Animas River: e.Coli is a culprit in water quality

E.coli Bacterium
E.coli Bacterium

From The Durango Herald (Dale Rodebaugh):

The main focus of the San Juan Watershed Group research is E. coli and nutrients – nitrogen and phosphorus. Certain strains of the former can cause nausea, fever and vomiting. The latter, in excess, robs water of oxygen needed by aquatic life.

The group tested only for E. coli last year. This year, nutrients were added. So far this year, the E. coli level has been well within limits at the New Mexico line, May said.

A Colorado partner, the Animas Watershed Partnership, which works on water-quality projects in New Mexico and with the Southern Ute Indian Tribe, also is following the work of May’s group, now in its second year, said Ann Oliver, coordinator of the Colorado project.

Oliver said her group is searching for funding for similar research at two points upstream – on the Animas upstream of the Florida River and on the Florida before it reaches the Animas, she said…

The hope is to get enough money to test for E. coli and nutrients at the Animas and Florida sites and pay for genetic testing at Bondad to determine the source of E. coli contamination, Oliver said. May’s volunteers measure the amount of E. coli and nutrients at the site here, but the organization can’t afford the cost of source analysis.

Last year, May’s volunteers sampled water once a week from April through October on the Animas at the state line (Bondad), Aztec and Farmington and on the San Juan River at Farmington and Hogback Canal, the point where the San Juan enters the Navajo Nation…

Laboratory tests can determine through DNA analysis if E. coli bacteria come from animals – and which animals – or from human sources. Tests last year in Colorado showed that E. coli met the state’s standards, indicating that contamination was originating downstream in New Mexico.

In fact, all 40 samples collected at Hogback Canal tested positive for human bacteria found in feces, the report said. Nearly all 40 samples from Farmington and 26 from Aztec tested positive for the human bacteria.

A story in the The Daily Times of Farmington quoted Mike Stark, the San Juan County operations officer, as saying that officials know that aging septic systems and illegal septic dumping are potential problems.

David Tomko, retired from the New Mexico Environment Department, now the San Juan Watershed Group coordinator, is cautious. Tests for human fecal matter in the Cimarron and Rio Grande rivers found no human waste, so conclusions about the Animas and San Juan readings require confirmation, he said.

The heavy metals leaching from shuttered hard-rock mines around Silverton present no problem at the state line because of dilution, Tomko said. The level of those metals never has exceeded the limit, he said.

Peter Butler, former chairman of the Colorado Water Quality Control Board and a coordinator of the group looking for a solution to the toxic waste draining from Silverton mines, said heavy metals are diluted enough to be below limits by the time the Animas River reaches Durango.

Even heavy-metal contributions from Lightner Creek don’t push Durango over the limit, Butler said.

May’s group also tests water for turbidity, pH, optical brighteners (detergent additives that brighten colors) and total dissolved solids.

On Monday, the Animas River water didn’t look as cloudy when May poured it from the dipper into sample bottles as it did flowing in the channel.

Last year at about the same time – the spring runoff – the Animas water registered 13.5 turbidity units, May said. During the later monsoon season, she found upward of 600 units.

Turbidity is measured by a nephelometer, an apparatus that records size and concentration of particles in a liquid by analyzing the refraction of light beamed into it.

More Animas River coverage here and here.

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