Re: Water quality in the Sierra -- Derlet

Livestock waste found to foul Sierra waters

By Tom Knudson

Published: Sunday, Apr. 25, 2010 - 12:00 am

As director of the emergency room at the UC Davis Medical Center, Robert Derlet always wondered what made people sick.

Each summer, on hiking trips into the high Sierra, he brought that curiosity along, asking himself: Where do you get infections in the wilderness? The most obvious possibility, he believed, was the water.

Now, after 10 years of fieldwork and 4,500 miles of backpacking, Derlet knows for sure. What he has learned – after analyzing hundreds of samples dipped from backcountry lakes and streams – is that parts of the high Sierra are not nearly as pristine as they look.


http://www.sacbee.com/2010/04/25/2703875/bee-exclusive-livestock-waste.html

Thanks for posting this article. Bob's studies were mentioned some months ago on this forum

see: http://yosemitenews.info/forum/read.php?1,15547,17434#msg-17434

but this looks like some new info. Previously, I think he argued that the High Sierra water was cleaner than expected. Sounds like he has focused on the animal factor, or at least the article is emphasizing that issue.


This appears to be the article referenced in the news report:

http://www.ncbi.nlm.nih.gov/pubmed/20154395

J Water Health. 2010 Jun;8(2):326-33. Epub 2009 Nov 9.
Reducing the impact of summer cattle grazing on water quality in the Sierra Nevada Mountains of California: a proposal.

Derlet RW, Goldman CR, Connor MJ.

University of California, Davis, 4150 V Street, PSSB Suite 2100, Sacramento CA, 95817, USA Tel.: (916) 734-8249 Fax: (916) 734-7950 E-mail: rwderlet@ucdavis.edu.
Abstract

The Sierra Nevada Mountain range serves as an important source of drinking water for the State of California. However, summer cattle grazing on federal lands affects the overall water quality yield from this essential watershed as cattle manure is washed into the lakes and streams or directly deposited into these bodies of water. This organic pollution introduces harmful microorganisms and also provides nutrients such as nitrogen and phosphorus which increase algae growth causing eutrophication of otherwise naturally oligotrophic mountain lakes and streams. Disinfection and filtration of this water by municipal water districts after it flows downstream will become increasingly costly. This will be compounded by increasing surface water temperatures and the potential for toxins release by cyanobacteria blooms. With increasing demands for clean water for a state population approaching 40 million, steps need to be implemented to mitigate the impact of cattle on the Sierra Nevada watershed. Compared to lower elevations, high elevation grazing has the greatest impact on the watershed because of fragile unforgiving ecosystems. The societal costs from non-point pollution exceed the benefit achieved through grazing of relatively few cattle at the higher elevations. We propose limiting summer cattle grazing on public lands to lower elevations, with a final goal of allowing summer grazing on public lands only below 1,500 m elevation in the Central and Northern Sierra and 2,000 m elevation in the Southern Sierra.

PMID: 20154395 [PubMed - in process]

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The cure for a fallacious argument is a better argument, not the suppression of ideas.
-- Carl Sagan



Edited 1 time(s). Last edit at 04/25/2010 09:51AM by Frank Furter.

The bottom line is though for hikers, don't dip and sip. Treat your water.

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Old Dude

One thing troubles me (actually many things, but that is another issue):

Quote
Bee article
Now, after 10 years of fieldwork and 4,500 miles of backpacking, Derlet knows for sure. What he has learned – after analyzing hundreds of samples dipped from backcountry lakes and streams – is that parts of the high Sierra are not nearly as pristine as they look.

I don't think even an ER doc has enough time to hike 450 miles a year in the Sierras. How far do you think the Goat-Chicken and associates hike each year?

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The cure for a fallacious argument is a better argument, not the suppression of ideas.
-- Carl Sagan

The Goat may well do a thousand a year.

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Old Dude

All of this amazes me when I think of the ponds we swam in as kids that were shared with dairy cows. Cow manure everywhere! The Giardia factor had to to be enormous. The only positive point was that we did not drink it.