Comments on: DWP dumps 6 million plastic balls in Silver Lake drinking water.

By: Anonymous

Anonymous — Fri, 29 Jan 2010 19:37:39 +0000

Thanks

By: Hathor

Hathor — Tue, 01 Jul 2008 23:44:09 +0000

Hi Donna, really great post, a bunch of us mothers were wondering about the black balls, and then the discussion turned to plastic bottles and drinking water and a why you should stop buying bottles and then when I was researching the birdballs I found your post which ties it all nicely together…thanks!
xox,
Heather Cushman-Dowdee

By: Eric

Eric — Fri, 13 Jun 2008 03:02:20 +0000

99% coverage will result in (roughly) a 99% decrease in the rate of Bromate formation, which should result in a 99% reduction in Bromate levels.

Regarding leakage leaching, the main leachate from HDPE pipe is from phenol based antioxidants. Some phenol compounds could potentially be nasty, but if they didn’t care about degradation, and didn’t use the antioxidants in the bird balls, then there wouldn’t be much leachage from the balls. The HDPE itself is fairly inert, and will have (comparatively) harmless breakdown products.

By: Patrick

Patrick — Tue, 10 Jun 2008 23:12:26 +0000

I have never seen plastic that can stand up to extended exposure to the sun, even fence posts exposed to the sun eventually become brittle and break, pool deck furniture, etc. I cannot imagine that these balls will be different.

My big question is what will the effect be on bacteria and other microorganisms be if the temperature of the lake is raised by 10 to 15 degrees year-round? I would imagine that these balls will have the same effect as a black pool cover, reducing evaporation (cooling), collecting and trapping the heat from the sun.

Being in the tire industry myself, I know I would not want carbon black used in any product that was going to come close to my mouth or that I might breath in.

This whole idea seems ludicrous. Even if you cover the whole lake with balls, they are round and there will always be gaps between them so they will not completely prevent sunlight from reaching the water. Will covering 99% be able to give you the desired result?

By: dubby

dubby — Tue, 10 Jun 2008 21:34:45 +0000

And how will we dispose of all this plastic? Aren’t our landfills impacted enough?

Umm and what about Heat Island Effect – did they just essentially create a huge asphalt parking lot?

By: Donna

Donna — Wed, 16 Apr 2008 22:55:19 +0000

Thanks, Mr. HDPE.

As you say, no promises here. As I understand it, the quality and safety of plastic can change radically as it’s processed to make an item. That’s why the grade can change in different products.

By: Mr HDPE Pellet

Mr HDPE Pellet — Tue, 15 Apr 2008 13:56:31 +0000

whoops “…presence of sunlight is a **loss** of the physical strength…”

By: Mr HDPE Pellet

Mr HDPE Pellet — Tue, 15 Apr 2008 13:55:09 +0000

There are clearly other issues here beyond HDPE that I am unqualified to comment. But I do know something about HDPE. The degradation of HDPE that occurs in the presence of sunlight is a determination of the physical strength of the polymer and color of the polymer; additives are used to maintain these properties. However, even if completely unstabilized the new balls and aged balls would not leach anything into the water. It is a simple issue of 1) hydrophobic polyethylene and 2) the molecular weights of the polymer involved (several hundred thousand). That leaves the additives. Since, these balls are under no continuous strain and only need the strength not to break when handled in a future removal (remember HDPE floats, so broken balls will not sink and add to any problem). Also, nobody is going to care if the color of these balls does not evolve over time, like they might a child’s play house or other consumer item. Thus, the HDPE in these balls are likely minimally stabilized (no promises here). Meaning that the polymer is only stabilized enough to be processed into the ball (@ 450F). The Nelson Environmental site indicates that the balls are black, indicating the use of carbon black as a stabilizer (like in tires). The carbon black is a very very effective thermal and light stabilizer (free radical trap) that is not going to leach from the polymer as it is also hydrophobic.