Is Extraction Using Carcinogenic, Odorous Drilling Mud at the Interchange Pad?

The odor complaints of residents living near the Interchange Pad have finally received some attention, but the most significant question remains unanswered:  Is Extraction using carcinogenic, odorous drilling mud at the Interchange Pad?  Adams County resident Barb Binder asked that question at Council on May 14 and several Broomfield residents have followed up with emails to ask if Extraction is using Gibson D822 drilling mud.  However, none have received a reply to that pressing health question five days later from the City Staff. 

During Tuesday, May 14 public comments, Barb Binder began her statement with, “I have been breathing an overwhelming odor of oil ever since drilling started there [at the Interchange Pad].”  She stated that Extraction was using Gibson D822 as a drilling mud which is known to be odorous and “incredibly toxic.”  She added, “It is time for a moratorium so you can get your ducks in a row.”  Regarding asking for the moratorium on drilling, she stated, “Maybe it is not going to help me but maybe it will help your residents going forward.”  She cited that Erie had banned the use of Gibson D822 in their renegotiated Operator Agreement with Crestone in November 2018.  (This happened after thousands of odor complaints were filed by residents living near the Pratt site in Erie.) 

Ms. Binder also displayed the Safety Data Sheet (SDS) on Gibson D822 which lists that it a carcinogen. In an April 25 email, Extraction told her that they were using “low aromatic drilling mud.”   

During the May 14 Oil and Gas Update presentation, Director of Special Initiatives Tami Yellico stated that the Colorado Oil and Gas Conservation Commission (COGCC) inspector was onsite the previous evening of May 13 and smelled the odor.  He had issued a corrective action for Extraction to respond to questions about its drilling.  Extraction responded on May 15 by stating that it would begin to use a second mud chiller and an “additional odor neutralizer called Odor-Armor from Benzaco Scientific” in addition to Ecosorb that it was already using.  Residents are concerned that this is just masking the odor while the toxic chemicals are still being dispersed through the air and are continuing to ask questions of the City.  You can write Council at or Ms. Yellico at

In response to questions from Council Member Castriotta, Assistant Director of Special Initiatives Laura Davis stated that Gibson D822 is consistently used in the industry to enable drilling in certain “geological formations.”  She stated that the COGCC was not investigating the chemicals in the drilling mud but investigating if the intermittent nature of the odors were caused by “connections of piping” and “the raising and lowering of pipes.”  She stated that the COGCC inspector said that he would talk to COGCC management if the problem had to be escalated.  

Council Member Castriotta continued at the May 14 Council meeting by stating that, “Extraction stood in these chambers and said their mud didn’t stink.”  She reiterated that Erie prohibited Crestone from using Gibson D822 in its renegotiated Operator Agreement and inquired if the City could ask Extraction to change their drilling mud.  Director of Strategic Initiatives Tami Yellico replied, “We will talk to them about that.” 

Ms. Yellico had stated that they were meeting the next day on May 15 but no information has been forthcoming. In response to an email inquiry on Thursday from a resident (the author), Ms. Yellico stated, “Broomfield staff is of course monitoring the outcome of this COGCC corrective action and will add requirements in the corrective action to our inspection protocols.”  The resident’s email also asked for the Staff to post a current status on the Oil and Gas Update Webpage but there is none there.   At least one Council Member replied in a subsequent email that it was understood that the Staff would ask Extraction if an allowable mud is being used.      

The Operator Agreement between Extraction and the City states:

“48. Odor. Odor emitting from Well Sites must be controlled. Operator to prevent odors from  oil and gas operations by proactively addressing and, to the extent possible, resolving complaints filed by impacted members of the community, in coordination with City public health staff. Operator must use a filtration system or additives to the drilling and fracturing fluids to minimize odors. Operator is prohibited from masking odors from any oil and gas facility site by using masking fragrances.”

Residents are concerned that this is just masking the odor while the toxic chemicals are still being dispersed through the air.