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.
Nets on the outlets of drainage pipes save waterways from pollution
71–80 of 88 posts
Re: Nets on the outlets of drainage pipes save waterways from pollution
#72This 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.
That only works for vertical storm drains, no? Could it be installed in outflow pipes as seen in the pictures? And what about cost?
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...
Re: Nets on the outlets of drainage pipes save waterways from pollution
#73I 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.
Re: Nets on the outlets of drainage pipes save waterways from pollution
#74Wet 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.
What is specific about a circular drain opening for this to work?
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.
Re: Nets on the outlets of drainage pipes save waterways from pollution
#75I 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 ind…
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.
Re: Nets on the outlets of drainage pipes save waterways from pollution
#76What 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.
Mining is such a big industry in Australia and has been for such a long time that dirty coal money has influenced the politicians in government for a long time now.
Re: Nets on the outlets of drainage pipes save waterways from pollution
#77I 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…
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...
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.
Re: Nets on the outlets of drainage pipes save waterways from pollution
#78Earlier quoted context omitted.
So what if people were lied to? Is the government the citizenry's only source of information? Do they even trust the government? Are there not competing sources of information? What basis do you have for concluding that the Australian government has any significant ability to sway the opinion of its citizens?
You're being directly obtuse, but to humour you: > So what if people were lied to? This is fairly serious when you consider that this is the entity which takes a portion of your working income as tax to provide services based on the needs of the community. If the policies which are decided on are based on a misinformed public opinion, then the services which are actually required (as opposed to being perceived as bei…
> I'd put the onus of proof on you for this one, what makes you think that they do not? Governments spend tens of millions of dollars in prime-time advertising with the sole intention of sway opinions of citizens. This seems beyond ridiculous to me that you would want to make that point.
Look, your point is that the government lies to people and that this influences they way they vote. I’m sure that has some marginal effect. But here you are completely unaffected by these lies. So what’s the difference between you and somebody who votes differently? Is it that they are a hopeless rube who has been taken in? You seem to think so. But you have not demonstrated at all that it isn’t an alternative hypothesis which explains their different voting record. And the alternative hypothesis that I would put forward is that their different political leanings account for most of their different voting record. And that their lack of concern about the veracity of the information put out by the government is a result of these different political leanings, not its cause.
Re: Nets on the outlets of drainage pipes save waterways from pollution
#79I 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…
[deleted]
Re: Nets on the outlets of drainage pipes save waterways from pollution
#80Earlier quoted context omitted.
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”
Why does that matter? The issue is that they claim to be recycling and then just dump it in the ocean instead.
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.