Summit Daily News SUNNY 39°   

  Search:    Classifieds | Place an Ad March 24, 2008  

Tree-spraying chemicals detected in water

Without careful disposal, insecticide use could threaten water quality

Get News Feeds RSS Feed Add to My Yahoo!

summit daily news
Summit County, CO Colorado

March 24, 2008

Print Friendly Print Email Email

SILVERTHORNE — The chemicals local towns and neighborhoods are spraying to prevent the spread of the pine beetle could be contaminating local water supplies, according to the Silverthorne/Dillon Joint Sewer Authority.

Last May, employees at the Silverthorne treatment plant performed a toxicology test on water that had been treated and was on its way out into the Blue River. The routine test — usually done twice a year — involved placing 20 minnows and 20 water fleas in a container of plant effluent and seeing how they did. After 48 hours, the minnows survived, but all 20 of the water fleas died.

“We’d been doing these tests for 10 to 12 years,” plant manager Mike Bittner said. “And we’d never failed one.”

The initial toxicology test didn’t identify any specific chemical, but it triggered increased monitoring and a series of more extensive investigation of the plant’s effluent. It wasn’t until July that test results returned to normal, and it took that long to pinpoint the chemical culprit: carbaryl — an insecticide also known as Sevin.

One of the three most commonly used pesticides in the U.S., carbaryl has been an agent of choice for the majority of those spraying Summit County’s lodgepoles to protect them from the pine beetles during the local beetle spraying season, which runs from May through July. As with other hazardous materials, it’s illegal to dump the insecticide into the sewer system.

At its peak, the concentration of carbaryl in the Silverthorne plant effluent was fairly small — only 3 parts per billion (ppb) — not enough, once diluted in the river, to have an impact on wildlife, but the fact that it showed up at all concerns Bittner. Stone flies, a common indicator of mountain stream water quality, are even more sensitive to carbaryl than the water fleas used in the toxicology test.

“It’s a food chain thing,” Bittner said. “You kill the stone flies— and that’s what the trout eats.”

So far, among Summit County water treatment plants, Silverthorne’s is the only one to find carbaryl in its effluence. The follow-up testing required because of the initial positive finding cost the Joint Sewer Authority around $15,000, Bittner estimated.

The results didn’t surprise High Country Conservation director Carly Wier.

“I think it was just a matter of time before it showed up in our treatment plants.” she said. Wier predicted an increase of carbaryl use this year, as homeowners spray more and more trees, and warned that being as careful as possible with the substance is an important “precautionary principle.”

“Any time we’re introducing a mass quantity of a fairly unknown chemical into an ecosystem, we have to see long-term effects,” she said. “We just don’t know enough about carbaryl.”

Because of its persistence throughout the entire spraying season, Bittner suspects the carbaryl that showed up in his treatment plant — which services Dillon, Silverthorne, Dillon Valley, Mesa Cortina and Wildernest — came from a careless commercial applicator, rather than from a homeowner. Last year, it had cleared up by the time the chemical had been identified. This year, however, Bittner will be ready for it.

“If it happens again, we should be able to trace it upstream,” he said.

A right way and a wrong way
As director of operations at Fort Collins-based Giving Tree Care, Inc., Dave Kunkel sprayed nearly 17,000 trees in the High Country in 2007. This year, he expects to treat between 25,000 and 28,000 in Summit County alone. When it comes to disposal of leftover insecticide, Kunkel cuts no corners.

“I do it by the book,” he said. After flushing his tank system with water, he sprays trees for free with the diluted solution. Once he’s finished with that step, he neutralizes the tank with a chemical degreaser, empties it into a 55-gallon drum, and disposes of it at a Larimer County hazardous waste company.

In Summit County, the Household Hazardous Waste Collection Program offers free disposal of small amounts of carbaryl and similar substances. According to Bittner, any container used for pesticides should be air dried, and never rinsed in a sink, toilet, storm drain, or gutter.

Although his training with insecticides gives him confidence in their safety, Kunkel acknowledges their limitations in fighting an infestation of such huge proportions.

“You can spray all day,” he said, “But I highly recommend people think about cutting down (infected) trees instead.”

Leftovers remain from 1980s epidemic
Twenty-five years ago, during the last beetle epidemic, ethylene dibromide (EDB) was used by the Forest Service on its property in Summit County to kill the insects. And unacceptable levels of the substance — banned by the Environmental Protection Agency in 1984 for most uses — showed up recently in a test well on the Frisco peninsula.

“(EDB) was the chemical of choice the last time the pine beetle came through,” said Dave Koop, Frisco’s water operations foreman.

According to Koop, wholesale spraying of EDB settled deep in the alluvial soil on the peninsula. The substance will eventually degrade naturally, but its continued presence after 20 years is a sobering reminder of potential effects of chemical use.

“I hope in treating this latest round of bugs, we haven’t caused new problems,” he added.

Harriet Hamilton can be reached at (970) 668-4651, or at

Carbaryl facts
An organic insecticide in use since 1958.
Product names include Sevin, Adios, Carbamec, and Slam.
Commonly used on apples, pecans, grapes, citrus, and asparagus.
Benign to birds, but acutely toxic to honeybees and aquatic insects.
For local disposal of carbaryl, contact Summit County’s Household Hazardous Waste Collection Program at (970) 468-9263.

NOTE: Please limit your comments to 500 words. The system will not recognize formatting such as italics, underlines, or bold.

 By posting you agree to the terms and conditions

March 21, 2008 - DOW restocks Summit Lake after sucker problems
March 21, 2008 - Deputies investigate killing of 30 bison on Park County ranch
March 19, 2008 - Lake County asks for more study of leaking drainage tunnel
March 19, 2008 - Leaking tunnel almost considered Superfund site
March 19, 2008 - What is a Superfund?
March 19, 2008 - Pennsylvania Mine could become Superfund site
March 17, 2008 - Forest Service land eyed for housing
March 17, 2008 - Acting ranger deals with Summit's big issues
March 17, 2008 - Forest service budget cuts hit hard
March 17, 2008 - Acting ranger deals with big issues
March 13, 2008 - Feds reject most of Ritter's plan for Roan Plateau
March 12, 2008 - New bill offers incentives for beetle-kill removal
March 12, 2008 - Mountain lion spotted just west of Aspen
March 12, 2008 - Denver to measure how city driving style affects greenhouse gases
March 11, 2008 - Few issues more complicated than deciding how to share water
March 11, 2008 - Feds: Colorado’s lynx don't need critical habitat
March 10, 2008 - Coalition hopes to add 700,000 acres of wilderness in Colorado
March 8, 2008 - Environmentalists urge end to federal predator-control program
March 8, 2008 - Copper, Frisco employees launch green giving program
March 7, 2008 - Colorado drilling applications soar
March 7, 2008 - Forest Service boss calls for penalties for roadless states
March 7, 2008 - Forest fines increase, but will they work?
March 5, 2008 - Lake County government defends emergency response
March 5, 2008 - Forest Health Task Force talks beetles Thursday
March 5, 2008 - Leadville mine threat was overstated
March 5, 2008 - County adopts control of Summit wetlands
March 4, 2008 - Vail Mountain won’t inject its trees
March 1, 2008 - Vail Resorts to try injecting beetle trees
February 29, 2008 - BLM seeks nominees for several Resource Advisory Council seats
February 29, 2008 - Forest Service increases fines for forest infractions
February 29, 2008 - Enviros: EPA action on auto emissions ties Colorado's hands
February 29, 2008 - EPA releases justification for denying Cal greenhouse gas waiver
February 28, 2008 - Division of Wildlife sends out moose alert
February 26, 2008 - DOW still hoping to halt drilling in New Castle wildlife habitat
February 26, 2008 - County gives nod to Keystone land trade
February 21, 2008 - Gray wolves in Northern Rockies coming off endangered list
February 20, 2008 - Commissioners to comment on Peak 6 expansion
February 20, 2008 - EPA raises concerns about Colorado's roadless plan
February 20, 2008 - Report: stressed Colorado forests need to be managed
February 20, 2008 - Drugged moose carried through Vail house
February 19, 2008 - Will Reclamation take responsibility?
February 17, 2008 - Lynx sightings increase in Tenmile Range
February 16, 2008 - Starving deer will soon be fed in Eagle County
February 15, 2008 - Gov. Ritter asks Bush to act on Leadville mine threat
February 14, 2008 - Frisco moves on peninsula plans
February 14, 2008 - Mine contamination rings alarms in Leadville
February 13, 2008 - Researchers: Key Western storage reservoirs could be all dry by 2021
February 12, 2008 - State, fed agencies outline a plan to fight bark beetles
February 12, 2008 - Energy is complex—conserving it isn’t
February 10, 2008 - Agencies ponder Lower Blue usage cap


Privacy Policy | Advertise | Contact Us | Archives | Classifieds | Subscribe | Site Map | RSS Feeds Add to My Yahoo!

Visit our other news and portal sites.
All contents © Copyright 2008
Summit Daily - 40 West Main Street - Frisco, CO 80443
P.O. Box 329 · Frisco, CO 80443-0329