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_ _ _ ~ v ~ Continued from page 1 <br />ranges you're pro- _ <br />r ~a~ <br />A. The biggest change we're making is <br />with river nutrient standards. Last time, <br />we adopted lake nutrient standards, <br />and in this review we're adopting river <br />nutrient standards. <br />r ~ rl <br />=d z > hor c- <br />A. The same way phosphorus grows <br />excess algae in lakes, it really does the <br />same in rivers and there is concern <br />about the impact on aquatic communi- <br />ties. It creates large swings in the daily <br />dissolved oxygen concentration, anal it <br />has impacts on the biological commu- <br />nity that resides in rivers and streams. <br />C. ss <br />_ t ~ 1 ~~ <br />A. It likely would be more strict than the <br />current water quality standard we have <br />for drinking water systems, and the sim- <br />plest way to think about that is aquatic <br />organisms live in water their whole life- <br />time, where we only ingest it part of our <br />lifetime. We don't reside in it. <br /> <br /> <br />x:,: <br />F ~, ~~. <br />-~ c <br />a <br /> ~~, <br /> ~.~ <br /> ;~ <br /> . r <br /> `~_ ". <br /> r _ <br />Mark Tomasek, MPCA supervisor <br />Q.Tha ;_ ii' ~n <br />pour is ~ e v~raters <br />e-~~°h ~rore~ <br />r 2 per- <br />t e ial <br />_t_~t____a____J <br />s _. _, f ~ s rces ? <br />A. For any particular river or stream, the <br />exact percentages and the load reduc- <br />tions that might be needed from these <br />individual sources would differ from <br />these numbers and be more based on <br />C r . aqua o _ - <br />A. Fish and invertebrates, fish and bugs <br />that live in the aquatic system. <br />u .. _ _? <br />A. People would see a change in two <br />ways. They'd see an improvement in the <br />water clarity itself. The water wouldn't <br />have a green color to it. Also, in rivers <br />where algae grows on the bottom sedi- <br />ments you would see less of that algae or <br />slime on the rocks. <br />_°', _se standard< <br />A. I think there will be some people who <br />question the standards, who disagree <br />with the levels we're setting. So there <br />will be some controversy and discussion <br />about them, but I think there is also a <br />great deal of support from people who <br />see a real need for the standards. We're <br />trying to react to both of those and set a <br />standard that's based on science, research <br />and guidance from EPA <br />that particular site. <br />sct farrrse <br />A. Just adopting the standard doesn't <br />give the PCA any new regulatory author- <br />ity, and farmers comply with impaired <br />waters listings and implementing plans <br />through voluntary measures and best <br />management practices. We think that by <br />pointing out those problem areas that it's <br />quantifiable, it's scientific and it provides <br />the impetus for those implementation <br />measures to occur. <br />{_ ~ .a <br />A. We haven't done the same detailed <br />assessment of nitrogen sources like we <br />have phosphorus, but in general, my <br />understanding would be that some <br />agricultural systems-fertilizers, drain <br />the systems-can be large sources of <br />nitrogen., and wastewater treatment <br />plants can be a large source of nitrogen. <br />Certainly, fertilization of urban areas is <br />another source. I think agriculture and <br />wastewater would be the primary ones. <br />C ~ ould be .. . <br />ge.. st_...~ard you'. _ ~ o__ig? <br />A. Agricultural systems that use nitrogen <br />fertilizer and likely wastewater treatment <br />plants. <br />,€t ~ turbidity s9 <br />A. Turbidity is a measure of scattering <br />of light in water. It really is a measure of <br />water clarity. Our turbidity standard has <br />been used for impairments listings and <br />we want to consider changing that to a <br />total suspended solids sample to make <br />TMDL (Total Maximum Daily Load) <br />plans more straightforward, and we <br />are looking to regionalize our turbidity <br />standard. <br />~ a r <br />s. J - i t? <br />A. We are evaluating a turbidity standard <br />revision that will be protective of aquatic <br />life and aquatic recreation based on mini- <br />mally impacted rivers and streams. We <br />know that the geology, soils and topogra- <br />phy vary across the state and expect that <br />a regional standard would better account <br />for these natural land features. It may <br />result in a revised standard that is higher <br />than the current standard in some areas <br />of the state and lower in others. <br />°e i v a <br />A. Nonylphenol is a breakdown product <br />of alkylphenols that are used primarily <br />in industrial detergents, can be inert <br />ingredients in pesticide products and <br />have been used in textile and paper <br />production. Wastewater effluents are the <br />source most studied, but other possible <br />sources to surface waters include leach- <br />ing from individual septic systems and in <br />runoff from areas treated with pesticides. <br />Besides the toxicity to aquatic life, we are <br />evaluating endocrine-disrupting activity <br />in fish. Nonylphenol. is banned in the <br />European Union. In the U.S, the EPA has <br />established an effort to have companies <br />voluntarily phase alkylphenols out of <br />products. - <br />FACETS March 2009 <br />