Denver Direct: Purple Pipewater Pollution Prevention People – P5

Sunday, July 11, 2010

Purple Pipewater Pollution Prevention People – P5

See end of this post for explanation
P5 is the unofficial name of an unofficial group; an ad hoc email group some of whom have started using the name Purple Pipewater Pollution Prevention People, P5 for short. Further details as soon as available.

Below is an “official” response to one member’s query regarding the Duck Pond duck deaths and the Purple Pipewater Pollution issue:

Subject: duck deaths at City Park
Date: Wed, 7 Jul 2010 18:45:04 -0600
From: [email protected]
To: [email protected]
CC: [email protected]; [email protected]; [email protected]

Dear Ms. Ferris:
I wanted to respond to your recent e-mail regarding the duck deaths at City Park.  You had also contacted Jill McGranahan with Denver Parks and Recreation Department.  Please consider this a response from Jill as well, as this e-mail incorporates information from Parks and Recreation.  There are a number of important factors at play regarding the duck deaths at Duck Pond.   
As you know, there is a large population of cormorants and other waterfowl at Duck Pond, some of which have recently died.  As in previous years, duck samples were taken to the Colorado Division of Wildlife, who confirmed that the ducks died from avian botulism.  Unfortunately, there have been recurring instances of duck deaths due to avian botulism at Duck Pond for many years, including well before any recycled water was ever directed into the City Park lakes.  Over the years, we have consulted with numerous experts for suggestions on how to eliminate the duck deaths due to avian botulism. The experts tell us that dormant spores of the avian botulism bacterium are widely distributed in many wetland sediments, including within healthy birds living in healthy environments.  However, when a number of environmental conditions occur simultaneously, the spores germinate, botulism bacteria reproduce rapidly, and the bacteria produce the botulism toxin. 
Some of these environmental conditions include shallow warm water, presence of decaying matter on the lake bottom, and the presence of a protein source.  These factors combine to create a lack of oxygen in the water column which is also necessary for the bacteria to reproduce. The presence of animal carcasses from prior botulism-infected birds provide the opportunity for fly larvae and other scavengers to concentrate the toxin.  Diving and dabbling ducks as well as other diving birds, such as cormorants, may be more susceptible as they dive and feed from bottom sediments.  While it is very hard to completely remove botulism from the lake sediment once it is established, modifications to the lake can help minimize opportunities and the severity of future outbreaks.
We all want healthy and aesthetically pleasing lakes in our parks, including Duck Pond at City Park.  Denver has been working to improve City Park lake quality and habitat over numerous years through a variety of drainage and lake improvements.  I imagine you have noticed construction activities in the park over the last several years, as improvements to Ferrill Lake were made.  This summer, Denver is working on a joint effort with the Denver Zoo to refurbish Duck Pond.  As a part of this renovation, Duck Pond will be deepened, resulting in slightly cooler water which should improve oxygen levels.  Excess sediments will be removed from the lake bottom, decreasing the amount of organic matter decomposing at the lake bottom, also improving oxygen levels in the lake.  Aeration features will be incorporated, and water flow will be increased, again with the goal of improving oxygen content.  We are hopeful that these improvements will provide a more favorable habitat for the animals that live in City Park.  As you can imagine, the renovations are costly and it has taken years to assemble the funds to undertake these improvements, which were made possible through a combination of funding from the Denver Zoo, the City and County of Denver, and a recent significant grant from Great Outdoors Colorado.  We continue to investigate additional constructed features that could be installed to improve water quality as well, which will be dependent in part upon appropriate design and securing needed funding. 
If you wish to learn more about avian botulism, here are a few resources:
Denver uses recycled water as a water supply in a number of Denver’s lakes.  The use of recycled water has many environmental benefits, especially in a semi-arid environment such as Denver where much of our potable water must be diverted and transported from other areas of Colorado.  All of the recycled water has been treated twice before entering Denver’s lakes – once at the Denver Metro Wastewater Robert W. Hite Treatment Plant, and again at the Denver Water Recycle Plant. 
[Emphasis added]: That tiny portion of the flow that may have come from the Lowry Landfill went through an extensive treatment process at the landfill before being piped to the Denver Metro Wastewater Treatment Plant.  After passing through Metro’s full wastewater treatment process, prior to discharge to the South Platte River, a portion is diverted to Denver Water’s Recycle Treatment Plant. The water then undergoes further treatment including additional settling, filtration, and disinfection. Recycled water treatment processes and uses have been reviewed and approved by the U.S. Environmental Protection Agency, the Colorado Department of Public Health and Environment, Denver Water, and the City and County of Denver.  You can get more information about the recycled water treatment processes at, about the Metro Wastewater District treatment processes at, and about the Lowry Landfill at  
I hope that this e-mail addresses your concerns.  If you have any questions, please contact me directly.
Celia VanDerLoop, Director
Environmental Quality Division
Denver Department of Environmental Health
200 W. 14th, Suite 310
Denver, CO  80204
[email protected]

Date: Sun, 11 Jul 2010


 Thanks for forwarding this. I’m going to make a few comments and then forward it to our email stream  (Purple Pipewater Pollution Prevention People – P5), and post it at

To fully understand this issue, we have to do a little homework. Go to and enter Eileen Welsome in their search box. You should find 3 articles, starting with “The Lowdown on Lowry”. Welsome is an award-winning author and the articles are dense with facts. I’ve had to read them a number of times myself to comprehend the “fix” that was accomplished by the then secret deal. Keep in mind that these articles were written before the Purple Pipewater system was built. As I recall, the final piece, off-loading the toxins to our lakes and parks, was not done until 2004.

 You may also want to familiarize yourself with two Colorado State Regulations: Regulation 31 and Regulation 84. Also see my discussion [of how they get away with not obeying Reg 31 on the use of recycled water by flushing it directly into the lake and then to the lawn for irrigation] here. 

 Thanks for joining in – if enough people are made aware maybe we can stop the pollution of our parks. Just think about it – shutting off one valve could remove 157 pollutants and 10 radionuclides from our recycled water.


From an earlier email by Adrienne Anderson:

For our collective education, I’ve found a very concise publication which discusses avian botulism and the conditions leading to outbreaks in a book Field Manual of Wildlife Diseases.  The pertinent chapter is attached for your review.  Within the chapter is a table which I’ve copied [above], and which shows the human activities which are thought to contribute to conditions which can spawn avian botulism outbreaks.

Rather than seeing this as “normal” as Ms. Vanderloop wishes to portray, it’s significant to note that the City and County of Denver’s own actions – including those conducted in secret deals over its Lowry Landfill – have resulted in creating all three conditions in City Park’s lakes in recent years, to the demise of the ducks and other waterfowl and fish.  

Given this, avian botulism should be considered a PREDICTABLE outcome of these policy actions, and ones that can and should be reversed.  

This should be considered a “canary in the coal mine” alert, and one we ignore at our own peril in the community.  Added to that are other impacts from decreased enjoyment of our public-owned assets, risks to property values, etc.   

Do we want our parks and other public spaces to be breeding grounds for disease and death?  Who controls our parks and recreation areas?  Coors, or you?