Colorado Trout Unlimited testimony re Cottonwood Presented by John Woodling, PhD.

CTU certainly wants to support water reuse. The more water that can be reused perhaps the more water that can be left in trout streams. Photo on left = brown trout fry from wild fish parents taken from Idaho River. This is the reason CTU is concerned about selenium is streams, lakes and reservoirs. A little selenium is not good for brown trout and other living things. Cottonwood did not fully respond to CTU questions raised in Responsive prehearing statement Photo taken from newsdiscovery.com

For example, Cottonwood proposal indicated “prevalence of Se related deformities was very low” (UAA page 44). Cottonwood proposal also indicated that these impacts were “negligible” since less than 5% of fish were impacted. Quote taken from the reference methodology used by Cottonwood when doing their study. fair enough. However, Cottonwood sampled larger fish, not fish larvae or eggs from fish taken from streams. Fish larva are the life stage to sample and the eggs of fish resident to the streams in question CTU asked (in responsive prehearing statement) that Cottonwood needed to modify conclusion since larvae were not sampled. Cottonwood’s rebuttal response was that they sampled “many young of the year fish and juveniles, as well as adults for Fathead Minnows, Creek Chub, White Sucker, and Brook Stickleback” (Page 12 REI rebuttal).

For example, Cottonwood proposal indicated “prevalence of Se related deformities was very low” (UAA page 44) However the Cottonwood response is like comparing grapes and Cantaloupe. Larvae of most species Cottonwood sampled are from 4-6 mm in length, about 1/5 of an inch. They were close with white sucker. Deformed larvae would have likely died before reaching the sizes sampled by Cottonwood. Three individuals seemed to have survived. Cottonwood did NOT provide data that proves the selenium impact to resident fishes was negligible. They did not sample larvae or resident eggs.

Cottonwood proposal does not demonstrate that “ambient” selenium standards are appropriate where the ambient level is in excess of 4.6 ug/L. Additional work with Cherry Creek Basin Authority, WQCD staff and DPW would be needed to assess actual relationship of ambient Se and fishes resident to the Cottonwood Creek Basin. CTU requests that the WQCC should delay any action concerning selenium standards in the Cottonwood Creek Basin until appropriate analyses are completed.

Selenium impact to duck. Photo from No “do over” here folks

Total impact of RO brine not presented or discussed by Cottonwood. This issue is not part of hearing specifically but certainly should be part of discussion. Standards not set in a vacuum. Goal is to protect designated uses. RO effluents are new to Colorado. CTU would suggest that more information and discussion is needed to determine how the water quality of RO brine needs to be regulated. The effluent from an RO facility is profoundly different than an effluent from a typical drinking water treatment plant. The existing NPDES permit for the Cottonwood RO stream is based on limits for a typical drinking water treatment plant.

Total impact of RO brine not presented or discussed by Cottonwood. Lack of understanding concerning appropriate way to regulate RO effluents and uncertainty concerning impacts of ambient selenium are enough to delay action concerning the Cottonwood Basin. The WQCC should not make changes to existing selenium standards based on information presented to date.