URS

 

May 16, 2001

Arizona Department of Emergency and Military Affairs

Army National Guard, FMO Environmental Office

5636 East McDowell Road, Building M5330

Phoenix, Arizona 85008-3495

 

Attn:Ms. Whitney Kirk

Compliance Manager

 

Re:12-Month Evaluation Report

URS Job No. 29679-006-058

 

Dear Ms. Kirk:

URS Corporation, formerly Dames & Moore, is pleased to submit one copy of this 12-month Evaluation Report to summarize field observations performed on Saturday March 3, 2001, for the implementation of Dust Control Measures at the Arizona Army National Guard (AZ ARNG) Florence Military Reservation (FMR).

Should you have any questions regarding the information or conclusions presented in this report, please feel free to contact me at (602) 371-1100.

Sincerely,

URS Corporation

Kevin R. Somerville

Project Manager

KRS/cd

 

1.0 INTRODUCTION

URS Corporation (formerly Dames & Moore) is providing this 12-month Evaluation Report as the third in a series of three evaluation reports for the Implementation of Fugitive Dust Control Measures Project, at the Florence Military Reservation (FMR). This report was prepared for the Arizona Department of Emergency and Military Affairs (ADEMA) Project No. AZ08099008-2 in accordance with the scopes of work presented in our proposal dated August 30, 1999. This last evaluation report took place on March 3, 2001.

 

2.0 PURPOSE OF EVALUATION

The purpose of the site visit was to evaluate the effectiveness of two soil stabilization dust palliatives that were preciously applied at two locations within the FMR as follows:

The primary objectives of the evaluation and reporting identified in the task assignment offer (TAO) request and described in the URS proposal are as follows:

Two URS Expert Visible Emissions Evaluators performed opaciity observations, the primary method of evaluation of the fugitive dust generated from vehicle traffic during training activities at the FMR.The URS representatives performed these observations in general accordance with the U.S. Environmental Protection Agency (EPA) Reference Method 9 as codified in 40 Code of Federal Regulations (CFR) Part 60, Appendix A.

Reference Method 9 as presented in 40CFR60 Appendix A applies to point stationary sources generating a plume of particulate emissions. The methods outline the observation techniques, training and certification testing for qualified observers. The method also covers data reduction methods for presenting the visual opacity measurements. The method states that a minimum of twenty-four 15-second observations be recorded on an observational record sheet and that the average of the 24 observations is the reduced number to be used when reporting opacity. The 24 observations taken every 15 seconds equates to six minutes so the data reduction method of averaging every 6 minutes is also known as the 6-minute rolling average method. Although the 6-minute date reduction method is called for in EPA Method 9, a 3-minute rolling average was used for data reduction during this study. A 3-minute rolling average was utilized for data reduction because limited observation data could be collected during the study period.The limited data was due to the intermittent nature of the vehicle traffic on the study areas during the observation periods. This 3-minute rolling average, a more conservative data reduction, was agreed to by all involved in the evaluation efforts before the observations were performed.

3.0 SCOPE OF EVALUATION

URS performed this 12-month evaluation for the following two palliative products that were previously applied at the FMR:

The first product, EnviroKleen®; was applied at the MSA (on top of a layer of crushed aggregate material) beginning January 11, 2000.The second product, Soil-Sement®; was applied to the MSA Helipad on January 12, 2000.EnviroKleen® was then applied to the MSR beginning February 7, 2000. A subsequent application of EnviroKleen® was applied to the MSA on February 10, 2000. Soil-Sement® was applied to MSR beginning February 7, 2000 at locations where the road crossed small natural desert washes, ranging from 55 feet to 428 feet in length.

On the morning of Saturday March 3, 2001, Mr. Bob Estes, a URS air quality specialist, who had been scheduled to perform opacity observations, drove a truck to simulate a convoy instead. Mr. Romann Diaz, a URS Expert Visible Emissions Evaluator performed three visual opacity observations. The locations selected, also shown on Figure 1, and observers were as follows:

Due to the unexpected early departure of the military convoy, the visual opacity were performed using both a ˝-ton truck and a Chevy Suburban as test vehicles.

These two vehicles were able to reach higher rates of speed in comparison to the standard military vehicles and repeated passes by each of the evaluation points.

 

4.0 METEOROLOGICAL DATA

A meteorological station was not used during the 12-month evaluation due to lack of equivalent availability. Meteorological data was obtained from the National Weather Service Gauge Station located in Coolidge, Arizona and are included in Table 1.

According to the data from the weather station, on March 3, 2001, the wind speed at the Coolidge Station averaged 4 miles per hour and the average temperature was 55 degrees Fahrenheit. The maximum and minimum temperatures for that day were 74 and 34 degrees Fahrenheit, respectively. The total precipitation from February 1 to March 4, 2001 was 0.64 inch, with precipitation occurring on a total of 6 days.

 

5.0 OBSERVATIONS

In accordance with EPA Reference Method 9, opacity observations were made at 15-second intervals. The resultant data set was used to calculate 3-minute rolling average values (for intermittent sources). With the amount, speed and spacing of the vehicles traveling along the MSR, the 15-second interval corresponded to a maximum of three readings after every vehicle. URS representatives, Mr. Bob Estes and Mr. Romann Diaz, observed the Florence Military Operations (FMO) maneuvers on March 3, 2001. The observations included documenting the observation time and opacity measured for each event. Mr. Diaz, a certified Expert Visible Emissions Evaluator, conducted the visual opacity observations for this 12-month evaluation.General observations at the MSA included heavy rutting by truck vehicle maneuvers. Vegetation (weeds) appeared to be widespread in less traveled areas. Visual opacity observations averaged from zero to 40 percent. The maximum 3-minute rolling average, for the 12-month evaluation, was 12.5 percent.The opacity observation data are included in Tables 2 through 4.

 

6.0 WASH CROSSING OBSERVATIONS

URS and the AZ ARNG identified 15 wash crossings that possibly would require soil stabilization to protect from both storm water erosion and dust from vehicles. Figure 1 shows these crossings at their corresponding reference numbers. A small sign was placed at the southeast corner of each wash crossing along the MSR to indicate the crossing number (1 through 15). Of these, 12 were treated with Soil-Sement® blended with Aggregate Base material (AB). The remaining three wash crossings will be observed to assess if soil stabilization is necessary to keep the dust control intact.

 

The wash crossing observations were intended to evaluate the presence of the following:

 

The type or degree of erosion or diminished dust control is dependent upon the soil matrix adjacent to the Soil-Sement® -treated section, the size and frequency of rock content, steepness of grade, and exposure to direct runoff.

Mr. Romann Diaz of URS recorded observations of the fifteen wash crossings on March 3, 2001. The observations, including qualitative descriptions of the crossings, are included in Table 5.

7.0 CONCLUSIONS

The following are conclusions drawn from the 12-month observations and opacity measurements performed at the FMR:

  1. The opacity of the dust plumes, generated by the convoys, on both the EnviroKleen® and the Soil-Sement® treated areas were all lower than the 20 percent as required at the property line according to Pinal County Air Pollution Control Regulation 2-8-300. The more conservative 3-minute rolling average data reduction method was used to calculate the maximum opacities for each area observed.
  2. The combined application of coarse rock material and EnviroKleen® dust palliative at the MSA appear to provide excellent control of fugitive dust generation.
  3. Opacity observations at Wash Crossing #9 suggests that the Soil-Sement® dust palliative provided a greater degree of dust control than the EnviroKleen® product for the soil conditions of the MSR.
  4. Both the EnviroKleen® and Soil-Sement® palliatives appear to continue to exhibit a tolerance to the type of vehicular traffic of the MSR (generally heavy vehicles with both rubber tires and tracks). At the time of this evaluation, the Soil-Sement® appeared to maintain its general integrity at the surface after receiving heavy, abrasive traffic, particularly from tracked vehicles, over a period of 12 months.
  5. These observations of fugitive dust generation and treated surface degradation should not be considered complete evidence of the long-term performance of either product, or its one-time application.

 

8.0 RECOMMENDATIONS

The following summarize our recommendations based on the 12-month observations and opacity measurements performed at the FMR:

  1. The MSA area should be lightly graded after each use to redistribute the aggregate in areas where it is significantly disturbed by vehicle traffic (i.e.: tracked vehicles performing hard turning maneuvers) and to control weed growth.Weeds around the Soil-Sement® and concrete Helipad should be controlled with hand tools and weed-control sprays.
  2. URS recommends that, for best results, a reapplication of EncirKleen® occur 9 months after the initial application to insure the complete saturation of the target surface and the overall reduction of fugitive dust. However, reapplication at 12-month intervals (or greater) may be suffieient to maintain opacity below 20 percent (average).
  3. This type of evaluation should be continued every 6 months to evaluate the performance of the products after repeated use and long-term exposure to the elements. These evaluations will help to assess the need (or schedule) for maintenance re-applications of one or both palliatives.
  4. Future evaluations should be scheduled covertly so as not to miss the convoy and observe them in maneuvers as close to “normal” as possible.
  5. The downstream edge of the Soil-Sement® -treated wash crossing should be specifically treated with additional Soil-Sement® , particularly at the expected discharge point(s) to reduce or eliminate erosion (head-cutting). Rip-rap material may also be used to control erosion to maintain the integrity of the dust control palliative at the crossing.

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