Plant to keep condoms out of Lake Michigan

My question is: How did they get in there in the first place?
Do people flush them down the toilet or something?
Wouldn't that clog up the toilet?

Inquiring minds want to know!

(Added later this evening:)
The Lake Michigan condom mystery explained!

Here are some clips from this week's episode of Smallville....
Maybe all those condoms are SUPERcondoms!