Bennett: So when food goes to a landfill, it often breaks down without any oxygen. And so it breaks it breaking down and aerobically. When that happens, it releases methane as a product of that. And landfills are actually the third leading cause of methane emissions in the United States.-That. And the second is agriculture, mostly from dairy cows. There's a lot of things that are coming out. The back sides of of dairy cows are very methane because there are so many dairy cows that that is the second, but after that, landfills. So it's a major contributor of methane emissions, which is a greenhouse gas. And when you compost, there's no the methane is not emitted because you're doing it with oxygen.
MEREDITH: IN 2015 THE USDA AND EPA ANNOUNCED A GOAL TO CUT FOOD WASTE IN HALF BY 2030. SO FAR THE AMOUNT OF FOOD WASTE GOING INTO LANDFILLS HAS ONLY INCREASED.
Tim Bennett: We’re still despite the growth we've had and success, we're only picking up a tiny fraction of it. Right? We're picking up from less than 2% of the households throughout the city. So all the work we're doing and you multiply that times 50 times 60, right? Like that's that's how much food waste there is just from households in Philadelphia
MEREDITH: PHILADELPHIA THROWS OUT 206 MILLION POUNDS OF FOOD – LIKE ACTUAL FOOD THAT COULD HAVE BE EATEN NOT JUST BANANA PEELS AND EGG SHELLS. IN FACT, NEARLY 17% OF PHILADELPHIA’S TRASH IS WASTED FOOD. SO REDUCING FOOD WASTE – ESPECIALLY WHEN 600,000 PHILADELPHIANS EXPERIENCE FOOD INSECURITY. STILL, FOOD SCRAPS MAKE UP SOME OF THE FOOD WASTE THAT MAKES ITS WAY TO THE LANDFILLS AND THEY NEED TO BE DIVERTED TOO. SO WHY IS IT SO HARD FOR CITIES LIKE PHILADELPHIA TO CREATE A CURBSIDE PICK UP COMPOSTING PROGRAM ALONG WITH TRASH AND RECYCLING?
Tim Bennett: Even if the city said, we want to start composting tomorrow, we have the money, we have the workforce, we have the vehicles, and everyone tomorrow can put out a bucket or a container of food scraps and yard waste and we're going to collect it all.
Tim Bennett: There is not the infrastructure in the Philadelphia region to handle it right. So you need to build there needs to be additional infrastructure built up. And it's really hard to ship food waste long distances because it is the heaviest part of the stuff of the of the trash. I mean, it is mostly water and water is heavy, right.
Tim Bennett: And so shipping it doesn't kind of really make it make sense. But outside of that, there's also just kind of the economic realities of like, how does that work with how does additional collections, how do you pay for that? So roughly the big city, it's got lots of challenges. So it has to figure out kind of what its priorities are and where where it should be. Um, spend this money and I think that there's a definitely a place for the city to be, I mean, to be a part of it. The question is like, is it how does that fit in with the bigger, with the bigger picture? I think those are going to be always the two challenges. How are you paying for collection and then where are you taking kind of material?
MEREDITH: JUST TO GIVE YOU AN IDEA, NEW YORK LAUNCHED A PILOT COMPOSTING PROGRAM IN 2013 AND BY 2017 IT WAS REACHING 3.3 MILLION PEOPLE AND COSTING UP TO $20 MILLION DOLLARS ANNUALLY. BUT YOU HAVE TO REMEMBER FOOD SCRAPS COST MONEY TO PUT LAND FILLS TOO. IT’S ESTIMATED THAT IF THE US CAN INCREASE ITS COMPOST BY 8% IT WOULD SAVE 16 BILLION DOLLARS IN WASTE MANAGEMENT COSTS. OF COURSE MONEY ISN’T THE ONLY PROBLEM.
Tim Bennett: the other thing that we have going for is that sometimes bigger municipal programs run into is that because the people who are using our program are choosing to use the program, It's first of all, it's an opt in like no one has been mandated to do it. And secondly, people are they're not just opting in. They're paying money to opt in. So they're very committed to making sure that the right stuff stays in and the stuff that we compost it doesn't. And some municipal program programs, especially ones that have been mandated, have run the problems of high levels of contamination,
MEREDITH: CONTAMINATION CAN BE SOMETHING WE CAN SEE LIKE BROKEN GLASS OR BIG PLASTICS – THOSE THINGS ARE ANNOYING BUT CAN SIFTED OUT. BUT CONTAMINATION CAN ALSO BE IN THE FORM OF TOXIC CHEMICALS THAT DON’T BREAK DOWN AND ARE INVISIBLE. REMOVING THOSE CAN BE A LOT HARDER. AND IT’S NOT ALWAYS INTENTIONAL. SOME OF IT CAN BE LACK OF EDUCATION AND IT’S HARD WHEN THERE’S A TENDANCY FOR COMPANIES TO GREENWASH PRODUCTS HINTING THAT THEY ARE MORE ECOLOGICALLY FRIENDLY THAN THEY ARE.
Tim Bennett: compostable it means they will actually turn like you will actually kind of become compost. It will become this this soil element that you can use. Biodegradable generally just means that it will degrade into very tiny, tiny, tiny, tiny pieces of microplastics.
MEREDITH: OH MICROPLASTICS – IT SEEMS LIKE EVERY MONTH THERE’S A NEW ORGAN IN WHICH RESEARCHERS ARE DISCOVERING MICROPLASTICS. THEY’VE BEEN IN BLOOD, LUNGS, INTESTINES, CROSSING THE PLACENTAL BARRIER IN PREGNANT WOMEN, IN BREAST MILK AND IN EVERY TESTICAL TESTED IN ONE STUDY. THEY ARE EVERYWHERE. AND WE JUST DON’T KNOW YET WHAT THEY ARE DOING TO OUR BODIES BUT IT’S NOT LOOKING GOOD.
Tim Bennett: It's not actually going to compost in our in our piles or other people's piles, we we can't accept it for a composting. It does not mean that, you know, you know, in a in a giant dusted off facility with a grinder or in a lab setting, it didn't break down. I'm sure it did. If it meets compostable certifications. But again, if you that facility where your material is going to is not being if not able to handle it, it doesn't it might as well be be trash because that's what most of what they're going to do is probably remove it at some point and put it in the trash.
MEREDITH: SO IT’S BEEN A CHALLENGE TO CREATE CITYWIDE COMPOSTING PROGRAMS. AND THAT’S THE VOID THAT COMMERCIAL CURBSIDE FOOD WASTE PICK UPS PROVIDE. BUT PHILADELPHIA IS WORKING ON IT THROUGH A PARTNERSHIP WITH BENNETT.
Tim Bennett: We do program where we're collecting photographs from the rec center
MEREDITH: THE CITY’S REC CENTERS SERVE OVER 2 MILLION MEALS TO CHILDREN AND ELDERLY THROUGH DIFFERENT CITY RUN PROGRAMMING. THOSE MEALS PRODUCE OVER 150 TONS OF WASTE A YEAR. BUT STARTING IN 2021 BENNETT HAS BEEN COLLECTING THAT FOOD WASTE AND TURNING IT INTO COMPOST THAT IS THEN RETURNED TO CITY FOR USE IN THE URBAN GARDENS AND FARMS IN THEIR FARM PHILLY NETWORK! PLEASE NOTE AN EARILY VERSION OF THIS PODCAST INCLUDED INFORMATION ABOUT THE COMMUNITY COMPOST NETWORK. THAT IS A SEPARATE BUT ALSO EXCITING CITY COMPOST PROJECT THAT BENNETT SUPPORTS THROUGH SOME TRAINING AND EDUCATION.
Tim Bennett: our goal has always been to make composting easy for people in Philadelphia and when I started the business 15 years ago, I used to tell people I was in the typewriter business because that was like within ten years the city will probably figure this out and we'll be obsolete in the way that the people don't use typewriters anymore. They just, they use computers, right?
And here we are 15 years later and the city is still not doing composting. But I think more than ever, I'm a believer now that you don't there's not just going to be one model that's going to work for everybody.
MEREDITH: OF COURSE ALONG WITH COMPOSTING COMPANIES AND CITY PROGRAMS THERE IS A THIRD OPTION --
Tim Bennett: If you have outside space, then there are kind of various systems, kind of multibeam systems or tumblers that you kind of build these composting bins. Have you done a lot of outside space there are kind of really the best option is kind of Vermont composting, which is composting with worms.
MEREDITH: OF COURSE THERE ARE CHALLENGES TO DOING ALL THIS AT HOME WITH LIMITED SPACE. AND THEY CAN BE CREEPY – LIKE CRITTER CREEPY – LIKE RAT CRITTERS.
Tim Bennett: one of the reasons that we don't have issues, you know, the two things that we do that we found that keep kind of rodents away from our paths is when our public get really hot. And so it's not comfortable for an animal to be in 150 degrees the same way. It's not comfortable for you to stick your hand. So there's 150 degrees. We also we also move the piles a lot, right? Like moving them piles are not sitting for for months and months and months. And sometimes that's what can be tricky in the city.
You're trying to do it in your own backyard. As you may, it may not be getting moved around a lot. And so then it may be kind of a nice, dark, moist, kind of warm. You even just taking the like potential of food inside. Like it's also like a warm, nice, dark place for an animal to to be in
MEREDITH: EVEN WITHOUT THE RATS -- FINDING THE RIGHT MIX OF MATERIALS TO CREATE THAT WONDERFUL ECOSYSTEM OF MICROBES FOUND IN BENNETT’S PILE IS PRETTY TRICKY.
Tim Bennett: Food waste estate each have their own kind of ratio. So generally the standard rule of thumb is that you want kind of two parks that we call brown. So that's like your leaves, woodchips. Some will use shredded newspaper. They don't have that that people use straw depending on sawdust, putting in kind of what they have access to. Two parts of that to the one part food waste and they that's very rough for a back.
That's very rough from a scientific respect. But for most backyard people that will get them kind of the ratio that they need. But that can be challenging. When you're living in the Philly Road Home and you're like, Where am I supposed to get all these leaves or all of this, you know, all this carbon material? And that is one of the challenges of kind of matching these to materials that you have, because if you don't, I kind of like a kind of quite a little bit like making a gravy, right?
Like if you don't have enough of that and the food scraps are like the the flavor and the browns, the carbons are the, the like the flour, the, the thickness. Right. If you have too much food scraps and it tends to sometimes and not enough too much created non browns it's going to be runny might be smelly, doesn't tend to work right.
And if you have not enough of that, it doesn't really nothing happens to it. So it is kind of tricky to balance those things. And I see your point in the interim environment like Philadelphia. There's not just you don't have a big backyard that's just dumping leaves all over the place for you to kind of gather and store and use in your household file, at least in kind of like the real neighborhoods where as someone who lives in northwest Philadelphia or West Philadelphia or the Northeast might have more active Phillies and they might be able to kind of like manage a backyard in a way that's a little bit more challenging for someone who's in some of the denser neighborhoods.
MEREDITH: THIS NOT TO DISCOURAGE YOU FROM COMPOSTING AT HOME. AS YOU HEARD AT THE START OF THIS EPISODE I’VE HAD A WORM BIN FOR OVER A DECADE AND I ALSO HAVE A TUMBLER. BUT JUST LIKE ANYTHING LIVING IT TAKES SOME TIME TO LEARN HOW TO GET IT RIGHT. AND, IF YOU DON’T WANT TO – THERE’S ALWAYS BENNETT.
Tim Bennett: I think that community groups have a part to play with it. I think that urban agriculture is a part of that. I think that, uh, small businesses like ourselves, I'm a part and I'll have part of that.
MEREDITH: THAT WAS TIM BENNETT FROM BENNETT COMPOSTING. YOU CAN FIND OUT MORE ABOUT THEIR WORK AT BENNETTCOMPOST.COM
AND I’LL PUT MORE INFORMATION ABOUT THE CITY’S COMPOSTING PARTNERSHIP IN THE SHOW NOTES.
IN A PODCAST ABOUT URBAN GARDENING TALKING ABOUT SOIL I’D BE REMISS IF I DIDN’T TALK ABOUT THE RISKS OF GARDENING IN THE CITY.
URBAN SOIL CAN HAVE A LOT OF CONTAMINATION FROM PAST INDUSTRY, VEHICALS, LEAD-BASED PAINTS, AND IMPROPER WASTE REMOVAL. HEAVY MEATLS LIKE LEAD CADMIUM ARSENIC AND MERCURY CAN HANG AROUND IN THE SOIL FOR DECADES. LEAD IS PROBALBY THE MOST COMMON BECAUSE UNTIL THE 1970S IT WAS IN EVERYTHING.
EVEN IF YOU AREN’T GARDENING, THE HEAVY METAL IN THE SOILS CAN BE AN ISSUE BECAUSE THEY STICK TO THE DUST AND GET KICKED UP IN THE AIR AND WE BREATHE IN OR INJEST THE PARTICLES. AND OF COURSE THEY CAN CAUSE A SLEW OF HEALTH ISSUES.
CADMIUM AND ARSENIC ARE CARCINOGENIC AND CAN CAUSE KIDNEY DAMANGE AND OTHER CHRONIC CONDITIONS. MERCURY CAN RESULT IN NEUROLOGICAL AND DEVELOPMENTAL DIFFERENCES.
LEAD IS THE MOST CONCERNING AS IT AFFECTS CHILDREN TO A GREAT DEGREE DAMAGING THEIR NERVOUS SYSTEMS LEADING TO COGNITIVE AND BEHAVIORAL DIFFERENCES AND LEARNING CHALLENGES. IN PHILLY AT LEAST, YOUNG KIDS HAVE REGULAR LEAD SCREENINGS. BECOMING EXPOSED TO LEAD CAN BE AS EASY AS LIVING NEXT TO A CONSTRUCTION SITE. SO YOU CAN IMAGINE THAT IF BREATHING IN DUST COULD BE HARMFUL, KNEELING DOWN WITH YOUR FACE A FOOT FROM THE URBAN SOIL YOU’RE DIGGING IN COULD BE TOXIC.
SO SHOULD WE GIVE UP GARDENING?
NO. BUT EVERYONE SHOULD HAVE THEIR SOIL TESTED FOR HEAVY METALS, ESPECIALLY IF THEY’LL BE PLAYING OR DIGGING OR GARDENING. TO DO THAT YOU GO TO THE PENN EXTENSION WEBSITE – I’LL PUT IT IN THE SHOW NOTES – AND FILL IN THE SOIL TESTING FORM AND THEN GET YOUR SAMPLES. THE WEBSITE HAS A DETAILED EXPLAINER BUT BASICALLY YOU TAKE A SCOOP OF SOIL FROM ABOUT 10 DIFFERENT SPOTS AROUND YOUR YARD, DRY THEM OUT, PUT HTEM IN A PLASTIC BAG AND SEND THEM IN THE MAIL. IN A WEEK OR SO YOUR RESULTS WILL COME IN.
IF THE RESULTS INDICATE HIGH LEVELS OF HEAVY METAL YOU MAY WANT TO LOOK INTO REMOVING IT OR COVERING IT TO AVOID LEAD EXPOSURE.
THERE ARE SOME PLANTS THAT ARE USED AS BIOREMEDIATORS – SUNFLOWERS ARE A POPULAR ONE BEING STUDIED. THESE PLANTS CAN REMOVE LEAD FROM THE SOIL AND STORE THEM IN THEIR TISSUES SO YOU CAN DISPOSE OF THEM BUT THE EFFECTIVENESS OF THIS PROCESS IS STILL BEING STUDIED.
REGARDLESS OF HEAVY METALS IN YOUR SOIL THOUGH, YOU PROBABLY DON’T WANT TO BE PLANTING IN IT MAINLY BECAUSE IT’S NOT GREAT FOR PLANT GROWTH. A LOT OF IT COMPACT AND CLAY – WHAT YOU REALLY WANT IS A RATIO OF ABOUT A 1/3 SOIL, A 1/3 COMPOST AND 1/3 SAND. YOU ALSO WANT ALL THOSE GREAT MICROBES TIM BENNETT WAS TALKING ABOUT.
YOU COULD TEST YOUR SOIL FOR NUTRIENTS SIMILAR TO TESTING FOR HEAVY METALS BUT A DIFFERENT FORM TO FILL OUT – OR YOU COULD DO RAISED BEDS. IN SMALL SPACES RAISED BEDS ALLOWS YOUR GARDEN TO BE EASILY DELINIATED INTO PLANT SPACE AND HUMAN OR DOG SPACE. I’M A BIG FAN. YOU CAN BUY A RAISED BED SOIL MIX OR MAKE YOUR OWN. ONE LITTLE TIP – PHILADELPHIA OFFERS FREE COMPOST, MULCH AND MANURE TO RESIDENTS. IT’S AT THE FAIRMONT ORGANIC RECYCLING CENTER AND IT’S A REALLY GREAT WAY TO FILL BEDS WITHOUT KILLING YOUR BUDGET.
SO THAT’S THE DIRT ON – DIRT!
NOW, LET’S ANSWER SOME OF YOUR GARDEN QUESTIONS!
Caller: Hi. So my question is about municipal dirt. I know that some cities and towns do leaf collection and lawn clipping stuff then return it as compost. I’ve been warned against using it by some people because if folks use chemicals on their lawns then that’s going to end up in the lawn clippings and then make whatever the recycling product is, the compost, it will have those chemicals in them. So do you know anything about how that material is processed and how you would tell if the material from your city does have that kind of chemical in it? Thanks so much.
MEREDITH: GREAT QUESTION ESPECIALLY THIS EPISODE! IN A COMMERCIAL COMPOST SET UP – ON TO THOSE HIGH TEMPERATURES LIKE WE HEARD TIM BENNETT TALK ABOUT – SOME CHEMICALS DO BREAK DOWN. HOWEVER, THERE ARE A FEW PERSISTENT HERBICIDES THAT DON’T – MAINLY CLOPYRALID AND AMINOPYRALID. THESE HERBACIDES TARGET BROADLEAF PLANTS LIKE THISTLE AND NIGHTSHADES AND ARE VERY PERSISTANT IN THE ENVIRONMENT. EVEN SMALL AMOUNTS CAN DAMAGE SENSATIVE CROPS LIKE TOMATOES, BEANS AND SUNFLOWERS. YOU MAY SEE TWISTED, STUNTED GROWTH AND DEFORMED LEAVES.
SO SHOULD YOU USE THE MUNICIPAL COMPOST?
THAT KIND OF DEPENDS ON YOUR GOALS AND YOUR RISK TOLERANCE.
IN PHILADELPHIA THE MUNICIPAL COMPOST OFFERED TO THE PUBLIC IS MADE FROM LEAVES, GRASS CLIPPINGS AND VEGETARIAN ANIMAL MANURE BROADLY FROM ACROSS THE CITY.
PRECOVID THE COMPOST WAS REGULARLY TESTED THROUGH THE SEAL OF TESTING ASSURANCE PROGRAM (STA) WHICH TESTED FOR NUTRIENT CONTENT, PH, MOISTURE CONTNET AND THE PRESENCE OF CONTAMINANTS SUCH AS HEAVY METALS AND PATHOGENS. AT THE TIME THE CITY’S COMPOST MET THE REQUIREMENTS FOR THE STA CERTIFIED COMPOST LABEL. NOTHING HAS CHANGED IN THE WAY THE CITY MAKES THE COMPOST BUT IT DOESN’T CURRENTLY HOLD THE STA CERTIFICATE. COVID RELATED STAFFING TURNOVERS LED TO IT LAPSING, THOUGH THE CITY HOPES TO REGAIN THAT STATUS AND START REGULARLY TESTING AGAIN IN THE FUTURE.
HOWEVER -- THE STANDARD TEST DOES NOT TEST FOR THESE PERSISTANT HERBICIDES SO IF THE CITY DOES REINSTATE ITS CERTIFICATION IT WOULD NEED TO OPT INTO THAT TESTING TOO.
SO LONG ANSWER SHORT – IF YOU’RE KEEN ON EVERTYING IN YOUR GARDEN BEING 100% CHEMICAL FREE YOU MAY NOT WANT TO RISK IT. IF YOU’RE PLANTING THE LAST OF YOUR GRANDMOTHER’S HEIRLOOM TOMATO SEEDS – YOU MAY NOT WANT TO RISK IT. PERSONALLY I KNOW PLENTY OF GARDENERS WHO HAVEN’T HAD AN ISSUE WITH THE CITY’S COMPOST AND I WILL CERTAINLY CONTINUE TO USE THIS FREE RESOURCE IN MY GARDEN.
I HOPE THAT HELPS YOU CHOOSE WHAT’S BEST FOR YOU AND YOUR GARDEN.
IF YOU HAVE ANY GARDEN RELATED QUESTIONS EMAIL ME AT GRITTYANDGREEN@COOLGOONPRODUCTIONS.COM
THANKS SO MUCH FOR JOINING ME FOR THIS EPISODE OF GRITTY AND GREEN. AND A SPECIAL THANKS TO TIM BENNETT FROM BENNETT COMPOSTING. IF YOU WANT TO LEARN MORE ABOUT THEIR WORK PLEASE GO TO BENNETTCOMPOS.COM
IF YOU’RE ENJOYING THIS PODCAST I’D LOVE IT IF YOU’D LIKE, SUBSCRIBE, RATE ANDSHARE IT SO THAT OTHERS CAN FIND IT.
GRITTY AND GREEN IS PRESENTED BY GREEN PHILLY.
IN COLLABORATION WITH COOL GOON PRODUCTIONS.
IT WAS WRITTEN, DIRECTED AND EDITED BY ME, MEREDITH NUTTING.
THEME MUSIC BY KAZUYA
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