Eric: I've already emailed Ms. Weideman with an excerpt from DC's post. I'll await her reply to post that response. However, knowing the load she currently has on her plate, it might be awhile
Quite honestly, a technical loop hole has always existed regarding pesticide registration requirements. The looming issue in this thread, and in the marketplace in general, is whether or not a product's manufacturer MAKES a pesticide claim (i.e. does the manufacturer say it will impact a pest organism?). If so, it is the industry's long-held understanding that the product conforms to the definition of a pesticide - and thereby must be registered as such. If not, and if in this instance a lake colorant is simply marketed for "aesthetic enhancement", then a pesticide registration is not required. But, this scenario may also infer that the product's aesthetic benefits may not replicate the effects of a registered colorant for curbing weed & algae growth. Maybe it does, maybe it doesn't. Either way, there's no regulatory oversight to validate the product's contents, safety and environmental impact - all of which, as in this case, are left to the discretion of the manufacturer's voluntary and non-verified disclosures.
This latent debate may become a mute point next April. When I last reviewed the proposed NPDES regulations, even microbial agents (commercial "pond bugs") would constitute a "pollutant" and thereby fall under the new NPDES statues. I'll double-check the latest version to verify that understanding in relation to lake colorants. For better or worse, the proposed regs have seemingly been written in pencil thus far, with a lot of erasure-marks.
From a slightly different perspective, would anyone want to apply a substance to their pond that has not passed through regulatory filters that are intended to protect the buyer and the environment?
I generally agree with Bill regarding the use of colorants (of any type) in ponds that are managed for fishing. There are other means for reducing sunlight penetration - besides colorants, which are more likely to benefit the natural food-chain rather than impede it. Urban ponds & lakes (where fish are not a primary concern) are another story.
