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Mr. Conrad Simon Director Air and Waste Management DivisionJuly

### 20, 1995

United States Environmental ProtectionAgency Region II 

### 290 Broadway NewYork, NewYork 10007-1866

Dear Mr. Simon: Michael D. Zagata Commissioner

The purpose ofthis letter is twofold

. This letter represents a preliminary submission forthe PM 10 (particulate matterwith an aerodynamic diameter smallerthan ten microns) State Implementation Plan due July 

### 20, 1995. Certain deficits in the planning process have slowed plan development, thus NewYork State is not in a position to submit a fully modelled attainment demonstration atthis time

. .Be assured that efforts (to be described later) are still moving forward to complete the PM 10 attainment demonstration as quickly as possible.

Additionally, I am writing to request that the United States Environmental Protection Agency (EPA) redesignate NewYork County as attaining the PM 10 National · AmbientAir Quality Standard (NAAQS).

Iwould liketo begin with the latter issue

. The measured PM10 levels in NewYork County, NewYork State's only PM 10 nonattainment county, have not exceeded the PM10 NAAQS since 

### 1992. Infact, with the exception of 

### 1994, ambient levels of PM10 have been dropping steadily, city-wide, since 1988. Also, it has been determined that the PM 10 problem in NewYork County is diesel vehicle exhaust related. Furthermore, ambient PM 10 levels measured at rooftop monitoring sites have not approached the magnitude recorded at the Madison Avenue, street level, sampling location. Therefore, the PM 10 problem has been determined notto be area-wide, but rather a "hot-spot" orsite specific problem.

New York Countywas designated as nonattainmentfor PM10 on January

### 20,1994. This designation was based on data collected atthe Madison

### .'

Mr. Conrad Simon 

### 2.

Avenue sampling location in Manhattan. The precise location ofthis monitor is the Eastern side ofMadison Avenue, mid blockbetween 47 and48 Streets, two meters from the ground. The MadisonAvenue monitoring site is the only site in the county which has recorded violations ofthe PM10 NAAQS. All PM 10violations recorded to date

are violations ofthe annual NAAQS (notto exceed an arithmetic mean of50 J..l.g/m3 for three consecutive calendar years), as opposed to violations ofthe 24-hour PM 10 NAAQS (not to exceed 150J..l.g/m3 in a24 hourperiod more than once during three consecutive years) which have never been recorded in Manhattan. Please find ambient air monitoring dataforthe MadisonAvenue site and a rooftop site located at Public School 59 in Attachment 1.

MadisonAvenue was chosen as a street level PM10 monitoring site for the high diesel bus volumes running along its corridor and its striking urban canyon characteristics, perhapsthe most exaggerated canyon ofall the majorthoroughfares in Manhattan. When compared to Fifth Avenue, which is similarly populated with diesel vehicles, MadisonAvenue is narrower by21 feet. It is hypothesized thatthe narrower canyon at MadisonAvenue entraps the particulate matter more readily than the wider streets

.
MadisonAvenue has recorded exceedances ofthe annual PM10 NAAQS during the years 1990 and 1991. From 1992 to the present, there have been no exceedances ofthe PM10annual standard, although during 1994 several high PM 10valueswere recorded, pushingthe 1994 average above 50 J..l.g/m3• These 1994 readings, however, did not result in a violation ofthe annual PM 10 NAAQS. Preliminaryfirst quarter, 1995 PM10data for MadisonAvenue has not been as high as the first quarter 1994 data

.
Other PM10 sampling sites inthe NewYork Metropolitan area have not recorded annual ambient levels ofPM 10 nearly as high as those measured at Madison Avenue

norwere there any exceedances ofthe annual PM10 NAAQS atthose sites. A PM10 monitor located on the rooftop ofthe Bowery Savings Bank, located on Seventh Avenue at 34 Street, measured the highest overall non-MadisonAvenue annual PM 10 reading, in 1989, of44 J..l.Qim3

. Offurther note, PM10 levels have been dropping rather steadily since 1988, city-wide

. The city-wide average was 35 J..l.Q/m3 in 1989and dropped quite steadilyto 28 J..l.g/m3 by 1993. Data for 1994seems a bit higheracross the boardfor all sites, notjust Madison Avenue. Explanationsforthis downward trend could be the diesel engine emission regulations adopted in March 1985, which reduced emissions significantlyfrom diesel vehicles during the years 1988to 1994. Also, ozone control programs adopted to reduce the amount ofsecondaryformationwhich occurs in the atmosphere have the extra benefit ofreducing the amount ofsecondary particulate generated in the atmosphere.

In 1993, the NewYork State Department of Environmental Conservation (DEC), in conjunction witt) the Desert Research Institute (DRI), initiated a study to determine /Mr. Conrad Simon 

### 3.

where the ambient PM 10 atthe MadisonAvenue sampling site originated. Diesel buses
were suspected to be the primary contributors. The study employed optical microscopy, scanning electron microscopy, x-ray fluorescence, Fourier-transform infrared spectroscopy, and chemical mass balance techniques to determine the
sources of PM 10 and the quantities of PM 10 associated with those sources. It was established that 52.8% of PM 10 collected at Madison Avenue was attributable to diesel exhaust. Ofthe remainder, 6% was automobile exhaust, 8.5% road dust, 8.7% ammonium nitrates, 13% ammonium sulfates, 6% sea salt, 4% iron particulate and 1% residual oil combustion products (indicative ofoil heating). The DRI report is included in Attachment 2.

The DRIIDEC study implicates diesel vehicles as the largest and most controllable segment ofthe PM 10 sources identified. Any offsets obtained from automotive or stationary sources of PM 10would be unlikelyto have a significant benefit. Road dust is difficultto control, and natural sources of PM 10 are uncontrollable. Ammonium sulfates and nitrates are generally secondarily formed particulate from precursors generated outside ofthe nonattainment area, and consequently do notfall within NewYork State'sjurisdiction. As diesel vehicles are the largest direct source of PM 10 in Manhattan, any PM10 offsets obtainedfrom this segment could be quite sizable. Certain federal measures promise to significantly reduce the amount ofparticulate matter emitted by heavy duty diesel vehicles, buses in particular.

These diesel vehicles will be affected byfederal particulate matter (PM) control
measures from which significant reductions are expected. As the problem is recognized as a hot-spot only, the federal PM control measures will have large impacts at specific locations heavilytrafficked by diesel vehicles. On March 24, 1993, a final rule was published in the Federal Register regarding particulate emission regulations for 1993 bus engines and 1994 and later bus engines. These regulations follow a requirement published on March 15, 1985, 50FR10653, which required new diesel trucks (as opposed to buses) to adhere to particulate emission standards set for 1988, 1991 and 1994. The March 1993 requirementwas followed by a similar action published on April 21, 1993, specifying particulate matter emission requirements for rebuilt or retrofitted 1993 orearlier model year urban bus engines. These bus engine standards promise significant reductions in particulate matter emissions and the Part 5 model reflects these emission benefits. The model, when run forthe years 1990, 1995 and 2000 predicts a significant drop in tailpipe particulate emissions. There is a distinct benefit associated with the emission requirements ofthese federal mandates. The emission factors alone, incorporated into the Part 5 model, represent this. For example, the model predicts a drop of44% between the exhaust emissions ofa model year 1995 bus and a model year2000 bus. Heavy-heavy duty diesel vehicle engine emissions factors drop 41% during those model years. This decrease in emissions will greatly offset any vehicle growth during those years. We note that EPA has recently announced an initiative tofurther reduce emissions of NOx and possibly PM from dieselMr. Conrad Simon
engines. Also, the Federal low sulfur diesel fuel regulation, 55 FR34210, adopted on August 21, 1990, effective October 1,1993, promotes further reduction of PM 10 when combined with the aforementioned diesel truck and bus engine emission standards. Please find NewYork City DEP's Part 5 model results and observations in Attachment 3. 

### 4.

Concentrations ofambient PM 10 atthe Manhattan hot-spot seem directly related to the total volume ofdiesel vehicles and street geometry. Specifically, in the case of NewYork's nonattainment site in midtown Manhattan, at Madison Avenue, the problem is almost directly related to publicly owned diesel buses and the Avenue's geometric characteristics. In the period from March 1992through December 1993, DEC performed a rapid assessment ofparticulate matter concentrations at several Manhattan locations impacted heavily by diesel vehicles. Two locationswere identified

as potential PM 10 hot-spots. These sites are at 37th Street between Seventh and Eighth Avenues and Canal Street at the intersection ofWest Broadway. The portable PM monitors used in this study are not reference instruments as they collected particulate matter somewhat largerthan PM 10• Therefore, these sites are scheduled to have permanent PM 10 reference instruments installed at orvery nearthese exact locations. Please see Attachment 4 for draft results ofthis rapid assessment.

NewYork State is pursuing the identification of PM 10 hot-spots, since it has been determined that the NewYork PM 10 problem exists on a microscale level. Despite the current PM 10 nonattainment designation in placefor NewYork County, the county has

come into attainment, as far as the State can determine, and therefore the State must ask EPAfora redesignation ofthe countyto attainment ofthe PM 10 NAAQS. The State is and will continue to pursue the identification of PM 10 hot-spots, but, thus far, has found no other sites to be in nonattainment ofthe PM 10 NAAQS besides Madison Avenue. Federal control measures which are orwill shortly be activated, will further reduce PM 10to such an extent that these emission controlswill offset any growth that

can occur in the future. The State further believes these measures will serve to maintain the standard, but until the Part 5 model is functioning properly, we cannot fully demonstrate this strategy.

Regardless ofwhether or not NewYork County is redesignated to attainment of the PM 10 NAAQS, NewYork State will submit an attainment demonstration to address the county's January 20, 1994 designation ofmoderate PM 10 nonattainment. NewYork State is unable to submit this attainment demonstration on this date primarily due to problems encountered with the mobile source particulate emissions model, Part 5.

While EPA released its Part 5 model in July, the model has notyet been officially designatedfor use in completing PM 10 attainment designations. NewYork State believes that additional work must be completed on the model before it will properly predictfuture PM 10 contributions. The lack ofthis modelling tool putsMr. Conrad Simon 

### 5.

NewYork State in a difficult position, as the area is now in attainment and federal control measures should allowfor both maintenance and attainment demonstrations. The tool needed to make these demonstrations is not yet available to us. The State is committed to completing this work in conjunction with EPA, the City of NewYork, affected government agencies, environmental groups and others.

Our main difficultywith the Part 5 model lies in the way the model calculates fugitive dust. Our best local input data, when run in the Part 5 model, used in conjunction with the known PM 10 background levels, significantly over predicts microscale PM 10 concentrations measured atthe Madison Avenue monitoring site. Of secondary concern is the emission factor that is supplied for the heavy-heavy duty diesel engines.

Default fugitive dust predictions ofthe Part 5 model are generally much higher than would be expected in Manhattan. The model's prediction offugitive/road dust is greatly affected byvehicle volume, roadway silt loading and average vehicle weight. Changes in any ofthese defaults can affect modeling results vastly. The default roadway silt values given for MadisonAvenue estimate extremely high fugitive dust emissions, thus NewYork State applied the actual silt loading factorfor this location, a number significantly lowerthan the model default. The modeling exercise, using the actual silt loadingfactor, resulted in a much more realistic estimate offugitive PM 10 emissions. Although, when actual vehicle weights were input into the model (the default is 3 tons/vehicle, whereas transit buses weigh on the order of20 tons/vehicle, the first two lanes on Madison Avenue being populated primarily by diesel transit buses during peak hours), the modeled PM 10due to fugitive dust again increased well beyond reasonable limits. This second, vehicle weight related issue has developed recently and the NewYork City Department of Environmental Protection (DEP) is grappling with it along with DEC. Any guidancefrom EPA as to howto resolve this issue would be appreciated.

Another concern which DEP has shared with DEC, regarding the Part 5 model deals with the emission factors supplied forvehicles otherthan heavy urban buses, especially the heavy-heavy duty diesel engines. No emission factor speed adjustments

are supplied in Part 5 forvehicles otherthan buses. This seems unrealistic. Heavyheavy duty diesel vehicles are of most interest here because their emission factors are closerto those ofthe heavy urban bus group than any othervehicle class, yet even these emission factors do not approach those ofthe buses. Emission factors for heavy-heavy duty diesel trucks vary from 1.215 grams per mile (g/mile) for 1990trucks to 0.262 g/mile for 1999 trucks. In contrast, bus emission factors, depending on the driving cycle, varyfrom 7.722 g/mile in 1990forthe heavy urban bus cycle (3.9 mph) to 0.195 g/mile forthe transit bus cycle (18.5 mph). Without a speed adjustmentfor all vehicle types, it is questioned whether realistic PM 10 emissions are modeled by Part 5. This is a concern which merits the attention ofthe model developers. We understandMr. Conrad Simon 

### 7.

In conclusion, NewYork State requests that EPA redesignate NewYork County as attainment ofthe PM10 NAAQS. Regardless, the State will make every effort to submit an Attainment Demonstration/Maintenance Plan as soon as concerns with the Part 5 model can be resolved. NewYorkwill work closelywith EPAto make this submittal a timely one.

Attachments

cc: Commissioner Zagata (w/attach.) G. Spielmann " C. Barrella II D. Sterman " G. Sheffer II

bee: T. Allen II B. Baker, USEPA II 

### J. Paisey, USEPA II G. Kelpin, NYCDEP II B. Kirch, NYSDOT II D. Shaw II C. McCarthy II Sincerely, 

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**~//f~** ArthurJ.



# Fos~~~ Director Division ofAir Resources