I've always wondered why we don't see any of these signs around Ferril Lake, Duck Lake, or Grasmere Lake where "recycled water" is currently in use. Colorado Department of Public Health and Environment Reg. 84 - Reclaimed Water Control Regulation, requires signs to be posted and care to be taken in the use of recycled water.
Thanks to Doug Woods, Director of Park Operations, I now know. In response to my recent email, he says:
"Some factors to consider in why the City Ditch water is not classified as recycled water are:
-The City Ditch is classified as Waters of the State and there are specific water quality criteria associated with the permit to allow supply of water to the ditch. Denver Water operates a dechlorination facility at the start of City Ditch.
-Once water enters the City Ditch, Denver Water no longer has any control over the quality of water since there are numerous external influences, such as storm sewer inlets.
-The compliance point for the permit that Denver Water must satisfy is at the start of the City Ditch once the water leaves the dechlorination facility. Denver Water has never violated this permit."
The Denver (City) Ditch to which he refers used to be an open irrigation ditch (read the history here). The Ditch was terminated at I-25 during the T-REX rebuild. Claiming that putting the Lowry Landfill Superfund Site effluent ("recycled water") into the Ditch changes its nature is pure magic - a useful fiction that conceals the fact that this toxic effluent is flushed into these lakes. So that's why there are no signs around these park and lakes to warn the public as required by Colorado Reg. 84. I'm guessing that this clever magic also relieves Denver Water from any liability coming from citizen exposure to this toxic mix.