A history of environmental leadership

At ROCKWOOL, we have an unbreakable commitment to meet and exceed the environmental protection standards set by governments and regulators wherever we operate globally. West Virginia is no exception. Our facility is in full compliance with local, state, and federal laws and regulations.

Responsible environmental stewardship has been one of our core values for more than 80 years and we continually strive to do better in terms of reducing the environmental impact of our manufacturing activities.

This is realized in practice through the robust environmental management systems that we have in place at each of our manufacturing facilities and our investments in state-of-the-art abatement technologies when building new production facilities, such as the one in Ranson, as well as when retrofitting existing facilities.

Don't have time to read the full page right now? No problem. For your convenience you can download a PDF version of our Environment Fact Sheet and get the information you need.

Protecting the air quality in Jefferson County

For decades, we have successfully operated multiple manufacturing facilities around the world, many situated near schools, neighborhoods, businesses, recreational facilities, vineyards, and even national parks.

We truly believe that we can achieve the same outcome in Ranson. We are minimizing the environmental impact of our operations through the implementation of our most advanced emission-control technology developed to date.

In West Virginia, our permitted emissions will be well within the limits set by the U.S. Environmental Protection Agency (EPA), West Virginia Department of Environmental Protection (WV DEP), and in accordance with the Federal Clean Air Act.

Strict emissions limits are specifically designed to safeguard sensitive populations including children, the elderly, and asthmatics. We will also ensure full compliance with the MACT (Maximum Achievable Control Technology) standards, most recently updated in 2015 and in whose development the Sierra Club played a significant role.

Research and analysis from the U.S. Environmental Protection Agency on National Ambient Air Quality Standards (NAAQS) and Maximum Achievable Control Technology (MACT) standards support the determination that the ROCKWOOL facility in Ranson will have no negative consequences in Jefferson County or in neighboring counties such as Loudoun, VA. Additionally, these stringent standards are designed to protect the health of sensitive populations like children, asthmatics, and the elderly under worst-case scenarios.

Air quality dispersion modeling has been carried out for the main emissions (PM10, PM2.5, NOx, SO2). On top of that, we brought in ERM as a third-party environmental consultancy to conduct a thorough assessment in the proximity of the plant for formaldehyde, methanol, and phenol. The results show that in all cases, maximum contribution based on worst-case scenarios meet strict chemical substance limits including 1/10th the allowable limit for formaldehyde, 1/100th for phenol, and 1/1000th for methanol).* 

And as expected, now that our Ranson plant is up and running, actual emissions are significantly below the permitted levels.

*West Virginia does not regulate formaldehyde, phenol, or methanol emissions. Virginia was selected due to the close proximity to our Ranson facility.

Locally, the WVDEP re-affirmed the above after issuing the air permit to ROCKWOOL, noting in a statement dated September 18, 2018, that the “air permit approved by WVDEP met strict state and federal standards that are protective of human health and the environment.”

The “Wet Electrostatic Precipitator” (WESP) technology that has been installed in Ranson, uses electricity in a wet environment to electrically charge and collect particles, reducing particulate matter by 95-99 percent. This system is considered Best Available Control Technology (BACT) for PM 2.5 (particulate matter 2.5 microns).

Additional abatement (emissions minimizing) technologies reduce the concentration of volatile organic compounds (VOCs) and oxides of nitrogen (NOx) to a level defined as “insignificant” by the National Ambient Air Quality Standard (NAAQS).

Even while meeting and exceeding environmental requirements, we also understand that some residents have concerns about the facility’s potential impact on local air quality. To provide additional reassurance regarding the facility’s environmental safety, the company fully funded two local air monitoring stations that monitored air quality from around one year before the expected start of operations through to June 30, 2023. 

Taking this step was not a standard procedure, but we did so to provide the community with independent, publicly-available data to track air quality – notwithstanding our 80+ years of experience operating in communities with schools, homes, hospitals, and areas of natural beauty nearby. 

In agreement with the Jefferson County Board of Education, a third-party environmental consulting firm – Environmental Resources Management (ERM) – installed, operated and maintained the air monitoring equipment as well as provided the monitoring data for the public. ERM identified the two locations for the air monitors – North Jefferson and TA Lowery Elementary Schools – based on EPA siting criteria, the location of sensitive receptors (e.g., children) in proximity of the facility, local wind patterns, and an air quality dispersion model analysis. 

Through the air monitoring program, community members have access to publicly available data to track air quality levels of fine particulate matter (PM2.5), formaldehyde, nitrogen dioxide (NO2), and sulfur dioxide (SO2). The monitors measured air quality that is affected by all emitting sources, including the ROCKWOOL facility when it became operational.  

Quarterly Summary Reports

These quarterly reports provide a summary with statistics on the overall conditions during a three-month period, and beginning in year two of the ambient air quality monitoring program, the reports contain data for completing a comparison against the same period in the previous year.





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Flechtingen achieved clean air resort status in 1999 with ROCKWOOL factory just a half mile from the town.
We’re about 300 meters from the factory… There’s no noise or smell or anything else from the factory because the environmental conditions and equipment are so state-of-the-art.

Berndt Gabriel

Resident of Flechtingen
Based on all available information that we have gathered and that we have reviewed, we see no threat to the health of our citizens and no threat to our environment.

Austin Caperton

WVDEP Cabinet Secretary
Download the DEP letter

Preventing groundwater contamination

We have ambitious goals to reduce water usage across our operations as part of the commitment we’ve made to the United Nations Sustainable Development Goals (SDGs) and are investing in research and development to uncover even more efficient technologies.

The facility in Ranson operates using a closed-loop production process water system which means it’s designed to prevent the contamination of soil and groundwater. Once water enters the closed-loop production process, it stays in. The production process water is continually recycled and reused, and no production process water is discharged into the county’s waterways, sewer systems or the groundwater sources. In fact, the only water we discharge into the sewer system is from sinks, toilets, and showers, and residual water from the reverse osmosis treatment processes.

As part of our efforts to reduce water consumption, this new facility uses rainwater, collected in secure on-site basins (ponds), as the primary source of water in the production process. Total water consumption will not exceed 125,000 gallons per day. In cases when rainwater is not sufficient, our water supply will be supplemented by the local public water utility. For a sense of perspective, the local aquifer replenishes at a rate of approximately 91 million gallons per day.

The rainwater collection ponds have both been designed and developed with sufficient capacity to withstand a 100-year storm event. In addition, the rainwater collection pond shown to the right of our facility in the image below has been engineered by ROCKWOOL with an additional 250 percent storage capacity to provide a greater margin of environmental safety to prevent flooding or overflow from excess rainfall. The second on-site pond is connected to a controlled overflow area where it is permitted to discharge excess collected rainwater in compliance with the West Virginia Multi-Sector Permit.

Building on karst geology has been taken into consideration in the design of this manufacturing site. The specific design elements that contribute to ensuring the protection of the karst geology include:

  • The production process water is in a closed-loop (some will naturally evaporate). 
  • Rainwater from areas outside production and from raw material storage areas is collected and used in the production process.
  • Storage tanks are in secondary containment and both the tanks, as well as the pipes connecting them, are above ground to enable close monitoring of the system. 

Several additional steps are being taken to prevent any contamination – most notably that special tank loading and unloading areas will capture and manage any incidental drips, and the binder is stored under a closed roof in above-ground storage tanks. 

Drinking water we take in from the utility water supply is purified for use in the industrial process by removing lime and other minerals, and then the residual is discharged into the sewer system. The discharged wastewater contains a similar mineral makeup to what’s in the utility water supply albeit in greater concentrations (ca. 4x). The maximum volume of residual water from the purification process that will go to the Charles Town Waste Water Treatment Plant (CTWWTP) is 14,900 gallons per day (GPD).

The visual below shows how we recycle water in our production process and utilize rainwater capture as part of a process that avoids production process wastewater discharges into any waterways, sewer systems or the ground. 

Ensuring the site was safe for construction

Following extensive sampling of the former Jefferson Orchards site which revealed elevated concentrations of pesticides in the soil, ROCKWOOL entered the West Virginia Department of Environmental Protection (WV DEP) Voluntary Remediation Program to properly restore the contaminated soil. We then excavated and properly disposed of the polluted soil, and secured approval for industrial use from the WV DEP.

Visit the WV DEP ROCKWOOL page for more information

ROCKWOOL is using the best practices available to minimize any negative effect on the environment and the company continues to work toward improving its processes.

Patsy Noland

Commissioner, JCC

Reducing noise levels during operations

Under the local noise ordinance, the general requirement is to not exceed 65dB (equal to the average volume of conversation in a school classroom) for more than 30 minutes. The facility will not exceed these permitted levels as outlined in the Jefferson County Commission (JCC) Noise Ordinance Policy.

During operations, our experiences from other factories that we operate show that we do not anticipate levels above 50 dB at our property line, which is equivalent to a quiet suburb or a conversation at home.

At ROCKWOOL, we strive to maintain strong relationships with our neighbors through open communication and have accomplished that with our factories in North America and around the world. We take complaints seriously, investigate and take corrective actions.

Since it began operations in 2014, our sister facility in Marshall County, Mississippi has received zero noise complaints. ROCKWOOL uses much of the same technology that has achieved those results, at our Ranson, West Virginia location.



1EPA Jefferson County Inventory, 2014 (data published in July of 2018)

2Phenol is not included in the EPA database but does appear in our permit.

3Jefferson County Development Authority - Tourism

We can co-exist with an environmentally-conscious local community and ensure industry, agriculture, tourism, and trade.

Marco Boi

Production Operations Director, ROCKWOOL
See the full Spirit article



Who is ROCKWOOL and what is stone wool insulation?

Founded as a family business, ROCKWOOL has always been committed to strengthening the communities of which we are a part. Today, we are the world’s leading manufacturer of stone wool insulation. Find out about our company history, North American presence, and leadership in the field of fire safety.


Community and Economic Impact

We seek to make a positive impact in the City of Ranson and more broadly in Jefferson County, West Virginia.

By building our state-of-the-art manufacturing facility in Ranson, we are committing to making a long-term and positive impact on the economy of Jefferson County. The $218 million investment includes $64 million in payroll and $4 million in taxes over the first 10 years, in addition to the community support we have already started to provide through partnerships with local organizations.


Jobs Opportunities

Manufacturing jobs and employment coming to Jefferson County, WV.

We are proud to be bringing 150 new manufacturing jobs to Ranson that will provide local workers the opportunity to build meaningful careers in manufacturing a product that is used worldwide to create safe and more sustainable living environments. At ROCKWOOL, we offer employees an attractive benefits package, investments in learning and development, and a supportive workplace culture.


Construction and Permitting

We're driving investment in infrastructure to attract more business and development for the years to come.

All permits that have been obtained to date for the Ranson facility have been done in accordance with local, state, and federal laws and regulations. We’ve also outlined the site selection process, progress of the development project, and safety procedures that are in place during the construction process.



At ROCKWOOL, sustainability is always top of mind.

While manufacturing any product requires using resources, we are focused on ensuring our products leave the smallest footprint possible during production while delivering the biggest benefit during their use. To accomplish this, we have committed to several UN Sustainable Development Goals and are proud to say that during the lifetime of its use, the building insulation we sold in 2018 will save 100 times the carbon emitted in its production.


Factory Operations and Production

Interested in how the day-to-day operations of our facilities and how our stone wool insulation is made?

ROCKWOOL’s new manufacturing facility will produce stone wool insulation for residential, commercial, and industrial uses. Stone wool is a natural product made mostly from volcanic rocks, which are supplemented with recycled mineral wool and slag from the steel industry during production. Get an inside look at our facilities and how insulation is made.

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