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 Project Manager
Re:6-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 6-month Evaluation Report to summarize field observations performed on Saturday, September 9, 2000, for the implementation of Dust Control Measures at the Arizona Army National Guard (AZARNG) 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
URS Corporation
7720 North 16th Street, Suite 100
Phoenix, AS85020
Tel:602.371.1100
Fax:602.371.1615
1.0 INTRODUCTION
URS Corporation (formerly Dames & Moore) is providing this 6-month Evaluation Report as the second 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. The last evaluation report installment will include a 12-month evaluation report, scheduled to take 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 previously applied at two locations within the FMR as follows:
- Mesa Staging Area (MSA)
- Main Supply Route (MSR)
The primary objectives of the evaluation and reporting identified in the task assignment offer (TAO) request and described in the URS (formerly Dames & Moore) proposal are as follows:
- Perform evaluations at three intervals over a period of one year to assess the effectiveness of the respective palliative at two locations on the FMR.The three intervals identified are as follows:
- Within two weeks following implementation
- Approximately 6 months following implementation
- Approximately 12 months following implementation
- Assess effectiveness of the evaluations quantifiably in accordance with Pinal County Air Pollution Control Regulation 2-8-300 and the ADEMA Scope of Work, which limits the opacity of air pollutant emissions to 20 percent at the fence line or property line. It also states that opacity from any site within the property should not exceed 25 percent.
- Assess the effectiveness of the evaluations by the general observations of dust plumes that may migrate westward toward the Florence Gardens Community and become a nuisant issue for residents of that community.
- Use the information gathered and conclusions drawn from each evaluation to prepare a final report and Operations and Maintenance Plan to assist the Arizona Army National Guard (AZ ARNG) with projecting maintenance and re-application activities and making recommendations for future projects.
Two URS expert Visible Emissions Evaluators performed opacity 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 method outlines 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 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 data 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 6-month evaluation for the following two palliative products that were previously applied at the FMR:
- EnviroKleen® - a synthetic hydrocarbon emulsion (clear oil) dust palliative
- Soil-Sement® - an acrylic polymer type dust palliative
The first product, EnviroKleen®; was applied at the MSA (ontop 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 Februay 7, 2000.A subsequent application of EnviroKleen® was applied to the MSA on February 10, 2000.Soil-Sement® was applied to the 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, September 9, 2000, Mr. Terry Skidmore, a URS air quality specialist, set up the meteorological monitoring station, and performed a visual opacity observation at Gate 4. Mr. Tom Carr, a URS Expert Visible Emissions Evaluator performed two visual opacity observations. The locations selected, also shown on Figure 1, and observers were as follows:
- Gate #4 and Firing RangeTom Carr
- MSR between Gates 3 and 4Tom Carr
- MSR – Wash Crossing #12Terry Skidmore
Observations were made only of vehicular travel on the MSR. Not all of the locations observed during the March 2000 post-implementation were duplicated due to unexpected vehicular movements. No military vehicles observed entered from the highway onto the MSR from the BIVUAC area. Dump trucks travelling to a nearby construction area were also observed travelling on the MSR.
4.0 METEOROLOGICAL STATION
URS field personnel arrived onsite early to set up a portable meteorological monitoring station on the southeast corner of the MSA. This portable station was assembled to measure and record the following weather data:
- Wind speed
- Wind direction
- Ambient temperature
- Relative humidity
- Barometric pressure
The station was assembled, set up to collect 15-minute average data, and operated at one location for the duration of the day’s observations, or about seven hours. For the purposes of this evaluation, only wind speed, wind direction, and ambient temperature were reported herein.The relevant meteorological monitoring station data are included as Table 1.
Climatological data obtained from the National Weather Service Gauge Station located in Coolidge, Arizona indicated that no precipitation had occurred since August 17, 2000, indicating the probability of low soil moisture. These precipitation data from the National Weather Service Gauge Station located in Coolidge, Arizona are included as Table 2.
On September 9, 2000, the wind speed at the FMR from 7:00 am to 2:00 pm ranged between 1.2 and 9.3 mph. The average wind speed for this time period was 6.3 mph.The wind direction varied from 30 to 242 degrees from north. The temperature increased from 77.1 degrees Fahrenheit at 7:00 am to 99.4 degrees Fahrenheit at 2:00 pm.The average temperature was calculated to be 91.7 degrees Fahrenheit. The total precipitation from August 1, 2000 to September 9, 2000 was 0.32 inch according to the National Weather Service Gauge Station located in Coolidge, Arizona.
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). At the speed and spacing at which the convoy vehicles traveled along the MSR, the 15-second interval corresponded to a maximum of two readings after every vehicle. Because of the very intermittent nature of the convoy travel along the MSR during this exercise, it was difficult to obtain enough opacity observations to calculate 3-minute average values.
URS representatives, Mr. Terry Skidmore and Mr. Tom Carr, observed the Florence Military Operations (FMO) maneuvers on September 9, 2000. The observations included documenting the number and type of vehicles passing a pre-determined point and recording the time and opacity observed for each event. Mr. Skidmore and Mr. Carr, both certified Expert Visible Emissions Evaluators, conducted the visual opacity observations for this 6-month evaluation.
Mr. Tom Carr stationed himself between Gate 4 and the firing range. Mr. Carr observed the following vehicles:
- Cargo Trucks6 wheel(5)
- Humvees4 wheel(5)
- Ambulance4 wheel(1)
- Hemets18 wheel(2)
- Passenger vehicles, various descriptions4 wheel(4)
Total number of vehicles(17)
Vehicle speeds were estimated at 10 to 20 mph.Visual opacity observations ranged from zero to 20 percent, immediately following the vehicle.The maximum 3-minute rolling average calculated for this data was 3.8 percent. The opacity data are presented in Tables 3 and 4.
Mr. Tom Carr’s second vantage point was between Gate 3 and Gate 4 where he observed the passing of several vehicles all traveling at speeds estimated at between 25 and 45 mph.
- Ten wheeler dump trucks 10 wheel (9)
- Passenger vehicles 4 wheel (2)
Total number of vehicles (11)
Visual opacity observations ranged from zero to 60 percent, immediately following the vehicle. The maximum 3-minute rolling average calculated for these data was 9.6 percent. The opacity data are presented in Table 5.
Mr. Terry Skidmore, stationed along the MSR at Gate 4, observed the passing of:
- Half track personnel/cargo carrierstrack (3)
- Humvees4 wheel (4)
- Passenger vehicles4 wheel (6)
- Fuel transport18 wheel (2)
- Ten-wheeled dump truck10 wheel (1)
Total number of vehicles (16)
Vehicles were observed turning onto the MSR from the paved roadway and proceeding at an estimated 10 to 15 mph eastward from Gate #4. Visual opacity observations were made immediately behind each vehicle and ranged between zero and 20 percent and the majority were 10 percent or below. The maximum 3-minute rolling average calculated for this data was 9.2 percent. The opacity data are presented in Table 6.
Mr. Terry Skidmore, positioned at Gate 4, also observed two (2) 10 WHEELED DUMP TRUCKS. One was headed south on the MSR empty and was directly observed to produce an immediate dust cloud of 50 percent opacity, which dissipated in just over 24 seconds. The other dump truck was dissipated in less than 20 seconds. The visual opacity observations ranged from zero to 75 percent, with a maximum 3-minute rolling average of 15.4 percent.The opacity data are presented in Table 7.
Mr. Skidmore then proceeded south on the MSR and stationed himself at wash crossing no. 12 along the MSR where he could observe the same vehicle traveling across two treatment areas, on treated with EnviroKleen® and the other with Soil-Sement®. Two ten-wheeled dump trucks were observed traveling north fully loaded.In each case, visual opacity observations of 75 percent were noted as the vehicle traveled on the EnviroKleen® treated area and of either 15 percent or 25 percent maximum when on the Soil-Sement® treated sections. The higher observation was due in part to the presence of a 10 to 15 mph wind in the same direction as the vehicle travel causing the dust cloud to "follow” the vehicle. A third ten-wheeled dump truck traveling south, empty, was observed with a visual opacity of 50 perscent on the EnviroKleen® treated area. No observations were made on the Soil-Sement® treated area on the last ten-wheeled dump truck, due to the unexpected arrival of a vehicle not allowing sufficient time to make the observations. The visual opacity observations made for the EnviroKleen® treated area ranged from zero to 75 percent while the observations made for the Soil-Sement® treated area ranged from zero to 25 percent. The maximum 3-minute rolling averages for the EnviroKleen® treated area and the Soil-Sement® treated area were 8.8 and 2.1 percent, respectively.The opacity data are presented in Table 8.
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:
- Raveling
- Cracking
- Rutting
- Erosion rills
- Abrasions
- Carry over
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. Kevin Somerville of URS recorded observations of the fifteen wash crossings on September 15, 2000. The observations included the qualitative descriptions above and some recommendations for further treatment of the crossings. The wash crossing observations are included in Table 9.
7.0 CONCLUSION
The following are conclusions drawn from the 6-month observations and opacity measurements performed at the FMR:
- 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.
- The combined application of coarse rock material and EnviroKleen® dust palliative at the MSA appear to provide excellent control of fugitive dust generation.
- Both the EnviroKleen® and Soil-Sement® appeared 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 show some signs of wear but maintains its general integrity at the surface after receiving heavy, abrasive traffic, particularly from tracked vehicles. The spalling observed appears to be predominantly from the aggregate being crushed or “popped” out of the surface, with only minor flaking of the Soil-Sement® -treated crossing.
- The rubber-tired military vehicles appeared to develop appreciably more fugitive dust than the tracked vehicles. The 18-wheel variety of military vehicles created the most sustaining dust plume, presumably because of the multiple tires in contact with the road and capability of traveling faster than the tracked vehicles.
- 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 6-month observations and opacity measurements performed at the FMR:
- 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).
- URS still recommends that a reapplication of EnviroKleen® 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 sufficient to maintain opacity below 20 percent (average).
- This type of evaluation should be continued at the 12-month interval to evaluate the performance of the products after repeated use and long-term exposure to the elements in order to reasonably assess the need (or schedule) for maintenance re-applications of one or both palliatives.
The 12-month evaluation should be scheduled closely with the training site personnel to ensure that the convoy of military vehicles will travel the MSR at speeds ranging from 15 to 35 mph, as normally as possible, without slowing down or altering their movements from the MSR because of the presence of the evaluators.
