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Rainbow Open Space: From Protected Land to a Class III Compost Facility?


Yellow Scene Magazine is doing a 3-part series on Boulder County’s Compost facility at Open Space Rainbow Nursery 

This is PART 1. 

Part 2: Rainbow Open Space Composting Facility: Origins, RCAB, Minutiae, and Staff Errors

Screenshot, Boulder County Community Planning & Permitting Department

Boulder County has proposed building a class III composting facility on a roughly 40 acre plot, once home to the former Rainbow Nursery, and currently the Rainbow Open Space, on the eastern edge of the county. The new project hopes to help the county work towards its Zero Waste Action Plan but has been met with increasing scrutiny in recent weeks.

There are many benefits to having an in-county composting facility, such as cutting down on waste transport emissions and costs, diverting organic waste away from landfills, and achieving county sustainability initiative goals, the new project has faced backlash by concerned residents as the plans came to light. With two active lawsuits, local residents are voicing their contempt for the county’s plans and the negative impacts a facility of this scale can have on the area. Major potential issues associated with the new facility may include odor, property devaluation, potential groundwater contamination, the use of biosolids, destructive environmental impacts, and traffic increases along US-287, and have all been highlighted as concerns the county needs to address . 

Fueling the fire, the county, prior to purchasing the land, held a Conservation Easement (CE) on the property. CEs provide protection against development of property deemed of significant value and are meant to exist in ‘perpetuity’. The property is designated significant agricultural land of national importance. Any private citizen would be restricted by the CE but because the ownership of the CE and the property merged under one owner (the county), the Easement was extinguished and the restrictions were removed due to the doctrine of merger. Professor Nancy Mclaughlin, Law Professor at the University of Utah, says “relying on the doctrine of merger to extinguish the easement is entirely inappropriate.” Moreover, the county used Open Space funds to purchase the property, acknowledging in a closing memo that they were considering using the property as part of the county’s zero waste initiative. 

At the time of writing this, the county has placed a hold on the project while they reassess to ensure that the special use review process goes according to plan. Andrew Barth, Communications Specialist at Boulder County Public Works, the contact listed on the official Boulder County Compost Facility website, explains, “the team from public works and our consultants are diving back into the plans right now to refine … because we don’t want to go through special use review and then have them say no.” Asked what caused the hold, Barth says, “it’s just making sure we really do what we’re saying, we can build, will mitigate all the environmental concerns that everybody’s having.”

Programs of this scale have specific requirements as to how they must be communicated to the public prior to their approval by the Board of Commissioners. If the special use review is continued and the hold is released, there will be opportunities for the public to join the conversation as the local government goes through the motions to potentially approve the project. Local residents and all of the Trustees and the Mayor for the Town of Erie have expressed discontent with how the project has been publicly vetted. Local resident and neighbor to the property in question, Nancy Davis, told Yellow Scene that only twelve people were notified of the project at first. Barth refutes this claim, stating, “it was actually, I think, twenty-two properties were informed directly and invited to a meeting on site.” Erie Trustee, Brandon Bell, puts it plainly that “the lack of transparency on this is sickening,” and Erie Trustee Sara Loflin said, “It is clear to me that there has not been substantial outreach or public process on the part of the county.” 

According to Barth, the project was still “in the design phase where we’re trying to ensure that it could happen” and that the four public hearings would occur down the line once the project has moved to the Boulder County Commissioners and also the Parks & Open Space Advisory Committee.

Although all Erie Trustees and the Mayor have expressed their frustrations in light of the public outcry at the February 9th, 2021 meeting, an email chain acquired by Yellow Scene shows that, on behalf of the Town of Erie, Deborah Bachelder, the Planning Manager/Deputy Director at Planning and Development, sent a memo to Boulder County Community Planning & Permitting acknowledging the benefits of the new facility. In the memo were three conditions for the county to address: commit to an odor study if complaints occur, mitigation of materials being blown off-site due to high winds, and additional controls if traffic increases exceeding 5-10% depending on the road.

Although this project only came to fruition in the past year, the idea for a composting facility has long been in the works as a beneficial in-county opportunity to help advance sustainability initiatives. Former Mayor and current Executive Director of Eco-Cycle Suzanne Jones explains that, “having a community owned compost facility in Boulder County is something that’s been discussed for over 15 years.” Boulder County currently takes its organic waste to the A1 Organics facility in Keenesburg, whose Chief Technical Officer, Bob Yost, has worked as a paid consultant for PEH Architects to help design the new facility. Removing the need to bring waste to Keenesburg would cut down on truck emissions and associated costs thereby allowing compost to become more affordable. Furthermore, the facility would aid in the slowing of landfill expansion by diverting organic waste to be reused as compost, however Boulder County already brings much of its organic waste to the A1 Organics facility in Keenesburg.

Compost is a nutrient-rich substance that would allow residents and farmers alike access to valuable soil that allows for carbon sequestration and improves crop health. CDOT is also a large user of compost for various infrastructure developments. Suzanne Jones says it’s “a really wonderful vision that’s been in the works for many years and would help all of the cities in the county reach their goals around climate zero waste and regenerative ag. (agriculture)” 

Residents are concerned, however, that a facility of this scale would increase traffic in the surrounding area and on US-287, commonly regarded as both a busy and accident prone roadway. Barth clarified that, “we really didn’t … find it was gonna create a massive addition to traffic on 287… those trucks are already on those roads.” But residents have raised the concern that the facility will accommodate around 70 active companies and that although outbound truck traffic may decrease, traffic coming into the county is bound to increase. In an email acquired by Yellow Scene, CDOT’s Tim Bilobran questions the traffic report conducted by Fox Tuttle, questioning the projection of, “37 real truck trips per day, which seems very low to me if potentially over 70 companies will be using this location and drawing vehicles from as far away as Keenesburg.” Another concern is the increase in production that the facility may experience over the next two decades. Slanted to produce 100,000,000 pounds of compost each year, the facility may increase those numbers by another 25 – 100 million pounds. Residents want to be assured that the county has put enough work into knowing just how much traffic will increase in the surrounding area.

Screenshot, Boulder County Community Planning & Permitting Department Boulder County Compost Facility, PEH Architects, A1 Organics, SCS Engineering

At this time, it has not yet been decided who will run the facility. Barth mentioned that when the time is right the county will decide whether to run the facility or open it up to a bidding process. A1 Organics is certainly a strong contender, or at least has an interest. When asked why he would help to build a facility that would take business from A1 Organics, Bob Yost responded with, “I’d rather do it that way than be given the opportunity to bid on operating it and [it] be designed poorly.” 

Another potential contender mentioned by residents is Ecocycle. Suzanne Jones, when asked, said, “It seems much more likely that an expert compost facility operator like A1 Organic[s], who is helping them on the design build, would be a likely candidate for operating the facility.”



Boulder County’s proposed compost facility will be a class III facility, which means it will also be allowed to accept Class A Biosolids for composting. Whether the facility will process them from the getgo is to be determined, Barth says. “We’re designing the facility to accept them, whether or not they would be accepted right away would be a part of the operations plan.” It’ll largely be up to who runs the facility.

Biosolids, or treated sewage sludge, is the product of local wastewater treatment plants and defined by the U.S. Environmental Protection Agency (EPA) as “nutrient-rich organic materials resulting from the treatment of domestic sewage in a treatment facility… that can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth.” Boulder County has at least seven different wastewater facilities. Using biosolids at the proposed facility will allow Boulder County (and others) to reuse their sewage sludge for compost. According to the study, “Pathogens in Biosolids” (2006), biosolids have been shown to “improve the productivity of soils or enhance revegetation of disturbed ecosystems,” when applied to farmland. 

Biosolids are commonly designated as Class A or Class B, depending on the amount of pathogens removed. According to the EPA, federal regulation “40 CFR Part 503 treatment processes for Class A biosolids eliminate pathogens, including viruses. Generally, pathogens may exist when requirements are met under 40 CFR Part 503 for Class B biosolids.” The facility will potentially be accepting Class A biosolids.

Biosolids have been a point of controversy due to the potential for pathogens to remain even after they’ve been treated at wastewater facilities. One example, according to the City of Boulder Water Resource Recovery Facility, is that they are “not equipped to completely remove all of the chemicals and compounds found in various medications” if they were to be flushed down the toilet. Pathogens such as bacteria, viruses, protozoa, and helminths (parasites) can lead to illness, but according to a study titled, “Human Health Risks From Biosolids Applied to Land” (2006) “Class A biosolids are not intended to have detectable concentrations of pathogens.” The study goes on to conclude that “there is no scientifically documented evidence of the public having health problems from pathogens in biosolids, knowledge gaps and outdated operational criteria allow for doubts and concerns about the risk to the public from such organisms.” 

Biosolids are nutrient rich and contain nitrogen and phosphorus and small amounts of potassium. These nutrients are essential for crop growth. Other concerns about biosolids include potential runoff and leaching of nitrate, soluble and sediment bound phosphate in runoff and erosion, and a build up of soil potassium levels due to continued annual application.

The United States is a major user of biosolids for farming; the only areas where biosolids are federally banned are on certified organic farms. Some states have placed restrictions on their use and the country of Switzerland has banned them outright out of concern that any chemical soil contamination impairs soil fertility.



Odors can be lovely, but oftentimes they are not. With compost and biosolids come specifically offensive odors, and for local residents and specifically those living in Erie, it’s an unwelcome thought. Offensive odors are caused by the decomposition of material producing ammonia and the sulphuric smell often associated with biosolids. At the February 9th Erie Board of Trustees meeting, to which Boulder County was invited but declined, residents voiced concerns specifically about potential odors that may occur at the facility, especially if biosolids are used. 

Concern surrounds the potential for particulates to travel and be inhaled by surrounding neighbors. In a study conducted by the Canadian National Collaborating Centre for Environmental Health, titled “Odour from a Compost Facility” (2018), it’s explained that aerobic decomposition will emit bioaerosols and microbial volatile organic compounds (VOCs). The amount of bioaerosols and distance travelled will be largely dependent on the size and technology of the facility as well as the local winds but have been detected both upwind and downwind from composting facilities. The study says that, “microbial VOCs are considered to be the main source of odor from compost facilities as many of these compounds can be smelled at extremely small concentrations, below what is known to be harmful to human health.” In regards to health impacts to nearby residents of the facilities they reviewed, “exposure to VOCs has the potential to induce acute toxicological effects such as inflammatory and immune effects, as well as sensory irritation in the eye, nose, or throat.” They do mention that although “VOCs are odorous even at very low concentrations, they are not considered to be the primary cause of health symptoms for residents near to composting facilities.”

Among the many types of composting technology, the county has chosen to use aerated static pile composting, also known as in-vessel, that is shown to reduce odor by 90-95%. In-vessel technology is more expensive than other methods but it provides far greater control over the compost if properly managed. Bob Yost, A1 Organics, doesn’t think the odors will be much of an issue so long as the facility is properly managed.”This is an enclosed composting system, I don’t foresee, properly operated I think that there’ll be limited if any odor issues with the facility.” Nearby residents continue to be concerned about what that 5-10% could equate to. Some have even threatened to sell their properties and leave if the facility is built. 


Water contamination 

The Rainbow Open Space property’s eastern border follows along the Leggett ditch, a local irrigation canal that serves other surrounding properties. According to the ecological assessment done by Birch Ecology, groundwater sits at roughly five feet below the surface, there’s a small pond on the property, and wetlands border the north- and southeastern borders. Concerns have been raised that particulates from the facility could potentially contaminate the surface and groundwater either by being blown due to high winds or on the off chance that one of the in-vessel structures fractures and leaks water. Another concern has been that the Leggett ditch could be affected during construction or that groundwater could be exposed.

In a letter acquired by YS sent by the Leggett Ditch and Reservoir Company (the Company) to Jean Ott, Community Planning & Permitting, the Company asserts that they strongly oppose the new facility because “high water and rain events would result in a serious risk that storm flows and contaminants would be discharged into the ditch.” They go on to say that “ground water contamination including E.Coli and Salmonella is likely based on the hydrology information available” and that “the proposed Compost Facility would alter the natural drainage into the Leggett ditch from the property proposed to be developed.” This would “modify the manner and quantity of storm water discharges into the ditch.” 

Man made irrigation pond, wetlands. Via PEH Special Use Review

Another document acquired by YS through the public record are comments provided by Kim Hutton, Water Resources Manager at City of Boulder Public Works, and Bethany A. Collins, Real Estate Supervisor, City of Boulder Open Space and Mountain Parks Department. After acknowledging the significant benefits that the facility could provide, the letter goes on to say, “the City of Boulder has concerns regarding the potential impacts to water quality in the Leggett Ditch and Panama Reservoir posed by the construction and operation of the composting facility.” They continue that, “it is imperative to the City’s interests that appropriate conditions are put on the construction and operation of the facility to ensure that water quality in the Leggett Ditch and Panama Reservoir will not be degraded, as such water will be used for municipal and irrigation purposes.” Representing the City of Boulder they offer nine comments of recommendation, including: ensure that the surface and groundwater is not contaminated, that pre-construction well sample data be collected, and that high wind assessments are completed to prevent debris from blowing off-site.


Ecological Assessment

An Ecological Assessment & Wildlife Impact Report was conducted by Birch Ecology, located in Lyons, CO. The assessment is a thorough depiction of the existing conditions of the property as well as an assessment of what protected flora and fauna are or may be found on the property. Local residents have voiced concern that the assessment simply wasn’t robust enough and that true field studies must be conducted. In an interview with Delia Malone, Colorado Ecologist and chair of the Wildlife Committee of the Sierra Club’s Rocky Mountain Chapter, Malone believes that “the ecological resources addressed in this report are incomplete and thus are an inaccurate representation of the ecological resources of the area.” One threatened species that is specifically mentioned in the report is the Preble’s Meadow Jumping Mouse (PMJM). According to the Birch Ecology assessment, the property does not contain a suitable habitat for the PMJM. Malone says that the recon Birch Ecology conducted was nothing more than a walk through, “there’s no scientific rigor” and that “given the near proximity to other [PMJM] populations, what should occur are live-trapping surveys.” 

According to Andrew Barth, “What we found is that mostly, it’s just birds out in that canopy out there.” For Malone, even “just birds” are enough to want to protect the property. Malone explains that, “There has been an exponential decline [in birds]… about 2.9 billion less birds today in North America then we had in 1970” and blames the continued “conversion of natural habitat to all sorts of development”. When “this area [was designated] as open space [CE] 30 years ago, that was visionary. It’s not in pristine shape… but it still provides important habitat for wildlife, habitat that is being converted and eaten up by human development.” When asked what else she would recommend the county do before deciding to build the facility, Malone pointed towards breeding bird surveys (during nesting season), more vegetation surveys, and a thorough understanding of the edge effect (i.e. how far the facility could impact surrounding areas, especially the wetlands and other habitats nearby).

Wetlands PEH Special Use Review

Conservation easements 

In 1994, the land owners at the time, Barney C. and Cheryn H. Barnett, entered into an agreement with the county for a Conservation Easement (CE). CE’s are generally considered to protect properties in perpetuity (i.e. forever). Their use has grown exponentially in recent decades as a way to protect land from development and are often advertised as doing just that. According to Nancy Mclaughlin, University of Utah, the issue with Rainbow Nursery is that Boulder County is setting a precedent that whenever land is purchased by the same entity that owns the CE, the CE and all its protections are automatically extinguished without any sort of process. 

Yellow Scene acquired the original deed between the Barnetts and the county in which the purpose of the CE is defined:

It is the purpose of this Easement to preserve and protect in perpetuity the significant agricultural attributes of the property, its continued agricultural use and its open space values.

Nowadays, CEs tend to have a section on how the easement may be extinguished, something that the 1994 CE did not include. A sample template of a CE that Boulder County would use today includes a section on extinguishment. The county asserts that what they are doing is legal, but even then, residents wonder if it should be. In the passed 2019 Colorado HB19-1264, any land with a CE that was used for a tax credit may not be extinguished by merging ownership. It’s not certain whether the Rainbow Nursery property was ever claimed as a tax credit. When asked why the new bill was so specific to tax credits, Mclaughlin says recent tax related abuses could have focused the bill, adding that it’s important to consider the potential for future amendments. “If people are upset about it, maybe they can convince the Colorado Legislature to tighten up the language about the merger.” 

The concept behind the Merger doctrine is that there is no need for the owner of a property to hold a CE upon themselves because they are the ones that want the easement. Why this should explain the ability for the county to build a composting facility on once protected land is not clear. Mclaughlin explains that although the ownership is the same, the two entities also need to be held in the same right. Because a CE is so specific and is meant to benefit the public, it may not be considered to be held in the same right as open space land. In the deed it states, “Whereas the grantee recognizes the public benefit to be served by such a preservation” and “Whereas, the Grantor desires to sell an interest in the Property to the Grantee in order to assure its preservation in perpetuity,” The Grantor being the Barnetts, the Grantee being the County. It is the purpose of the CE to protect the land indefinitely at the benefit of the public and according to Mclaughlin, “a conservation easement does not cease to serve any purpose when the holder of the easement acquires the underlying land. The easement continues to provide the significant benefits to the public for which it was created.”

Mclaughlin says the precedent shouldn’t be to simply extinguish CEs and that the County has other methods at their disposal, such as the option of condemnation. That would cause the County to be held accountable to explain their reasoning to take currently designated open space land and build a composting facility upon it. According to Mclaughlin, as well as many residents, CEs are meant to offer protection from development on one’s land including from the government and should require an extraordinary process to remove them. Mclaughlin wonders, “why did they say the CE was perpetual?”. If they wanted a way to get rid of the easement when it was signed in 1994, “why didn’t they draft the easement to give them the right to terminate”?


Where we are

Some residents are worried that, because they’re building a compost facility, many of the real concerns are falling to the wayside, that it’s almost taboo to speak negatively about a facility that should be inherently good. What residents want are the facts and the truth, and Boulder County has a duty to provide that and to ensure that all residents are taken care of, and taken into account, not just the greater good or the 12 (or 22) properties they think are important. It also doesn’t help that local groups such as the Coalition for Local Compost Climate Action, which is associated with Eco-Cycle and run by Dan Matsch, Manager at Eco-Cycle, is sharing information that simply isn’t accurate. In the FAQ question on the coalition webpage, it reads, [the property] “was never intended for public recreation or officially-designated open space.” In an interview with Janis Whisman, Real Estate Division Manager for Boulder County Parks & Open Space, she asserts, “I want to make sure that you understand that this property still is open space and it will remain open space until that process occurs.” By process, Whisman is referring to the need for the county to reimburse the Open Space tax fund via the Sustainability Tax fund if the facility were to be built.

As to what will occur at the former Rainbow Nursery, only time will tell, but both support and backlash are growing as the project becomes increasingly publicized. The concerns are real, the benefits are real, the potential harms are real, and the public process needs to exist for all to partake. Once the county continues the special use review, it is required that they notify the public and that public hearings occur. If the local government functions as it should, it will take all feedback into consideration to assure the public that the government is doing its job correctly and that it is serving its constituents to the level and competency, and transparency, that they deserve.


This is part 1 of a 3 part series by Laurenz Busch for Yellow Scene Magazine. Follow along by liking Yellow Scene.