FROM: Brent Auvermann, Texas A&M Department of Biological and Agricultural Engineering, 6500 Amarillo Blvd. West, Amarillo, TX

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1 TO: Texas Air Research Center FROM: Brent Auvermann, Texas A&M Department of Biological and Agricultural Engineering, 6500 Amarillo Blvd. West, Amarillo, TX SUBJECT: ANNUAL PROGRESS REPORT, PROJECT NUMBER: 413TAM0139A PROJECT TITLE: At last! A second, independent method: estimating fugitive PM 10 flux from commercial cattle feedyards using the integrated horizontal flux approach PROJECT PERIOD: 9/1/2013 7/15/2015 DATE: 9/15/2014 Project Description Sixteen years of visual observations at numerous commercial feedyards have confirmed that during the well-documented evening dust peak (EDP), the depth of the fugitive dust plume routinely decreases to less than m above the ground surface. Thanks to a instrumentation grant from NSF and the successful development of a low-cost, nephelometrybased dust sensor under a grant from USDA-AFRI (Klar et al., 2010), we are deploying a 2- dimensional, vertical array of dust sensors and 2-D sonic anemometers (Figure 1) along the downwind edge of a commercial-scale feedyard with whom we have an ongoing Research Land- Use Agreement. This vertical array, which is 900 m wide and up to 25 m high, permits us to adapt the mass-conserving IHF method (see e. g. McInnes et al., 1985) to estimate the net PM 10 flux, the mass emitted by a known source area in a given time interval. That emission flux, measured at 5-minute intervals, will then be integrated to hourly time steps and compared with hourly emission-flux estimates obtained using the usual IDM-AERMOD scaling method. Objectives Our primary goal is to generate seasonal, time-resolved estimates of the mass flux of fugitive PM 10 from cattle feedyards that are independent of estimates generated by the traditional, inverse dispersion modeling (IDM) technique, a technique whose estimates have not materially converged in absolute, model-independent terms. To accomplish that goal, we proposed two primary objectives: 1. Verify that a miniaturized nephelometer mounted beneath a tethered balloon, or kytoon, successfully and accurately locates the top of the feedyard PM 10 plume during the transient inversion that occurs shortly after sundown and persists for about 3 hours in the southern High Plains. 2. Estimate the mass flux of PM 10 during that inversion across the downwind face of an imaginary rectangular prism over the feedyard source area using the integrated horizontal flux (IHF) method.

2 Figure 1. Kevin Heflin and Jack Bush (Research Associates) troubleshoot 2-D sonic anemometers and temperature/rh sensors mounted on Tower 1 on the west end of the monitoring area. Foreground: a taperedelement, oscillating microbalance (TEOM) configured to measure PM 10 concentrations at 2-meter height on 5-minute averages. Methodology We proposed eighteen months (Dec 2013 through Jun 2015) of continuous monitoring of PM concentrations and wind speeds, distributed vertically upon six horizontally distributed instrument towers erected along the downwind edge of Feedyard C. The lowest dust sensor, at 2 m above ground level, is at the same height as the inlets of ground-level TEOMs at the foot of each tower, which serve as the real-time calibration references for the sensors. We proposed to chart the development of the evening dust peak/inversion and observe its compression below the top of the tower with both the kytoon-mounted nephelometer and the upper, tower-mounted sensors. We have also deployed all seven of our TEOMs, one at the upwind tower, and six distributed in an E-W array along the line of towers on the downwind side of the feedyard. At the conclusion of the project, we will use EPA s applicable regulatory model, AERMOD, to estimate emission fluxes using the IDM with the TEOM data, on-site weather data, and MM5-interpolated upper-air data from Lakes Environmental, Inc. (Waterloo, ON). For the IHF method, we will numerically integrate the product C(z) U(z) cosθ dy dz across the planar domain represented by the downwind face of a rectangular prism covering the

3 feedyard. That result will then be divided by the source area to obtain the emission flux from the feedyard surface. Accomplishments/Problems Successfully erecting the six towers, mounting the sensors, and writing and troubleshooting the data-acquisition and data-analysis code required a great deal more than three months of preparatory work, during which we lost our primary programmer, Ms. Sharon Preece. Following that unexpected loss, Dr. Auvermann requested and received from TARC permission to adjust the project budget to underwrite a series of Matlab (Mathworks, Inc.) and LabVIEW (National Instruments, Inc.) on-line training courses for himself. Dr. Auvermann is now the programmer of record for the project, and as of 13 Sep 2014 he has completed: 1. Development of version 2.0 of the data-acquisition program in LabVIEW 2014 (version 3.0 is under development); and 2. Development of multiple data-reduction modules in Matlab for both the on-site weather data and the tower data. Early construction of the towers proceeded quickly, with the two outside 10-meter towers and the two 16-meter towers going up first. We successfully instrumented the 10-meter towers in June 2014 while LabVIEW programming was underway, but during that same month, thunderstorms caused one of the guy-wire anchors on one of the 16-meter towers to fail, and the tower collapsed. Above-average rainfall during the summer of 2014 has forced us to spend a great deal of personnel time in weed control in the 7-acre strip of leased land where the towers and TEOMs are deployed. As of late summer 2014, we have collected enough TEOM and windprofile data to begin generating preliminary estimates of the emission flux, which we presented in August 2014 at the annual TARC meeting at Lamar University (Figure 2). The preliminary, 24-hour emission factors, normalized to the one-time capacity of the feedyard, average about 18 kg/1,000 hd-d (38.7 lb/1,000 hd-d). Future measurements will refine that estimate further. In coordination with Dr. Robert DeOtte, professor of Civil Engineering at West Texas A&M University (WTAMU), as of 13 Sep 2014 Dr. Auvermann has engaged an M. S. candidate in Civil Engineering to conduct systematic tests of the Kwon nephelometers in Dr. DeOtte s wind tunnel at WTAMU using a monodisperse aerosol generator. Following those tests, we will fabricate wind-direction-insensitive inlets for our nephelometers, build and test additional nephelometers, and deploy those nephelometers on the towers, with continuous, real-time data acquisition to follow for the duration of the project. Once installed and operating, the unit cost of data acquisition will be very low, and we plan to collect data as long as we can maintain access to the monitoring area via renewable Land-Use Agreement.

4 Figure 2. Time-averaged emission factors from integrated horizontal flux data collected 4-5 Aug Error bars represent the standard error for n=4 (east and west half of the feedyard, 2 days). Future Work During the next ten months and beyond, we will (a) complete the installation of the fallen 16- meter and the two remaining 25-meter towers, (b) deploy the miniature nephelometers on all instrument masts, and (c) collect vertical-profile data of both aerosol concentration and wind vector. As mentioned previously, once the entire system is installed, the unit cost of data will be very low, and we will continue data acquisition indefinitely. We will continue to improve the data-acquisition and -analysis programs as needed. We expect to be able to submit a manuscript to the Journal of the Air & Waste Management Association or Transactions of the ASABE during the fall of 2015, as well as a final report to TARC. List of Publications and Presentations Auvermann, B. W Particulate matter from open-lot dairies and cattle feedyards: research update. TO BE PRESENTED at the Western Dairy Air Symposium/Waste2Worth Conference, Seattle, WA, March 30-April 3. Auvermann, B. W Air quality in open-lot dairies and cattle feedyards: recent developments. Presented at the annual meeting of the American Association of Bovine Practitioners, Albuquerque, NM, September 19.

5 Bush, K. J., K. R. Heflin, G. W. Marek, T. C. Bryant, and B. W. Auvermann Increasing stocking density reduces emissions of fugitive dust from cattle feedyards. Applied Engineering in Agriculture (in press). Auvermann, B. W At last! A second, independent method to estimate fugitive PM 10 emissions from cattle feedyards. Presented at the annual meeting of the Texas Air Research Center, Beaumont, TX, August 8.