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City responds to Valmont concerns

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In response to Boulder Weekly’s “Ghosts of Valmont Butte” series and concerns from several local activist groups, City of Boulder officials have issued written memos defending their approach to remediating the property.

On March 30, Joe Castro, the city’s facilities and fleet manager, sent a letter to Carol Affleck of the Valmont School District #4 Cemetery Association, Steven Moore of the Valmont Butte Heritage Alliance and LeRoy Moore of the Rocky Mountain Peace and Justice Center, all of whom have raised concerns about cleanup plans at the site, in part due to the BW series.

In the letter, Castro reasserts many claims that Boulder Weekly has demonstrated to be questionable at best, including the idea that the only groundwater at the site is on the east end of the property and that groundwater can’t migrate to the north through the dike dam because Valmont Butte is a geologic barrier.

In addition, Castro maintains that city officials know the exact location of the radioactive soils buried by the city at the site in 1971, and that updated plans call for extending the cap over the area identified by Boulder Weekly as a likely site of at least one pit. He also repeats the claim that ground-penetrating radar (GPR) is not a suitable technology for identifying unmarked human graves outside Valmont Cemetery that may be unearthed during excavation, despite evidence to the contrary.

That same week, the city attorney’s office sent a memo regarding Valmont and BW’s coverage to the entire council, but spokesperson Sarah Huntley declined to release that document, saying it constitutes “attorney-client privilege and would not be a public record.”

City staff sent a longer version of the Castro letter to city council on April 12 as part of its “weekly information packet.” Boulder Weekly has prepared a point-by-point response to that memo, incorporating excerpts from an EPA report as evidence that contradicts the city’s claims.

Here is the full text of the city’s memo:

City of Boulder's Valmont Memo 4-12-2012

And here is BW response:

April 16, 2012

Boulder city council members,

In recent weeks, through confidential internal memos, letters to local activists and the April 12 weekly information packet, city staff members have attempted to reassure council that despite our extensively researched series which has been running in Boulder Weekly over the past several months and the concerns of several organizations, there are no flaws in the city’s current remediation plan at Valmont Butte. While the staff’s approach has primarily been to repeat assertions that we have called into question, we would like to respond in a more detailed way, pointing to specific evidence that casts doubt on the city staff’s statements. We have taken passages of the Valmont memo sent to you as part of the April 12 weekly information packet and, under each one, quoted directly from the EPA’s final 2005 final report on the Valmont Butte property (Valmont Butte / Allied Piles - SR/ARR, Revision: 0, Date: 01/2005, URS Operating Services, Inc., START2, EPA Region VIII, Contract No. 68-W-00-118) The statements in bold typeface are comments from Boulder Weekly staff.

Thank you for taking the time to read this information.

Groundwater Conditions at the Site

CITY STAFF: “The Boulder Weekly and the Organizations state that there is insufficient information about whether there is contaminated groundwater flowing from the Site to the north. First, only limited groundwater occurrence has been identified onsite, and that is at the east end of the Site.”

EPA: “There is evidence in the bores that water is contained within the area, with the mounding of groundwater in the center of the primary tailings area. If water were leaving the area there would be a downward gradient toward the area where the water is leaving the site.”

"The tailings are 20 feet to 30 feet in depth at the boundaries and more than 40 feet in the center of the tailings area. The groundwater levels encountered in the primary tailings area range from 10 feet bgs to 33 feet bgs. The more-shallow groundwater levels occur in the middle of the area.”

BOULDER WEEKLY: Please see attached engineering map showing that a “downward gradient” does, in fact, exist and that the slope is to the north (not east), directly into the dike dam, which, as shown by the engineering map, extends below the elevation of the Pierre Shale in the center of the primary tailings pond. This engineering drawing from the time that the dam was built demonstrates clearly that there is no Valmont dike formation serving as any form of a barrier to the northern migration of the above-the-Pierre groundwater found in the pond as described by the EPA.

EPA: “No definitive statement can be made about the hydrogeology in the secondary tailings area. The lack of saturated soils in the area does not eliminate the possibility that groundwater is flowing through and leaving this area. The fact that coarse sand and gravel that could act as channels were encountered in the borings adds to this uncertainty.”

“During the FSP planning process, a study to characterize on site and off-site groundwater was considered. Because of the cost and the likely extended time frame to conduct such a study, the best approach was determined to be an investigation of potential targets.”

“Although the extent to which leachate could permeate the fractured Pierre Shale and impact drinking water wells north of the site is unknown, analytical data do not indicate that this is happening at a level that poses a significant risk to human health and the environment."

BW: The EPA is quite clear in that to make definitive statements regarding the absence of groundwater and its ability to migrate away from the site — statements such as those currently being made by city staff to both concerned citizens and city council members — is simply wrong. If the scientists at the EPA can’t say with any certainty that contaminated groundwater isn’t leaving the site, how can city employees untrained in the environmental sciences make such proclamations? Has the city’s consultant now drilled the additional wells that would be needed to make such definitive statements regarding the groundwater, statements that directly contradict the findings of the EPA? The answer is no.

EPA: “The highest gross alpha and gross beta radiation levels were detected in samples collected in Butte Mill Ditch adjacent to the silos and from samples collected from the on-site wetlands (sample location VB-SE-10 on Figure 4). The silos are directly downgradient of the primary pond dike dam. The source of contamination near the silos may have been the spill reported to have occurred through a break in the primary dike dam that reportedly occurred around 1945 (Keeter 2004b). There is no evidence that releases are occurring at present.”

BW: There can be no evidence of “releases occurring at present” without a monitoring well below the dike dam drilled into the shallow groundwater that exists there.

Without such a well, there is currently no ability to monitor groundwater between the silos and the primary tailings pond. All current wells on the Keeter property are located north and west of this area and further down-flow in the aquifer. They are also drilled to depths below the shallow aquifer in some cases. As for the source of the contamination being from a spill 70 years ago, aerial photos showing the spill do not show it in the area of the silos, and the 2007 affidavit from the Keeters themselves states that the contamination on their property is from leaching through the dam, not a spill.

EPA:“A potential groundwater to surface water pathway exists and the drinking water target population is listed in the table below. About 40 percent of the city of Boulder’s water supply, serving approximately 106,000 people, comes from the Silver Lake/Lakewood Watershed on North Boulder Creek, 40 percent comes from Barker Reservoir on Middle Boulder Creek, and 20 percent comes from Boulder Reservoir, which is part of the Colorado Big Thompson Project. An estimated 20 percent of the Boulder Reservoir falls within the two- to three-mile radius and the remaining eighty percent falls within the three- to four-mile radius. (City of Boulder 2004a; City of Boulder 2004b). About 75 to 80 percent of the city of Lafayette water supply, serving approximately 26,000, comes from Base Line Reservoir that falls within the two- to three-mile radius (City of Lafayette 2004).”

“Drinking Water Target Population

Groundwater to Surface Water Pathway

Distance From Site Population
On site 0
>0 to 0.25 mile 0
>0.25 to 0.5 mile 0
>0.5 mile to 1 mile 0
>1 mile to 2 miles 20,800
>2 miles to 3 miles 4,240
>3 miles to 4 miles 16,960
Total 42,000

Sources: City of Boulder 2004a; City of Boulder 2004b; Colorado Department of Natural Resources 2004; City of Louisville 2004; City of Lafayette 2004; USDOC 2000.”

EPA: “Some concern exists that there is a potential for groundwater contamination from tailings leachate. In most of Boulder County there are no principal water supply aquifers. Minor supply aquifers of the area, including several zones in the Tertiary and Upper Cretaceous, outcrop east of the site. The shallow groundwater, if present, will likely follow the general slope of surface topography (USGS 1997a). Sources, pathways, and receptors are shown on the Conceptual Site Model (Figure 6).”

“Drinking Water Target Population

Groundwater Pathway Distance From Site Population On site

0>0 to 0.25 mile 29
>0.25 to 0.5 mile 0
>0.5 mile to 1 mile 123
>1 mile to 2 miles 924
>2 miles to 3 miles 1,588
>3 miles to 4 miles 1,709
Total 4,373”

BW: We can’t say it any more clearly than the EPA, “Some concern exists that there is a potential for groundwater contamination from tailings leachate” and “A potential groundwater to surface water pathway exists.”

The EPA is not alone in its willingness to admit what it doesn’t know. The U.S.Geological Survey was quite clear, after the first incorrect pronouncement that there was no groundwater at the property in the mid 1980s, in saying that it would take many more wells, including one below the dike dam, in order to get a complete picture of the groundwater occurrence and migration at the Butte property. Even though there was a dry hole drilled in the ravine that feeds the primary pond in1985, in recent years two monitoring wells drilled in the same area above the dryhole on Public Service property found groundwater, making it quite possible that the primary tailings pond groundwater is being recharged at least seasonally. If one dryhole in 1985 can be put forward as proof that no groundwater is going into the tailings pond, then two wells in the same ravine that did find groundwater in2010 should be considered equal and opposite proof. When it comes to public health, choosing to only champion that portion of available information that will save money should not be an option for a city such as Boulder.

As stated in its final report of 2005 as well as in other documents that outlined the work it would be doing at the site, the EPA has always claimed that there has never been a complete and thorough risk assessment done regarding groundwater at the Valmont Butte site due to costs and time restraints.

This is not the Boulder Weekly claim or the concerned citizens’ claim, as city staff would have council believe. This is the claim of the EPA. It would be helpful to the citizens who own the site if city staff would address all of the facts and evidence as opposed to accepting only that portion of the record that fits its current plan and budget.

Sadly, this seems to be true of all of the agencies that are currently charged with environmental oversight at the Valmont Butte. All are desperately short of funding and seem to have getting the Butte off of their books as the guiding priority.

CITY STAFF: “The Butte itself is a barrier to groundwater flow to the north. EPA’s 2005 Site Assessment states that the east-west trending volcanic dike (the Butte itself) rises 200 feet above the surrounding plains and is three miles in length. The fact that a man-made dam was built to control surface water flow where the Butte dips does not change the subsurface conditions (i.e., the geologic barrier).”

EPA: (From EPA document dated Aug. 16, 2004 regarding the steps it believes should be takenat the Valmont Butte to assess contamination dangers.)

“Fifth, EPA will install a temporary well into the alluvial aquifer north of the apparent gap/fracture in the dike to determine the quality of groundwater in this area. This information will be compared to background information to evaluate if the aquifer is being impacted by contamination from the site.”

BW: The EPA is well aware that the natural Valmont Dike has locations where it does not form a barrier to above-the-Pierre –shale groundwater movement, such as in the“gap/fracture” that required the construction of the dike dam. The groundwater in the primary tailings pond that is of concern is located above the Pierre shale and above the base of the dike dam. Again, please see the attached engineering map and drawing for the construction of the dam. The dam is approximately 60 feet deep and extends down to the elevation of 4,803 feet at its center. The center of the tailings pond at its deepest point is at approximately 4,820 feet, and the southern edge of the pond at its deepest is at 4,840 feet. This makes the slope of the pond to the north, through the dam, and it means that any and all of the groundwater in the pond found by the EPA above the Pierre shale has the ability to migrate through the dam.There is absolutely no Valmont Dike formation present along this section of the primary tailings pond to prevent such migration. To claim the dike is a barrier to the groundwater found in the primary pond by the EPA is not credible whatsoever, based on the available facts and evidence. This is one of the most easily debunked myths regarding the butte, and has no place in a substantive discussion of facts regarding remediation.

Boulder Weekly is not claiming that the groundwater in the pond is migrating. We have simply demonstrated that the argument that it can’t because of the Valmont dike formation is completely false. And we have repeatedly shown that there is a great deal of historical evidence in the way of contamination in the wells north of the property that seems to indicate that a pathway did exist at one time and therefore under the right circumstances could still exist to some degree, allowing lead to make its way into the aquifer.

It is apparent from the EPA’s statement above—where the agency says that it should put in a well below the dam—that some within the EPA understood the need for this critical monitoring well. Unfortunately, though drilling a monitoring well below the dam was planned on more than one occasion, to date it has still never been drilled, and the question of leachate from the pooling water in the pond making it into the aquifer to the north still remains unanswered.

CITY STAFF: “In addition, the permeability and porosity of silt and clay soils at the Site as documented with soil borings is very low; therefore, the mobility of water through the Site is very low.”

BW: We agree that this is the case within the primary tailings pond, but it is not the case in the secondary tailings pond (see EPA statement about secondary pond groundwater above) or other parts of the site, according to the EPA. It is completely inaccurate to apply this description to the entire property. In fact, it is the opposite of what the EPA has found on the vast majority of the property outside of the primary tailings pond. Approximately 88 acres out of the total 102 acres do not fit this description. City council should seek to find out why it is continually being fed such inaccurate information by staff who clearly know that the information is false, or certainly should, after a decade in possession of the research it is incorrectly citing.

CITY STAFF: “The man-made dam along the Site was sampled in September 2004, and was found to be dry (i.e., no evidence of groundwater flow).”

BW: Of course. This should be expected if you examine where the core sample was taken and the depth drilled to get the sample. The drilling took place on the north side of the dam, at its far western end. It was drilled to 27 feet in depth until it reached what would have been the side of the Valmont dike formation where it slopes downward into what the EPA refers to as the gap/fracture in the dike.

If groundwater is, in fact, migrating from the primary pond, it would be occurring at the bottom of the pond. When the water makes its way down to the Pierre shale that makes up the bottom of the pond, it would then follow the slope of the hard shale to the north, where it would then migrate through the dam (which is constructed only of coarse contaminated tailings) at its lowest point, which was the original ravine that crossed the property through what is now the pond.

In other words, for the dam sample to have contacted groundwater, it presumably would have to have been drilled to 60-plus feet in the center of the dam. It was not drilled to look for water, but rather to measure radioactivity and heavy metals contamination. Please examine attached engineering map to see why this claim by staff appears to be misinformed.

CITY STAFF: “Sampling shows that the tailings themselves are dry, except for a few isolated areas of perched water that do not have contact with the regional groundwater.”

EPA:“There is evidence in the bores that water is contained within the area, with the mounding of groundwater in the center of the primary tailings area. If water were leaving the area,there would be a downward gradient toward the area where the water is leaving the site.”

“The tailings are 20 feet to 30 feet in depth at the boundaries and more than 40 feet in the center of the tailings area. The groundwater levels encountered in the primary tailings area range from 10 feet bgs to 33 feet bgs. The more shallow groundwater levels occur in the middle of the area.”

BW: Staff’s description of the groundwater in the primary tailings pond as “isolated pockets” appears to be completely different than the EPA’s analysis, even though staff and their consultant have no information beyond that which was provided to them by the EPA. This is a very questionable rewrite of the data. As for staff once again definitively stating that the groundwater is not in contact with regional groundwater, we offer the EPA’s statements from earlier.

EPA: “If water were leaving the area, there would be a downward gradient toward the area where the water is leaving the site.”

“No definitive statement can be made about the hydrogeology in the secondary tailings area. The lack of saturated soils in the area does not eliminate the possibility that groundwater is flowing through and leaving this area. The fact that coarse sand and gravel that could act as channels were encountered in the borings adds to this uncertainty.”

“During the FSP planning process, a study to characterize on site and off-site groundwater was considered. Because of the cost and the likely extended time frame to conduct such a study [it was not done.]”

CITY STAFF: “Finally, 12 domestic water supply wells north of Valmont Butte were sampled in 2004,and none of the wells showed evidence of groundwater contamination from the Site.”

BW: We find it questionable that staff has not presented to council the decades worth of well tests from north of the property that showed contamination of lead and radiation above today’s drinking water standards. As we have written repeatedly in recent months, even the state is now willing to acknowledge that this contamination likely came from the Allied mill. The testing results were printed on the same report with tests from the Allied mill site, and made it clear that it was believed that the Allied site was the likely cause of the contamination. While it is true that the one round of tests in 2004 found that the levels had dropped in the wells north of the property, it was one test. For three decades the positive results in the wells varied wildly up and down, based on the time of year and other factors. Even a test three months later in 2004 on the Keeter well showed a spike upwards from o gross alpha to nearly half the drinking water limit. Has it spiked again since? Will it spike again next year or after the next torrential rain? We believe that council should have been presented with the historical evidence of groundwater contamination at the time they were asked to buy the property for the citizens of Boulder because even though there is admittedly less water to leach through the pond today than in the past, it could still be occurring, just at a slower rate. And lead is a very serious contaminant in any quantity. The EPA says 0.0 is the safe level for drinking water. At worst, the monitoring well below the dam should be put in and a seasonal testing program of the water wells should be put in place.

Location of Third and Pearl Material

CITY STAFF: “The Boulder Weekly and the Organizations have questioned whether the city has accurately identified the location of the Radium 226 “Third and Pearl” material from the Boulder Housing Authority’s (precursor to the Boulder Housing Partners) 1971 construction site. The city is confident that the identified location of the Third and Pearl material is accurate and that it will be covered with the previously described engineered cap during clean up. The city’s consultant did an extensive review of historic documents to identify the location of the Third and Pearl material.”

BW: We have no doubt that “the city’s consultant did an extensive review of historic documents.” We also know that such a review could not have produced a single document that makes it possible to definitively identify either of the two locations where “Third and Pearl” soil was buried. We don’t understand why staff makes it sound as though their consultant’s research allowed them to locate the disposal site conclusively; it did not. A cartoonish hand drawn map from 1976 is the closest thing to helping find a location for at least one of the two disposal pits that records show to exist. But this same map helped lead the EPA to locate the disposal pit well northwest of where the city plans to extend its cap.

Also, Boulder Weekly has repeatedly asked staff why it has never tested the area to confirm that it is, in fact, one of the disposal sites. The site that the EPA claims to be a disposal site had bore samplings that found elevated lead (over 2,000 parts at approximately 4.5 feet bgs) and some radioactivity. Yet city staff insists that the location of the EPA disposal pit is incorrect, all the while being unwilling to test to confirm that its conveniently located chosen site is correct. This is beyond suspicious and incredibly irresponsible, and yet another reckless gamble paid for with other people’s money. Should it be determined later, even though the VCUP has been signed off by the state, that the city did not properly deal with the contamination that it placed on the property in 1971, it would free the EPA to once again come back onto the property for a fourth reassessment, defeating the entire reason for the rush to finish the VCUP.

CITY STAFF: “The city’s consultant determined the exact location by using measurements from the existing buildings shown in a 1971 aerial photograph and the location of the Valmont Cemetery parking lot (not by measuring from the western edge of the tailings pond cover, as stated by the Boulder Weekly). The location identified by the Boulder Weekly is the same location identified by the city’s consultant, as shown in Figure 4 (page 79) of the VCUP. The preliminary design drawing presented in the VCUP did not illustrate the cover material covering the radium 226 pit, but the more detailed final cover design extends over the pit.”

BW: We’re glad that city staff has agreed to extend the cap to include the area we identified as a likely location for one of the pits. Still, the city’s consultant determined this pit location based on what appears to be some kind of ditch in an aerial photo from the time. This is also how BW identified the location. This is the only evidence whatsoever that the location that the city intends to cap is the site of the disposal pit. Not very scientific. The same aerial photo shows enormous amounts of soil piled that could never fit entirely into the city’s supposed disposal pit. While we agree that the ditch in the photo might be one of the two pits that public records say were used for the soil, we would never suggest spending taxpayer money to extend the cap over the area without first testing it to verify that the area contains the contaminated soil. Also, the same photo appears to show possible soil disposal in the area northwest of this location — in the area that the EPA has identified through its actual testing. And other areas also look as though they may have been involved. Once again, staff is trying to take a short cut that could end up costing taxpayers millions of dollars down the road. The idea of capping a spot based on one old aerial photo without even attempting to confirm that it is the correct spot by radiological testing is outrageous. And what about the second ditch that was used for disposal after the first one became full? Staff claim their aerial photo shows two side-by-side ditches. We have the same photo and find the claim beyond a stretch.

Council members should look at the attached photo and ask themselves if they can say with absolute certainty what is in that ditch. Would they be willing from the photo alone to bet millions of their own dollars that the all of the contaminated soil is there without running a single test? The answer is obviously “no.” Taxpayer dollars should be treated with the same respect. All of the problems for the city at Valmont Butte started with the Third and Pearl radium contaminated soils in 1971. Unless the city remediates the disposal pit identified by the EPA, confirms through testing that the area it claims is a disposal pit does, in fact, hold radium-contaminated soils, and locates the second disposal pit described in the records, then the same soil could be the city’s undoing yet again. Use of ground-penetrating radar (GPR) on the cemetery property.

CITY STAFF: “As the city has discussed with the Cemetery Association on multiple occasions, GPR is effective to locate subsurface metal objects, but is not reliable for identifying skeletal remains.”

BW: If GPR is not reliable for identifying skeletal remains, then why did Xcel use GPR to successfully locate unmarked human remains south of the cemetery property line before they were destroyed by earth-moving equipment? According to an August 2005 report by Greystone Environmental Consultants, Inc., which was hired by Xcel to study an area south of the cemetery, ground-penetrating radar and surface inspection “identified human bone and cultural features that may be associated with additional graves outside the currently fenced area of the Early Pioneer Cemetery/Valmont Historic Cemetery.” The company recommended re-fencing the area and including a buffer around the identified features, which Xcel did. One of the leading experts in the use of the technology to discover and map historic graves, University of Denver anthropology professor Lawrence Conyers, is practically in Boulder’s backyard. Another local geologist interviewed by Boulder Weekly says that GPR is not limited to locating metal objects.

Sincerely, Joel Dyer, Jefferson Dodge, Elizabeth Miller

Boulder Weekly's response to City of Boulder Memo 4-17-2012

Download engineering map here.

Download aerial photo here.

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