Water Environment Federation (WEF) Discussion ForumsWater Environment Federation (WEF) Discussion Forumshttp://www.wef.org/TechnicalDiscussions/jfuller@wef.orgSun, 12 Oct 2008 10:43:48 GMT20http://www.wef.org/TechnicalDiscussions/Topic8607-14-1.aspx<div class="Quote">Has anyone had experience with the root control chemical diquat dibromide? We're a nitrifying, activated sludge plant, about 3 MGD average daily flow -- and discharge to a very small river. The vendor has supplied some information, but it seems geared toward much larger facilities -- and is incomplete regarding the toxicity to fathead minnows. We'd like to be able to use the product to control roots in the collection system, but sure could benefit from other people's experiences.</div><br><br>I guess that I've always been somewhat skeptical about how chemicals can effectively be used to control root growth in sewers, given the fact that sewers are designed to "flow." In other words, they are designed to NOT allow a liquid chemical to just stand in the lines where they can make prolonged contact with roots. Copper sulfate (blue stone) was used long ago for this purpose, although I don't know how effective it was. Obviously, now that treatment plants are likely to have discharge limits on copper, that would probably be a no-no. It is still probably used to control algae growth in water bodies, as long as it's used in small dosages.Mon, 07 Apr 2008 17:50:45 GMTJeff Naumannhttp://www.wef.org/TechnicalDiscussions/Topic8607-14-1.aspxDTC, dithio carbamate is sometimes used for root control and is if not treated in the aeration basin has a huge chlorine demand and an extremely low % UV transmittance. Killed a couple of hundred thousand fish in the White River a couple years ago when a large amount was dumped from a metal plater. Wiped out the WWTP too.Mon, 07 Apr 2008 16:08:43 GMTRob Baurhttp://www.wef.org/TechnicalDiscussions/Topic8607-14-1.aspxDonna</P><P>Look at the following website:</P><P><A href="http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC33217">http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC33217</A></P><P>DavidSat, 15 Mar 2008 12:42:36 GMTd jenkinshttp://www.wef.org/TechnicalDiscussions/Topic8607-14-1.aspxHello All,<P>Has anyone had experience with the root control chemical diquat dibromide? We're a nitrifying, activated sludge plant, about 3 MGD average daily flow -- and discharge to a very small river. The vendor has supplied some information, but it seems geared toward much larger facilities -- and is incomplete regarding the toxicity to fathead minnows. We'd like to be able to use the product to control roots in the collection system, but sure could benefit from other people's experiences.</P><P>Thanks.Wed, 12 Mar 2008 16:47:27 GMTDonna