Concrete Batch Plants

Update on dust incident at Martin Marietta Ready Mix


Posted Aug. 5, 2019

Based on documents provided by representatives from Martin Marietta to the city and TCEQ, a more full picture of the events of July 18, 2019, is now known. On the evening of July 18, 2019, an automatic shutdown system for one of the cement silos failed to shut down a blower motor. The result was that the system continued to fill a silo with cement beyond the capacity of the silo. A pressure release value eventually activated and released the pressure along with the particulate matter. 


It is conservatively estimated that the event lasted approximately 5 hours and 15 minutes during which no more than 8,000 pounds (4 tons) of cement dust left the facility’s boundary. The facility was not operational or staffed during the event so the release continued until the system was shut down manually. Additional investigations are still ongoing and cleanup of the areas affected continues. Property owners seeking assistance with cleanup from this event are encouraged to contact Martin Marietta representatives at 972-647-3300 or mckinney@martinmarietta.com.



Posted July 20, 2019

At approximately 11:30 p.m. on July 18, 2019, the McKinney Fire Department was dispatched for a reported cloud of smoke from one of the facilities located on the east side of S.H. 5 (McDonald Street) just north of the intersection with Spur 399. No fire was found but they observed a cloud of dirt and dust being emitted from some equipment on site.


The City of McKinney is still investigating the incident and working with representatives with the Texas Commission on Environmental Quality (TCEQ). Individuals with detailed information about this incident are encouraged to contact Michael Quint, Executive Director of Development Services. Concerned residents can also contact the TCEQ to make an environmental complaint.


Due to the preliminary nature of the investigation, immediate health impacts are not known at this time. Residents are encouraged to take any health precautions that they deem appropriate.


Upon completion of its investigation, the City of McKinney will explore all enforcement options available. The city will also be requesting that the TCEQ do the same.


Statement and cleanup assistance information from Martin Marietta


Martin Marietta was distressed to learn of an apparent release of articulate matter at our McKinney Ready Mix Plant Thursday night. This site is regulated by the Texas Commission on Environmental Quality (TCEQ), which has visited the location in response to this incident. We are working with the TCEQ to determine what caused this release and will take the necessary steps to ensure it does not occur again. In the meantime, we have shut the Plant down as we investigate the release.


Additionally, we have hired companies to clean-up the release. We are committed to working with you, our neighbors, to remove the impacts of the release from your property. For those affected by the release, we are offering indoor and outdoor home cleaning, including cars, paid for by Martin Marietta.


In the coming days, members of our team will be available at our site and in your neighborhood to speak with you and answer questions you may have. At this time, we are focusing our efforts on cleaning and removing the particulate matter from your neighborhood.


We ask that residents who have been affected by this incident and would like cleaning services to contact Martin Marietta at:


Phone: 972-647-3300

Email: mckinney@martinmarietta.com


Information provided from Texas Commission on Environmental Quality (TCEQ)


Posted July 24, 2019

Although the vast majority of cement is comprised of limestone (primarily calcium carbonate), various metals are also present in cement, as noted by some citizens. However, in regard to this short-term emission event, the potential for health effects (e.g., skin, respiratory, eye irritation) stems from the physical presence and corrosive nature of the cement dust particulate matter itself rather than specific constituents. Once the dust is removed, this event is not expected to represent a long-term concern.


Posted July 22, 2019

In light of a presumed acute emission event where cement dust deposition occurred overnight on the off-site property, it should be noted that cement dust is corrosive so it is best to avoid direct skin, eye, respiratory system, or other contact with it. That is, care should be taken to prevent cement dust exposure of the skin, eyes, or respiratory system since irritation and even tissue damage could occur with sufficiently high exposure. For example, protective equipment such as safety goggles and impervious gloves/clothing/shoes can be used to help reduce the potential for significant eye or dermal exposure.


If you have come into contact with cement dust, use common sense. For example, wash skin with soap and water in the event of dermal contact, or rinse eyes thoroughly for several minutes with clean water (with any contacts removed) if eye exposure occurs, and seek timely medical attention from your doctor or other medical care provider for any health concerns (e.g., respiratory symptoms, skin or eye irritation). These recommendations are to help address this short-term concern; once the dust is removed, this event is not expected to represent a long-term concern.


Our Toxicology Section is available to speak with citizens concerned with impacts from the dust as well. They can be reached at 877-992-8370.


Frequently Asked Questions About Concrete Batch Plants

Posted July 2018

Some manufacturing operations located at State Highway 5 (McDonald Street) near Stewart Road have recently received attention from nearby residents due to concerns about various issues like noise, lighting and air quality. These operations include two concrete batch plants (TXI / Martin Marietta Ready Mix and Cowtown Redi-Mix) and a lime slurry facility (Lhoist North America of Texas). In response to citizens’ concerns, the city is actively monitoring the properties and working to gain compliance with all applicable city regulations.  


1. What is a concrete batch plant?

A concrete batch plant or batch plant is a manufacturing operation that uses equipment to combine various ingredients to form concrete.


2. What is lime slurry?

Lime slurry is used for a variety of industrial, municipal and environmental applications. In McKinney, it is commonly used to stabilize the ground underneath a roadway.


3. Why are concrete batch plants necessary?

In a rapidly growing community such as McKinney (and Collin County), the production of concrete is a critical part of construction activities. Concrete is used in sidewalks, roads, building foundations, walls for buildings, etc. Many concrete batch plant facilities operate temporarily for specific construction projects and often go unnoticed by the average citizen.


4. How long have these uses been at this location?

The area has been designated for industrial land uses since as far back as the 1964 General Development Plan (now referred to as a Comprehensive Plan) for the city. There have been manufacturing uses in this location, including concrete batch plants, since at least 1996.


5. Where are concrete batch plants allowed?

In general, temporary concrete batch plants that meet all applicable regulations are allowed to exist on a construction site in support of construction activities. However, permanent concrete batch plants are only allowed within certain industrial zoning districts as outlined in the city’s Zoning Ordinance. Zoning and rezoning requests that come before the city are reviewed and evaluated for conformance with the city’s comprehensive plan and are heard before the Planning and Zoning Commission and the City Council for consideration and action.


6. If allowed by the Zoning Ordinance, will City Council review and approve development applications for a permanent concrete batch plant?

No. Temporary concrete batch plants that meet all applicable regulations are permitted through the standard development permitting process by city staff. In order to build a permanent concrete batch plant, a site plan must first be approved. Typically, site plans that meet applicable development regulations are approved at the staff level. Staff does not have the authority to disapprove a site plan that meets all applicable regulations. If a site plan does not meet all applicable regulations, staff must forward the site plan to the Planning and Zoning Commission for action. In rare instances, a property’s zoning may require City Council approval.


7. What types of regulations apply to these types of facilities to ensure the health, safety, and general welfare of the public?

The city has regulations that govern a number of aspects of the built environment, including but not limited to noise, lighting, air quality, vehicular traffic, stormwater, landscaping, screening and the overall development of a site.


8. How does the city enforce its regulations and ordinances?

Enforcing regulations in McKinney is a partnership between city staff and the public. While staff strives to proactively monitor and enforce all applicable city regulations, due to the rapid growth and large incorporated area of McKinney, some enforcement comes about as a result of citizen-initiated concerns.


9. What can the city do about air pollution?

Air quality is primarily governed by statewide rules set forth by the Texas Commission on Environmental Quality (TCEQ). The city proactively works with the TCEQ to ensure that all applicable regulations are satisfied. Given recent concerns related to air quality raised by some McKinney citizens, the city is currently evaluating ways in which we can supplement the work that TCEQ has performed to date.


10. What is the city doing to protect residents located near permanent concrete batch plants?

The Texas Commission on Environmental Quality (TCEQ) receives many complaints statewide related to many different environmental issues. Because of the volume of complaints received, their resources are typically spread very thin, making enforcement difficult. However, the McKinney Code of Ordinances allows the city to assist the TCEQ in this process. Ensuring that businesses and operators comply with all applicable city code requirements is a priority to the city, and we are currently evaluating ways in which we can supplement the work that TCEQ has performed to date.


11. What is the city doing to control the overnight lighting of permanent concrete batch plants?

The city’s Code of Ordinances governs the lighting on all properties within the city. This governance includes capping the amount of light that can cross a property line and how light is controlled on a site. A site’s lighting is designed, installed and inspected as part of the traditional development process but old properties may have lighting in place that no longer meets current regulations. Regardless of the age of the site, city staff investigates all lighting complaints and utilizes equipment to test lighting levels. If violations are identified, then appropriate enforcement actions will be pursued in order to gain compliance with applicable regulations.