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Public Citizen Urges Texas Legislature to Rein in Aggregate Pollution

Concrete batch plants, excavation operations threaten Texans' health and safety

By Adrian Shelley

October 30, 2020

To the members of the House Committee on Aggregate Production Operations, Interim Study.

Re: Aggregate Production Operations best management practices

Dear Chairman Wilson and members of the committee:

Public Citizen appreciates the opportunity to deliver these written comments. For these comments I draw upon years of advocacy and experience with the aggregate industry, particularly concrete batch plants in the Houston area. These comments reference comments by the following people who joined Chair Wilson for his Sept. 29, 2020 APO town hall:1

  • Jill Shackleford, former APO Owner/Operator.
  • Carcy and Cleve Clinton, owners of the Houston Clinton Company.
    I have indicated when one of these individuals specifically endorsed a given strategy by placing their initials in parentheses after that strategy (e.g. “Covered conveyors (JS) (CC)”).Due to space limitations, I am restricting my comments to discussion of best management practices. You can view slides from a presentation I gave to Chair Wilson’s Oct. 1 town hall at tinyurl.com/APOSlides.I look forward to discussing these issues throughout the legislative session and can be contacted for further comment at ashelley@citizen.org, 713-702-8063.


    Route optimization can limit travel distance and exposure to residential areas (JS). Ms. Shackleford developed recommendations for truck routes in cooperation with her advisory council. Her facility worked with local stakeholders and the school district and agreed to hold truck traffic while school zone lights were flashing. Ms. Shackleford indicated that this strategy did not affect production rates and was well received. Ms. Shackleford also recommended a facility install appropriate turn lanes and road improvements, especially for facilities located on a highway. The Houston Clinton Company also employs setbacks from highways at its operation.

    Ms. Shackleford said that although other companies might argue that holding trucks at certain times might affect their bottom line, she believed it would be hard to compare that expense to that of a highway accident. Other commenters during Chair Wilson’s town halls even cited deaths resulting from collisions with commercial vehicles from APO operations.


    Vehicles should have designated locations for all activities. Onsite trucks should have speed limits (JS). Speed limits should be 10 mph on paved roads and 5 mph on unpaved roads. Vehicles should be parked and equipment maintained in designated locations to help locate and contain spills and leaks.

    1 Available online at https://www.facebook.com/1652344371711700/videos/644354586508821.

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Employ onsite mobile fuel service truck or an onsite fueling station (JS). An onsite fuel containment center can optimize vehicle operation and contain or prevent fuel spills (JS).

Vehicles hauling loose material should be covered. Wheels should be washed when leaving facility. The tire wash station should be located just inside the facility gate (JS).

Noise is reduced by replacing backup beeping alarms with white noise alarms (JS).

Roads and Process Areas

All roads and process areas should be paved. Public Citizen supported HB 4422 (86R) by Chair Wilson, which would have required internal roads to be paved at all aggregate operations and concrete plants. Paved haul roads are more effective than dirt roads employing dust suppression (JS). At quarries, haul roads should be paved all the way to the pit (JS).

Vacuum sweepers should be used on all paved areas; this can avoid road traffic creating mud and leaving material on roads. Alternatively, wet dust suppression (misting) should be required on all roads, all paved areas, and all working areas. Road edges and pathways should be dampened and hand swept. Road spills should be cleaned immediately to minimize vehicle entrainment. Haul roads should be wide (JS).

Where allowed, unpaved process areas can employ chlorides or other dust control chemicals.

Delivery and Loading Design and Controls

Delivery procedures to minimize dust should be developed and clearly posted for the benefit of delivery drivers. Off-loading procedures should be developed and clearly posted. Deliveries of dusty materials should be sprayed with water.

Truck loading bays should be completely enclosed or at least have a roof. Loading bays should employ dust control equipment. Drive-over hoppers make unloading neater and more efficient. Dust should be limited during loading with procedures including: loading rate limits (slower rates reduce dust) and loading sequence controls.

Transfer points should be covered or located underground.


Conveyor belts should be covered (JS)(CC) or completely enclosed. Conveyor belts should be equipped with belt cleaners. Conveyor drop points should employ misters for wet dust suppression (JS).

Conveyor belts can be flipped for their return trip so that the top of the belt during transportation remains on top for the return trip (CC). This minimizes dust from the belt’s movement during the return trip.


Aggregate bunkers can be located underground to minimize emissions. Aggregate stockpiles should be enclosed in bins, with the height of the enclosed stockpiles never exceeding the height of the bins. Stockpiles should be shielded from wind if not stored in bins.

The following control equipment will minimize emissions from stockpiles: wet dust suppression by sprinkling both coarse and lightweight aggregate stockpiles, bin storage or

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enclosed bins, wind shields, hoardings (high temporary fences) and sheeting to prevent migration.

Wind Controls

Wind breaks can reduce wind velocity and the amount of suspended particles, these include wind fences, tarp curtains, hay bales, crate walls, or sediment wants (JS citing U.S. EPA, 1992).

To control blowing soil wind barriers are placed at intervals of 15 times their height at right angles to prevailing currents (JS).


Current law includes a 440-yard setback from residences and certain sensitive land uses for concrete crushers.2 We believe at a minimum that this existing setback should be applied to all APO facilities. We further recommend increasing to at least 880 yards the setback between these uses and all aggregate production operations, concrete crushers, and concrete batch plants. Legislation that we supported to this end last session (86R) included:

  • SB 208 (Campbell)/ HB 3817 (Kacal). Doubles the setback requirement from 440 yards to 880 yards for all concrete crushing facilities and all concrete batch plants that apply for the “enhanced controls” permit.
  • HB 4247 (Wilson). Doubling the setback for rock and concrete crushers to 880 yards andadding hospitals to the setback list.•

    Carcy Clinton was proud to point out that the quarry face of his operation was 1.5 miles from the nearest residence. This distance illustrates the benefit of setbacks greater than those provided under current law. The Houston Clinton Compnay also employs highway setbacks (CC).

    Vegetative Cover

    Vegetative cover can minimize emissions on non-paved plant grounds. Vegetative cover can include preservation of native plants, trees, and shrubs (JS described this as an “easy” strategy to control dust and runoff).

    Tree lines can limit particulate emissions from quarries (CC). Overburden (that is, the topsoil that must be removed in an active quarry operation) can cover rocks and nonproductive shallow soil in order to grow grass and increase vegetative cover (CC).

    Dust Suppression Generally

    Vacuum sweeping of paved areas is ideal. Wet dust suppression of paved areas is an alternative (CC). Stockpiles should also employ wet dust suppression. Chemical dust suppression by chlorides or other chemicals may be an option in some areas.

    Suppression activity should be increased during dry and/or windy periods.

    “Dry Plant” Operations

    2 See Health and Safety Code § 382.065(a).

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Ms. Jill Shackleford employed “dry plant” controls at her operation, taking extra steps to limit dust generation and migration. These extra controls took six months to implement at a new facility. She stated one reason for this approach was operating over the Barton Springs Edwards Aquifer region where groundwater use is a concern, particularly during droughts. She argued that all plants could operate as if over the aquifer and that this would benefit nearby communities. Dry plants reduce the need for on-site water, a scarce resource in parts of Texas. Her dry plant strategies included:

  • Vacuuming dust from rocks rather than washing.
  • Sealed conveyors with air-pressured dust collectors.
  • Small baghouses throughout the plant to store collected dust.
  • Minimal use of water.Water Controls and ConsiderationsBerms should be built to control runoff (JS). Prevent flow of irrigation water on to neighboring properties (JS).

    Carcy Clinton indicated that his facility deals with drainage from the quarry production area by shaping the terrain to avoid drainage to the nearby Hamilton and Delaware Creeks, which are on either side of his operation.

    Near waterways, spilt material should be cleaned up immediately to prevent contamination of waterways.


    Blasting schedules should be communicated to local stakeholders via text message or email (JS). Ms. Shackleford recommends public events to invite interested parties to witness onsite blasting. She says blasting is typically done by “very sophisticated” third-parties and is “uneventful” if done right. She cited the Bureau of Mining as a resource for safe blasting practices.

    Other Operational Strategies

    Facilities should employ an in-house environmental manager and expert rather than simply using environmental consultants to write permits and emissions compliance plans (JS). The environmental manager should work with the project manager to conduct regular reviews of mitigation strategies and control technologies.

    Facilities should regularly review and monitor potential dust sources and update control and mitigation measures. This should occur both on and off site to ensure no migration of dust.

    Regular checks should be conducted for visible signs of dust emissions and deposition. Air monitoring should be required at all facilities.


    Public Citizen supported HB 4409/SB 2233 By Chair Wilson and Sen. Buckingham (86R), which required real time air monitoring by aggregate facilities and concrete plants with public data access. Many good industry actors will recommend the same. Ms. Jill Shackleford

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recommend onsite air monitoring and cited a cost of $700 per onsite monitor per month. Ms. Shackleford’s presentation indicated she was likely using volumetric particulate matter monitors with mechanical filters and offsite analysis similar to, for example, the MiniVolTAS particulate matter monitor.3

Carcy Clinton indicated that TCEQ installed a particulate matter monitor near his operation and close to the Seaton Hospital on Highway 281. Mr. Clinton said that his facility had always passed air quality checks with “flying colors.” This illustrates (1) the importance of air monitoring near sensitive land uses such as hospitals and (2) that facilities that are well-run should have no concerns about nearby air monitoring.

On direct questioning from Rep. Wilson, Cleve Clinton did not say that air monitoring was too expensive. On the question of whether air monitors should be required, Cleve Clinton was clear, “If I was the guy living next door to it, I’d think it was a great idea. But if I was the guy operating, I’m not sure I would think it was such a great idea.” Health and safety regulations are written for the guy living next door. Air monitoring is a great idea and should be required at all APO operations.

Further Comments by Jill Shackleford

Ms. Shackleford concluded her presentation by stating her opinion that all operators should follow the best practices that she has developed for her own facility. She did not believe this would be an economic burden to companies. She stated that, “back up alarms, dust monitoring, berms, and other typical BMPs did not impact my bottom line.”

Ms. Shackleford said plainly, “I don’t feel like the state overreaches, I feel like a good operator is going to follow stringent operations and not have a problem with it.”


Thank you for the opportunity to provide these comments and this testimony, if you wish to discuss them further, I can be reached by email at ashelley@citizen.org or by phone at 713-702- 8063.


Adrian Shelley
Texas Office Director Public Citizen

CC: Chair Terry Wilson, Vice Chair Armando Martinez, Rep. Alma Allen, Rep. J. M. Lozano, Rep. Andrew S. Murr, Rep. Jared Patterson, Rep. Erin Zwiener.

3 See, e.g., https://publiclab.org/wiki/minivol.