
Nets on the outlets of drainage pipes save waterways from pollution - lelf
https://themindcircle.com/save-water-from-plastic-pollution/
======
specialp
I kayak and fish in the bays of NYC. A fact not known by much of the
population of the city is that almost every time it rains, the sewage
treatment plants release raw sewage into the ocean. This is due to the storm
drains being drained by the same system that sewage is treated from. Due to
this the water is filled with trash, floating condoms, and wet wipes. So this
isn't just third world countries. It is bad enough that bacteria and nitrogen
wastes get into the water when this happens. They should at least capture the
trash and disgusting sewage products.

~~~
hammock
Because this is top comment and no one has provided further explanation yet,
here is a link:
[https://www1.nyc.gov/html/dep/html/stormwater/combined_sewer...](https://www1.nyc.gov/html/dep/html/stormwater/combined_sewer_overflow.shtml)

Most older cities have what are called combined sewers (there is a good
wikipedia article on it) and have to deal with this problem in various ways.

~~~
isalmon
Not just older cities. I live in San Diego and we have exactly the same
problem here. Can't swim or surf after the rain. Not exactly sure why it was
done this way - maybe because it rains very rarely and they just did not
design the sewage system to handle rare (but sometimes heavy) rains.

~~~
acdha
California built a ton of great infrastructure and then people decided they
didn’t want to pay to maintain it. The entire state is full of projects where
the people who ran them are begging for money to avoid needing to spend even
more after it finally breaks. One of the big problems was the sprawl due to
the highway system – when San Diego raises its property taxes that means
people may still work and play in the city but will buy a house somewhere
else, paying no taxes at all.

This is a common story around the world but Prop 13 adds the wrinkle that it
mostly affects new buyers and people who haven’t figured out how to pass
property to their descendants without resetting the tax assessment. That guy
who bought a place in PB with his back pay when he got out of the Navy is
still paying $100 a year in taxes. He has a massive incentive not to do
anything which will reset that, so the city won’t be getting more revenue that
way until he (or his heirs) sell the place.

------
amluto
This seems worse in almost every respect than a hydrodynamic stormwater
separator. With the latter, you pop open a manhole cover and suck out the goo
with a vacuum truck. With a net, you have to somehow pick it up without
spilling the contents. Then you hope you can empty it without destroying it or
you replace it. This sounds much harder.

Oh, and hydrodynamic separators claim to catch oils, too.

~~~
ricardobeat
That only works for vertical storm drains, no? Could it be installed in
outflow pipes as seen in the pictures?

And what about cost?

~~~
VSerge
Looking around, a number of widths exist for these systems, and installing
what is called pre-cast units would start at about 10k$ for the smallest (4ft
in diameter), and go up from there (see EPA paper below for additional
details). Maintenance costs are said to be really low in what I could find
(1000$ a year or so), as maintenance (emptying the trash) can be done by one
vacuum truck in 30 minutes. So it may be a better choice for systems that are
there to last rather than nets, but nets would still be best for temporary
sites. [http://www.water-
research.net/Waterlibrary/Stormwater/hydrod...](http://www.water-
research.net/Waterlibrary/Stormwater/hydrodynamic.pdf)

------
sv7n
Wet garbage is extremely heavy and hard to clean up. These socks typically
require heavy equipment to remove/maintain. These filters also only work well
in very specific drain configurations. Not as effective as the article
suggests.

~~~
manigandham
What is specific about a circular drain opening for this to work?

~~~
pge
I think the answer to this is the same as the answer to the classic interview
question, “why are manhole covers round?” With a round hole, a ring of
slightly larger diameter (to hold the net in this case) cannot pass through
the hole, no matter what angle it gets turned. With any other hole shape (eg
rectangular), the “ring” that sits outside the hole to hold the net can be
turned such that it can go through the hole.

------
teambob
Strayan here. These nets are used quite widely by a number of local councils
including Greater Sydney. They are not universally used though. Larger
waterways may have a boom, a number have these nets, some have something like
a metal sieve and many have nothing

Some people have suggested a vacuum may be easier. But a council in Australia
always has bulldozers and rubbish trucks available, so it may fit better into
that existing infrastructure

------
gingabriska
I wonder why we don't have them at every level.

If we make it legally mandatory to put such a filter in every house then it
will often get clogged and cost money and people will learn not to flush down
the waste in toilet.

I read somewhere that people learn best when mistakes cost them money.

Imagine hotels having a massive filter then some might want to install sensors
in individual drainage pipe coming from the individual units and charge their
customers based on the amount of waste they flush down the toilet which ends
up costing the money to hotel on subsequent cleanup.

~~~
michaelt
It looks like these are applied to waterways that are largely free of faeces,
such as storm drains.

A net applied to pipes intended to transport faeces would presumably need
holes so big it couldn't catch condoms, sanitary products or wet wipes.

------
snazz
> _Though the installation and the manufacture of these nets cost money (about
> $10,000 each)_

That seems exceedingly expensive for a net and a metal ring to hold it (maybe
because drainage outlets aren’t standard sizes?), but I’m impressed with the
claims of how effective it is.

~~~
abryzak
The city's website [1] says that cost includes the design, manufacture,
install and associated civil works.

[1] [https://www.kwinana.wa.gov.au/our-
city/news/Pages/City%E2%80...](https://www.kwinana.wa.gov.au/our-
city/news/Pages/City%E2%80%99s-Drainage-Nets-Post-Goes-Viral.aspx)

~~~
ceejayoz
Plus, it goes on to indicate that's a cost savings over the old "roam around
and pick it up by hand" approach.

------
treelovinhippie
Australian. I've seen this circle the internet many times, but I've never seen
one in the wild at any beach or river outlet.

~~~
incompatible
I doubt that "Australia" Found a Way is putting credit where it deserves to
go. It's not exactly a national priority.

~~~
zizee
You make it sound like Australia has a huge problem with plastic/trash in
waterways that "Australia" is actively ignoring.

In general, Australian's culture is to use rubbish bins and keep things tidy.

Sidepoint: I am not sure if it is something only Australians do, but whenever
something about Australia comes up, there will be an Australian there
bemoaning how badly we do things. Yes, there is always room for improvement,
but Australia is so far ahead of most countries in just about any measure that
you choose, that one has to wonder where this sentiment stems from.

~~~
sundvor
It's probably because a lot of people feel we could _easily_ do better when it
comes to the environment - regardless of what other countries might be doing.

And there are a number of areas where we certainly aren't ahead either.

~~~
zizee
Oh I agree that we can do better, and should do better. I am more taking issue
at people who make it sound like Australia is terrible compared to just about
any other country, no matter what the discussion is about.

Whether the discussion be about environment, politics, innovation, corruption,
you name it, some Australian will start moaning about how badly we do X.

------
zeristor
I assume this can only work for outflows near a road in order to provide
access to the machinery. Outflows in forests, and at the foot of cliffs might
go uncaptured, but its a good stab at a solution.

In the Thames they have flotsam collectors that rubbish ends up as the tide
tos and fros along the river, it's called a passive driftwood collector:

[https://www.youtube.com/watch?v=n7YJXNfJwdg](https://www.youtube.com/watch?v=n7YJXNfJwdg)

~~~
jspash
I noticed this one a few weeks back when I was at the shops. There seemed to
be a weird crane-line contraption hidden in the woods where I knew there was a
creek or canal. Thinking it had something to do with canal boats I wanted to
have a closer look.
[https://goo.gl/maps/FuXrmR7TFRmm4r1r5](https://goo.gl/maps/FuXrmR7TFRmm4r1r5)

It's very much like those carnival crane games where you try to lift a prize
out of a glass box. I'm not sure how often it's emptied, but at the time it
was full of rubbish.

Seeing as a city reservoir is not far away I can understand why they would
want to filter as much as possible before it floats that way.

------
khole
This is great! It certainly helps but we humans also need to change our
behavior about littering.

~~~
sneak
Why?

------
lecarore
Interesting, I'm curious about the impact on wildlife and the way they switch
the full nets for empty ones. They imply there's an overflow system in place
I'd love to know how that works

More info on the company manufacturing those
[http://stormwatersystems.com/trash-
traps/](http://stormwatersystems.com/trash-traps/) They also make trash
collecting bots boats.

~~~
not_kurt_godel
At least one of the pictures shows the nets are on pipes that drain an open
cistern. It appears that if the nets get clogged, water will fill the cistern
and flow over, bypassing the nets. Seems like a fairly reasonable fallback
solution until the nets can be cleared and put back into action. Other
pictures show netted pipes that don't appear to have such a cistern, so I do
wonder how overflow is handled in those cases - maybe a cistern upstream
that's not visible?

------
lostlogin
Nets on the inlets to storm water systems help a lot too. Leaves, rubbish etc
get trapped and collected. I used to see them around building sites here in
Auckland, but they have started cropping up in other areas too. It probably
makes sense to filter it at multiple points.

------
stratigos
this is so damn simple, that I fear for us, for not having thought of it
sooner ><

~~~
3131s
Exactly what I thought first too.

------
DonHopkins
Expected this article would be about the series of tubes know as the Internet
of Drains.

[https://www.researchgate.net/publication/313366896_Internet_...](https://www.researchgate.net/publication/313366896_Internet_of_Things_in_Drainage_Management_System)

[https://www.terratrenchless.com/7-things-you-need-to-know-
ab...](https://www.terratrenchless.com/7-things-you-need-to-know-about-
internet-of-things-in-engineering/)

------
_bxg1
Holy crap. I did not realize this much litter came down drains. Insane.

------
pojzon
What a weird country, on the one hand they want to save environment from
plastic pollution.

On the other one tho.. invest in coal power plants, which will only make
drought issues bigger.

~~~
jamesb93
Trust me, a lot of Australians hate the current leadership and would love to
see them gone. Unfortunately we are tending towards the trial version of USA.

~~~
azinman2
But didn’t the public just vote for coal?

~~~
tty2300
The people I know who voted for the libs preferenced the greens first and only
voted for the libs because labor would leave them financially worse off.

~~~
sundvor
And we have to put our own finances before the environment! (Screw our
children, after all.)

------
soperj
800 pounds in a couple of weeks... kind of dispells the notion that it's not
coming from western countries.

~~~
forrestthewoods
800 pounds? China pumps 4,800,000,000 pounds (2.4 million tons) of plastic
into the ocean each year.

No, western countries are not perfect. Yes, the vast majority of ocean waste
comes from poor, non-Western countries. The US, 3rd largest country by
population, is #20 for ocean pollution. China alone produces 1/3 of all ocean
waste.

[https://www.scientificamerican.com/article/world-s-oceans-
cl...](https://www.scientificamerican.com/article/world-s-oceans-clogged-by-
millions-of-tons-of-plastic-trash/?redirect=1)

~~~
Xylakant
Western countries export most of their plastic waste to the countries named in
the article. Substantial amounts of the plastics China spills into the ocean
are ours, exported there for “recycling”

~~~
manigandham
Why does that matter? The issue is that they claim to be recycling and then
just dump it in the ocean instead.

~~~
gmiller123456
That's quite disingenuous to what's really happening. The companies in the US
claiming their "recycling" service are probably well aware of what's going on,
and China probably isn't making any promises that they're recycling anything.
The US companies accept money for "recycling" material, maybe cut off the
power cord for reuse, then pay China to take the rest as junk.

And it's a given that if you're transporting garbage to a landfill, some of it
isn't going to make it that far and will eventually end up in the ocean. Maybe
they are just dumping it as you say, but just the fact that some of it ends up
there isn't evidence of that fact.

~~~
manigandham
You contradicted yourself in your own post. If there's no evidence that
they're dumping it in the ocean then what exactly are the US companies
supposedly aware of?

The fact is that US companies are paying for a disposal service. What that
disposal service does is up to them, and if they just throw in the water then
it's their fault alone. Maybe there should be some regulations there to ensure
recycling companies actually do some recycling.

~~~
gmiller123456
_> what exactly are the US companies supposedly aware of?_

That it's not being recycled.

------
sydmeyer
This merely puts the plastic pollution somewhere else (into a dump near the
ocean most likely), so it doesn’t really save anything.

The problem is still the production of the materials in the first place.

~~~
danielharan
Sorry, that's just ludicrous.

Putting plastic in a dump is much better than letting it kill animal after
animal, decomposing into smaller pieces and getting into the food chain.

Ideally we design most plastics out, but barring that recycling would be fine
- and just burying it is still much better than either burning or letting it
drift into oceans.

~~~
dang
Your comment's great, except for the first sentence, which is what the site
guidelines refer to as calling names in arguments. Would you mind reviewing
[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)
and editing those bits out of your HN comments in the future?

I know it seems small, but it has a downgrading effect on conversation. Also,
it often doesn't seem small to the person being addressed that way (or some
other readers who happen upon it).

~~~
austinheap
Thank you for being the net on the outlets of our drainage pipes! Subtle & not
unnoticed work.

