Title 5 Emissions Quantification

© Dr. B. C. Paul

Dust Calculations

• Operations typical of quarry– Drill rock– Blast– Load– Haul– Primary Crusher– Screening– Conveying– Secondary Crushing

Quantifying Dust Emissions

• Start with a flow sheet of the operation

• Show major equipment and haul roads approximately relative to property boundaries

• On an annual basis quantify tonnage flows through your processes– knowing crusher settings and screening

efficiencies can be important

Next Step

• When process tonnages are calculated check AP42 for appropriate emission figures

• Many of the figures are given in lbs dust/ton of material processed

• Other figures come from formulas

• Sometimes spreadsheets have been prepared to facilitate fast calculation

Haul Roads Formula• Lbs PM10/Vehicle Mile Traveled (VMT)

• = 2.124 * (Silt Content %/12)*((365 - Days Rain)/365)*sqrt(# of wheels/4) * Avg Truck Speed/30*((Unloaded Truck Weight in tons + Average Loaded Truck Weight)/6)^0.7

• Silt Content of road can be picked from standard values in AP42 (9.6% for example)– or you can usually document your own sampling

(don’t do it on your first pass - spend money on most significant issues first)

The Rainy Day Mystery

• Rainy days - consider that if there is more than 0.01 inches of rain wet roads are not dusty)

• Use National Weather Service Data– it has been copied into AP42– Most of Illinois is between 110 and 120 days– we'll use 115 days

The Truck Parameters• Number of Wheels

– can use # of axel sides rather than number of tires– a quarry truck will typically have 2 axels and 4

wheels (two rear are dual)

• Need average speed (you know this from your ton mile per hour calculations) - 20 mph for this example

• Know empty and loaded weight 415 - 35 tare and 70 loaded for example

Haul Road Emissions

• Formula gives 5.75 lbs/VMT

• Know the tonnage hauled and haul distance and payload size so you can calculate VMT

• Example say 12,000 miles per year– This will be for all aggregate haul vehicles

combined– 5.75*12,000/2,000 = 34.5 tons per year

• This is termed the “actual emissions”

Other Emission Rates

• Need to calculate the Maximum Possible Emissions (usually used for determining whether you are a major generator)– For the Haul road consider how many vehicle

miles could be traveled– Quarries are usually market constrained so actual

emission are less than equipment would allow– Need to calculate with the maximum number of

miles the haul trucks could travel

What is the Maximum?

• Some felt that meant all trucks running 24 hours a day 365 day per year– EPA rulings indicate that you can work with

realistic constraints• You may have 5 trucks but your availability is not

100%

• The truck may be able to run after dark but if you have no haul road lighting you can’t run it

• There may be 12 months in a year but many quarries must shut down in deep winter for safety reasons

Title 5 Emissions

• Not all mine dust sources have to be considered in Title 5 permit -even though they may have to be disclosed to regulators– Aggregate Processing Equipment built prior to

Aug 31, 1983 is not subject to New Source Performance Standards NSPS

– If substantially rebuild it you loose exemption– If you replace it with like for like then you still

get grandfathered out of NSPS

Emissions with Constants

• Most emissions are calculated as a tonnage through-put times an emissions factor

• Drilling Tons rock produced * 0.00008 lb/ton– process is considered wet and already controlled

• Jaw Crusher Tons rock produced * 0.00057

• Conveyors Tons conveyed * 0.000046 lbs/ton - have a whole lot of conveyors

Aggregate Processing Plant

• There are factors for– Screening– Fine Screening– Factors for conditions wet or dry

• There are not factors for– Blasting– Equipment in a Wash Plant considered to

produce no dust

Open Stock Pile Storage

• Emissions combine 3 factors• Load in Load Out Factor

– 0.00224 * (Mean Wind Speed/5)^1.3/(Moisture %/2)^1.4

• Wind Speed Generally from local weather service data - we’ll use 8 mph

– Moisture content of stored aggregate - for crushed stone about 1.1 - can sample or AP42 has tables of typical values

Wind Erosion Factor• = 0.0125 * (Silt Content/1.5) * (Storage

Duration/90) * (Dry Days per year/235) * (% of time wind > 12mph/15)– Silt Content - typical values in AP42 or can

measure 1.6%

– Storage Duration 30 days (your handling records)

– Dry Days/ year - opposite of wet - use chart 250 for example

– Wind Speed - weather service records 22%

Activity Factor• = 0.05 * (Silt Content/1.5) * (Dry Days per

year/235) * Vehicle Activity Factor– Only new term here is activity factor - ratio of

time in which equipment actually in there working

– often about 0.25

• Totals = 0.0095 lb/ton for loadin load out– 0.0139 lbs/ton for wind

– 0.0142 lbs/ton for Activity

– Total is 0.0376 lbs/ton

Emissions from Stockpiles

• Your emissions factor is multiplied by quarries production through stockpiles for actual emissions

• By your quarries maximum practical production rate for potential to emit

Emissions Spreadsheet

FACILITY NAME MARTIN MARIETTA EXAMPLE Developed by Steven Vozzo, Raleigh Regional Office

FACILITY ID Reviewed by Ed Martin and Kevin Godwin, Central Office

SPREADSHEET FOR STONE QUARRY/GRANITE CRUSHING - see notes on last page North Carolina

Division of Environmental Management

Quarry General Parameters : Is Quarry NSPS affected : yes (Y OR N) Air Quality Section

Rated Capacity (Tons/Hr) : 0 Actual Total Plant Production (tons) : 0.01

Actual Hours : 0 Max Potential Total Plant Production (tons) : 0

Potential Hours : 0 [based on Permit Stips else Rated Capacity, see note 3 for explanation*]

* Note that one of first concerns is planned and potentialhours of operation and tonnage - needed for actual andmaximum potential emissions

Other Notes

• Note that on maximum potential emissions that the limit could be an operational design constraint on production or that the existing permit already limits hours of operation

• Also note ask whether equipment is NSPS effected because that influences whether it goes into Title 5 Emissions Totals– There is a charge for Title 5 Emissions that funds

the program

Emission CalculationCrushing Operations : Emis Fctr - dry and wet

Amount Wet Sprn (lbs/ton material) or Rate (Y/N) TSP PM10

Primary Crushing - ID# ________

Actual Processed (TPY) 0 yes 0.00504 0.00240Rated Capacity (TP-Hr) 0 0.00124 0.00059

Primary Crushing - ID# ________

Actual Processed (TPY) 0 yes 0.00504 0.00240Rated Capacity (TP-Hr) 0 0.00124 0.00059

Secondary Crushing - ID# ________ Actual Processed (TPY) 0 yes 0.00504 0.00240Rated Capacity (TP-Hr) 0 0.00124 0.00059

Secondary Crushing - ID# ________ Actual Processed (TPY) 0 yes 0.00504 0.00240Rated Capacity (TP-Hr) 0 0.00124 0.00059

Things to Note• Note that the spreadsheet includes multiple

crushers– Each crusher has an ID number which will match it

to your material balance flow diagram (and potentially to State Regulatory program)

• Some spreadsheets go equipment item by equipment item for NSPS effected - this NC spreadsheet does all

• NC requires wet supression on crushers - and uses wet factors for emissions calcs