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Scientists Use Recycled Sewage Water to Grow 500-Acre Forest in the Desert (goodnewsnetwork.org)
222 points by ph0rque 87 days ago | hide | past | web | favorite | 84 comments

A little beside the topic perhaps, but my all time favorite desert greening project is connecting the huge Qattara Depression in Egypt with the ocean.

This would create a huge lake in northwestern Egypt, potentially home for millions. It would also negate one year of climate change induced sea rise, or so I read somewhere.


Map of the potential lake, if brought up to sea level: https://en.wikipedia.org/wiki/Qattara_Depression#/media/File...

The 1989 paper on this is well worth reading, although it only looks at the electricity and fresh water generation prospects: https://www.sci-hub.tw/10.1080/00908318908908939

> it is apparent that the hydro plant alone would be cost effective at an oil price of 34 $/barrel.

The novel hydro-solar scheme is also really interesting but appears not to have gone anywhere; I suspect the economics of the whole thing are now dwarfed by solar, although "use the depression as a pumped storage scheme" plan has some mileage there.

To me the main value would be a new big area of habitable land in Egypt, where tens of millions could live.

Focusing on power generation misses the big picture for me.

Couple dozen 55km Boring Company Tunnels could do the trick, no?

> Couple dozen 55km Boring Company Tunnels could do the trick, no?

The Boring Company is not the only one using COTS tunneling equipment, nor has any relevant engineering project under it's portfolio. Although it excels at marketing, I fail to see how it should be used as a measuring stick in geothecnical work.

If they ever dig a tunnel this long.

It sounds like a neat idea from the point of view of the sort of person who thinks it might be cool to use nukes to excavate mountain passes, or do large scale geo-engineering of the oceans to stop global warming, but...if you don't like habitat destruction and climate change I don't think you're going to get behind this plan.

That's mostly a question about your values, and not much to argue about.

On the factual level, there is very little habitat to destroy there. It's about as lifeless an area as there is on Earth.

I'm not expressing an opinion, I'm just saying people who care about the environment would not be happy. It's not the moon.

Even deserts have ecosystems. See the section on flora and fauna in https://en.wikipedia.org/wiki/Atacama_Desert which in parts has been used for a stand-in for Mars.

The Qattara depression doesn't seem to be in the same league as the Atacama, as far as lifelessness goes. I mean, gazelles, cheetahs, vast wetlands?

We've devastated absurd quantities of woodland, marshland, plains, rainforest, river, beach and ocean ecosystems. Devastating a few microscopic specks of desert ecosystem seems like the least of our worries.

Well, the current ecosystem would be destroyed, but it would be replaced with one a 1000 times richer.

It would also give millions of people in one of the most densely populated poor countries in the world a new place to live.

To me, that's an easy tradeoff. But I can see the other side of the argument.

The people worried about the desert are going to be worried about the Moon too.

This is awesome! See also "Greening the Desert" [1] about integrated systems ("Permaculture" is a school of applied ecology.)

These systems, properly designed, create the materials needed to build new copies of themselves. They're (potentially) self-replicating. A bit of labor and a lot of intelligence and we can convert deserts into gardens and food forests. And, given time, they will alter the (micro- then macro-) climate.

(I feel like we have all the technology we need to solve our problems now, but we are distracted and incoherent.)

[1] https://greeningthedesertproject.org/about-us/


> The Greening the Desert Project started with the purchase of land about ten years ago, and it expanded slowly until that mounted into exponential growth. Things started at the top, literally, with a large water tank that feeds a shower/toilet block just downhill. The toilets are dry composting, supplying fertilizer for plants on site, and the greywater from the showers and sinks goes to a nearby reed bed. The reed bed, still high in the landscape, is then able to send gravity-fed irrigation to many trees throughout the site. It’s all used onsite for beneficial biological cleaning.

> The food forest with stone walls and earth-backed swales moves through the landscape to rabbit and chicken houses, which combine manures in a system that creates a cubic meter of compost every five weeks. That goes to the main crop garden, a shade-covered kitchen garden. The surplus fertilizer (compost) goes to food forest trees and the nursery. The runoff from the nursery goes through to the kitchen garden. The accommodation building has an office, a classroom, and eight bedrooms. It’s two stories high and made with earth brick and straw bale. The roof has a beautiful garden made up of wicking beds.

Yes! I am hoping and planning to get my PDC (Permaculture Design Certificate) this year.

Hey, you're the AutoMicroFarm guy?

There was a company years ago that remodeled/landscaped people's yards into permie gardens and then harvested the crops and distributed them like a CSA. You could integrate a market function into your offering, eh?

Yes, there are lots of possibilities... but figuring out the business side of things has proven harder than I expected.

I'd be interested to hear more. As I said in a sib comment, permaculture et. al. obviously works and (in many ways) is more desirable than conventional agriculture† yet integrating it with the existing economy seems challenging. The existing systems really do provide tremendous amounts of food at very low prices, and it's hard to compete. It seems like you have to work with the kitchen budget that would be saved by growing one's own veggies in the backyard.

†Farms turn forest into desert, while permaculture turns desert into forest!

That's great to hear! My ambitions for https://edible.estate/ are to use the climate, weather, and plant data available to help guide the user and eventually provide auto-generated permaculture designs for a given plot of land (essentially, permaculture in an app). I realize that the app might get you only 50% (maybe eventually 90%) there, but a lot of the design principles and rules of thumb I've learned are amenable to being captured in code logic.

If you would like to continue the dialog, please email me (andrew at automicrofarm.com) or set up a time to video chat (https://automicrofarm.com/book-an-appointment.html). Thanks, looking forward to it!

It's amazing what they accomplished in such an arid location with minimal input. I worked on Geoff's farm in Australia and it's also a very impressive project!

To me Geoff Lawton (and others) have shown the undeniable viability of Permaculture, and the big question is how to replicate it at scale, faster?

If giant techno-farms are more economically efficient they will win out over more ecologically efficient forms, despite being fundamentally less desirable, unless there's some other countervailing "force" or "pressure" (I don't mean physical force).

(Ideally economic and ecologic efficiency would be unified, but we're not quite there yet. Remember that life is four-billion-year-old self-improving nanotechnology, eh?)

> Although desertification is sometimes thought of as the swallowing of lands adjacent to deserts, it is actually a process whereby land that was once fertile or semi-arable becomes desert as a result of things like unsustainable agricultural practices, or long-lasting drought.

So, desert doesn't encroach. Does this imply that de-desertification also doesn't encroach?

I'd like to think that a green vanguard paves the way for further colonizatiin, including by better water retention than sand; and capturing morning dew.

Think there's more layers to the desertification problem.

Desertification also can be linked to activities impacting climate - One paper talks about aerosols (likely via coal use in europe in the early 1900's) as a driver to droughts in Sahelian Africa and the Amazon: http://citeseerx.ist.psu.edu/viewdoc/download?doi=

So you can find me a large barren field in a rainy region that was created by unsustainable agriculture?

On the contrary, life finds a way. unless an area is nearly 100% devoid of water you're going to find some life there, and if it's rainy, something will certainly be growing.

> "So you can find me a large barren field in a rainy region that was created by unsustainable agriculture?"

Is 40 acres big enough?

>"The Desert of Maine is a 40-acre (160,000 m2) tract of exposed glacial silt (a sand-like substance, but finer-grained than sand) surrounded by a pine forest near the town of Freeport, Maine, in the United States. The Desert of Maine is not a true desert, as it receives an abundance of precipitation, and the surrounding vegetation is being allowed to encroach on the barren dunes."

>"The Desert of Maine originated when the Tuttle family purchased and began farming the site beginning in 1797. Failure to rotate their potato crops, combined with land clearance and followed by overgrazing by sheep, led to soil erosion, exposing a dune of sand-like glacial silt. The initially-exposed small patch of sand gradually spread and overtook the entire farm. The Tuttles abandoned the land in 1919 when it was purchased for $300 ($7.50/acre) by Henry Goldrup, who converted it to a tourist attraction in 1925.[1]"


"40 acres and a mule" is what each freed family was proverbially promised after the US Civil War, so it seems like it wasn't considered a huge amount in 1865.

Whether or not the Tuttle family were wealthy is beyond the point. 400^2 meters of Maine turning into sand dunes is plenty large enough to demonstrate that mismanagement of farm land can destroy the fertility of that land.

Unsustainable agriculture is one of the reasons for desertification. Deforestation, sedentary cultivation of lands that normally only support pastoralism, groundwater depletion, these can trigger desertification. The most affected are indeed the areas that have a more precarious balance like drylands. But this comprises almost half of the Earth's freely accessible land surface. Being in a rainy region covers up for the issue, gives you a wider margin for error.

> life finds a way

That's not a good reason to screw with it wherever and whenever we can. This is more appropriate to say in the context of humans being gone because otherwise we have so many ways to let life only find the way to extinction.

But like op is asking. Is there an example of desertification from unsustainable agriculture? Seems kind of unbelievable to me too.

In fact I’d do some unsustainable agriculture on my sidewalk to stop weeds from growing.

Weren't large areas of North Africa that are now desert used as Roman farmland?

Dust Bowl?

For a time that’s true but it didn’t turn into a permanent desert. As least as far as my bing searches are turning up.

The Céide Fields in Ireland [1] are believed to be caused by previous unsustainable agriculture. There’s stuff growing, but it’s definitely not productive land anymore.

[1] https://en.m.wikipedia.org/wiki/Céide_Fields

Soil salinization as a result of unsustainable farming practices messing up the water table are one example of life not just finding a way.

Soil moisture retention is determined by soil structure and composition.

Yout could collect biodegradable trash from the same city, compost it and help change the soil structure.

Yes, I have one. Just monoculture grass and dandelions. Not "nothing" but very little diversity.

If you like this you might also like Groasis, a company that produces boxes that can be placed around young trees so they can grow from condensation the first years. They also have a lot of success in deserts and mountain areas.


Funny that Groasis was founded in '03 while Tree T-PEE of Shark Tank fame was founded in '05. Similar inventions popping up at the same time is always fun to see in action.

The concept of collecting moisture from air is somewhere between decades-old (the modern plastic version) and centuries old.

"Fog or dew collection is an ancient practice. Archaeologists have found evidence in Israel of low circular walls that were built around plants and vines to collect moisture from condensation. In South America’s Atacama Desert and in Egypt, piles of stones were arranged so that condensation could trickle down the inside walls where it was collected and then stored."


I saw a documentary about a guy named Luke who lived on a planet with two suns. He was supposed to be harvesting moisture on the farm, but he was always getting distracted by dreams of warfare.

The movie was okay at the beginning, but it got distracted by a bunch of stuff about politics.

I believe the real Groasis inventions are:

- A paper planter with a special coating that lasts for around 2 years. After that the planter will be gone and the plant has roots long enough to get water from the ground.

- The planter also provides warmth at night because the water inside the box get's warm during the day. This is why the condensation happens and also saves little plants from extreme cold.

A lot of people eat food grown with recycled sewage and don't even know it.

Every excretion flushed in the city of Chicago ends up as fertilizer on midwest farms. Mostly soybeans, IIRC.

A lot of zoos sell their surplus animal dung in big bags called "zoo poo." It's used in home gardens and small scale community farms.

Sewage in Washington, DC gets treated to such a degree that the remaining “biosolids” are sold as a soil conditioner/fertilizer:


They also generate 8MW of electricity from burning the methane produced during treatment, which is about a third of their electricity requirement.

> Every excretion flushed in the city of Chicago ends up as fertilizer on midwest farms. Mostly soybeans, IIRC.

Is this meaningfully true? My understanding is that the wastewater is treated and emptied into the Chicago river where it flows toward Missouri. Insofar as that water is rich in organic compounds, it "fertilizes" the fields that draw from that river and its distributaries; however, this model is different than the picture you paint, which sounds more like dumping more-or-less raw sewage directly on fields. If the latter is indeed the case, it's news to me, especially since I understand human sewage fertilizer to be prohibited as a health risk.

Is this meaningfully true?


My understanding is that the wastewater is treated and emptied into the Chicago river where it flows toward Missouri.

The clean water goes into the Sanitary and Ship Canal. The solids fertilize fields.


No parts of the sewage are filtered out and turned into fertilizer. At least that's how it works in ny.

Chicago is not in New York.


“What it does is essentially recovers the phosphorous and the nitrogen in the wastewater at the Stickney plant and coverts that into a high-grade, slow-release fertilizer that can be used for all sorts of agricultural applications.”

When I was growing up, it was not uncommon for urine to be added to watering the plants as a fertilizer, but not feces; I believe the latter creates a significant problem of bacterial contamination.

You can use nightsoil safely as long as you compost it long enough for pathogens to die off (2 years is good I think?).

There must be many types of different pharmaceuticals in human waste that may or may not break down.

Orange County, CA has a toilet to tap program that turns sewage water back into drinking water.


Cyprus has been using sewage to irrigate crops for ages. What's different here is they're using to build greenways to stop desert creep. Very cool.

It used to be that you couldn't even flush toilet paper in Cyprus - you had to use a separate bin to this side. I expect more sewage reuse in the future. Expect in ~50years time for it to be exceptional to release any sewage into nature.

Apart from sewage being useful for irrigation, it's also a goldmine of minerals, and drugs to reclaim. I expect the same to happen with garbage dumps slowly. We already divert aluminum cans and paper, slowly the rest will be reclaimed too.

I think this is a great idea! Does anyone from Egypt have an opinion of how far along this is? I ask because I thought "Cool, let's check that out on Google maps." and got this :https://www.google.com/maps/place/Serapium+Forest/@30.486290... Which shows a fairly aspirational project rather than a forest.

How exactly is wastewater distributed throughout the 500 acres? Article says a system of pipes. Is it percolating throughout the entirety of the pipes or are there just a few endpoints with massive ponds? Really interesting read.

It looks like drip irrigation. It is more efficient, especially in arid climates.

This reminded me of a recent Economist [1] article about China's "Great Green Wall" around the Gobi. Per the article scientists think the tree wall might not actually prevent desertification, and that there are potential externalities from planting masses of non-native vegetation.

Nonetheless it sounds really cool and I hope the sceptics are wrong!

[1] I found an archived link but I wasn't able to view it for more than a second in the browser. In the end I just curl-ed it to see the source:


Is this it? https://goo.gl/maps/mqtoyiSgzFbU8xkA6 Why would one call it 500 mile forest?

The title and one place in the body call it 500 acre, while one other place calls it 500 mile.

500 square miles is 320,000 acres. (500 miles) squared is 160,000,000 acres.

One other place in the body refers to 1,600,000 acres being viable to reforest.

I think it was just a typo for 500 acre.

And, the narrator, in the video at 5:49, calls it 240 hectares, which is 593.0524 acres.

500 acres isn't very large.

640 acres/square mile

What a brilliant idea. I wonder if the same method would be applicable for growing rice in dry areas?

Great question!

It's not safe to grow veggies and grains with human manures.

For safety, the human manure should be used as an input feedstock for growing and expanding forest.

Then we use the forest's outputs as feed stock for grains and veggies and fruits and trees.

The forest outputs are leaves and wood, both of which may be processed into composts, or used as mulches for veggies, orchards, and grains.

This is what I practice.

> It's not safe to grow veggies and grains with human manures.

Not true. My wife does research on this and post-sewage treatment dried sludge actually has better values than some of the food the used as reference samples.

Have you explored humaneur production? It strikes me that properly composting the waste ought to be enough to destroy any problematic bacteria. Would love to know what you ran into that may have prevented doing that. Been thinking about incorporating regenerative systems to build a food forest and trying to figure out safely handling biowaste. Even goose poop is potentially toxic.

Yes you can properly compost human manure, to make it safe... But the process is more complicated and involves processes which cannot be skipped. I would rather do less work and be safer.

This means I simply don't use human manure on my agriculture crops, I use it in my forested areas.

That said, I do use urine in my grass/leaf compost, and recently I started charging biochar with human urine. Urine is much safer that feces.

There's not only problematic bacteria, there's parasites and pharmaceutical remnants.


It's just a superstition but I wouldn't eat veggies grown directly in human manure (although the guy has done and hasn't gotten the sponge-brain: https://humanurehandbook.com/ )


Being unfit for human consumption is actually a feature not a draw back. We need to trigger growth and get humans off the sand so that nature can do her thing.

I met someone once who after sinking tons of his own money into projects argued you need poop and some kind of toxins to keep people and their goats away for at least 30-50 years. His experience was that people destroying everything scales much faster than constructive effort. You turn your back and everything is gone.

Of course something is to be said for economically viable greening but if you just want to restore nature you should aim to do just that.

I don't have the numbers here but I found calculating how many large trees you need to sustain 1 human vs how much electrolysis it would take pretty mind boggling.

> The federal effort, called the National Program for the Safe Use of Treated Sewage Water for Afforestation is going a long way towards achieving the country’s commendable ambitions voiced in the 1992 UN Rio conference on climate change—because so many trees can soak up hundreds of tons of CO2.

My understanding is that commercial forests like these don't generally capture the carbon, depending on how the harvested wood is used.

A forest will be carbon negative regardless of how the harvested wood is used. Forests increase soil depth through dropping leaves or needles, and by light-starving prior growth. The trees also leave behind roots, a substantial fraction of the total organism weight.

The vast majority of carbon in a tree is from the air, so the sum is a net win. Most wood is also put to long-lasting uses, or made into paper which is eventually buried.

But even burning trees for power, while short-sighted, is net carbon negative, due to the first set of reasons I've mentioned.

Oh, that’s great news. Thanks for setting me straight. There are so few unambiguous wins when it comes to environmentalism.

i'm no expert but don't the roots (and everything else left behind) rot away and release co2?

Most of the CO2 is captured in soil. And there is a very good chance that such good soil will sprout other plants, continuing the carbon capture cycle. (In fact, dead trees in the forests are sometimes called tree nurseries.) So the effect is net-carbon-capture.

(I meant carbon, not CO2)

Why do "scientists" always get credit for this stuff? Sounds to me like engineers, technicians, plumbers, and foresters did it.

PSA: 500 acre = 2.02 km²

Sewage water tends to be high in salt. Especially in a desert where there is high evaporation and low rainfall, irrigating with this type of water increases soil salinity, eventually to the point where it is toxic to native plants and most crop plants. They will get greenery and good growth for a while, and then as salt accumulates over the years, the plants will start dying and they will have poisoned the soil to the point where almost nothing will grow on it anymore.

Great PR, but in the long term, it’s a lousy idea. We have many decades of knowledge on how salination plays out in desert agriculture.

Anyone know of any similar projects in the US? I think we also have similar desertification issues here too.

Which plants are they using?

Second paragraph:

> 10 miles west of the Suez Canal—you would see bountiful forests of eucalyptus, teak, and mahogany trees limned against the orange sand and blue sky of the Sahara?

I see no reason to use anything but native plants.

Which makes eucalyptus problematic. Its introduction to California has done an incredible amount of damage, especially because the ecosystem can't process it, the bugs etc that can eat eucalyptus leaves and wood don't exist outside of Australia

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