2018 #COleg: HB18-1008 Mussel-free Colorado Act status update

Photo via Colorado Parks and Wildlife.

From The Summit Daily (Deepan Dutta):

Should the non-native quaggas infest the [Green Mountain Reservoir], millions in taxpayer money will be spent to ensure they do not clog or damage water infrastructure, as well as to prevent destruction of the aquatic ecosystem and the associated recreational fishing industry.

The danger posed by this critter is so high that Colorado Parks and Wildlife, the U.S. Forest Service, the Bureau of Reclamation, Summit County and other agencies are combining efforts to make sure the quagga does not wind up ruining the reservoir as it has other water bodies in Colorado.

Legislatively, a bill called the “Mussel-Free Colorado Act” dedicated to eradicating quagga and zebra mussels is well on its way to becoming state law. The bill requires boat owners to purchase an aquatic invasive species sticker on top of their regular boat registration to fund mussel prevention measures.

County Commissioner Karn Stiegelmeier has been following developments at the reservoir intently since last August, when the Bureau of Reclamation discovered quagga veliger, or larvae, in the reservoir. At the time, Stiegelmeier said she was furious with the lack of federal funding to pay for boat inspections preventing mussel infestation in the first place.

“Other reservoirs like Dillon Dam and Wolford are taken care of by the responsible dam owners,” Stiegelmeier said. “They pay for regular boat inspections before they get in the water, as they should. But the federal government reservoirs always contract out recreation and claim it’s not their job to making sure boats aren’t contaminated before they launch.”


Federal authorities were put on high alert and finally turned their attention to Green Mountain once mussel larvae was detected. Stiegelmeier said that it will be a much more expensive endeavor to try to ward off infestation after it starts.

“Once a reservoir is infested, the feds wind up having to pay many times as much to deal with the infestation,” she said. “Once the adult mussels get in there you can’t get rid of them. We have a huge number of reservoirs, like Lake Powell, that are infested. It costs an enormous amount of money to get mussels off the dam infrastructure, and it absolutely destroys the aquatic ecosystem.”

While samples at Green Mountain have come back clean since the initial detection, Bill Jackson, head of the U.S. Forest Service’s Dillon Ranger District, said that concern over quagga is far from over…

Jackson said that to prevent the infestation, the Forest Service and other agencies will monitor water at Green Mountain for at least three years — the maximum amount of time quagga need to fully develop. The agencies are also working to divert all incoming boat traffic to a single launch point at Heeney Marina, where they can be centrally inspected and decontaminated before reaching the water. Jackson said that one major risk factor for contamination was how many boats were previously launched from unauthorized areas along the shoreline.

“We had a lot of motorboat launches into the reservoir without proper inspection and decontamination,” Jackson said. “We’ve really been trying to make sure that we got on that right away to prevent folks from doing that.”

Jackson said that the Northern Colorado Water Conservancy District, which gets some of the water from the reservoir, helped in providing rocks, boulders and other implements to block off the known boat entry points. He also said that signage will be put around the reservoir directing boat owners to proper launch points where they will be inspected and decontaminated before hitting the water.

In the months leading to boating season, Jackson said that a major collaborative project will be taking place to improve the inspection and decontamination process at Green Mountain.

The Bureau of Reclamation and other partners will help Heeney Marina to improve its boat launch facilities and parking to accommodate the large amount of boat traffic being funneled there. The Forest Service will do its part by allowing modifications to the marina’s permit for construction there, as it operates on Forest Service land.

The project will also require Summit County to help by closing down and improving the county roads leading into and out of the reservoir, as well as introducing more signage. Details of the project have yet to be released in full to the public, but Jackson said a press release is forthcoming.

Jackson added that they needed the public’s help in preventing contamination.

“If folks are not getting their boats inspected, that doesn’t help anyone, and we wind up dealing with the aftermath of cleanup efforts. Prevention is where we want to be.”

Jackson said that boat owners can help by following a three part procedure: Clean, drain and dry.

Click here to view the list of the West’s worst invasive species according to the Western Governors’ Association.

Dillon Reservoir still mainly ice-free for this season

Dillon townsite prior to construction of Dillon Reservoir via Denver Water

From CBS Denver (Matt Kroschel):

Warmer temps have left Dillon Reservoir for the most part unfrozen, typically the large body of water freezes over by the end of December. Not this year, though.

More dry weather and above average temperatures are predicted for the next few days. That leaves open the possibility of breaking the record this year.

Summit County reacts to CDPHE decision to delay action on Climax Molydenum’s standard request

Grays and Torreys, Dillon Reservoir. Photo credit Greg Hobbs.

From The Summit Daily (Deepan Dutta):

Officials from CDPHE and the Environmental Protection Agency decided to move a hearing on the proposal from December 12 to November 2019, citing the need for further study of the proposed limit increase on humans and the environment.

Summit County officials, while welcoming the public health’s delay in making a decision, are standing together against the proposal to allow more molybdenum in Summit’s waterways.

A group of local stakeholders issued a joint statement opposing the increase before Wednesday’s hearing. Representatives from the Town of Frisco, Copper Mountain Consolidated Metropolitan District, Northwest Colorado Council of Governments, and several other local government bodies stated that Climax’s proposal carried “unacceptable levels of uncertainty and risk” to human and animal health.

Lane Wyatt, co-director of the NCCG’s Water Quality/Quantity Committee, has been advising local leaders on the molybdenum issue. Wyatt believes the state is prudent in delaying its decision and welcomes Climax’s attempts to be transparent.

However, Wyatt says the initial research done by independent experts have already shown that high concentrations of molybdenum pose increased risks to human health, and that is enough to consider the molybdenum increase a non-starter.

Additionally, he sees Climax’s effort to get the state’s approval on increased molybdenum levels as a small foothold for its bigger ambitions to export molybdenum to other places, such as the European Union with its stricter environmental standards.

“Climax has been a good neighbor to Summit County,” Wyatt says, “but the community does not want to be a guinea pig for fooling around with how much molybdenum is in the water before it becomes a problem.”

Before the November 2019 hearing, the department of public heath’s water quality commission will hold other limited-scope hearings. One such hearing will take place on January 8 on whether to extend a site-specific temporary modification. The NCCG says it welcomes comments regarding molybdenum, and the public may do so by email at cdphe.wqcc@state.co.us. The commission is requesting all public input by Wednesday, Dec. 27.

@DenverWater estimates $600 million in costs to treat for molybdenum if temp standard is made permanent

Climax Mine

From The Denver Post (Bruce Finley):

Chronic ingestion of molybdenum can cause diarrhea, stunted growth, infertility, low birth weights and gout

Colorado health officials on Wednesday ignored state scientists and delayed for two years a decision on a mining giant’s push to weaken statewide limits on molybdenum pollution of streams, including a creek flowing into Dillon Reservoir, Denver’s drinking water supply.

Denver Water contends that Climax Molybdenum’s campaign to jack up molybdenum pollution limits 43 times higher than at present could cost ratepayers up to $600 million for expansion of a water treatment plant. Trace amounts of molybdenum — below a health advisory level — already flow out of Denver taps.

But Colorado Department of Public Health and Environment officials and federal Environmental Protection Agency officials on Wednesday rescheduled a Dec. 12 molybdenum rule hearing for November 2019.

A CDPHE hearing officer said the delay will allow time for industry-financed studies to move through a peer-review process and for the Agency for Toxic Substances and Disease Registry to make decisions on molybdenum toxicity. A “temporary modification” that currently allows elevated molybdenum pollution from the Climax Mine was extended this year through 2018, and CDPHE officials at Wednesday’s meeting opened the possibility it could be extended again.

CDPHE scientists opposed the delay. The scientists, Denver Water and a coalition of mountain towns have opposed the push by Climax to allow more molybdenum pollution of Tenmile Creek, which flows down from the Climax Mine above Leadville into Dillon Reservoir, where water flows out through a tunnel to Denver and the upper Colorado River Basin. CDPHE water-quality scientists have determined that molybdenum pollution at the proposed new limits would kill fish and could hurt people…

Denver Water treatment plants cannot remove molybdenum, and expanding one plant to do that would cost from $480 million to $600 million, utility officials said in documents filed to the CDPHE.

Those costs ultimately would hit ratepayers, the 1.4 million people who rely on Denver Water for their domestic water supply. The molybdenum pollution from Tenmile Creek that reaches Denver facilities today is “below the human health advisory levels,” Denver Water spokeswoman Stacy Chesney said.

“We’d likely exceed the human health advisory standard if that (new limit) were to become the statewide water quality standard. … Currently, the concentrations in Tenmile Creek have not been at a high enough concentration that would result in an exceedance of the human health advisory level, so an extension of the ‘temporary modification’ for molybdenum is acceptable,” Chesney said.

A subsidiary of the $46 billion mining giant Freeport-McMoRan, Climax Molybdenum runs the Climax Mine, which was closed for 25 years and reopened in 2012. This led to elevated molybdenum pollution at levels up to 2,500 ppb, 10 times higher than the current statewide limit. The “temporary modification” granted by CDPHE water commissioners, and extended this year, allows this elevated pollution through December 2018…

EPA officials recently said a molybdenum pollution limit as high as 10,000 ppb could be sufficient. But EPA scientists previously have advised lower limits.

“Denver Water’s current position is that the molybdenum limit should be based on scientific evidence. While Climax Molybdenum Company has presented scientific studies in support of its proposed standard, the studies fail to account for the effect high molybdenum concentrations will have on individuals with a copper deficiency,” Chesney said. “Because we do not know how high molybdenum concentrations will affect people with copper deficiencies, and EPA has not modified the Human Health Advisory for molybdenum to correspond with Climax’s proposed standard, the (state water quality control) commission should decline to increase the molybdenum standard to the level proposed by Climax.”

A coalition of mountain towns also is fighting the proposed higher limits for molybdenum pollution of waterways.

“Because of scientific uncertainty regarding the effects of varying molybdenum concentrations on human health, the commission should decline to make the changes that Climax Molybdenum Company has proposed in the statewide molybdenum standards,” Frisco attorney Jennifer DiLalla said. “The town’s primary goal is ensuring that any action the commission may take with respect to molydenum standards is protective of the health of those who live and work and play in Frisco.”

Swan River restoration update

Photo credit: Summit Magazine

From The Summit Daily News (Jack Queen):

The Swan hasn’t flowed freely since the dredges chewed up its banks, kept the gold and spat the rocks back out. All of the sand and silt that kept the water out of the ground washed downstream, so the river has quietly gurgled under the rocks for the century since.

“One way to think of it is like a bathtub full of marbles, and the water is just sort of flowing through those,” Lederer said. “Sometimes you see it on the surface and sometimes you don’t.”

The Open Space and Trail Department has teamed up with Breckenridge and at least a half-dozen other partners to breathe life back into the Swan. Clearing out all of the marbles is the first step.

For the past two years, workers have been collecting and milling hundreds of thousands of cubic yards of the gravel and rocks that have been suffocating the river.

On Wednesday, Nov. 22, crews are set to wrap up another season of work, pulling out more than 43,000 tons of material since July. Over that time, roughly $122,000 in royalties from the sale of that processed material have gone to help offset the cost of the project.

A big load of the rock from last season was used for the Iron Springs bypass project, an ambitious re-routing of Highway 9 between Breckenridge and Frisco that was finished just weeks ago…

Last summer, the project liberated one of four sections of the Swan, digging out a channel that now meanders across a wide floodplain.

“We look at the geometry of the valley as a whole: how wide it is, how steep it is, how big the floodplain is,” Lederer explained. “And looking at these different parameters, we can make an inference into what the channel should look like.”

This summer, workers planted thousands of willows along the new banks of the Swan to help anchor the river while it stretches it legs for the first time in years. But it’s not stuck in place just yet.

“We’ve given the stream a lot of flexibility to move across the floodplain,” Lederer said. “It’s able to move a little bit over time, and that’s OK — that’s kind of what we want up there.”

After a dry start to the season, the area greened up nicely before the first snowfall, a stark contrast to the moonlike surface from just two years ago.

The stretch that’s flowing, dubbed Reach A, is one of four sections identified for de-dredging. That phase cost around $2.3 million total, provided by a combination of state and local government grants.

Gravel milling work this summer has taken place upriver on Reach B, and that’s set to continue next summer. Workers need to clear at least 195,000 cubic yards of material before restoration can begin.

The final two sections, however, are being actively quarried on private land and could take some time to free up for restoration.

“Everyone in the valley is sort of supportive of this work, but I don’t have a good idea of the timing on anything on private property,” Lederer said. “But ideally, we’ll continue to move upstream as the opportunity allows.”

From Colorado Summit Magazine (Devon O’Neil):

Today’s excavator work represents the latest step in a landmark project undertaken by local, state, and federal government agencies, as well as a group of private organizations that share a commitment to undoing the environmental damage inflicted by Summit County’s pioneers.

“It’s just basically a big mess. There is no real stream, to be honest. There’s no life,” Jason Lederer, an open space and trails resource specialist for Summit County, says while observing the scene last summer. “Our goal is to reintroduce the natural channel to the valley and restore the ecological and environmental value.”

Lederer watches as the earth mover pulls another few hundred pounds of melted chocolate from its expanding hole. When the restoration effort began, no one had a clue where the river was supposed to go—or where it ran before the dredges turned it upside down in the early 1900s. “We don’t have any pictures, but we can imagine,” Lederer says. Which seems a tad crazy, no? How could you not know where the river flowed as recently as a century ago?

Such is the legacy of dredge mining—not just in the Swan, but also French Gulch, one drainage south, and anywhere else a dredge ever operated.

Soon, though, this valley will be transformed, once again through a human touch. As part of a decades-long plan to restore three miles of the Swan, last summer’s work was a major step toward realizing the river’s potential once more. The envisioned final product evokes a page torn from a Colorado scenic calendar: a meandering stream with aspen and juniper on its banks, 10-inch brook trout snapping at your fly, native cutthroat trout flourishing just upstream (for the time being), and more than 130,000 cubic yards of dredge rock crushed and removed from the valley forever.

As Lederer says, “If we do our job right, nobody will ever know we—or the miners—were here.”


The first two dredges began churning up the river bottom in 1898, and two more followed in 1899. The four boats dug as deep as 70 feet, depositing their debris in giant piles next to the disappearing river channel. Before long, the Swan’s three forks—North, Middle, and South—no longer shared a visible confluence, having been driven underground by the mining. All that mattered was the gold. And if no one was making the mining companies clean up their mess, they weren’t about to do it of their own accord.

Just up the hill and south from where the boats were “flipping the river upside down,” as dredge mining’s impacts are described, the Cashier Mine pumped out ore in Browns Gulch (it remains one of the largest abandoned mines in the county). Workers loaded its waste into carts and scattered it about the valley, alongside the tens of thousands of smooth, round river rocks discarded by the dredge boats. This, of course, only made a bad problem worse.

What had once been a verdant river became a wasteland. People who have worked on the Swan restoration refer to the river they inherited as a “bathtub of marbles”—essentially a waterway that had been so churned up it no longer had a bottom … or any structure at all. Think of trying to contain water with a screen. That’s what the Swan had become: an underground trickle, dispersed to the brink of dissolution.

Even as work began last summer, questions remained: Was the river still there? If so, could it be channeled once more? What would it take to bring the ecosystem back to life?

There weren’t many precedents akin to the Swan, but one local project provided inspiration, and hope. From 2004 to 2006, Summit County government led an effort to restore the Blue River just north of Tiger Road along Highway 9. The 23-acre Four Mile Bridge Open Space, as it became known, turned out beautifully and served as a vital blueprint for the Swan, in that the remediated site was zoned strictly as open space with no concessions for development.

It took 10 years from when the county and town of Breckenridge began preliminary work on the Swan until the heavy equipment arrived last summer, but by the time operations ceased in mid-November, the progress was striking. They’d rebuilt nearly a mile of stream, including relocating a half mile of channel that had become a muddy ditch along Tiger Road. The reconstructed section of river—“Reach A” as it’s known in the broader plan—includes 22 riffles (minor rapids), glides (calm water stretches), and pools 3 to 6 feet deep, which combine to form optimal fish habitat. The river channel is 25 feet wide to accommodate high flows during spring runoff, anchoring a 65-foot-wide riparian corridor that will be populated this summer with native flora.

Best of all, the county did not have to line the riverbed to prevent water from seeping into the ground and disappearing. That’s because the Swan River, they discovered, is a “gaining stream” instead of a “losing stream”—that is, groundwater actually rises from the bed and into the river, increasing its flow. You could see this happening just upstream from the excavator last July; clear water spurted out of the gravel like a spring, then gradually coalesced as it moved downhill.

An uncommon range of backers has funded the restoration, with the largest financial contribution—$975,000—coming from the Colorado Water Conservation Board. Summit County added $500,000, the town of Breck gave $300,000, Colorado Parks and Wildlife anted in $184,000, and the US Forest Service and US Fish and Wildlife Service combined to donate $250,000. Also part of the mix: the Blue River Watershed Group and Trout Unlimited’s Gore Range Anglers Chapter, which works to protect, preserve, and restore coldwater fisheries. “This project hits every aspect of our mission,” says chapter president Greg Hardy.

Water Update — Colorado Central Magazine

Roberto Salmon and Edward Drusina at the Minute 323 signing ceremony September 27, 2017. Photo credit .U.S. Bureau of Reclamation.

Here’s my latest column for Colorado Central Magazine


Several tributaries of the Colorado River get their start in the crags of the Central Colorado mountains. Storied rivers: Blue, Eagle, Roaring Fork and the powerhouse Gunnison. They’ve all faced the footstep of humankind. The mines dotting the slopes, hay fields, ranching, orchards and cornfields bear witness and are now part of the allure of the high country. Folks cast a line, shoot rapids and enjoy the scenery of those waterways.

On September 27, 2017, the International Boundary and Water Commission, United States and Mexico inked Minute 323, the amendment to the 1944 United States-Mexico Treaty for Utilization of Water covering operations on the Colorado, Rio Grande and Tijuana rivers. (The Rio Grande is another of Central Colorado’s contributions to the Western U.S. economy.)

An important part of Minute 323 are environmental flows for the Colorado River Delta. Most everyone knows the river doesn’t reach the sea any longer. Environmental streamflow was initiated under Minute 319 signed by then Secretary of Interior Ken Salazar.

Young girl enjoying the river restored temporarily by the pulse flow March 2014 via National Geographic

In March 2016 a diverse group of conservationists, biologists, irrigators and government officials effected a release of 100,000 acre-feet of water from Morelos Dam into the dry Colorado River Delta. There was a line of vehicles racing point to point along the river to witness the river’s front. At San Luis Rio Colorado, most of the residents went down to the river to celebrate the return of the river although many had no memory of running water in the sandy channel.

There was a great deal of success from channeling some of the streamflow to restoration sites in the Delta. Within weeks, new growth sprouted – cottonwoods and willows. Much of the diverted water served to replenish groundwater supplies. Wildlife immediately started using the habitat.

There probably won’t be a repeat of the Colorado River once again reaching the sea. The environmental flows in Minute 323 are planned to be set to work in the restoration of the Delta. It was great to see the river reach the sea but the conservationists want to concentrate flows like irrigators do for maximum yield.

Another feature of the deal allows Mexico to store water in Lake Mead to better manage their diversions for agriculture. The U.S. is also helping to rebuild and upgrade Mexican infrastructure. Under Minute 319, Mexico was allowed to continue storing water, and that water was used for the pulse flow. The idea is that greater efficiency in Mexico will lead to more storage in Lake Mead.

Currently, Arizona, California and Nevada are working on a drought contingency plan to stave off a shortage declaration in Lake Mead. Arizona’s Colorado River allocation takes a big hit under a declaration. Mexico’s water in Lake Mead will help. Negotiations about the drought contingency plan will now move forward with greater certainty with the signing of Minute 323.

The final signatures for the Minute came from Roberto Salmón (Mexico) and Edward Drusina (U.S.). There were several officials from President Obama’s administration in attendance, including Jennifer Gimbel and Mike O’Connor. The negotiations started before last year’s election but did not conclude before the inauguration.

Minute 323 is an important piece of the puzzle for administering the Colorado River.

Central Colorado is joined at the economic hip with the Colorado River. A lot of transbasin water flows down the Arkansas River from the Twin Lakes and Fryingpan-Arkansas projects. Some is pumped over to South Park by Colorado Springs and Aurora but most of it goes down to Lake Pueblo and the Fry-Ark partners. Colorado Springs, Fountain and Security pump some back north in the Fountain Valley. Cities along the river divert and treat the water for their populations. The water also is used to grow the famous crops in the Arkansas Valley: Rocky Ford melons, Pueblo chile, corn and others. Timing the releases from Twin Lakes and Turquoise Reservoir also contributes to the rafting economy. 100 miles of the Arkansas River are designated as gold medal fisheries. Transbasin flows help the riparian habitat.


• Comments about managing the Arkansas Headwaters Recreation Area are due by November 10, 2017. Check out the AHRA Plan Revision page on the Colorado Parks & Wildlife website.

• Congratulations to Wet Mountain Valley ranchers Randy and Claricy Rusk for winning the Dodge Award for a lifetime of conservation from the Palmer Land Trust.

• Congratulations to the Colorado Parks & Wildlife folks at the Roaring Judy Hatchery for successfully spawning the line of Cutthroat trout rescued from Hayden Creek during the Hayden Pass Fire.

• James Eklund has moved on from the Colorado Water Conservation Board and Becky Mitchell is the new director.

• Coloradans cam now legally collect rain off their roofs. Governor John Hickenlooper signed House Bill 1005 in May.

• R.I.P. Gary Bostrom. He was one of the driving forces behind Colorado Springs’ $825 million Southern Delivery System.

John Orr works for a Front Range water utility where he keeps one eye on the sky to monitor Colorado snowpack. He covers Colorado water issues at Coyote Gulch (www.coyotegulch.blog) and on Twitter @CoyoteGulch.

Martha Gomez-Sapiens, a monitoring team member and postdoctoral research associate in the UA Department of Geosciences, stands on a riverbank next to willows and cottonwoods that germinated as a result of the pulse flow. (Photo: Karl W. Flessa/UA Department of Geosciences)

Proposed Climax molybdenum limits, “would be acutely lethal to aquatic life” — CDPHE

Frozen mists over the Blue River Valley turn the sun into a diamond — Bob Berwyn

From The Denver Post (Bruce Finley):

CDPHE scientists warn Climax Mine molybdenum may pose health risk, oppose company push to raise statewide pollution limit

The Colorado Department of Public Health and Environment water-quality scientists said, in a recommendation to state commissioners, that Climax Molybdenum’s proposed hike “would be acutely lethal to aquatic life” and probably not protective of people.

A Climax report on molybdenum exposures in Colorado “demonstrates that current levels of molybdenum in drinking water may pose a public health risk to communities downstream” of the mine, CDPHE scientists said in filings reviewed by The Denver Post.

State data show molybdenum discharges from the Climax Mine above Leadville in recent years increased to levels 10 times higher than the current statewide limit of 210 parts per billion. CDPHE water-quality control commissioners granted Climax a “temporary modification.” When it expired, the commissioners extended the modification to provide more time to complete a study of molybdenum.

CDPHE officials Tuesday declined to discuss this issue.

Federal Environmental Protection Agency officials, who oversee Colorado’s compliance with the Clean Water Act, informed state commissioners last week that the EPA would allow a limit higher than what Climax Molybdenum is proposing, according to a document filed Friday.

A regional EPA spokesman issued a prepared statement saying the EPA’s filing is “preliminary,” confirming that “our initial review indicates that the proposed standard would protect water supply uses,” but declined to further discuss this issue

State commissioners often follow EPA guidance in setting pollution limits sufficient to protect people while accounting for variability and uncertainty…

Climax officials cited three rat studies the company helped fund in asking CDPHE to relax the statewide water quality limit for molybdenum in streams used for domestic water to 9,000 ppb billion from 210 ppb. Climax also wants limits for waterways used for agricultural irrigation raised to 1,000 ppb from 160 ppb.

EPA recommendations submitted to the CDPHE said a molybdenum limit for streams tapped for drinking water of 10,000 ppb “would be protective … and consistent with Clean Water Act requirements.” However, EPA regional officials said in the document filed Friday that they would not object if Colorado’s commission “chooses to be more conservative and adopts a more stringent table value standard of 9,000 ug/L (ppb) as proposed by Climax Molybdenum Company.”

The EPA “must review and act upon any revised standards once they are adopted by the commission for them to be in effect under the Clean Water Act,” the agency’s statement said. “If the commission chooses to retain current standards, EPA will not have an approval or disapproval role.”


The CDPHE scientists submitted their recommendation Friday to state commissioners, who are scheduled to deal with the matter in December.

Denver Water is opposing the push for a looser statewide limit, along with downstream communities including Frisco, the Copper Mountain resort and people to the west along the Eagle River…

Denver Water treatment plants lack the capacity to remove molybdenum, which in trace amounts can be healthy. While data on human toxicity is limited, chronic ingestion of molybdenum can cause diarrhea, stunted growth, infertility, low birth weights and gout, and can also affect the lungs, kidneys and liver.

Climax officials have told state water quality commissioners their proposal “is not based on any intent or need to increase molybdenum in Climax discharges, and, in particular, Climax does not intend to change its mining or water treatment process in a manner that would cause an increase in the historical discharge of molybdenum into Tenmile Creek.”